Issue #1258 - Part 1: Import mailnews, ldap, and mork from comm-esr52.9.1

2 files changed, 2529 insertions, 0 deletions

diff --git a/db/mork/public/mdb.h b/db/mork/public/mdb.h
new file mode 100644
index 000000000..62ab1adc7
--- /dev/null
+++ b/db/mork/public/mdb.h
@@ -0,0 +1,2520 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-  */
+/* ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is mozilla.org code.
+ *
+ * The Initial Developer of the Original Code is
+ * Netscape Communications Corporation.
+ * Portions created by the Initial Developer are Copyright (C) 1999
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *   Blake Ross (blake@blakeross.com)
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either of the GNU General Public License Version 2 or later (the "GPL"),
+ * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+#ifndef _MDB_
+#define _MDB_ 1
+
+#include "nscore.h"
+#include "nsISupports.h"
+//3456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789
+
+// { %%%%% begin scalar typedefs %%%%%
+typedef unsigned char  mdb_u1;  // make sure this is one byte
+typedef unsigned short mdb_u2;  // make sure this is two bytes
+typedef short          mdb_i2;  // make sure this is two bytes
+typedef uint32_t       mdb_u4;  // make sure this is four bytes
+typedef int32_t        mdb_i4;  // make sure this is four bytes
+typedef PRWord         mdb_ip;  // make sure sizeof(mdb_ip) == sizeof(void*)
+
+typedef mdb_u1 mdb_bool;  // unsigned byte with zero=false, nonzero=true
+
+/* canonical boolean constants provided only for code clarity: */
+#define mdbBool_kTrue  ((mdb_bool) 1) /* actually any nonzero means true */
+#define mdbBool_kFalse ((mdb_bool) 0) /* only zero means false */
+
+typedef mdb_u4 mdb_id;    // unsigned object identity in a scope
+typedef mdb_id mdb_rid;          // unsigned row identity inside scope
+typedef mdb_id mdb_tid;          // unsigned table identity inside scope
+typedef mdb_u4 mdb_token; // unsigned token for atomized string
+typedef mdb_token mdb_scope;     // token used to id scope for rows
+typedef mdb_token mdb_kind;      // token used to id kind for tables
+typedef mdb_token mdb_column;    // token used to id columns for rows
+typedef mdb_token mdb_cscode;    // token used to id charset names
+typedef mdb_u4 mdb_seed;  // unsigned collection change counter
+typedef mdb_u4 mdb_count; // unsigned collection member count
+typedef mdb_u4 mdb_size;  // unsigned physical media size
+typedef mdb_u4 mdb_fill;  // unsigned logical content size
+typedef mdb_u4 mdb_more;  // more available bytes for larger buffer
+
+typedef mdb_u2 mork_uses;    // 2-byte strong uses count
+typedef mdb_u2 mork_refs;    // 2-byte actual reference count
+
+#define mdbId_kNone ((mdb_id) -1) /* never a valid Mork object ID */
+
+typedef mdb_u4 mdb_percent; // 0..100, with values >100 same as 100
+
+typedef mdb_u1 mdb_priority; // 0..9, for a total of ten different values
+
+// sequence position is signed; negative is useful to mean "before first":
+typedef mdb_i4 mdb_pos; // signed zero-based ordinal collection position
+
+#define mdbPos_kBeforeFirst ((mdb_pos) -1) /* any negative is before zero */
+
+// order is also signed, so we can use three states for comparison order:
+typedef mdb_i4 mdb_order; // neg:lessthan, zero:equalto, pos:greaterthan 
+
+typedef mdb_order (* mdbAny_Order)(const void* inA, const void* inB, 
+  const void* inClosure);
+
+// } %%%%% end scalar typedefs %%%%%
+
+// { %%%%% begin C structs %%%%%
+
+#ifndef mdbScopeStringSet_typedef
+typedef struct mdbScopeStringSet mdbScopeStringSet;
+#define mdbScopeStringSet_typedef 1
+#endif
+
+/*| mdbScopeStringSet: a set of null-terminated C strings that enumerate some
+**| names of row scopes, so that row scopes intended for use by an application
+**| can be declared by an app when trying to open or create a database file.
+**| (We use strings and not tokens because we cannot know the tokens for any
+**| particular db without having first opened the db.)  The goal is to inform
+**| a db runtime that scopes not appearing in this list can be given relatively
+**| short shrift in runtime representation, with the expectation that other
+**| scopes will not actually be used.  However, a db should still be prepared
+**| to handle accessing row scopes not in this list, rather than raising errors.
+**| But it could be quite expensive to access a row scope not on the list.
+**| Note a zero count for the string set means no such string set is being
+**| specified, and that a db should handle all row scopes efficiently. 
+**| (It does NOT mean an app plans to use no content whatsoever.)
+|*/
+#ifndef mdbScopeStringSet_struct
+#define mdbScopeStringSet_struct 1
+struct mdbScopeStringSet { // vector of scopes for use in db opening policy
+  // when mScopeStringSet_Count is zero, this means no scope constraints 
+  mdb_count     mScopeStringSet_Count;    // number of strings in vector below
+  const char**  mScopeStringSet_Strings;  // null-ended ascii scope strings
+};
+#endif /*mdbScopeStringSet_struct*/
+
+#ifndef mdbOpenPolicy_typedef
+typedef struct mdbOpenPolicy mdbOpenPolicy;
+#define mdbOpenPolicy_typedef 1
+#endif
+
+#ifndef mdbOpenPolicy_struct
+#define mdbOpenPolicy_struct 1
+struct mdbOpenPolicy { // policies affecting db usage for ports and stores
+  mdbScopeStringSet  mOpenPolicy_ScopePlan; // predeclare scope usage plan
+  mdb_bool           mOpenPolicy_MaxLazy;   // nonzero: do least work
+  mdb_bool           mOpenPolicy_MinMemory; // nonzero: use least memory
+};
+#endif /*mdbOpenPolicy_struct*/
+
+#ifndef mdbTokenSet_typedef
+typedef struct mdbTokenSet mdbTokenSet;
+#define mdbTokenSet_typedef 1
+#endif
+
+#ifndef mdbTokenSet_struct
+#define mdbTokenSet_struct 1
+struct mdbTokenSet { // array for a set of tokens, and actual slots used
+  mdb_count   mTokenSet_Count;   // number of token slots in the array
+  mdb_fill    mTokenSet_Fill;    // the subset of count slots actually used
+  mdb_more    mTokenSet_More;    // more tokens available for bigger array
+  mdb_token*  mTokenSet_Tokens;  // array of count mdb_token instances
+};
+#endif /*mdbTokenSet_struct*/
+
+#ifndef mdbUsagePolicy_typedef
+typedef struct mdbUsagePolicy mdbUsagePolicy;
+#define mdbUsagePolicy_typedef 1
+#endif
+
+/*| mdbUsagePolicy: another version of mdbOpenPolicy which uses tokens instead
+**| of scope strings, because usage policies can be constructed for use with a
+**| db that is already open, while an open policy must be constructed before a
+**| db has yet been opened.
+|*/
+#ifndef mdbUsagePolicy_struct
+#define mdbUsagePolicy_struct 1
+struct mdbUsagePolicy { // policies affecting db usage for ports and stores
+  mdbTokenSet  mUsagePolicy_ScopePlan; // current scope usage plan
+  mdb_bool     mUsagePolicy_MaxLazy;   // nonzero: do least work
+  mdb_bool     mUsagePolicy_MinMemory; // nonzero: use least memory
+};
+#endif /*mdbUsagePolicy_struct*/
+
+#ifndef mdbOid_typedef
+typedef struct mdbOid mdbOid;
+#define mdbOid_typedef 1
+#endif
+
+#ifndef mdbOid_struct
+#define mdbOid_struct 1
+struct mdbOid { // identity of some row or table inside a database
+  mdb_scope   mOid_Scope;  // scope token for an id's namespace
+  mdb_id      mOid_Id;     // identity of object inside scope namespace
+};
+#endif /*mdbOid_struct*/
+
+#ifndef mdbRange_typedef
+typedef struct mdbRange mdbRange;
+#define mdbRange_typedef 1
+#endif
+
+#ifndef mdbRange_struct
+#define mdbRange_struct 1
+struct mdbRange { // range of row positions in a table
+  mdb_pos   mRange_FirstPos;  // position of first row
+  mdb_pos   mRange_LastPos;   // position of last row
+};
+#endif /*mdbRange_struct*/
+
+#ifndef mdbColumnSet_typedef
+typedef struct mdbColumnSet mdbColumnSet;
+#define mdbColumnSet_typedef 1
+#endif
+
+#ifndef mdbColumnSet_struct
+#define mdbColumnSet_struct 1
+struct mdbColumnSet { // array of column tokens (just the same as mdbTokenSet)
+  mdb_count    mColumnSet_Count;    // number of columns
+  mdb_column*  mColumnSet_Columns;  // count mdb_column instances
+};
+#endif /*mdbColumnSet_struct*/
+
+#ifndef mdbYarn_typedef
+typedef struct mdbYarn mdbYarn;
+#define mdbYarn_typedef 1
+#endif
+
+#ifdef MDB_BEGIN_C_LINKAGE_define
+#define MDB_BEGIN_C_LINKAGE_define 1
+#define MDB_BEGIN_C_LINKAGE extern "C" {
+#define MDB_END_C_LINKAGE }
+#endif /*MDB_BEGIN_C_LINKAGE_define*/
+
+/*| mdbYarn_mGrow: an abstract API for growing the size of a mdbYarn
+**| instance.  With respect to a specific API that requires a caller
+**| to supply a string (mdbYarn) that a callee fills with content
+**| that might exceed the specified size, mdbYarn_mGrow is a caller-
+**| supplied means of letting a callee attempt to increase the string
+**| size to become large enough to receive all content available.
+**|
+**|| Grow(): a method for requesting that a yarn instance be made
+**| larger in size.  Note that such requests need not be honored, and
+**| need not be honored in full if only partial size growth is desired.
+**| (Note that no nsIMdbEnv instance is passed as argument, although one
+**| might be needed in some circumstances.  So if an nsIMdbEnv is needed,
+**| a reference to one might be held inside a mdbYarn member slot.)
+**|
+**|| self: a yarn instance to be grown.  Presumably this yarn is
+**| the instance which holds the mYarn_Grow method pointer.  Yarn
+**| instancesshould only be passed to grow methods which they were
+**| specifically designed to fit, as indicated by the mYarn_Grow slot.
+**|
+**|| inNewSize: the new desired value for slot mYarn_Size in self.
+**| If mYarn_Size is already this big, then nothing should be done.
+**| If inNewSize is larger than seems feasible or desirable to honor,
+**| then any size restriction policy can be used to grow to some size
+**| greater than mYarn_Size.  (Grow() might even grow to a size
+**| greater than inNewSize in order to make the increase in size seem
+**| worthwhile, rather than growing in many smaller steps over time.)
+|*/
+typedef void (* mdbYarn_mGrow)(mdbYarn* self, mdb_size inNewSize);
+// mdbYarn_mGrow methods must be declared with C linkage in C++
+
+/*| mdbYarn: a variable length "string" of arbitrary binary bytes,
+**| whose length is mYarn_Fill, inside a buffer mYarn_Buf that has
+**| at most mYarn_Size byte of physical space.
+**|
+**|| mYarn_Buf: a pointer to space containing content.  This slot
+**| might never be nil when mYarn_Size is nonzero, but checks for nil
+**| are recommended anyway.
+**| (Implementations of mdbYarn_mGrow methods should take care to
+**| ensure the existence of a replacement before dropping old Bufs.)
+**| Content in Buf can be anything in any format, but the mYarn_Form
+**| implies the actual format by some caller-to-callee convention.
+**| mYarn_Form==0 implies US-ASCII iso-8859-1 Latin1 string content.
+**|
+**|| mYarn_Size: the physical size of Buf in bytes.  Note that if one
+**| intends to terminate a string with a null byte, that it must not
+**| be written at or after mYarn_Buf[mYarn_Size] because this is after
+**| the last byte in the physical buffer space.  Size can be zero,
+**| which means the string has no content whatsoever; note that when
+**| Size is zero, this is a suitable reason for Buf==nil as well.
+**|
+**|| mYarn_Fill: the logical content in Buf in bytes, where Fill must
+**| never exceed mYarn_Size.  Note that yarn strings might not have a
+**| terminating null byte (since they might not even be C strings), but
+**| when they do, such terminating nulls are considered part of content
+**| and therefore Fill will count such null bytes.  So an "empty" C
+**| string will have Fill==1, because content includes one null byte.
+**| Fill does not mean "length" when applied to C strings for this
+**| reason.  However, clients using yarns to hold C strings can infer
+**| that length is equal to Fill-1 (but should take care to handle the
+**| case where Fill==0).  To be paranoid, one can always copy to a
+**| destination with size exceeding Fill, and place a redundant null
+**| byte in the Fill position when this simplifies matters.
+**|
+**|| mYarn_Form: a designation of content format within mYarn_Buf.
+**| The semantics of this slot are the least well defined, since the
+**| actual meaning is context dependent, to the extent that callers
+**| and callees must agree on format encoding conventions when such
+**| are not standardized in many computing contexts.  However, in the
+**| context of a specific mdb database, mYarn_Form is a token for an
+**| atomized string in that database that typically names a preferred
+**| mime type charset designation.  If and when mdbYarn is used for
+**| other purposes away from the mdb interface, folks can use another
+**| convention system for encoding content formats.  However, in all
+**| contexts is it useful to maintain the convention that Form==0
+**| implies Buf contains US-ASCII iso-8859-1 Latin1 string content.
+**|
+**|| mYarn_Grow: either a mdbYarn_mGrow method, or else nil.  When
+**| a mdbYarn_mGrow method is provided, this method can be used to
+**| request a yarn buf size increase.  A caller who constructs the 
+**| original mdbYarn instance decides whether a grow method is necessary
+**| or desirable, and uses only grow methods suitable for the buffering
+**| nature of a specific mdbYarn instance.  (For example, Buf might be a
+**| staticly allocated string space which switches to something heap-based
+**| when grown, and subsequent calls to grow the yarn must distinguish the
+**| original static string from heap allocated space, etc.) Note that the
+**| method stored in mYarn_Grow can change, and this might be a common way
+**| to track memory managent changes in policy for mYarn_Buf.
+|*/
+#ifndef mdbYarn_struct
+#define mdbYarn_struct 1
+struct mdbYarn { // buffer with caller space allocation semantics
+  void*         mYarn_Buf;   // space for holding any binary content
+  mdb_fill      mYarn_Fill;  // logical content in Buf in bytes
+  mdb_size      mYarn_Size;  // physical size of Buf in bytes
+  mdb_more      mYarn_More;  // more available bytes if Buf is bigger
+  mdb_cscode    mYarn_Form;  // charset format encoding
+  mdbYarn_mGrow mYarn_Grow;  // optional method to grow mYarn_Buf
+  
+  // Subclasses might add further slots after mYarn_Grow in order to
+  // maintain bookkeeping needs, such as state info about mYarn_Buf.
+};
+#endif /*mdbYarn_struct*/
+
+// } %%%%% end C structs %%%%%
+
+// { %%%%% begin class forward defines %%%%%
+class nsIMdbEnv;
+class nsIMdbObject;
+class nsIMdbErrorHook;
+class nsIMdbThumb;
+class nsIMdbFactory;
+class nsIMdbFile;
+class nsIMdbPort;
+class nsIMdbStore;
+class nsIMdbCursor;
+class nsIMdbPortTableCursor;
+class nsIMdbCollection;
+class nsIMdbTable;
+class nsIMdbTableRowCursor;
+class nsIMdbRow;
+class nsIMdbRowCellCursor;
+class nsIMdbBlob;
+class nsIMdbCell;
+class nsIMdbSorting;
+// } %%%%% end class forward defines %%%%%
+
+
+// { %%%%% begin C++ abstract class interfaces %%%%%
+
+/*| nsIMdbObject: base class for all message db class interfaces
+**|
+**|| factory: all nsIMdbObjects from the same code suite have the same factory
+**|
+**|| refcounting: both strong and weak references, to ensure strong refs are
+**| acyclic, while weak refs can cause cycles.  CloseMdbObject() is
+**| called when (strong) use counts hit zero, but clients can call this close
+**| method early for some reason, if absolutely necessary even though it will
+**| thwart the other uses of the same object.  Note that implementations must
+**| cope with close methods being called arbitrary numbers of times.  The COM
+**| calls to AddRef() and release ref map directly to strong use ref calls,
+**| but the total ref count for COM objects is the sum of weak & strong refs.
+|*/
+
+#define NS_IMDBOBJECT_IID_STR "5533ea4b-14c3-4bef-ac60-22f9e9a49084"
+
+#define NS_IMDBOBJECT_IID \
+{0x5533ea4b, 0x14c3, 0x4bef, \
+{ 0xac, 0x60, 0x22, 0xf9, 0xe9, 0xa4, 0x90, 0x84}}
+
+class nsIMdbObject : public nsISupports { // msg db base class
+public:
+
+  NS_DECLARE_STATIC_IID_ACCESSOR(NS_IMDBOBJECT_IID)
+// { ===== begin nsIMdbObject methods =====
+
+  // { ----- begin attribute methods -----
+  NS_IMETHOD IsFrozenMdbObject(nsIMdbEnv* ev, mdb_bool* outIsReadonly) = 0;
+  // same as nsIMdbPort::GetIsPortReadonly() when this object is inside a port.
+  // } ----- end attribute methods -----
+
+  // { ----- begin factory methods -----
+  NS_IMETHOD GetMdbFactory(nsIMdbEnv* ev, nsIMdbFactory** acqFactory) = 0; 
+  // } ----- end factory methods -----
+
+  // { ----- begin ref counting for well-behaved cyclic graphs -----
+  NS_IMETHOD GetWeakRefCount(nsIMdbEnv* ev, // weak refs
+    mdb_count* outCount) = 0;  
+  NS_IMETHOD GetStrongRefCount(nsIMdbEnv* ev, // strong refs
+    mdb_count* outCount) = 0;
+
+  NS_IMETHOD AddWeakRef(nsIMdbEnv* ev) = 0;
+  NS_IMETHOD_(mork_uses) AddStrongRef(nsIMdbEnv* ev) = 0;
+
+  NS_IMETHOD CutWeakRef(nsIMdbEnv* ev) = 0;
+  NS_IMETHOD CutStrongRef(nsIMdbEnv* ev) = 0;
+  
+  NS_IMETHOD CloseMdbObject(nsIMdbEnv* ev) = 0; // called at strong refs zero
+  NS_IMETHOD IsOpenMdbObject(nsIMdbEnv* ev, mdb_bool* outOpen) = 0;
+  // } ----- end ref counting -----
+  
+// } ===== end nsIMdbObject methods =====
+};
+
+NS_DEFINE_STATIC_IID_ACCESSOR(nsIMdbObject, NS_IMDBOBJECT_IID)
+
+/*| nsIMdbErrorHook: a base class for clients of this API to subclass, in order
+**| to provide a callback installable in nsIMdbEnv for error notifications. If
+**| apps that subclass nsIMdbErrorHook wish to maintain a reference to the env
+**| that contains the hook, then this should be a weak ref to avoid cycles.
+**|
+**|| OnError: when nsIMdbEnv has an error condition that causes the total count
+**| of errors to increase, then nsIMdbEnv should call OnError() to report the
+**| error in some fashion when an instance of nsIMdbErrorHook is installed.  The
+**| variety of string flavors is currently due to the uncertainty here in the
+**| nsIMdbBlob and nsIMdbCell interfaces.  (Note that overloading by using the
+**| same method name is not necessary here, and potentially less clear.)
+|*/
+class nsIMdbErrorHook : public nsISupports{ // env callback handler to report errors
+public:
+
+// { ===== begin error methods =====
+  NS_IMETHOD OnErrorString(nsIMdbEnv* ev, const char* inAscii) = 0;
+  NS_IMETHOD OnErrorYarn(nsIMdbEnv* ev, const mdbYarn* inYarn) = 0;
+// } ===== end error methods =====
+
+// { ===== begin warning methods =====
+  NS_IMETHOD OnWarningString(nsIMdbEnv* ev, const char* inAscii) = 0;
+  NS_IMETHOD OnWarningYarn(nsIMdbEnv* ev, const mdbYarn* inYarn) = 0;
+// } ===== end warning methods =====
+
+// { ===== begin abort hint methods =====
+  NS_IMETHOD OnAbortHintString(nsIMdbEnv* ev, const char* inAscii) = 0;
+  NS_IMETHOD OnAbortHintYarn(nsIMdbEnv* ev, const mdbYarn* inYarn) = 0;
+// } ===== end abort hint methods =====
+};
+
+/*| nsIMdbHeap: abstract memory allocation interface. 
+**|
+**|| Alloc: return a block at least inSize bytes in size with alignment
+**| suitable for any native type (such as long integers).  When no such
+**| block can be allocated, failure is indicated by a null address in
+**| addition to reporting an error in the environment.
+**|
+**|| Free: deallocate a block allocated or resized earlier by the same
+**| heap instance.  If the inBlock parameter is nil, the heap should do
+**| nothing (and crashing is strongly discouraged).
+|*/
+class nsIMdbHeap { // caller-supplied memory management interface
+public:
+// { ===== begin nsIMdbHeap methods =====
+  NS_IMETHOD Alloc(nsIMdbEnv* ev, // allocate a piece of memory
+    mdb_size inSize,        // requested byte size of new memory block 
+    void** outBlock) = 0;   // memory block of inSize bytes, or nil
+    
+  NS_IMETHOD Free(nsIMdbEnv* ev, // free block from Alloc or Resize()
+    void* ioBlock) = 0;     // block to be destroyed/deallocated
+
+  virtual size_t GetUsedSize() = 0;
+
+  virtual ~nsIMdbHeap() {};
+// } ===== end nsIMdbHeap methods =====
+};
+
+/*| nsIMdbCPlusHeap: Alloc() with global ::new(), Free() with global ::delete(). 
+**| Resize() is done by ::new() followed by ::delete().
+|*/
+class nsIMdbCPlusHeap { // caller-supplied memory management interface
+public:
+// { ===== begin nsIMdbHeap methods =====
+  NS_IMETHOD Alloc(nsIMdbEnv* ev, // allocate a piece of memory
+    mdb_size inSize,   // requested size of new memory block 
+    void** outBlock);  // memory block of inSize bytes, or nil
+    
+  NS_IMETHOD Free(nsIMdbEnv* ev, // free block allocated earlier by Alloc()
+    void* inBlock);
+    
+  NS_IMETHOD HeapAddStrongRef(nsIMdbEnv* ev);
+  NS_IMETHOD HeapCutStrongRef(nsIMdbEnv* ev);
+// } ===== end nsIMdbHeap methods =====
+};
+
+/*| nsIMdbThumb: 
+|*/
+
+
+#define NS_IMDBTHUMB_IID_STR "6d3ad7c1-a809-4e74-8577-49fa9a4562fa"
+
+#define NS_IMDBTHUMB_IID \
+{0x6d3ad7c1, 0xa809, 0x4e74, \
+{ 0x85, 0x77, 0x49, 0xfa, 0x9a, 0x45, 0x62, 0xfa}}
+
+
+class nsIMdbThumb : public nsISupports { // closure for repeating incremental method
+public:
+  NS_DECLARE_STATIC_IID_ACCESSOR(NS_IMDBTHUMB_IID)
+
+// { ===== begin nsIMdbThumb methods =====
+  NS_IMETHOD GetProgress(nsIMdbEnv* ev,
+    mdb_count* outTotal,    // total somethings to do in operation
+    mdb_count* outCurrent,  // subportion of total completed so far
+    mdb_bool* outDone,      // is operation finished?
+    mdb_bool* outBroken     // is operation irreparably dead and broken?
+  ) = 0;
+  
+  NS_IMETHOD DoMore(nsIMdbEnv* ev,
+    mdb_count* outTotal,    // total somethings to do in operation
+    mdb_count* outCurrent,  // subportion of total completed so far
+    mdb_bool* outDone,      // is operation finished?
+    mdb_bool* outBroken     // is operation irreparably dead and broken?
+  ) = 0;
+  
+  NS_IMETHOD CancelAndBreakThumb( // cancel pending operation
+    nsIMdbEnv* ev) = 0;
+// } ===== end nsIMdbThumb methods =====
+};
+
+NS_DEFINE_STATIC_IID_ACCESSOR(nsIMdbThumb, NS_IMDBTHUMB_IID)
+
+/*| nsIMdbEnv: a context parameter used when calling most abstract db methods.
+**| The main purpose of such an object is to permit a database implementation
+**| to avoid the use of globals to share information between various parts of
+**| the implementation behind the abstract db interface.  An environment acts
+**| like a session object for a given calling thread, and callers should use
+**| at least one different nsIMdbEnv instance for each thread calling the API.
+**| While the database implementation might not be threaded, it is highly
+**| desirable that the db be thread-safe if calling threads use distinct
+**| instances of nsIMdbEnv.  Callers can stop at one nsIMdbEnv per thread, or they
+**| might decide to make on nsIMdbEnv instance for every nsIMdbPort opened, so that
+**| error information is segregated by database instance.  Callers create
+**| instances of nsIMdbEnv by calling the MakeEnv() method in nsIMdbFactory. 
+**|
+**|| tracing: an environment might support some kind of tracing, and this
+**| boolean attribute permits such activity to be enabled or disabled.
+**|
+**|| errors: when a call to the abstract db interface returns, a caller might
+**| check the number of outstanding errors to see whether the operation did
+**| actually succeed. Each nsIMdbEnv should have all its errors cleared by a
+**| call to ClearErrors() before making each call to the abstract db API,
+**| because outstanding errors might disable further database actions.  (This
+**| is not done inside the db interface, because the db cannot in general know
+**| when a call originates from inside or outside -- only the app knows this.)
+**|
+**|| error hook: callers can install an instance of nsIMdbErrorHook to receive
+**| error notifications whenever the error count increases.  The hook can
+**| be uninstalled by passing a null pointer.
+**|
+|*/
+
+#define NS_IMDBENV_IID_STR "a765e46b-efb6-41e6-b75b-c5d6bd710594"
+
+#define NS_IMDBENV_IID \
+{0xa765e46b, 0xefb6, 0x41e6, \
+{ 0xb7, 0x5b, 0xc5, 0xd6, 0xbd, 0x71, 0x05, 0x94}}
+
+class nsIMdbEnv : public nsISupports { // db specific context parameter
+public:
+
+  NS_DECLARE_STATIC_IID_ACCESSOR(NS_IMDBENV_IID)
+// { ===== begin nsIMdbEnv methods =====
+
+  // { ----- begin attribute methods -----
+  NS_IMETHOD GetErrorCount(mdb_count* outCount,
+    mdb_bool* outShouldAbort) = 0;
+  NS_IMETHOD GetWarningCount(mdb_count* outCount,
+    mdb_bool* outShouldAbort) = 0;
+  
+  NS_IMETHOD GetEnvBeVerbose(mdb_bool* outBeVerbose) = 0;
+  NS_IMETHOD SetEnvBeVerbose(mdb_bool inBeVerbose) = 0;
+  
+  NS_IMETHOD GetDoTrace(mdb_bool* outDoTrace) = 0;
+  NS_IMETHOD SetDoTrace(mdb_bool inDoTrace) = 0;
+  
+  NS_IMETHOD GetAutoClear(mdb_bool* outAutoClear) = 0;
+  NS_IMETHOD SetAutoClear(mdb_bool inAutoClear) = 0;
+  
+  NS_IMETHOD GetErrorHook(nsIMdbErrorHook** acqErrorHook) = 0;
+  NS_IMETHOD SetErrorHook(
+    nsIMdbErrorHook* ioErrorHook) = 0; // becomes referenced
+  
+  NS_IMETHOD GetHeap(nsIMdbHeap** acqHeap) = 0;
+  NS_IMETHOD SetHeap(
+    nsIMdbHeap* ioHeap) = 0; // becomes referenced
+  // } ----- end attribute methods -----
+  
+  NS_IMETHOD ClearErrors() = 0; // clear errors beore re-entering db API
+  NS_IMETHOD ClearWarnings() = 0; // clear warnings
+  NS_IMETHOD ClearErrorsAndWarnings() = 0; // clear both errors & warnings
+// } ===== end nsIMdbEnv methods =====
+};
+
+NS_DEFINE_STATIC_IID_ACCESSOR(nsIMdbEnv, NS_IMDBENV_IID)
+
+/*| nsIMdbFactory: the main entry points to the abstract db interface.  A DLL
+**| that supports this mdb interface need only have a single exported method
+**| that will return an instance of nsIMdbFactory, so that further methods in
+**| the suite can be accessed from objects returned by nsIMdbFactory methods.
+**|
+**|| mdbYarn: note all nsIMdbFactory subclasses must guarantee null
+**| termination of all strings written into mdbYarn instances, as long as
+**| mYarn_Size and mYarn_Buf are nonzero.  Even truncated string values must
+**| be null terminated.  This is more strict behavior than mdbYarn requires,
+**| but it is part of the nsIMdbFactory interface.
+**|
+**|| envs: an environment instance is required as per-thread context for
+**| most of the db method calls, so nsIMdbFactory creates such instances.
+**|
+**|| rows: callers must be able to create row instances that are independent
+**| of storage space that is part of the db content graph.  Many interfaces
+**| for data exchange have strictly copy semantics, so that a row instance
+**| has no specific identity inside the db content model, and the text in
+**| cells are an independenty copy of unexposed content inside the db model.
+**| Callers are expected to maintain one or more row instances as a buffer
+**| for staging cell content copied into or out of a table inside the db.
+**| Callers are urged to use an instance of nsIMdbRow created by the nsIMdbFactory
+**| code suite, because reading and writing might be much more efficient than
+**| when using a hand-rolled nsIMdbRow subclass with no relation to the suite.
+**|
+**|| ports: a port is a readonly interface to a specific database file. Most
+**| of the methods to access a db file are suitable for a readonly interface,
+**| so a port is the basic minimum for accessing content.  This makes it
+**| possible to read other external formats for import purposes, without
+**| needing the code or competence necessary to write every such format.  So
+**| we can write generic import code just once, as long as every format can
+**| show a face based on nsIMdbPort. (However, same suite import can be faster.)
+**| Given a file name and the first 512 bytes of a file, a factory can say if
+**| a port can be opened by this factory.  Presumably an app maintains chains
+**| of factories for different suites, and asks each in turn about opening a
+**| a prospective file for reading (as a port) or writing (as a store).  I'm
+**| not ready to tackle issues of format fidelity and factory chain ordering.
+**|
+**|| stores: a store is a mutable interface to a specific database file, and
+**| includes the port interface plus any methods particular to writing, which
+**| are few in number.  Presumably the set of files that can be opened as
+**| stores is a subset of the set of files that can be opened as ports.  A
+**| new store can be created with CreateNewFileStore() by supplying a new
+**| file name which does not yet exist (callers are always responsible for
+**| destroying any existing files before calling this method). 
+|*/
+
+#define NS_IMDBFACTORY_IID_STR "2b80395c-b91e-4990-b1a7-023e99ab14e9"
+
+#define NS_IMDBFACTORY_IID \
+{0xf04aa4ab, 0x1fe, 0x4115, \
+{ 0xa4, 0xa5, 0x68, 0x19, 0xdf, 0xf1, 0x10, 0x3d}}
+
+
+class nsIMdbFactory : public nsISupports { // suite entry points
+public:
+
+  NS_DECLARE_STATIC_IID_ACCESSOR(NS_IMDBFACTORY_IID)
+// { ===== begin nsIMdbFactory methods =====
+
+  // { ----- begin file methods -----
+  NS_IMETHOD OpenOldFile(nsIMdbEnv* ev, nsIMdbHeap* ioHeap,
+    const char* inFilePath,
+    mdb_bool inFrozen, nsIMdbFile** acqFile) = 0;
+  // Choose some subclass of nsIMdbFile to instantiate, in order to read
+  // (and write if not frozen) the file known by inFilePath.  The file
+  // returned should be open and ready for use, and presumably positioned
+  // at the first byte position of the file.  The exact manner in which
+  // files must be opened is considered a subclass specific detail, and
+  // other portions or Mork source code don't want to know how it's done.
+
+  NS_IMETHOD CreateNewFile(nsIMdbEnv* ev, nsIMdbHeap* ioHeap,
+    const char* inFilePath,
+    nsIMdbFile** acqFile) = 0;
+  // Choose some subclass of nsIMdbFile to instantiate, in order to read
+  // (and write if not frozen) the file known by inFilePath.  The file
+  // returned should be created and ready for use, and presumably positioned
+  // at the first byte position of the file.  The exact manner in which
+  // files must be opened is considered a subclass specific detail, and
+  // other portions or Mork source code don't want to know how it's done.
+  // } ----- end file methods -----
+
+  // { ----- begin env methods -----
+  NS_IMETHOD MakeEnv(nsIMdbHeap* ioHeap, nsIMdbEnv** acqEnv) = 0; // acquire new env
+  // ioHeap can be nil, causing a MakeHeap() style heap instance to be used
+  // } ----- end env methods -----
+
+  // { ----- begin heap methods -----
+  NS_IMETHOD MakeHeap(nsIMdbEnv* ev, nsIMdbHeap** acqHeap) = 0; // acquire new heap
+  // } ----- end heap methods -----
+
+  // { ----- begin row methods -----
+  NS_IMETHOD MakeRow(nsIMdbEnv* ev, nsIMdbHeap* ioHeap, nsIMdbRow** acqRow) = 0; // new row
+  // ioHeap can be nil, causing the heap associated with ev to be used
+  // } ----- end row methods -----
+  
+  // { ----- begin port methods -----
+  NS_IMETHOD CanOpenFilePort(
+    nsIMdbEnv* ev, // context
+    // const char* inFilePath, // the file to investigate
+    // const mdbYarn* inFirst512Bytes,
+    nsIMdbFile* ioFile, // db abstract file interface
+    mdb_bool* outCanOpen, // whether OpenFilePort() might succeed
+    mdbYarn* outFormatVersion) = 0; // informal file format description
+    
+  NS_IMETHOD OpenFilePort(
+    nsIMdbEnv* ev, // context
+    nsIMdbHeap* ioHeap, // can be nil to cause ev's heap attribute to be used
+    // const char* inFilePath, // the file to open for readonly import
+    nsIMdbFile* ioFile, // db abstract file interface
+    const mdbOpenPolicy* inOpenPolicy, // runtime policies for using db
+    nsIMdbThumb** acqThumb) = 0; // acquire thumb for incremental port open
+  // Call nsIMdbThumb::DoMore() until done, or until the thumb is broken, and
+  // then call nsIMdbFactory::ThumbToOpenPort() to get the port instance.
+
+  NS_IMETHOD ThumbToOpenPort( // redeeming a completed thumb from OpenFilePort()
+    nsIMdbEnv* ev, // context
+    nsIMdbThumb* ioThumb, // thumb from OpenFilePort() with done status
+    nsIMdbPort** acqPort) = 0; // acquire new port object
+  // } ----- end port methods -----
+  
+  // { ----- begin store methods -----
+  NS_IMETHOD CanOpenFileStore(
+    nsIMdbEnv* ev, // context
+    // const char* inFilePath, // the file to investigate
+    // const mdbYarn* inFirst512Bytes,
+    nsIMdbFile* ioFile, // db abstract file interface
+    mdb_bool* outCanOpenAsStore, // whether OpenFileStore() might succeed
+    mdb_bool* outCanOpenAsPort, // whether OpenFilePort() might succeed
+    mdbYarn* outFormatVersion) = 0; // informal file format description
+    
+  NS_IMETHOD OpenFileStore( // open an existing database
+    nsIMdbEnv* ev, // context
+    nsIMdbHeap* ioHeap, // can be nil to cause ev's heap attribute to be used
+    // const char* inFilePath, // the file to open for general db usage
+    nsIMdbFile* ioFile, // db abstract file interface
+    const mdbOpenPolicy* inOpenPolicy, // runtime policies for using db
+    nsIMdbThumb** acqThumb) = 0; // acquire thumb for incremental store open
+  // Call nsIMdbThumb::DoMore() until done, or until the thumb is broken, and
+  // then call nsIMdbFactory::ThumbToOpenStore() to get the store instance.
+    
+  NS_IMETHOD
+  ThumbToOpenStore( // redeem completed thumb from OpenFileStore()
+    nsIMdbEnv* ev, // context
+    nsIMdbThumb* ioThumb, // thumb from OpenFileStore() with done status
+    nsIMdbStore** acqStore) = 0; // acquire new db store object
+  
+  NS_IMETHOD CreateNewFileStore( // create a new db with minimal content
+    nsIMdbEnv* ev, // context
+    nsIMdbHeap* ioHeap, // can be nil to cause ev's heap attribute to be used
+    // const char* inFilePath, // name of file which should not yet exist
+    nsIMdbFile* ioFile, // db abstract file interface
+    const mdbOpenPolicy* inOpenPolicy, // runtime policies for using db
+    nsIMdbStore** acqStore) = 0; // acquire new db store object
+  // } ----- end store methods -----
+
+// } ===== end nsIMdbFactory methods =====
+};
+
+NS_DEFINE_STATIC_IID_ACCESSOR(nsIMdbFactory, NS_IMDBFACTORY_IID)
+
+extern "C" nsIMdbFactory* MakeMdbFactory(); 
+
+/*| nsIMdbFile: abstract file interface resembling the original morkFile
+**| abstract interface (which was in turn modeled on the file interface
+**| from public domain IronDoc).  The design of this file interface is
+**| complicated by the fact that some DB's will not find this interface
+**| adequate for all runtime requirements (even though this file API is
+**| enough to implement text-based DB's like Mork).  For this reason,
+**| more methods have been added to let a DB library force the file to
+**| become closed so the DB can reopen the file in some other manner.
+**| Folks are encouraged to suggest ways to tune this interface to suit
+**| DB's that cannot manage to pull their maneuvers even given this API.
+**|
+**|| Tell: get the current i/o position in file
+**|
+**|| Seek: change the current i/o position in file
+**|
+**|| Eof: return file's total length in bytes
+**|
+**|| Read: input inSize bytes into outBuf, returning actual transfer size
+**|
+**|| Get: read starting at specific file offset (e.g. Seek(); Read();)
+**|
+**|| Write: output inSize bytes from inBuf, returning actual transfer size
+**|
+**|| Put: write starting at specific file offset (e.g. Seek(); Write();)
+**|
+**|| Flush: if written bytes are buffered, push them to final destination
+**|
+**|| Path: get file path in some string representation.  This is intended
+**| either to support the display of file name in a user presentation, or
+**| to support the closing and reopening of the file when the DB needs more
+**| exotic file access than is presented by the nsIMdbFile interface.
+**|
+**|| Steal: tell this file to close any associated i/o stream in the file
+**| system, because the file ioThief intends to reopen the file in order
+**| to provide the MDB implementation with more exotic file access than is
+**| offered by the nsIMdbFile alone.  Presumably the thief knows enough
+**| from Path() in order to know which file to reopen.  If Steal() is
+**| successful, this file should probably delegate all future calls to
+**| the nsIMdbFile interface down to the thief files, so that even after
+**| the file has been stolen, it can still be read, written, or forcibly
+**| closed (by a call to CloseMdbObject()).
+**|
+**|| Thief: acquire and return thief passed to an earlier call to Steal().
+|*/
+
+#define NS_IMDBFILE_IID_STR "f04aa4ab-1fe7-4115-a4a5-6819dff1103d"
+
+#define NS_IMDBFILE_IID \
+{0xf04aa4ab, 0x1fe, 0x4115, \
+{ 0xa4, 0xa5, 0x68, 0x19, 0xdf, 0xf1, 0x10, 0x3d}}
+
+class nsIMdbFile : public nsISupports { // minimal file interface
+public:
+
+  NS_DECLARE_STATIC_IID_ACCESSOR(NS_IMDBFILE_IID)
+// { ===== begin nsIMdbFile methods =====
+
+  // { ----- begin pos methods -----
+  NS_IMETHOD Tell(nsIMdbEnv* ev, mdb_pos* outPos) const = 0;
+  NS_IMETHOD Seek(nsIMdbEnv* ev, mdb_pos inPos, mdb_pos *outPos) = 0;
+  NS_IMETHOD Eof(nsIMdbEnv* ev, mdb_pos* outPos) = 0;
+  // } ----- end pos methods -----
+
+  // { ----- begin read methods -----
+  NS_IMETHOD Read(nsIMdbEnv* ev, void* outBuf, mdb_size inSize,
+    mdb_size* outActualSize) = 0;
+  NS_IMETHOD Get(nsIMdbEnv* ev, void* outBuf, mdb_size inSize,
+    mdb_pos inPos, mdb_size* outActualSize) = 0;
+  // } ----- end read methods -----
+    
+  // { ----- begin write methods -----
+  NS_IMETHOD  Write(nsIMdbEnv* ev, const void* inBuf, mdb_size inSize,
+    mdb_size* outActualSize) = 0;
+  NS_IMETHOD  Put(nsIMdbEnv* ev, const void* inBuf, mdb_size inSize,
+    mdb_pos inPos, mdb_size* outActualSize) = 0;
+  NS_IMETHOD  Flush(nsIMdbEnv* ev) = 0;
+  // } ----- end attribute methods -----
+    
+  // { ----- begin path methods -----
+  NS_IMETHOD  Path(nsIMdbEnv* ev, mdbYarn* outFilePath) = 0;
+  // } ----- end path methods -----
+    
+  // { ----- begin replacement methods -----
+  NS_IMETHOD  Steal(nsIMdbEnv* ev, nsIMdbFile* ioThief) = 0;
+  NS_IMETHOD  Thief(nsIMdbEnv* ev, nsIMdbFile** acqThief) = 0;
+  // } ----- end replacement methods -----
+
+  // { ----- begin versioning methods -----
+  NS_IMETHOD BecomeTrunk(nsIMdbEnv* ev) = 0;
+  // If this file is a file version branch created by calling AcquireBud(),
+  // BecomeTrunk() causes this file's content to replace the original
+  // file's content, typically by assuming the original file's identity.
+  // This default implementation of BecomeTrunk() does nothing, and this
+  // is appropriate behavior for files which are not branches, and is
+  // also the right behavior for files returned from AcquireBud() which are
+  // in fact the original file that has been truncated down to zero length.
+
+  NS_IMETHOD AcquireBud(nsIMdbEnv* ev, nsIMdbHeap* ioHeap,
+    nsIMdbFile** acqBud) = 0; // acquired file for new version of content
+  // AcquireBud() starts a new "branch" version of the file, empty of content,
+  // so that a new version of the file can be written.  This new file
+  // can later be told to BecomeTrunk() the original file, so the branch
+  // created by budding the file will replace the original file.  Some
+  // file subclasses might initially take the unsafe but expedient
+  // approach of simply truncating this file down to zero length, and
+  // then returning the same morkFile pointer as this, with an extra
+  // reference count increment.  Note that the caller of AcquireBud() is
+  // expected to eventually call CutStrongRef() on the returned file
+  // in order to release the strong reference.  High quality versions
+  // of morkFile subclasses will create entirely new files which later
+  // are renamed to become the old file, so that better transactional
+  // behavior is exhibited by the file, so crashes protect old files.
+  // Note that AcquireBud() is an illegal operation on readonly files.
+  // } ----- end versioning methods -----
+
+// } ===== end nsIMdbFile methods =====
+};
+
+NS_DEFINE_STATIC_IID_ACCESSOR(nsIMdbFile, NS_IMDBFILE_IID)
+
+/*| nsIMdbPort: a readonly interface to a specific database file. The mutable
+**| nsIMdbStore interface is a subclass that includes writing behavior, but
+**| most of the needed db methods appear in the readonly nsIMdbPort interface.
+**|
+**|| mdbYarn: note all nsIMdbPort and nsIMdbStore subclasses must guarantee null
+**| termination of all strings written into mdbYarn instances, as long as
+**| mYarn_Size and mYarn_Buf are nonzero.  Even truncated string values must
+**| be null terminated.  This is more strict behavior than mdbYarn requires,
+**| but it is part of the nsIMdbPort and nsIMdbStore interface.
+**|
+**|| attributes: methods are provided to distinguish a readonly port from a
+**| mutable store, and whether a mutable store actually has any dirty content.
+**|
+**|| filepath: the file path used to open the port from the nsIMdbFactory can be
+**| queried and discovered by GetPortFilePath(), which includes format info.
+**|
+**|| export: a port can write itself in other formats, with perhaps a typical
+**| emphasis on text interchange formats used by other systems.  A port can be
+**| queried to determine its preferred export interchange format, and a port
+**| can be queried to see whether a specific export format is supported.  And
+**| actually exporting a port requires a new destination file name and format.
+**|
+**|| tokens: a port supports queries about atomized strings to map tokens to
+**| strings or strings to token integers.  (All atomized strings must be in
+**| US-ASCII iso-8859-1 Latin1 charset encoding.)  When a port is actually a
+**| mutable store and a string has not yet been atomized, then StringToToken()
+**| will actually do so and modify the store.  The QueryToken() method will not
+**| atomize a string if it has not already been atomized yet, even in stores.
+**|
+**|| tables: other than string tokens, all port content is presented through
+**| tables, which are ordered collections of rows.  Tables are identified by
+**| row scope and table kind, which might or might not be unique in a port,
+**| depending on app convention.  When tables are effectively unique, then
+**| queries for specific scope and kind pairs will find those tables.  To see
+**| all tables that match specific row scope and table kind patterns, even in
+**| the presence of duplicates, every port supports a GetPortTableCursor()
+**| method that returns an iterator over all matching tables.  Table kind is
+**| considered scoped inside row scope, so passing a zero for table kind will
+**| find all table kinds for some nonzero row scope.  Passing a zero for row
+**| scope will iterate over all tables in the port, in some undefined order.
+**| (A new table can be added to a port using nsIMdbStore::NewTable(), even when
+**| the requested scope and kind combination is already used by other tables.)
+**|
+**|| memory: callers can request that a database use less memory footprint in
+**| several flavors, from an inconsequential idle flavor to a rather drastic
+**| panic flavor. Callers might perform an idle purge very frequently if desired
+**| with very little cost, since only normally scheduled memory management will
+**| be conducted, such as freeing resources for objects scheduled to be dropped.
+**| Callers should perform session memory purges infrequently because they might
+**| involve costly scanning of data structures to removed cached content, and
+**| session purges are recommended only when a caller experiences memory crunch.
+**| Callers should only rarely perform a panic purge, in response to dire memory
+**| straits, since this is likely to make db operations much more expensive
+**| than they would be otherwise.  A panic purge asks a database to free as much
+**| memory as possible while staying effective and operational, because a caller
+**| thinks application failure might otherwise occur.  (Apps might better close
+**| an open db, so panic purges only make sense when a db is urgently needed.)
+|*/
+class nsIMdbPort : public nsISupports {
+public:
+
+// { ===== begin nsIMdbPort methods =====
+
+  // { ----- begin attribute methods -----
+  NS_IMETHOD GetIsPortReadonly(nsIMdbEnv* ev, mdb_bool* outBool) = 0;
+  NS_IMETHOD GetIsStore(nsIMdbEnv* ev, mdb_bool* outBool) = 0;
+  NS_IMETHOD GetIsStoreAndDirty(nsIMdbEnv* ev, mdb_bool* outBool) = 0;
+
+  NS_IMETHOD GetUsagePolicy(nsIMdbEnv* ev, 
+    mdbUsagePolicy* ioUsagePolicy) = 0;
+
+  NS_IMETHOD SetUsagePolicy(nsIMdbEnv* ev, 
+    const mdbUsagePolicy* inUsagePolicy) = 0;
+  // } ----- end attribute methods -----
+
+  // { ----- begin memory policy methods -----  
+  NS_IMETHOD IdleMemoryPurge( // do memory management already scheduled
+    nsIMdbEnv* ev, // context
+    mdb_size* outEstimatedBytesFreed) = 0; // approximate bytes actually freed
+
+  NS_IMETHOD SessionMemoryPurge( // request specific footprint decrease
+    nsIMdbEnv* ev, // context
+    mdb_size inDesiredBytesFreed, // approximate number of bytes wanted
+    mdb_size* outEstimatedBytesFreed) = 0; // approximate bytes actually freed
+
+  NS_IMETHOD PanicMemoryPurge( // desperately free all possible memory
+    nsIMdbEnv* ev, // context
+    mdb_size* outEstimatedBytesFreed) = 0; // approximate bytes actually freed
+  // } ----- end memory policy methods -----
+
+  // { ----- begin filepath methods -----
+  NS_IMETHOD GetPortFilePath(
+    nsIMdbEnv* ev, // context
+    mdbYarn* outFilePath, // name of file holding port content
+    mdbYarn* outFormatVersion) = 0; // file format description
+    
+  NS_IMETHOD GetPortFile(
+    nsIMdbEnv* ev, // context
+    nsIMdbFile** acqFile) = 0; // acquire file used by port or store
+  // } ----- end filepath methods -----
+
+  // { ----- begin export methods -----
+  NS_IMETHOD BestExportFormat( // determine preferred export format
+    nsIMdbEnv* ev, // context
+    mdbYarn* outFormatVersion) = 0; // file format description
+
+  // some tentative suggested import/export formats
+  // "ns:msg:db:port:format:ldif:ns4.0:passthrough" // necessary
+  // "ns:msg:db:port:format:ldif:ns4.5:utf8"        // necessary
+  // "ns:msg:db:port:format:ldif:ns4.5:tabbed"
+  // "ns:msg:db:port:format:ldif:ns4.5:binary"      // necessary
+  // "ns:msg:db:port:format:html:ns3.0:addressbook" // necessary
+  // "ns:msg:db:port:format:html:display:verbose"
+  // "ns:msg:db:port:format:html:display:concise"
+  // "ns:msg:db:port:format:mork:zany:verbose"      // necessary
+  // "ns:msg:db:port:format:mork:zany:atomized"     // necessary
+  // "ns:msg:db:port:format:rdf:xml"
+  // "ns:msg:db:port:format:xml:mork"
+  // "ns:msg:db:port:format:xml:display:verbose"
+  // "ns:msg:db:port:format:xml:display:concise"
+  // "ns:msg:db:port:format:xml:print:verbose"      // recommended
+  // "ns:msg:db:port:format:xml:print:concise"
+
+  NS_IMETHOD
+  CanExportToFormat( // can export content in given specific format?
+    nsIMdbEnv* ev, // context
+    const char* inFormatVersion, // file format description
+    mdb_bool* outCanExport) = 0; // whether ExportSource() might succeed
+
+  NS_IMETHOD ExportToFormat( // export content in given specific format
+    nsIMdbEnv* ev, // context
+    // const char* inFilePath, // the file to receive exported content
+    nsIMdbFile* ioFile, // destination abstract file interface
+    const char* inFormatVersion, // file format description
+    nsIMdbThumb** acqThumb) = 0; // acquire thumb for incremental export
+  // Call nsIMdbThumb::DoMore() until done, or until the thumb is broken, and
+  // then the export will be finished.
+
+  // } ----- end export methods -----
+
+  // { ----- begin token methods -----
+  NS_IMETHOD TokenToString( // return a string name for an integer token
+    nsIMdbEnv* ev, // context
+    mdb_token inToken, // token for inTokenName inside this port
+    mdbYarn* outTokenName) = 0; // the type of table to access
+  
+  NS_IMETHOD StringToToken( // return an integer token for scope name
+    nsIMdbEnv* ev, // context
+    const char* inTokenName, // Latin1 string to tokenize if possible
+    mdb_token* outToken) = 0; // token for inTokenName inside this port
+    
+  // String token zero is never used and never supported. If the port
+  // is a mutable store, then StringToToken() to create a new
+  // association of inTokenName with a new integer token if possible.
+  // But a readonly port will return zero for an unknown scope name.
+
+  NS_IMETHOD QueryToken( // like StringToToken(), but without adding
+    nsIMdbEnv* ev, // context
+    const char* inTokenName, // Latin1 string to tokenize if possible
+    mdb_token* outToken) = 0; // token for inTokenName inside this port
+  
+  // QueryToken() will return a string token if one already exists,
+  // but unlike StringToToken(), will not assign a new token if not
+  // already in use.
+
+  // } ----- end token methods -----
+
+  // { ----- begin row methods -----  
+  NS_IMETHOD HasRow( // contains a row with the specified oid?
+    nsIMdbEnv* ev, // context
+    const mdbOid* inOid,  // hypothetical row oid
+    mdb_bool* outHasRow) = 0; // whether GetRow() might succeed
+
+  NS_IMETHOD GetRowRefCount( // get number of tables that contain a row 
+    nsIMdbEnv* ev, // context
+    const mdbOid* inOid,  // hypothetical row oid
+    mdb_count* outRefCount) = 0; // number of tables containing inRowKey 
+    
+  NS_IMETHOD GetRow( // access one row with specific oid
+    nsIMdbEnv* ev, // context
+    const mdbOid* inOid,  // hypothetical row oid
+    nsIMdbRow** acqRow) = 0; // acquire specific row (or null)
+    
+  // NS_IMETHOD
+  // GetPortRowCursor( // get cursor for all rows in specific scope
+  //   nsIMdbEnv* ev, // context
+  //   mdb_scope inRowScope, // row scope for row ids
+  //   nsIMdbPortRowCursor** acqCursor) = 0; // all such rows in the port
+
+  NS_IMETHOD FindRow(nsIMdbEnv* ev, // search for row with matching cell
+    mdb_scope inRowScope,   // row scope for row ids
+    mdb_column inColumn,   // the column to search (and maintain an index)
+    const mdbYarn* inTargetCellValue, // cell value for which to search
+    mdbOid* outRowOid, // out row oid on match (or {0,-1} for no match)
+    nsIMdbRow** acqRow) = 0; // acquire matching row (or nil for no match)
+                             // can be null if you only want the oid
+  // FindRow() searches for one row that has a cell in column inColumn with
+  // a contained value with the same form (i.e. charset) and is byte-wise
+  // identical to the blob described by yarn inTargetCellValue.  Both content
+  // and form of the yarn must be an exact match to find a matching row.
+  //
+  // (In other words, both a yarn's blob bytes and form are significant.  The
+  // form is not expected to vary in columns used for identity anyway.  This
+  // is intended to make the cost of FindRow() cheaper for MDB implementors,
+  // since any cell value atomization performed internally must necessarily
+  // make yarn form significant in order to avoid data loss in atomization.)
+  //
+  // FindRow() can lazily create an index on attribute inColumn for all rows
+  // with that attribute in row space scope inRowScope, so that subsequent
+  // calls to FindRow() will perform faster.  Such an index might or might
+  // not be persistent (but this seems desirable if it is cheap to do so).
+  // Note that lazy index creation in readonly DBs is not very feasible.
+  //
+  // This FindRow() interface assumes that attribute inColumn is effectively
+  // an alternative means of unique identification for a row in a rowspace,
+  // so correct behavior is only guaranteed when no duplicates for this col
+  // appear in the given set of rows.  (If more than one row has the same cell
+  // value in this column, no more than one will be found; and cutting one of
+  // two duplicate rows can cause the index to assume no other such row lives
+  // in the row space, so future calls return nil for negative search results
+  // even though some duplicate row might still live within the rowspace.)
+  //
+  // In other words, the FindRow() implementation is allowed to assume simple
+  // hash tables mapping unqiue column keys to associated row values will be
+  // sufficient, where any duplication is not recorded because only one copy
+  // of a given key need be remembered.  Implementors are not required to sort
+  // all rows by the specified column.
+  // } ----- end row methods -----
+
+  // { ----- begin table methods -----  
+  NS_IMETHOD HasTable( // supports a table with the specified oid?
+    nsIMdbEnv* ev, // context
+    const mdbOid* inOid,  // hypothetical table oid
+    mdb_bool* outHasTable) = 0; // whether GetTable() might succeed
+    
+  NS_IMETHOD GetTable( // access one table with specific oid
+    nsIMdbEnv* ev, // context
+    const mdbOid* inOid,  // hypothetical table oid
+    nsIMdbTable** acqTable) = 0; // acquire specific table (or null)
+  
+  NS_IMETHOD HasTableKind( // supports a table of the specified type?
+    nsIMdbEnv* ev, // context
+    mdb_scope inRowScope, // rid scope for row ids
+    mdb_kind inTableKind, // the type of table to access
+    mdb_count* outTableCount, // current number of such tables
+    mdb_bool* outSupportsTable) = 0; // whether GetTableKind() might succeed
+    
+  // row scopes to be supported include the following suggestions:
+  // "ns:msg:db:row:scope:address:cards:all"
+  // "ns:msg:db:row:scope:mail:messages:all"
+  // "ns:msg:db:row:scope:news:articles:all"
+ 
+  // table kinds to be supported include the following suggestions:
+  // "ns:msg:db:table:kind:address:cards:main"
+  // "ns:msg:db:table:kind:address:lists:all" 
+  // "ns:msg:db:table:kind:address:list" 
+  // "ns:msg:db:table:kind:news:threads:all" 
+  // "ns:msg:db:table:kind:news:thread" 
+  // "ns:msg:db:table:kind:mail:threads:all"
+  // "ns:msg:db:table:kind:mail:thread"
+    
+  NS_IMETHOD GetTableKind( // access one (random) table of specific type
+    nsIMdbEnv* ev, // context
+    mdb_scope inRowScope,      // row scope for row ids
+    mdb_kind inTableKind,      // the type of table to access
+    mdb_count* outTableCount, // current number of such tables
+    mdb_bool* outMustBeUnique, // whether port can hold only one of these
+    nsIMdbTable** acqTable) = 0;       // acquire scoped collection of rows
+    
+  NS_IMETHOD
+  GetPortTableCursor( // get cursor for all tables of specific type
+    nsIMdbEnv* ev, // context
+    mdb_scope inRowScope, // row scope for row ids
+    mdb_kind inTableKind, // the type of table to access
+    nsIMdbPortTableCursor** acqCursor) = 0; // all such tables in the port
+  // } ----- end table methods -----
+
+
+  // { ----- begin commit methods -----
+
+  NS_IMETHOD ShouldCompress( // store wastes at least inPercentWaste?
+    nsIMdbEnv* ev, // context
+    mdb_percent inPercentWaste, // 0..100 percent file size waste threshold
+    mdb_percent* outActualWaste, // 0..100 percent of file actually wasted
+    mdb_bool* outShould) = 0; // true when about inPercentWaste% is wasted
+  // ShouldCompress() returns true if the store can determine that the file
+  // will shrink by an estimated percentage of inPercentWaste% (or more) if
+  // CompressCommit() is called, because that percentage of the file seems
+  // to be recoverable free space.  The granularity is only in terms of 
+  // percentage points, and any value over 100 is considered equal to 100.
+  //
+  // If a store only has an approximate idea how much space might be saved
+  // during a compress, then a best guess should be made.  For example, the
+  // Mork implementation might keep track of how much file space began with
+  // text content before the first updating transaction, and then consider
+  // all content following the start of the first transaction as potentially
+  // wasted space if it is all updates and not just new content.  (This is
+  // a safe assumption in the sense that behavior will stabilize on a low
+  // estimate of wastage after a commit removes all transaction updates.)
+  //
+  // Some db formats might attempt to keep a very accurate reckoning of free
+  // space size, so a very accurate determination can be made.  But other db
+  // formats might have difficulty determining size of free space, and might
+  // require some lengthy calculation to answer.  This is the reason for
+  // passing in the percentage threshold of interest, so that such lengthy
+  // computations can terminate early as soon as at least inPercentWaste is
+  // found, so that the entire file need not be groveled when unnecessary.
+  // However, we hope implementations will always favor fast but imprecise
+  // heuristic answers instead of extremely slow but very precise answers.
+  //
+  // If the outActualWaste parameter is non-nil, it will be used to return
+  // the actual estimated space wasted as a percentage of file size.  (This
+  // parameter is provided so callers need not call repeatedly with altered
+  // inPercentWaste values to isolate the actual wastage figure.)  Note the
+  // actual wastage figure returned can exactly equal inPercentWaste even
+  // when this grossly underestimates the real figure involved, if the db
+  // finds it very expensive to determine the extent of wastage after it is
+  // known to at least exceed inPercentWaste.  Note we expect that whenever
+  // outShould returns true, that outActualWaste returns >= inPercentWaste.
+  //
+  // The effect of different inPercentWaste values is not very uniform over
+  // the permitted range.  For example, 50 represents 50% wastage, or a file
+  // that is about double what it should be ideally.  But 99 represents 99%
+  // wastage, or a file that is about ninety-nine times as big as it should
+  // be ideally.  In the smaller direction, 25 represents 25% wastage, or
+  // a file that is only 33% larger than it should be ideally.
+  //
+  // Callers can determine what policy they want to use for considering when
+  // a file holds too much wasted space, and express this as a percentage
+  // of total file size to pass as in the inPercentWaste parameter.  A zero
+  // likely returns always trivially true, and 100 always trivially false.
+  // The great majority of callers are expected to use values from 25 to 75,
+  // since most plausible thresholds for compressing might fall between the
+  // extremes of 133% of ideal size and 400% of ideal size.  (Presumably the
+  // larger a file gets, the more important the percentage waste involved, so
+  // a sliding scale for compress thresholds might use smaller numbers for
+  // much bigger file sizes.)
+  
+  // } ----- end commit methods -----
+
+// } ===== end nsIMdbPort methods =====
+};
+
+/*| nsIMdbStore: a mutable interface to a specific database file.
+**|
+**|| tables: one can force a new table to exist in a store with NewTable()
+**| and nonzero values for both row scope and table kind.  (If one wishes only
+**| one table of a certain kind, then one might look for it first using the
+**| GetTableKind() method).  One can pass inMustBeUnique to force future
+**| users of this store to be unable to create other tables with the same pair
+**| of scope and kind attributes.  When inMustBeUnique is true, and the table
+**| with the given scope and kind pair already exists, then the existing one
+**| is returned instead of making a new table.  Similarly, if one passes false
+**| for inMustBeUnique, but the table kind has already been marked unique by a
+**| previous user of the store, then the existing unique table is returned.
+**|
+**|| import: all or some of another port's content can be imported by calling
+**| AddPortContent() with a row scope identifying the extent of content to
+**| be imported.  A zero row scope will import everything.  A nonzero row
+**| scope will only import tables with a matching row scope.  Note that one
+**| must somehow find a way to negotiate possible conflicts between existing
+**| row content and imported row content, and this involves a specific kind of
+**| definition for row identity involving either row IDs or unique attributes,
+**| or some combination of these two.  At the moment I am just going to wave
+**| my hands, and say the default behavior is to assign all new row identities
+**| to all imported content, which will result in no merging of content; this
+**| must change later because it is unacceptable in some contexts.
+**|
+**|| commits: to manage modifications in a mutable store, very few methods are
+**| really needed to indicate global policy choices that are independent of 
+**| the actual modifications that happen in objects at the level of tables,
+**| rows, and cells, etc.  The most important policy to specify is which sets
+**| of changes are considered associated in a manner such that they should be
+**| applied together atomically to a given store.  We call each such group of
+**| changes a transaction.  We handle three different grades of transaction,
+**| but they differ only in semantic significance to the application, and are
+**| not intended to nest.  (If small transactions were nested inside large
+**| transactions, that would imply that a single large transaction must be
+**| atomic over all the contained small transactions; but actually we intend
+**| smalls transaction never be undone once commited due to, say, aborting a
+**| transaction of greater significance.)  The small, large, and session level
+**| commits have equal granularity, and differ only in risk of loss from the
+**| perspective of an application.  Small commits characterize changes that
+**| can be lost with relatively small risk, so small transactions can delay
+**| until later if they are expensive or impractical to commit.  Large commits
+**| involve changes that would probably inconvenience users if lost, so the
+**| need to pay costs of writing is rather greater than with small commits.
+**| Session commits are last ditch attempts to save outstanding changes before
+**| stopping the use of a particular database, so there will be no later point
+**| in time to save changes that have been delayed due to possible high cost.
+**| If large commits are never delayed, then a session commit has about the
+**| same performance effect as another large commit; but if small and large
+**| commits are always delayed, then a session commit is likely to be rather
+**| expensive as a runtime cost compared to any earlier database usage.
+**|
+**|| aborts: the only way to abort changes to a store is by closing the store.
+**| So there is no specific method for causing any abort.  Stores must discard
+**| all changes made that are uncommited when a store is closed.  This design
+**| choice makes the implementations of tables, rows, and cells much less
+**| complex because they need not maintain a record of undobable changes.  When
+**| a store is closed, presumably this precipitates the closure of all tables,
+**| rows, and cells in the store as well.   So an application can revert the
+**| state of a store in the user interface by quietly closing and reopening a
+**| store, because this will discard uncommited changes and show old content.
+**| This implies an app that closes a store will need to send a "scramble"
+**| event notification to any views that depend on old discarded content.
+|*/
+
+#define NS_IMDBSTORE_IID_STR "74d6218d-44b0-43b5-9ebe-69a17dfb562c"
+#define NS_IMDBSTORE_IID \
+{0x74d6218d, 0x44b0, 0x43b5, \
+{0x9e, 0xbe, 0x69, 0xa1, 0x7d, 0xfb, 0x56, 0x2c}}
+
+class nsIMdbStore : public nsIMdbPort {
+public:
+  NS_DECLARE_STATIC_IID_ACCESSOR(NS_IMDBSTORE_IID)
+
+// { ===== begin nsIMdbStore methods =====
+
+  // { ----- begin table methods -----
+  NS_IMETHOD NewTable( // make one new table of specific type
+    nsIMdbEnv* ev, // context
+    mdb_scope inRowScope,    // row scope for row ids
+    mdb_kind inTableKind,    // the type of table to access
+    mdb_bool inMustBeUnique, // whether store can hold only one of these
+    const mdbOid* inOptionalMetaRowOid, // can be nil to avoid specifying
+    nsIMdbTable** acqTable) = 0;     // acquire scoped collection of rows
+    
+  NS_IMETHOD NewTableWithOid( // make one new table of specific type
+    nsIMdbEnv* ev, // context
+    const mdbOid* inOid,   // caller assigned oid
+    mdb_kind inTableKind,    // the type of table to access
+    mdb_bool inMustBeUnique, // whether store can hold only one of these
+    const mdbOid* inOptionalMetaRowOid, // can be nil to avoid specifying 
+    nsIMdbTable** acqTable) = 0;     // acquire scoped collection of rows
+  // } ----- end table methods -----
+
+  // { ----- begin row scope methods -----
+  NS_IMETHOD RowScopeHasAssignedIds(nsIMdbEnv* ev,
+    mdb_scope inRowScope,   // row scope for row ids
+    mdb_bool* outCallerAssigned, // nonzero if caller assigned specified
+    mdb_bool* outStoreAssigned) = 0; // nonzero if store db assigned specified
+
+  NS_IMETHOD SetCallerAssignedIds(nsIMdbEnv* ev,
+    mdb_scope inRowScope,   // row scope for row ids
+    mdb_bool* outCallerAssigned, // nonzero if caller assigned specified
+    mdb_bool* outStoreAssigned) = 0; // nonzero if store db assigned specified
+
+  NS_IMETHOD SetStoreAssignedIds(nsIMdbEnv* ev,
+    mdb_scope inRowScope,   // row scope for row ids
+    mdb_bool* outCallerAssigned, // nonzero if caller assigned specified
+    mdb_bool* outStoreAssigned) = 0; // nonzero if store db assigned specified
+  // } ----- end row scope methods -----
+
+  // { ----- begin row methods -----
+  NS_IMETHOD NewRowWithOid(nsIMdbEnv* ev, // new row w/ caller assigned oid
+    const mdbOid* inOid,   // caller assigned oid
+    nsIMdbRow** acqRow) = 0; // create new row
+
+  NS_IMETHOD NewRow(nsIMdbEnv* ev, // new row with db assigned oid
+    mdb_scope inRowScope,   // row scope for row ids
+    nsIMdbRow** acqRow) = 0; // create new row
+  // Note this row must be added to some table or cell child before the
+  // store is closed in order to make this row persist across sesssions.
+
+  // } ----- end row methods -----
+
+  // { ----- begin inport/export methods -----
+  NS_IMETHOD ImportContent( // import content from port
+    nsIMdbEnv* ev, // context
+    mdb_scope inRowScope, // scope for rows (or zero for all?)
+    nsIMdbPort* ioPort, // the port with content to add to store
+    nsIMdbThumb** acqThumb) = 0; // acquire thumb for incremental import
+  // Call nsIMdbThumb::DoMore() until done, or until the thumb is broken, and
+  // then the import will be finished.
+
+  NS_IMETHOD ImportFile( // import content from port
+    nsIMdbEnv* ev, // context
+    nsIMdbFile* ioFile, // the file with content to add to store
+    nsIMdbThumb** acqThumb) = 0; // acquire thumb for incremental import
+  // Call nsIMdbThumb::DoMore() until done, or until the thumb is broken, and
+  // then the import will be finished.
+  // } ----- end inport/export methods -----
+
+  // { ----- begin hinting methods -----
+  NS_IMETHOD
+  ShareAtomColumnsHint( // advise re shared column content atomizing
+    nsIMdbEnv* ev, // context
+    mdb_scope inScopeHint, // zero, or suggested shared namespace
+    const mdbColumnSet* inColumnSet) = 0; // cols desired tokenized together
+
+  NS_IMETHOD
+  AvoidAtomColumnsHint( // advise column with poor atomizing prospects
+    nsIMdbEnv* ev, // context
+    const mdbColumnSet* inColumnSet) = 0; // cols with poor atomizing prospects
+  // } ----- end hinting methods -----
+
+  // { ----- begin commit methods -----
+  NS_IMETHOD LargeCommit( // save important changes if at all possible
+    nsIMdbEnv* ev, // context
+    nsIMdbThumb** acqThumb) = 0; // acquire thumb for incremental commit
+  // Call nsIMdbThumb::DoMore() until done, or until the thumb is broken, and
+  // then the commit will be finished.  Note the store is effectively write
+  // locked until commit is finished or canceled through the thumb instance.
+  // Until the commit is done, the store will report it has readonly status.
+
+  NS_IMETHOD SessionCommit( // save all changes if large commits delayed
+    nsIMdbEnv* ev, // context
+    nsIMdbThumb** acqThumb) = 0; // acquire thumb for incremental commit
+  // Call nsIMdbThumb::DoMore() until done, or until the thumb is broken, and
+  // then the commit will be finished.  Note the store is effectively write
+  // locked until commit is finished or canceled through the thumb instance.
+  // Until the commit is done, the store will report it has readonly status.
+
+  NS_IMETHOD
+  CompressCommit( // commit and make db physically smaller if possible
+    nsIMdbEnv* ev, // context
+    nsIMdbThumb** acqThumb) = 0; // acquire thumb for incremental commit
+  // Call nsIMdbThumb::DoMore() until done, or until the thumb is broken, and
+  // then the commit will be finished.  Note the store is effectively write
+  // locked until commit is finished or canceled through the thumb instance.
+  // Until the commit is done, the store will report it has readonly status.
+  
+  // } ----- end commit methods -----
+
+// } ===== end nsIMdbStore methods =====
+};
+
+NS_DEFINE_STATIC_IID_ACCESSOR(nsIMdbStore, NS_IMDBSTORE_IID)
+
+/*| nsIMdbCursor: base cursor class for iterating row cells and table rows
+**|
+**|| count: the number of elements in the collection (table or row)
+**|
+**|| seed: the change count in the underlying collection, which is synced
+**| with the collection when the iteration position is set, and henceforth
+**| acts to show whether the iter has lost collection synchronization, in
+**| case it matters to clients whether any change happens during iteration.
+**|
+**|| pos: the position of the current element in the collection.  Negative
+**| means a position logically before the first element.  A positive value
+**| equal to count (or larger) implies a position after the last element.
+**| To iterate over all elements, set the position to negative, so subsequent
+**| calls to any 'next' method will access the first collection element.
+**|
+**|| doFailOnSeedOutOfSync: whether a cursor should return an error if the
+**| cursor's snapshot of a table's seed becomes stale with respect the table's
+**| current seed value (which implies the iteration is less than total) in
+**| between to cursor calls that actually access collection content.  By
+**| default, a cursor should assume this attribute is false until specified,
+**| so that iterations quietly try to re-sync when they lose coherence.
+|*/
+
+#define NS_IMDBCURSOR_IID_STR "a0c37337-6ebc-474c-90db-e65ea0b850aa"
+
+#define NS_IMDBCURSOR_IID \
+{0xa0c37337, 0x6ebc, 0x474c, \
+{0x90, 0xdb, 0xe6, 0x5e, 0xa0, 0xb8, 0x50, 0xaa}}
+
+class nsIMdbCursor  : public nsISupports  { // collection iterator
+public:
+
+  NS_DECLARE_STATIC_IID_ACCESSOR(NS_IMDBCURSOR_IID)
+// { ===== begin nsIMdbCursor methods =====
+
+  // { ----- begin attribute methods -----
+  NS_IMETHOD GetCount(nsIMdbEnv* ev, mdb_count* outCount) = 0; // readonly
+  NS_IMETHOD GetSeed(nsIMdbEnv* ev, mdb_seed* outSeed) = 0;    // readonly
+  
+  NS_IMETHOD SetPos(nsIMdbEnv* ev, mdb_pos inPos) = 0;   // mutable
+  NS_IMETHOD GetPos(nsIMdbEnv* ev, mdb_pos* outPos) = 0;
+  
+  NS_IMETHOD SetDoFailOnSeedOutOfSync(nsIMdbEnv* ev, mdb_bool inFail) = 0;
+  NS_IMETHOD GetDoFailOnSeedOutOfSync(nsIMdbEnv* ev, mdb_bool* outFail) = 0;
+  // } ----- end attribute methods -----
+
+// } ===== end nsIMdbCursor methods =====
+};
+
+NS_DEFINE_STATIC_IID_ACCESSOR(nsIMdbCursor, NS_IMDBCURSOR_IID)
+
+#define NS_IMDBPORTTABLECURSOR_IID_STR = "f181a41e-933d-49b3-af93-20d3634b8b78"
+
+#define NS_IMDBPORTTABLECURSOR_IID \
+{0xf181a41e, 0x933d, 0x49b3, \
+{0xaf, 0x93, 0x20, 0xd3, 0x63, 0x4b, 0x8b, 0x78}}
+
+/*| nsIMdbPortTableCursor: cursor class for iterating port tables
+**|
+**|| port: the cursor is associated with a specific port, which can be
+**| set to a different port (which resets the position to -1 so the
+**| next table acquired is the first in the port.
+**|
+|*/
+class nsIMdbPortTableCursor : public nsISupports { // table collection iterator
+public:
+
+  NS_DECLARE_STATIC_IID_ACCESSOR(NS_IMDBPORTTABLECURSOR_IID)
+// { ===== begin nsIMdbPortTableCursor methods =====
+
+  // { ----- begin attribute methods -----
+  NS_IMETHOD SetPort(nsIMdbEnv* ev, nsIMdbPort* ioPort) = 0; // sets pos to -1
+  NS_IMETHOD GetPort(nsIMdbEnv* ev, nsIMdbPort** acqPort) = 0;
+  
+  NS_IMETHOD SetRowScope(nsIMdbEnv* ev, // sets pos to -1
+    mdb_scope inRowScope) = 0;
+  NS_IMETHOD GetRowScope(nsIMdbEnv* ev, mdb_scope* outRowScope) = 0; 
+  // setting row scope to zero iterates over all row scopes in port
+    
+  NS_IMETHOD SetTableKind(nsIMdbEnv* ev, // sets pos to -1
+    mdb_kind inTableKind) = 0;
+  NS_IMETHOD GetTableKind(nsIMdbEnv* ev, mdb_kind* outTableKind) = 0;
+  // setting table kind to zero iterates over all table kinds in row scope
+  // } ----- end attribute methods -----
+
+  // { ----- begin table iteration methods -----
+  NS_IMETHOD NextTable( // get table at next position in the db
+    nsIMdbEnv* ev, // context
+    nsIMdbTable** acqTable) = 0; // the next table in the iteration
+  // } ----- end table iteration methods -----
+
+// } ===== end nsIMdbPortTableCursor methods =====
+};
+
+NS_DEFINE_STATIC_IID_ACCESSOR(nsIMdbPortTableCursor,
+                              NS_IMDBPORTTABLECURSOR_IID)
+
+/*| nsIMdbCollection: an object that collects a set of other objects as members.
+**| The main purpose of this base class is to unify the perceived semantics
+**| of tables and rows where their collection behavior is similar.  This helps
+**| isolate the mechanics of collection behavior from the other semantics that
+**| are more characteristic of rows and tables.
+**|
+**|| count: the number of objects in a collection is the member count. (Some
+**| collection interfaces call this attribute the 'size', but that can be a
+**| little ambiguous, and counting actual members is harder to confuse.)
+**|
+**|| seed: the seed of a collection is a counter for changes in membership in
+**| a specific collection.  This seed should change when members are added to
+**| or removed from a collection, but not when a member changes internal state.
+**| The seed should also change whenever the internal collection of members has
+**| a complex state change that reorders member positions (say by sorting) that
+**| would affect the nature of an iteration over that collection of members.
+**| The purpose of a seed is to inform any outstanding collection cursors that
+**| they might be stale, without incurring the cost of broadcasting an event
+**| notification to such cursors, which would need more data structure support.
+**| Presumably a cursor in a particular mdb code suite has much more direct
+**| access to a collection seed member slot that this abstract COM interface,
+**| so this information is intended more for clients outside mdb that want to
+**| make inferences similar to those made by the collection cursors.  The seed
+**| value as an integer magnitude is not very important, and callers should not
+**| assume meaningful information can be derived from an integer value beyond
+**| whether it is equal or different from a previous inspection.  A seed uses
+**| integers of many bits in order to make the odds of wrapping and becoming
+**| equal to an earlier seed value have probability that is vanishingly small.
+**|
+**|| port: every collection is associated with a specific database instance.
+**|
+**|| cursor: a subclass of nsIMdbCursor suitable for this specific collection
+**| subclass.  The ability to GetCursor() from the base nsIMdbCollection class
+**| is not really as useful as getting a more specifically typed cursor more
+**| directly from the base class without any casting involved.  So including
+**| this method here is more for conceptual illustration.
+**|
+**|| oid: every collection has an identity that persists from session to
+**| session. Implementations are probably able to distinguish row IDs from
+**| table IDs, but we don't specify anything official in this regard.  A
+**| collection has the same identity for the lifetime of the collection,
+**| unless identity is swapped with another collection by means of a call to
+**| BecomeContent(), which is considered a way to swap a new representation
+**| for an old well-known object.  (Even so, only content appears to change,
+**| while the identity seems to stay the same.)
+**|
+**|| become: developers can effectively cause two objects to swap identities,
+**| in order to effect a complete swap between what persistent content is
+**| represented by two oids.  The caller should consider this a content swap,
+**| and not identity wap, because identities will seem to stay the same while
+**| only content changes.  However, implementations will likely do this
+**| internally by swapping identities.  Callers must swap content only
+**| between objects of similar type, such as a row with another row, and a
+**| table with another table, because implementations need not support
+**| cross-object swapping because it might break object name spaces.
+**|
+**|| dropping: when a caller expects a row or table will no longer be used, the
+**| caller can tell the collection to 'drop activity', which means the runtime
+**| object can have its internal representation purged to save memory or any
+**| other resource that is being consumed by the collection's representation.
+**| This has no effect on the collection's persistent content or semantics,
+**| and is only considered a runtime effect.  After a collection drops
+**| activity, the object should still be as usable as before (because it has
+**| NOT been closed), but further usage can be expensive to re-instate because
+**| it might involve reallocating space and/or re-reading disk space.  But
+**| since this future usage is not expected, the caller does not expect to
+**| pay the extra expense.  An implementation can choose to implement
+**| 'dropping activity' in different ways, or even not at all if this
+**| operation is not really feasible.  Callers cannot ask objects whether they
+**| are 'dropped' or not, so this should be transparent. (Note that
+**| implementors might fear callers do not really know whether future
+**| usage will occur, and therefore might delay the act of dropping until
+**| the near future, until seeing whether the object is used again
+**| immediately elsewhere. Such use soon after the drop request might cause
+**| the drop to be cancelled.)
+|*/
+class nsIMdbCollection : public nsISupports { // sequence of objects
+public:
+
+// { ===== begin nsIMdbCollection methods =====
+
+  // { ----- begin attribute methods -----
+  NS_IMETHOD GetSeed(nsIMdbEnv* ev,
+    mdb_seed* outSeed) = 0;    // member change count
+  NS_IMETHOD GetCount(nsIMdbEnv* ev,
+    mdb_count* outCount) = 0; // member count
+
+  NS_IMETHOD GetPort(nsIMdbEnv* ev,
+    nsIMdbPort** acqPort) = 0; // collection container
+  // } ----- end attribute methods -----
+
+  // { ----- begin cursor methods -----
+  NS_IMETHOD GetCursor( // make a cursor starting iter at inMemberPos
+    nsIMdbEnv* ev, // context
+    mdb_pos inMemberPos, // zero-based ordinal pos of member in collection
+    nsIMdbCursor** acqCursor) = 0; // acquire new cursor instance
+  // } ----- end cursor methods -----
+
+  // { ----- begin ID methods -----
+  NS_IMETHOD GetOid(nsIMdbEnv* ev,
+    mdbOid* outOid) = 0; // read object identity
+  NS_IMETHOD BecomeContent(nsIMdbEnv* ev,
+    const mdbOid* inOid) = 0; // exchange content
+  // } ----- end ID methods -----
+
+  // { ----- begin activity dropping methods -----
+  NS_IMETHOD DropActivity( // tell collection usage no longer expected
+    nsIMdbEnv* ev) = 0;
+  // } ----- end activity dropping methods -----
+
+// } ===== end nsIMdbCollection methods =====
+};
+
+/*| nsIMdbTable: an ordered collection of rows
+**|
+**|| row scope: an integer token for an atomized string in this database
+**| that names a space for row IDs.  This attribute of a table is intended
+**| as guidance metainformation that helps with searching a database for
+**| tables that operate on collections of rows of the specific type.  By
+**| convention, a table with a specific row scope is expected to focus on
+**| containing rows that belong to that scope, however exceptions are easily
+**| allowed because all rows in a table are known by both row ID and scope.
+**| (A table with zero row scope is never allowed because this would make it
+**| ambiguous to use a zero row scope when iterating over tables in a port to
+**| indicate that all row scopes should be seen by a cursor.)
+**|
+**|| table kind: an integer token for an atomized string in this database
+**| that names a kind of table as a subset of the associated row scope. This
+**| attribute is intended as guidance metainformation to clarify the role of
+**| this table with respect to other tables in the same row scope, and this
+**| also helps search for such tables in a database.  By convention, a table
+**| with a specific table kind has a consistent role for containing rows with
+**| respect to other collections of such rows in the same row scope.  Also by
+**| convention, at least one table in a row scope has a table kind purporting
+**| to contain ALL the rows that belong in that row scope, so that at least
+**| one table exists that allows all rows in a scope to be interated over.
+**| (A table with zero table kind is never allowed because this would make it
+**| ambiguous to use a zero table kind when iterating over tables in a port to
+**| indicate that all table kinds in a row scope should be seen by a cursor.)
+**|
+**|| port: every table is considered part of some port that contains the
+**| table, so that closing the containing port will cause the table to be
+**| indirectly closed as well.  We make it easy to get the containing port for
+**| a table, because the port supports important semantic interfaces that will
+**| affect how content in table is presented; the most important port context
+**| that affects a table is specified by the set of token to string mappings
+**| that affect all tokens used throughout the database, and which drive the
+**| meanings of row scope, table kind, cell columns, etc.
+**|
+**|| cursor: a cursor that iterates over the rows in this table, where rows
+**| have zero-based index positions from zero to count-1.  Making a cursor
+**| with negative position will next iterate over the first row in the table.
+**|
+**|| position: given any position from zero to count-1, a table will return
+**| the row ID and row scope for the row at that position.  (One can use the
+**| GetRowAllCells() method to read that row, or else use a row cursor to both
+**| get the row at some position and read its content at the same time.)  The
+**| position depends on whether a table is sorted, and upon the actual sort.
+**| Note that moving a row's position is only possible in unsorted tables.
+**|
+**|| row set: every table contains a collection of rows, where a member row is
+**| referenced by the table using the row ID and row scope for the row.  No
+**| single table owns a given row instance, because rows are effectively ref-
+**| counted and destroyed only when the last table removes a reference to that
+**| particular row.  (But a row can be emptied of all content no matter how
+**| many refs exist, and this might be the next best thing to destruction.)
+**| Once a row exists in a least one table (after NewRow() is called), then it
+**| can be added to any other table by calling AddRow(), or removed from any
+**| table by calling CutRow(), or queried as a member by calling HasRow().  A
+**| row can only be added to a table once, and further additions do nothing and
+**| complain not at all.  Cutting a row from a table only does something when
+**| the row was actually a member, and otherwise does nothing silently.
+**|
+**|| row ref count: one can query the number of tables (and/or cells)
+**| containing a row as a member or a child.
+**|
+**|| row content: one can access or modify the cell content in a table's row
+**| by moving content to or from an instance of nsIMdbRow.  Note that nsIMdbRow
+**| never represents the actual row inside a table, and this is the reason
+**| why nsIMdbRow instances do not have row IDs or row scopes.  So an instance
+**| of nsIMdbRow always and only contains a snapshot of some or all content in
+**| past, present, or future persistent row inside a table.  This means that
+**| reading and writing rows in tables has strictly copy semantics, and we
+**| currently do not plan any exceptions for specific performance reasons.
+**|
+**|| sorting: note all rows are assumed sorted by row ID as a secondary
+**| sort following the primary column sort, when table rows are sorted.
+**|
+**|| indexes:
+|*/
+
+
+#define NS_IMDBTABLE_IID_STR = "fe11bc98-d02b-4128-9fac-87042fdf9639"
+
+#define NS_IMDBTABLE_IID \
+{0xfe11bc98, 0xd02b, 0x4128, \
+{0x9f, 0xac, 0x87, 0x04, 0x2f, 0xdf, 0x96, 0x39}}
+
+class nsIMdbTable : public nsIMdbCollection { // a collection of rows
+public:
+
+  NS_DECLARE_STATIC_IID_ACCESSOR(NS_IMDBTABLE_IID)
+// { ===== begin nsIMdbTable methods =====
+
+  // { ----- begin meta attribute methods -----
+  NS_IMETHOD SetTablePriority(nsIMdbEnv* ev, mdb_priority inPrio) = 0;
+  NS_IMETHOD GetTablePriority(nsIMdbEnv* ev, mdb_priority* outPrio) = 0;
+  
+  NS_IMETHOD GetTableBeVerbose(nsIMdbEnv* ev, mdb_bool* outBeVerbose) = 0;
+  NS_IMETHOD SetTableBeVerbose(nsIMdbEnv* ev, mdb_bool inBeVerbose) = 0;
+  
+  NS_IMETHOD GetTableIsUnique(nsIMdbEnv* ev, mdb_bool* outIsUnique) = 0;
+  
+  NS_IMETHOD GetTableKind(nsIMdbEnv* ev, mdb_kind* outTableKind) = 0;
+  NS_IMETHOD GetRowScope(nsIMdbEnv* ev, mdb_scope* outRowScope) = 0;
+  
+  NS_IMETHOD GetMetaRow(
+    nsIMdbEnv* ev, // context
+    const mdbOid* inOptionalMetaRowOid, // can be nil to avoid specifying 
+    mdbOid* outOid, // output meta row oid, can be nil to suppress output
+    nsIMdbRow** acqRow) = 0; // acquire table's unique singleton meta row
+    // The purpose of a meta row is to support the persistent recording of
+    // meta info about a table as cells put into the distinguished meta row.
+    // Each table has exactly one meta row, which is not considered a member
+    // of the collection of rows inside the table.  The only way to tell
+    // whether a row is a meta row is by the fact that it is returned by this
+    // GetMetaRow() method from some table. Otherwise nothing distinguishes
+    // a meta row from any other row.  A meta row can be used anyplace that
+    // any other row can be used, and can even be put into other tables (or
+    // the same table) as a table member, if this is useful for some reason.
+    // The first attempt to access a table's meta row using GetMetaRow() will
+    // cause the meta row to be created if it did not already exist.  When the
+    // meta row is created, it will have the row oid that was previously
+    // requested for this table's meta row; or if no oid was ever explicitly
+    // specified for this meta row, then a unique oid will be generated in
+    // the row scope named "m" (so obviously MDB clients should not
+    // manually allocate any row IDs from that special meta scope namespace).
+    // The meta row oid can be specified either when the table is created, or
+    // else the first time that GetMetaRow() is called, by passing a non-nil
+    // pointer to an oid for parameter inOptionalMetaRowOid.  The meta row's
+    // actual oid is returned in outOid (if this is a non-nil pointer), and
+    // it will be different from inOptionalMetaRowOid when the meta row was
+    // already given a different oid earlier.
+  // } ----- end meta attribute methods -----
+
+
+  // { ----- begin cursor methods -----
+  NS_IMETHOD GetTableRowCursor( // make a cursor, starting iteration at inRowPos
+    nsIMdbEnv* ev, // context
+    mdb_pos inRowPos, // zero-based ordinal position of row in table
+    nsIMdbTableRowCursor** acqCursor) = 0; // acquire new cursor instance
+  // } ----- end row position methods -----
+
+  // { ----- begin row position methods -----
+  NS_IMETHOD PosToOid( // get row member for a table position
+    nsIMdbEnv* ev, // context
+    mdb_pos inRowPos, // zero-based ordinal position of row in table
+    mdbOid* outOid) = 0; // row oid at the specified position
+
+  NS_IMETHOD OidToPos( // test for the table position of a row member
+    nsIMdbEnv* ev, // context
+    const mdbOid* inOid, // row to find in table
+    mdb_pos* outPos) = 0; // zero-based ordinal position of row in table
+    
+  NS_IMETHOD PosToRow( // test for the table position of a row member
+    nsIMdbEnv* ev, // context
+    mdb_pos inRowPos, // zero-based ordinal position of row in table
+    nsIMdbRow** acqRow) = 0; // acquire row at table position inRowPos
+    
+  NS_IMETHOD RowToPos( // test for the table position of a row member
+    nsIMdbEnv* ev, // context
+    nsIMdbRow* ioRow, // row to find in table
+    mdb_pos* outPos) = 0; // zero-based ordinal position of row in table
+  // } ----- end row position methods -----
+
+  // { ----- begin oid set methods -----
+  NS_IMETHOD AddOid( // make sure the row with inOid is a table member 
+    nsIMdbEnv* ev, // context
+    const mdbOid* inOid) = 0; // row to ensure membership in table
+
+  NS_IMETHOD HasOid( // test for the table position of a row member
+    nsIMdbEnv* ev, // context
+    const mdbOid* inOid, // row to find in table
+    mdb_bool* outHasOid) = 0; // whether inOid is a member row
+
+  NS_IMETHOD CutOid( // make sure the row with inOid is not a member 
+    nsIMdbEnv* ev, // context
+    const mdbOid* inOid) = 0; // row to remove from table
+  // } ----- end oid set methods -----
+
+  // { ----- begin row set methods -----
+  NS_IMETHOD NewRow( // create a new row instance in table
+    nsIMdbEnv* ev, // context
+    mdbOid* ioOid, // please use minus one (unbound) rowId for db-assigned IDs
+    nsIMdbRow** acqRow) = 0; // create new row
+
+  NS_IMETHOD AddRow( // make sure the row with inOid is a table member 
+    nsIMdbEnv* ev, // context
+    nsIMdbRow* ioRow) = 0; // row to ensure membership in table
+
+  NS_IMETHOD HasRow( // test for the table position of a row member
+    nsIMdbEnv* ev, // context
+    nsIMdbRow* ioRow, // row to find in table
+    mdb_bool* outHasRow) = 0; // whether row is a table member
+
+  NS_IMETHOD CutRow( // make sure the row with inOid is not a member 
+    nsIMdbEnv* ev, // context
+    nsIMdbRow* ioRow) = 0; // row to remove from table
+
+  NS_IMETHOD CutAllRows( // remove all rows from the table
+    nsIMdbEnv* ev) = 0; // context
+  // } ----- end row set methods -----
+
+  // { ----- begin hinting methods -----
+  NS_IMETHOD SearchColumnsHint( // advise re future expected search cols  
+    nsIMdbEnv* ev, // context
+    const mdbColumnSet* inColumnSet) = 0; // columns likely to be searched
+    
+  NS_IMETHOD SortColumnsHint( // advise re future expected sort columns  
+    nsIMdbEnv* ev, // context
+    const mdbColumnSet* inColumnSet) = 0; // columns for likely sort requests
+    
+  NS_IMETHOD StartBatchChangeHint( // advise before many adds and cuts  
+    nsIMdbEnv* ev, // context
+    const void* inLabel) = 0; // intend unique address to match end call
+    // If batch starts nest by virtue of nesting calls in the stack, then
+    // the address of a local variable makes a good batch start label that
+    // can be used at batch end time, and such addresses remain unique.
+    
+  NS_IMETHOD EndBatchChangeHint( // advise before many adds and cuts  
+    nsIMdbEnv* ev, // context
+    const void* inLabel) = 0; // label matching start label
+    // Suppose a table is maintaining one or many sort orders for a table,
+    // so that every row added to the table must be inserted in each sort,
+    // and every row cut must be removed from each sort.  If a db client
+    // intends to make many such changes before needing any information
+    // about the order or positions of rows inside a table, then a client
+    // might tell the table to start batch changes in order to disable
+    // sorting of rows for the interim.  Presumably a table will then do
+    // a full sort of all rows at need when the batch changes end, or when
+    // a surprise request occurs for row position during batch changes.
+  // } ----- end hinting methods -----
+
+  // { ----- begin searching methods -----
+  NS_IMETHOD FindRowMatches( // search variable number of sorted cols
+    nsIMdbEnv* ev, // context
+    const mdbYarn* inPrefix, // content to find as prefix in row's column cell
+    nsIMdbTableRowCursor** acqCursor) = 0; // set of matching rows
+    
+  NS_IMETHOD GetSearchColumns( // query columns used by FindRowMatches()
+    nsIMdbEnv* ev, // context
+    mdb_count* outCount, // context
+    mdbColumnSet* outColSet) = 0; // caller supplied space to put columns
+    // GetSearchColumns() returns the columns actually searched when the
+    // FindRowMatches() method is called.  No more than mColumnSet_Count
+    // slots of mColumnSet_Columns will be written, since mColumnSet_Count
+    // indicates how many slots are present in the column array.  The
+    // actual number of search column used by the table is returned in
+    // the outCount parameter; if this number exceeds mColumnSet_Count,
+    // then a caller needs a bigger array to read the entire column set.
+    // The minimum of mColumnSet_Count and outCount is the number slots
+    // in mColumnSet_Columns that were actually written by this method.
+    //
+    // Callers are expected to change this set of columns by calls to
+    // nsIMdbTable::SearchColumnsHint() or SetSearchSorting(), or both.
+  // } ----- end searching methods -----
+
+  // { ----- begin sorting methods -----
+  // sorting: note all rows are assumed sorted by row ID as a secondary
+  // sort following the primary column sort, when table rows are sorted.
+
+  NS_IMETHOD
+  CanSortColumn( // query which column is currently used for sorting
+    nsIMdbEnv* ev, // context
+    mdb_column inColumn, // column to query sorting potential
+    mdb_bool* outCanSort) = 0; // whether the column can be sorted
+    
+  NS_IMETHOD GetSorting( // view same table in particular sorting
+    nsIMdbEnv* ev, // context
+    mdb_column inColumn, // requested new column for sorting table
+    nsIMdbSorting** acqSorting) = 0; // acquire sorting for column
+    
+  NS_IMETHOD SetSearchSorting( // use this sorting in FindRowMatches()
+    nsIMdbEnv* ev, // context
+    mdb_column inColumn, // often same as nsIMdbSorting::GetSortColumn()
+    nsIMdbSorting* ioSorting) = 0; // requested sorting for some column
+    // SetSearchSorting() attempts to inform the table that ioSorting
+    // should be used during calls to FindRowMatches() for searching
+    // the column which is actually sorted by ioSorting.  This method
+    // is most useful in conjunction with nsIMdbSorting::SetCompare(),
+    // because otherwise a caller would not be able to override the
+    // comparison ordering method used during searchs.  Note that some
+    // database implementations might be unable to use an arbitrarily
+    // specified sort order, either due to schema or runtime interface
+    // constraints, in which case ioSorting might not actually be used.
+    // Presumably ioSorting is an instance that was returned from some
+    // earlier call to nsIMdbTable::GetSorting().  A caller can also
+    // use nsIMdbTable::SearchColumnsHint() to specify desired change
+    // in which columns are sorted and searched by FindRowMatches().
+    //
+    // A caller can pass a nil pointer for ioSorting to request that
+    // column inColumn no longer be used at all by FindRowMatches().
+    // But when ioSorting is non-nil, then inColumn should match the
+    // column actually sorted by ioSorting; when these do not agree,
+    // implementations are instructed to give precedence to the column
+    // specified by ioSorting (so this means callers might just pass
+    // zero for inColumn when ioSorting is also provided, since then
+    // inColumn is both redundant and ignored).
+  // } ----- end sorting methods -----
+
+  // { ----- begin moving methods -----
+  // moving a row does nothing unless a table is currently unsorted
+  
+  NS_IMETHOD MoveOid( // change position of row in unsorted table
+    nsIMdbEnv* ev, // context
+    const mdbOid* inOid,  // row oid to find in table
+    mdb_pos inHintFromPos, // suggested hint regarding start position
+    mdb_pos inToPos,       // desired new position for row inRowId
+    mdb_pos* outActualPos) = 0; // actual new position of row in table
+
+  NS_IMETHOD MoveRow( // change position of row in unsorted table
+    nsIMdbEnv* ev, // context
+    nsIMdbRow* ioRow,  // row oid to find in table
+    mdb_pos inHintFromPos, // suggested hint regarding start position
+    mdb_pos inToPos,       // desired new position for row inRowId
+    mdb_pos* outActualPos) = 0; // actual new position of row in table
+  // } ----- end moving methods -----
+  
+  // { ----- begin index methods -----
+  NS_IMETHOD AddIndex( // create a sorting index for column if possible
+    nsIMdbEnv* ev, // context
+    mdb_column inColumn, // the column to sort by index
+    nsIMdbThumb** acqThumb) = 0; // acquire thumb for incremental index building
+  // Call nsIMdbThumb::DoMore() until done, or until the thumb is broken, and
+  // then the index addition will be finished.
+  
+  NS_IMETHOD CutIndex( // stop supporting a specific column index
+    nsIMdbEnv* ev, // context
+    mdb_column inColumn, // the column with index to be removed
+    nsIMdbThumb** acqThumb) = 0; // acquire thumb for incremental index destroy
+  // Call nsIMdbThumb::DoMore() until done, or until the thumb is broken, and
+  // then the index removal will be finished.
+  
+  NS_IMETHOD HasIndex( // query for current presence of a column index
+    nsIMdbEnv* ev, // context
+    mdb_column inColumn, // the column to investigate
+    mdb_bool* outHasIndex) = 0; // whether column has index for this column
+
+  
+  NS_IMETHOD EnableIndexOnSort( // create an index for col on first sort
+    nsIMdbEnv* ev, // context
+    mdb_column inColumn) = 0; // the column to index if ever sorted
+  
+  NS_IMETHOD QueryIndexOnSort( // check whether index on sort is enabled
+    nsIMdbEnv* ev, // context
+    mdb_column inColumn, // the column to investigate
+    mdb_bool* outIndexOnSort) = 0; // whether column has index-on-sort enabled
+  
+  NS_IMETHOD DisableIndexOnSort( // prevent future index creation on sort
+    nsIMdbEnv* ev, // context
+    mdb_column inColumn) = 0; // the column to index if ever sorted
+  // } ----- end index methods -----
+
+// } ===== end nsIMdbTable methods =====
+};
+
+NS_DEFINE_STATIC_IID_ACCESSOR(nsIMdbTable, NS_IMDBTABLE_IID)
+
+/*| nsIMdbSorting: a view of a table in some particular sort order.  This
+**| row order closely resembles a readonly array of rows with the same row
+**| membership as the underlying table, but in a different order than the
+**| table's explicit row order.  But the sorting's row membership changes
+**| whenever the table's membership changes (without any notification, so
+**| keep this in mind when modifying the table).
+**|
+**|| table: every sorting is associated with a particular table.  You
+**| cannot change which table is used by a sorting (just ask some new
+**| table for a suitable sorting instance instead).
+**|
+**|| compare: the ordering method used by a sorting, wrapped up in a
+**| abstract plug-in interface.  When this was never installed by an
+**| explicit call to SetNewCompare(), a compare object is still returned,
+**| and it might match the compare instance returned by the factory method
+**| nsIMdbFactory::MakeCompare(), which represents a default sort order
+**| (which we fervently hope is consistently ASCII byte ordering).
+**|
+**|| cursor: in case callers are more comfortable with a cursor style
+**| of accessing row members, each sorting will happily return a cursor
+**| instance with behavior very similar to a cursor returned from a call
+**| to nsIMdbTable::GetTableRowCursor(), but with different row order.
+**| A cursor should show exactly the same information as the pos methods.
+**|
+**|| pos: the PosToOid() and PosToRow() methods are just like the table
+**| methods of the same name, except they show rows in the sort order of 
+**| the sorting, rather than that of the table.  These methods are like
+**| readonly array position accessor's, or like a C++ operator[].
+|*/
+class nsIMdbSorting : public nsIMdbObject { // sorting of some table
+public:
+// { ===== begin nsIMdbSorting methods =====
+
+  // { ----- begin attribute methods -----
+  // sorting: note all rows are assumed sorted by row ID as a secondary
+  // sort following the primary column sort, when table rows are sorted.
+  
+  NS_IMETHOD GetTable(nsIMdbEnv* ev, nsIMdbTable** acqTable) = 0;
+  NS_IMETHOD GetSortColumn( // query which col is currently sorted
+    nsIMdbEnv* ev, // context
+    mdb_column* outColumn) = 0; // col the table uses for sorting (or zero)
+
+  // } ----- end attribute methods -----
+
+  // { ----- begin cursor methods -----
+  NS_IMETHOD GetSortingRowCursor( // make a cursor, starting at inRowPos
+    nsIMdbEnv* ev, // context
+    mdb_pos inRowPos, // zero-based ordinal position of row in table
+    nsIMdbTableRowCursor** acqCursor) = 0; // acquire new cursor instance
+    // A cursor interface turning same info as PosToOid() or PosToRow().
+  // } ----- end row position methods -----
+
+  // { ----- begin row position methods -----
+  NS_IMETHOD PosToOid( // get row member for a table position
+    nsIMdbEnv* ev, // context
+    mdb_pos inRowPos, // zero-based ordinal position of row in table
+    mdbOid* outOid) = 0; // row oid at the specified position
+    
+  NS_IMETHOD PosToRow( // test for the table position of a row member
+    nsIMdbEnv* ev, // context
+    mdb_pos inRowPos, // zero-based ordinal position of row in table
+    nsIMdbRow** acqRow) = 0; // acquire row at table position inRowPos
+  // } ----- end row position methods -----
+
+// } ===== end nsIMdbSorting methods =====
+};
+
+/*| nsIMdbTableRowCursor: cursor class for iterating table rows
+**|
+**|| table: the cursor is associated with a specific table, which can be
+**| set to a different table (which resets the position to -1 so the
+**| next row acquired is the first in the table.
+**|
+**|| NextRowId: the rows in the table can be iterated by identity alone,
+**| without actually reading the cells of any row with this method.
+**|
+**|| NextRowCells: read the next row in the table, but only read cells
+**| from the table which are already present in the row (so no new cells
+**| are added to the row, even if they are present in the table).  All the
+**| cells will have content specified, even it is the empty string.  No
+**| columns will be removed, even if missing from the row (because missing
+**| and empty are semantically equivalent).
+**|
+**|| NextRowAllCells: read the next row in the table, and access all the
+**| cells for this row in the table, adding any missing columns to the row
+**| as needed until all cells are represented.  All the
+**| cells will have content specified, even it is the empty string.  No
+**| columns will be removed, even if missing from the row (because missing
+**| and empty are semantically equivalent).
+**|
+|*/
+
+#define NS_IMDBTABLEROWCURSOR_IID_STR = "4f325dad-0385-4b62-a992-c914ab93587e"
+
+#define NS_IMDBTABLEROWCURSOR_IID \
+{0x4f325dad, 0x0385, 0x4b62, \
+{0xa9, 0x92, 0xc9, 0x14, 0xab, 0x93, 0x58, 0x7e}}
+
+
+
+class nsIMdbTableRowCursor : public nsISupports { // table row iterator
+public:
+  NS_DECLARE_STATIC_IID_ACCESSOR(NS_IMDBTABLEROWCURSOR_IID)
+
+// { ===== begin nsIMdbTableRowCursor methods =====
+
+  // { ----- begin attribute methods -----
+  // NS_IMETHOD SetTable(nsIMdbEnv* ev, nsIMdbTable* ioTable) = 0; // sets pos to -1
+  // Method SetTable() cut and made obsolete in keeping with new sorting methods.
+  
+  NS_IMETHOD GetTable(nsIMdbEnv* ev, nsIMdbTable** acqTable) = 0;
+  // } ----- end attribute methods -----
+
+  // { ----- begin duplicate row removal methods -----
+  NS_IMETHOD CanHaveDupRowMembers(nsIMdbEnv* ev, // cursor might hold dups?
+    mdb_bool* outCanHaveDups) = 0;
+    
+  NS_IMETHOD MakeUniqueCursor( // clone cursor, removing duplicate rows
+    nsIMdbEnv* ev, // context
+    nsIMdbTableRowCursor** acqCursor) = 0;    // acquire clone with no dups
+    // Note that MakeUniqueCursor() is never necessary for a cursor which was
+    // created by table method nsIMdbTable::GetTableRowCursor(), because a table
+    // never contains the same row as a member more than once.  However, a cursor
+    // created by table method nsIMdbTable::FindRowMatches() might contain the
+    // same row more than once, because the same row can generate a hit by more
+    // than one column with a matching string prefix.  Note this method can
+    // return the very same cursor instance with just an incremented refcount,
+    // when the original cursor could not contain any duplicate rows (calling
+    // CanHaveDupRowMembers() shows this case on a false return).  Otherwise
+    // this method returns a different cursor instance.  Callers should not use
+    // this MakeUniqueCursor() method lightly, because it tends to defeat the
+    // purpose of lazy programming techniques, since it can force creation of
+    // an explicit row collection in a new cursor's representation, in order to
+    // inspect the row membership and remove any duplicates; this can have big
+    // impact if a collection holds tens of thousands of rows or more, when
+    // the original cursor with dups simply referenced rows indirectly by row
+    // position ranges, without using an explicit row set representation.
+    // Callers are encouraged to use nsIMdbCursor::GetCount() to determine
+    // whether the row collection is very large (tens of thousands), and to
+    // delay calling MakeUniqueCursor() when possible, until a user interface
+    // element actually demands the creation of an explicit set representation.
+  // } ----- end duplicate row removal methods -----
+
+  // { ----- begin oid iteration methods -----
+  NS_IMETHOD NextRowOid( // get row id of next row in the table
+    nsIMdbEnv* ev, // context
+    mdbOid* outOid, // out row oid
+    mdb_pos* outRowPos) = 0;    // zero-based position of the row in table
+  // } ----- end oid iteration methods -----
+
+  // { ----- begin row iteration methods -----
+  NS_IMETHOD NextRow( // get row cells from table for cells already in row
+    nsIMdbEnv* ev, // context
+    nsIMdbRow** acqRow, // acquire next row in table
+    mdb_pos* outRowPos) = 0;    // zero-based position of the row in table
+
+  NS_IMETHOD PrevRowOid( // get row id of previous row in the table
+    nsIMdbEnv* ev, // context
+    mdbOid* outOid, // out row oid
+    mdb_pos* outRowPos) = 0;    // zero-based position of the row in table
+  // } ----- end oid iteration methods -----
+
+  // { ----- begin row iteration methods -----
+  NS_IMETHOD PrevRow( // get row cells from table for cells already in row
+    nsIMdbEnv* ev, // context
+    nsIMdbRow** acqRow, // acquire previous row in table
+    mdb_pos* outRowPos) = 0;    // zero-based position of the row in table
+
+  // } ----- end row iteration methods -----
+
+  // { ----- begin copy iteration methods -----
+  // NS_IMETHOD NextRowCopy( // put row cells into sink only when already in sink
+  //   nsIMdbEnv* ev, // context
+  //   nsIMdbRow* ioSinkRow, // sink for row cells read from next row
+  //   mdbOid* outOid, // out row oid
+  //   mdb_pos* outRowPos) = 0;    // zero-based position of the row in table
+  // 
+  // NS_IMETHOD NextRowCopyAll( // put all row cells into sink, adding to sink
+  //   nsIMdbEnv* ev, // context
+  //   nsIMdbRow* ioSinkRow, // sink for row cells read from next row
+  //   mdbOid* outOid, // out row oid
+  //   mdb_pos* outRowPos) = 0;    // zero-based position of the row in table
+  // } ----- end copy iteration methods -----
+
+// } ===== end nsIMdbTableRowCursor methods =====
+};
+
+NS_DEFINE_STATIC_IID_ACCESSOR(nsIMdbTableRowCursor, NS_IMDBTABLEROWCURSOR_IID)
+
+/*| nsIMdbRow: a collection of cells
+**|
+|*/
+
+#define NS_IMDBROW_IID_STR "271e8d6e-183a-40e3-9f18-36913b4c7853"
+
+
+#define NS_IMDBROW_IID \
+{0x271e8d6e, 0x183a, 0x40e3, \
+{0x9f, 0x18, 0x36, 0x91, 0x3b, 0x4c, 0x78, 0x53}}
+
+
+class nsIMdbRow : public nsIMdbCollection { // cell tuple
+public:
+
+  NS_DECLARE_STATIC_IID_ACCESSOR(NS_IMDBROW_IID)
+// { ===== begin nsIMdbRow methods =====
+
+  // { ----- begin cursor methods -----
+  NS_IMETHOD GetRowCellCursor( // make a cursor starting iteration at inCellPos
+    nsIMdbEnv* ev, // context
+    mdb_pos inCellPos, // zero-based ordinal position of cell in row
+    nsIMdbRowCellCursor** acqCursor) = 0; // acquire new cursor instance
+  // } ----- end cursor methods -----
+
+  // { ----- begin column methods -----
+  NS_IMETHOD AddColumn( // make sure a particular column is inside row
+    nsIMdbEnv* ev, // context
+    mdb_column inColumn, // column to add
+    const mdbYarn* inYarn) = 0; // cell value to install
+
+  NS_IMETHOD CutColumn( // make sure a column is absent from the row
+    nsIMdbEnv* ev, // context
+    mdb_column inColumn) = 0; // column to ensure absent from row
+
+  NS_IMETHOD CutAllColumns( // remove all columns from the row
+    nsIMdbEnv* ev) = 0; // context
+  // } ----- end column methods -----
+
+  // { ----- begin cell methods -----
+  NS_IMETHOD NewCell( // get cell for specified column, or add new one
+    nsIMdbEnv* ev, // context
+    mdb_column inColumn, // column to add
+    nsIMdbCell** acqCell) = 0; // cell column and value
+    
+  NS_IMETHOD AddCell( // copy a cell from another row to this row
+    nsIMdbEnv* ev, // context
+    const nsIMdbCell* inCell) = 0; // cell column and value
+    
+  NS_IMETHOD GetCell( // find a cell in this row
+    nsIMdbEnv* ev, // context
+    mdb_column inColumn, // column to find
+    nsIMdbCell** acqCell) = 0; // cell for specified column, or null
+    
+  NS_IMETHOD EmptyAllCells( // make all cells in row empty of content
+    nsIMdbEnv* ev) = 0; // context
+  // } ----- end cell methods -----
+
+  // { ----- begin row methods -----
+  NS_IMETHOD AddRow( // add all cells in another row to this one
+    nsIMdbEnv* ev, // context
+    nsIMdbRow* ioSourceRow) = 0; // row to union with
+    
+  NS_IMETHOD SetRow( // make exact duplicate of another row
+    nsIMdbEnv* ev, // context
+    nsIMdbRow* ioSourceRow) = 0; // row to duplicate
+  // } ----- end row methods -----
+
+  // { ----- begin blob methods -----  
+  NS_IMETHOD SetCellYarn(nsIMdbEnv* ev, // synonym for AddColumn()
+    mdb_column inColumn, // column to write
+    const mdbYarn* inYarn) = 0;   // reads from yarn slots
+  // make this text object contain content from the yarn's buffer
+  
+  NS_IMETHOD GetCellYarn(nsIMdbEnv* ev, 
+    mdb_column inColumn, // column to read 
+    mdbYarn* outYarn) = 0;  // writes some yarn slots 
+  // copy content into the yarn buffer, and update mYarn_Fill and mYarn_Form
+  
+  NS_IMETHOD AliasCellYarn(nsIMdbEnv* ev, 
+    mdb_column inColumn, // column to alias
+    mdbYarn* outYarn) = 0; // writes ALL yarn slots
+  
+  NS_IMETHOD NextCellYarn(nsIMdbEnv* ev, // iterative version of GetCellYarn()
+    mdb_column* ioColumn, // next column to read
+    mdbYarn* outYarn) = 0;  // writes some yarn slots 
+  // copy content into the yarn buffer, and update mYarn_Fill and mYarn_Form
+  //
+  // The ioColumn argument is an inout parameter which initially contains the
+  // last column accessed and returns the next column corresponding to the
+  // content read into the yarn.  Callers should start with a zero column
+  // value to say 'no previous column', which causes the first column to be
+  // read.  Then the value returned in ioColumn is perfect for the next call
+  // to NextCellYarn(), since it will then be the previous column accessed.
+  // Callers need only examine the column token returned to see which cell
+  // in the row is being read into the yarn.  When no more columns remain,
+  // and the iteration has ended, ioColumn will return a zero token again.
+  // So iterating over cells starts and ends with a zero column token.
+
+  NS_IMETHOD SeekCellYarn( // resembles nsIMdbRowCellCursor::SeekCell()
+    nsIMdbEnv* ev, // context
+    mdb_pos inPos, // position of cell in row sequence
+    mdb_column* outColumn, // column for this particular cell
+    mdbYarn* outYarn) = 0; // writes some yarn slots
+  // copy content into the yarn buffer, and update mYarn_Fill and mYarn_Form
+  // Callers can pass nil for outYarn to indicate no interest in content, so
+  // only the outColumn value is returned.  NOTE to subclasses: you must be
+  // able to ignore outYarn when the pointer is nil; please do not crash.
+
+  // } ----- end blob methods -----
+
+// } ===== end nsIMdbRow methods =====
+};
+
+NS_DEFINE_STATIC_IID_ACCESSOR(nsIMdbRow, NS_IMDBROW_IID)
+
+/*| nsIMdbRowCellCursor: cursor class for iterating row cells
+**|
+**|| row: the cursor is associated with a specific row, which can be
+**| set to a different row (which resets the position to -1 so the
+**| next cell acquired is the first in the row.
+**|
+**|| NextCell: get the next cell in the row and return its position and
+**| a new instance of a nsIMdbCell to represent this next cell.
+|*/
+
+#define NS_IMDBROWCELLCURSOR_IID_STR "b33371a7-5d63-4d10-85a8-e44dffe75c28"
+
+
+#define NS_IMDBROWCELLCURSOR_IID \
+{0x271e8d6e, 0x5d63, 0x4d10 , \
+{0x85, 0xa8, 0xe4, 0x4d, 0xff, 0xe7, 0x5c, 0x28}}
+
+
+class nsIMdbRowCellCursor : public nsISupports{ // cell collection iterator
+public:
+
+  NS_DECLARE_STATIC_IID_ACCESSOR(NS_IMDBROWCELLCURSOR_IID)
+// { ===== begin nsIMdbRowCellCursor methods =====
+
+  // { ----- begin attribute methods -----
+  NS_IMETHOD SetRow(nsIMdbEnv* ev, nsIMdbRow* ioRow) = 0; // sets pos to -1
+  NS_IMETHOD GetRow(nsIMdbEnv* ev, nsIMdbRow** acqRow) = 0;
+  // } ----- end attribute methods -----
+
+  // { ----- begin cell creation methods -----
+  NS_IMETHOD MakeCell( // get cell at current pos in the row
+    nsIMdbEnv* ev, // context
+    mdb_column* outColumn, // column for this particular cell
+    mdb_pos* outPos, // position of cell in row sequence
+    nsIMdbCell** acqCell) = 0; // the cell at inPos
+  // } ----- end cell creation methods -----
+
+  // { ----- begin cell seeking methods -----
+  NS_IMETHOD SeekCell( // same as SetRow() followed by MakeCell()
+    nsIMdbEnv* ev, // context
+    mdb_pos inPos, // position of cell in row sequence
+    mdb_column* outColumn, // column for this particular cell
+    nsIMdbCell** acqCell) = 0; // the cell at inPos
+  // } ----- end cell seeking methods -----
+
+  // { ----- begin cell iteration methods -----
+  NS_IMETHOD NextCell( // get next cell in the row
+    nsIMdbEnv* ev, // context
+    nsIMdbCell** acqCell, // changes to the next cell in the iteration
+    mdb_column* outColumn, // column for this particular cell
+    mdb_pos* outPos) = 0; // position of cell in row sequence
+    
+  NS_IMETHOD PickNextCell( // get next cell in row within filter set
+    nsIMdbEnv* ev, // context
+    nsIMdbCell* ioCell, // changes to the next cell in the iteration
+    const mdbColumnSet* inFilterSet, // col set of actual caller interest
+    mdb_column* outColumn, // column for this particular cell
+    mdb_pos* outPos) = 0; // position of cell in row sequence
+
+  // Note that inFilterSet should not have too many (many more than 10?)
+  // cols, since this might imply a potential excessive consumption of time
+  // over many cursor calls when looking for column and filter intersection.
+  // } ----- end cell iteration methods -----
+
+// } ===== end nsIMdbRowCellCursor methods =====
+};
+
+NS_DEFINE_STATIC_IID_ACCESSOR(nsIMdbRowCellCursor, NS_IMDBROWCELLCURSOR_IID)
+
+/*| nsIMdbBlob: a base class for objects composed mainly of byte sequence state.
+**| (This provides a base class for nsIMdbCell, so that cells themselves can
+**| be used to set state in another cell, without extracting a buffer.)
+|*/
+class nsIMdbBlob : public nsISupports { // a string with associated charset
+public:
+
+// { ===== begin nsIMdbBlob methods =====
+
+  // { ----- begin attribute methods -----
+  NS_IMETHOD SetBlob(nsIMdbEnv* ev,
+    nsIMdbBlob* ioBlob) = 0; // reads inBlob slots
+  // when inBlob is in the same suite, this might be fastest cell-to-cell
+  
+  NS_IMETHOD ClearBlob( // make empty (so content has zero length)
+    nsIMdbEnv* ev) = 0;
+  // clearing a yarn is like SetYarn() with empty yarn instance content
+  
+  NS_IMETHOD GetBlobFill(nsIMdbEnv* ev,
+    mdb_fill* outFill) = 0;  // size of blob 
+  // Same value that would be put into mYarn_Fill, if one called GetYarn()
+  // with a yarn instance that had mYarn_Buf==nil and mYarn_Size==0.
+  
+  NS_IMETHOD SetYarn(nsIMdbEnv* ev, 
+    const mdbYarn* inYarn) = 0;   // reads from yarn slots
+  // make this text object contain content from the yarn's buffer
+  
+  NS_IMETHOD GetYarn(nsIMdbEnv* ev, 
+    mdbYarn* outYarn) = 0;  // writes some yarn slots 
+  // copy content into the yarn buffer, and update mYarn_Fill and mYarn_Form
+  
+  NS_IMETHOD AliasYarn(nsIMdbEnv* ev, 
+    mdbYarn* outYarn) = 0; // writes ALL yarn slots
+  // AliasYarn() reveals sensitive internal text buffer state to the caller
+  // by setting mYarn_Buf to point into the guts of this text implementation.
+  //
+  // The caller must take great care to avoid writing on this space, and to
+  // avoid calling any method that would cause the state of this text object
+  // to change (say by directly or indirectly setting the text to hold more
+  // content that might grow the size of the buffer and free the old buffer).
+  // In particular, callers should scrupulously avoid making calls into the
+  // mdb interface to write any content while using the buffer pointer found
+  // in the returned yarn instance.  Best safe usage involves copying content
+  // into some other kind of external content representation beyond mdb.
+  //
+  // (The original design of this method a week earlier included the concept
+  // of very fast and efficient cooperative locking via a pointer to some lock
+  // member slot.  But let's ignore that complexity in the current design.)
+  //
+  // AliasYarn() is specifically intended as the first step in transferring
+  // content from nsIMdbBlob to a nsString representation, without forcing extra
+  // allocations and/or memory copies. (A standard nsIMdbBlob_AsString() utility
+  // will use AliasYarn() as the first step in setting a nsString instance.)
+  //
+  // This is an alternative to the GetYarn() method, which has copy semantics
+  // only; AliasYarn() relaxes a robust safety principle only for performance
+  // reasons, to accomodate the need for callers to transform text content to
+  // some other canonical representation that would necessitate an additional
+  // copy and transformation when such is incompatible with the mdbYarn format.
+  //
+  // The implementation of AliasYarn() should have extremely little overhead
+  // besides the virtual dispatch to the method implementation, and the code
+  // necessary to populate all the mdbYarn member slots with internal buffer
+  // address and metainformation that describes the buffer content.  Note that
+  // mYarn_Grow must always be set to nil to indicate no resizing is allowed.
+  
+  // } ----- end attribute methods -----
+
+// } ===== end nsIMdbBlob methods =====
+};
+
+/*| nsIMdbCell: the text in a single column of a row.  The base nsIMdbBlob
+**| class provides all the interface related to accessing cell text.
+**|
+**|| column: each cell in a row appears in a specific column, where this
+**| column is identified by the an integer mdb_scope value (generated by
+**| the StringToScopeToken() method in the containing nsIMdbPort instance).
+**| Because a row cannot have more than one cell with the same column,
+**| something must give if one calls SetColumn() with an existing column
+**| in the same row. When this happens, the other cell is replaced with
+**| this cell (and the old cell is closed if it has outstanding refs).
+**|
+**|| row: every cell instance is a part of some row, and every cell knows
+**| which row is the parent row.  (Note this should be represented by a
+**| weak backpointer, so that outstanding cell references cannot keep a
+**| row open that should be closed. Otherwise we'd have ref graph cycles.)
+**|
+**|| text: a cell can either be text, or it can have a child row or table,
+**| but not both at once.  If text is read from a cell with a child, the text
+**| content should be empty (for AliasYarn()) or a description of the type
+**| of child (perhaps "mdb:cell:child:row" or "mdb:cell:child:table").
+**|
+**|| child: a cell might reference another row or a table, rather than text.
+**| The interface for putting and getting children rows and tables was first
+**| defined in the nsIMdbTable interface, but then this was moved to this cell
+**| interface as more natural. 
+|*/
+
+
+
+#define NS_IMDBCELL_IID \
+{0xa3b62f71, 0xa181, 0x4a91, \
+{0xb6, 0x6b, 0x27, 0x10, 0x9b, 0x88, 0x98, 0x35}}
+
+#define NS_IMDBCELL_IID_STR = "a3b62f71-a181-4a91-b66b-27109b889835"
+
+class nsIMdbCell : public nsIMdbBlob { // text attribute in row with column scope
+public:
+
+  NS_DECLARE_STATIC_IID_ACCESSOR(NS_IMDBTABLEROWCURSOR_IID)
+// { ===== begin nsIMdbCell methods =====
+
+  // { ----- begin attribute methods -----
+  NS_IMETHOD SetColumn(nsIMdbEnv* ev, mdb_column inColumn) = 0; 
+  NS_IMETHOD GetColumn(nsIMdbEnv* ev, mdb_column* outColumn) = 0;
+  
+  NS_IMETHOD GetCellInfo(  // all cell metainfo except actual content
+    nsIMdbEnv* ev, 
+    mdb_column* outColumn,           // the column in the containing row
+    mdb_fill*   outBlobFill,         // the size of text content in bytes
+    mdbOid*     outChildOid,         // oid of possible row or table child
+    mdb_bool*   outIsRowChild) = 0;  // nonzero if child, and a row child
+
+  // Checking all cell metainfo is a good way to avoid forcing a large cell
+  // in to memory when you don't actually want to use the content.
+  
+  NS_IMETHOD GetRow(nsIMdbEnv* ev, // parent row for this cell
+    nsIMdbRow** acqRow) = 0;
+  NS_IMETHOD GetPort(nsIMdbEnv* ev, // port containing cell
+    nsIMdbPort** acqPort) = 0;
+  // } ----- end attribute methods -----
+
+  // { ----- begin children methods -----
+  NS_IMETHOD HasAnyChild( // does cell have a child instead of text?
+    nsIMdbEnv* ev,
+    mdbOid* outOid,  // out id of row or table (or unbound if no child)
+    mdb_bool* outIsRow) = 0; // nonzero if child is a row (rather than a table)
+
+  NS_IMETHOD GetAnyChild( // access table of specific attribute
+    nsIMdbEnv* ev, // context
+    nsIMdbRow** acqRow, // child row (or null)
+    nsIMdbTable** acqTable) = 0; // child table (or null)
+
+
+  NS_IMETHOD SetChildRow( // access table of specific attribute
+    nsIMdbEnv* ev, // context
+    nsIMdbRow* ioRow) = 0; // inRow must be bound inside this same db port
+
+  NS_IMETHOD GetChildRow( // access row of specific attribute
+    nsIMdbEnv* ev, // context
+    nsIMdbRow** acqRow) = 0; // acquire child row (or nil if no child)
+
+
+  NS_IMETHOD SetChildTable( // access table of specific attribute
+    nsIMdbEnv* ev, // context
+    nsIMdbTable* inTable) = 0; // table must be bound inside this same db port
+
+  NS_IMETHOD GetChildTable( // access table of specific attribute
+    nsIMdbEnv* ev, // context
+    nsIMdbTable** acqTable) = 0; // acquire child table (or nil if no child)
+  // } ----- end children methods -----
+
+// } ===== end nsIMdbCell methods =====
+};
+
+NS_DEFINE_STATIC_IID_ACCESSOR(nsIMdbCell, NS_IMDBTABLEROWCURSOR_IID)
+
+// } %%%%% end C++ abstract class interfaces %%%%%
+
+//3456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789
+
+#endif /* _MDB_ */
+
diff --git a/db/mork/public/moz.build b/db/mork/public/moz.build
new file mode 100644
index 000000000..7212c6eff
--- /dev/null
+++ b/db/mork/public/moz.build
@@ -0,0 +1,9 @@
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+EXPORTS += [
+    'mdb.h',
+]
+