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-rw-r--r--xpcom/glue/nsMemory.h136
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diff --git a/xpcom/glue/nsMemory.h b/xpcom/glue/nsMemory.h
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+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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/. */
+
+#ifndef nsMemory_h__
+#define nsMemory_h__
+
+#include "nsXPCOM.h"
+
+class nsIMemory;
+
+#define NS_MEMORY_CONTRACTID "@mozilla.org/xpcom/memory-service;1"
+#define NS_MEMORY_CID \
+{ /* 30a04e40-38e7-11d4-8cf5-0060b0fc14a3 */ \
+ 0x30a04e40, \
+ 0x38e7, \
+ 0x11d4, \
+ {0x8c, 0xf5, 0x00, 0x60, 0xb0, 0xfc, 0x14, 0xa3} \
+}
+
+
+/**
+ * Static helper routines to manage memory. These routines allow easy access
+ * to xpcom's built-in (global) nsIMemory implementation, without needing
+ * to go through the service manager to get it. However this requires clients
+ * to link with the xpcom DLL.
+ *
+ * This class is not threadsafe and is intented for use only on the main
+ * thread.
+ */
+class nsMemory
+{
+public:
+ static nsresult HeapMinimize(bool aImmediate);
+ static void* Clone(const void* aPtr, size_t aSize);
+ static nsIMemory* GetGlobalMemoryService(); // AddRefs
+};
+
+/**
+ * Macro to free all elements of an XPCOM array of a given size using
+ * freeFunc, then frees the array itself using free().
+ *
+ * Note that this macro (and its wrappers) can be used to deallocate a
+ * partially- or completely-built array while unwinding an error
+ * condition inside the XPCOM routine that was going to return the
+ * array. For this to work on a partially-built array, your code
+ * needs to be building the array from index 0 upwards, and simply
+ * pass the number of elements that have already been built (and thus
+ * need to be freed) as |size|.
+ *
+ * Thanks to <alecf@netscape.com> for suggesting this form, which
+ * allows the macro to be used with NS_RELEASE / NS_RELEASE_IF in
+ * addition to free.
+ *
+ * @param size Number of elements in the array. If not a constant, this
+ * should be a int32_t. Note that this means this macro
+ * will not work if size >= 2^31.
+ * @param array The array to be freed.
+ * @param freeFunc The function or macro to be used to free it.
+ * For arrays of nsISupports (or any class derived
+ * from it), NS_IF_RELEASE (or NS_RELEASE) should be
+ * passed as freeFunc. For most (all?) other pointer
+ * types (including XPCOM strings and wstrings),
+ * free should be used.
+ */
+#define NS_FREE_XPCOM_POINTER_ARRAY(size, array, freeFunc) \
+ PR_BEGIN_MACRO \
+ int32_t iter_ = int32_t(size); \
+ while (--iter_ >= 0) \
+ freeFunc((array)[iter_]); \
+ NS_Free((array)); \
+ PR_END_MACRO
+
+// convenience macros for commonly used calls. mmmmm. syntactic sugar.
+
+/**
+ * Macro to free arrays of non-refcounted objects allocated by the
+ * shared allocator (nsMemory) such as strings and wstrings. A
+ * convenience wrapper around NS_FREE_XPCOM_POINTER_ARRAY.
+ *
+ * @param size Number of elements in the array. If not a constant, this
+ * should be a int32_t. Note that this means this macro
+ * will not work if size >= 2^31.
+ * @param array The array to be freed.
+ */
+#define NS_FREE_XPCOM_ALLOCATED_POINTER_ARRAY(size, array) \
+ NS_FREE_XPCOM_POINTER_ARRAY((size), (array), NS_Free)
+
+/**
+ * Macro to free an array of pointers to nsISupports (or classes
+ * derived from it). A convenience wrapper around
+ * NS_FREE_XPCOM_POINTER_ARRAY.
+ *
+ * Note that if you know that none of your nsISupports pointers are
+ * going to be 0, you can gain a bit of speed by calling
+ * NS_FREE_XPCOM_POINTER_ARRAY directly and using NS_RELEASE as your
+ * free function.
+ *
+ * @param size Number of elements in the array. If not a constant, this
+ * should be a int32_t. Note that this means this macro
+ * will not work if size >= 2^31.
+ * @param array The array to be freed.
+ */
+#define NS_FREE_XPCOM_ISUPPORTS_POINTER_ARRAY(size, array) \
+ NS_FREE_XPCOM_POINTER_ARRAY((size), (array), NS_IF_RELEASE)
+
+/**
+ * A macro, NS_ALIGNMENT_OF(t_) that determines the alignment
+ * requirements of a type.
+ */
+namespace mozilla {
+template<class T>
+struct AlignmentTestStruct
+{
+ char c;
+ T t;
+};
+} // namespace mozilla
+
+#define NS_ALIGNMENT_OF(t_) \
+ (sizeof(mozilla::AlignmentTestStruct<t_>) - sizeof(t_))
+
+/**
+ * An enumeration type used to represent a method of assignment.
+ */
+enum nsAssignmentType
+{
+ NS_ASSIGNMENT_COPY, // copy by value
+ NS_ASSIGNMENT_DEPEND, // copy by reference
+ NS_ASSIGNMENT_ADOPT // copy by reference (take ownership of resource)
+};
+
+#endif // nsMemory_h__
+