1 files changed, 660 insertions, 0 deletions
diff --git a/xpcom/glue/nsHashKeys.h b/xpcom/glue/nsHashKeys.h
new file mode 100644
index 000000000..9c688691f
--- /dev/null
+++ b/xpcom/glue/nsHashKeys.h
@@ -0,0 +1,660 @@
+/* -*- 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 nsTHashKeys_h__
+#define nsTHashKeys_h__
+
+#include "nsID.h"
+#include "nsISupports.h"
+#include "nsIHashable.h"
+#include "nsAutoPtr.h"
+#include "nsCOMPtr.h"
+#include "PLDHashTable.h"
+#include <new>
+
+#include "nsStringGlue.h"
+#include "nsCRTGlue.h"
+#include "nsUnicharUtils.h"
+#include "nsPointerHashKeys.h"
+
+#include <stdlib.h>
+#include <string.h>
+
+#include "mozilla/HashFunctions.h"
+#include "mozilla/Move.h"
+
+namespace mozilla {
+
+// These are defined analogously to the HashString overloads in mfbt.
+
+inline uint32_t
+HashString(const nsAString& aStr)
+{
+  return HashString(aStr.BeginReading(), aStr.Length());
+}
+
+inline uint32_t
+HashString(const nsACString& aStr)
+{
+  return HashString(aStr.BeginReading(), aStr.Length());
+}
+
+} // namespace mozilla
+
+/** @file nsHashKeys.h
+ * standard HashKey classes for nsBaseHashtable and relatives. Each of these
+ * classes follows the nsTHashtable::EntryType specification
+ *
+ * Lightweight keytypes provided here:
+ * nsStringHashKey
+ * nsCStringHashKey
+ * nsUint32HashKey
+ * nsUint64HashKey
+ * nsFloatHashKey
+ * nsPtrHashKey
+ * nsClearingPtrHashKey
+ * nsVoidPtrHashKey
+ * nsClearingVoidPtrHashKey
+ * nsISupportsHashKey
+ * nsIDHashKey
+ * nsDepCharHashKey
+ * nsCharPtrHashKey
+ * nsUnicharPtrHashKey
+ * nsHashableHashKey
+ * nsGenericHashKey
+ */
+
+/**
+ * hashkey wrapper using nsAString KeyType
+ *
+ * @see nsTHashtable::EntryType for specification
+ */
+class nsStringHashKey : public PLDHashEntryHdr
+{
+public:
+  typedef const nsAString& KeyType;
+  typedef const nsAString* KeyTypePointer;
+
+  explicit nsStringHashKey(KeyTypePointer aStr) : mStr(*aStr) {}
+  nsStringHashKey(const nsStringHashKey& aToCopy) : mStr(aToCopy.mStr) {}
+  ~nsStringHashKey() {}
+
+  KeyType GetKey() const { return mStr; }
+  bool KeyEquals(const KeyTypePointer aKey) const
+  {
+    return mStr.Equals(*aKey);
+  }
+
+  static KeyTypePointer KeyToPointer(KeyType aKey) { return &aKey; }
+  static PLDHashNumber HashKey(const KeyTypePointer aKey)
+  {
+    return mozilla::HashString(*aKey);
+  }
+
+#ifdef MOZILLA_INTERNAL_API
+  // To avoid double-counting, only measure the string if it is unshared.
+  size_t SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const
+  {
+    return GetKey().SizeOfExcludingThisIfUnshared(aMallocSizeOf);
+  }
+#endif
+
+  enum { ALLOW_MEMMOVE = true };
+
+private:
+  const nsString mStr;
+};
+
+#ifdef MOZILLA_INTERNAL_API
+
+/**
+ * hashkey wrapper using nsAString KeyType
+ *
+ * This is internal-API only because nsCaseInsensitiveStringComparator is
+ * internal-only.
+ *
+ * @see nsTHashtable::EntryType for specification
+ */
+class nsStringCaseInsensitiveHashKey : public PLDHashEntryHdr
+{
+public:
+  typedef const nsAString& KeyType;
+  typedef const nsAString* KeyTypePointer;
+
+  explicit nsStringCaseInsensitiveHashKey(KeyTypePointer aStr)
+    : mStr(*aStr)
+  {
+    // take it easy just deal HashKey
+  }
+  nsStringCaseInsensitiveHashKey(const nsStringCaseInsensitiveHashKey& aToCopy)
+    : mStr(aToCopy.mStr)
+  {
+  }
+  ~nsStringCaseInsensitiveHashKey() {}
+
+  KeyType GetKey() const { return mStr; }
+  bool KeyEquals(const KeyTypePointer aKey) const
+  {
+    return mStr.Equals(*aKey, nsCaseInsensitiveStringComparator());
+  }
+
+  static KeyTypePointer KeyToPointer(KeyType aKey) { return &aKey; }
+  static PLDHashNumber HashKey(const KeyTypePointer aKey)
+  {
+    nsAutoString tmKey(*aKey);
+    ToLowerCase(tmKey);
+    return mozilla::HashString(tmKey);
+  }
+  enum { ALLOW_MEMMOVE = true };
+
+  // To avoid double-counting, only measure the string if it is unshared.
+  size_t SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const
+  {
+    return GetKey().SizeOfExcludingThisIfUnshared(aMallocSizeOf);
+  }
+
+private:
+  const nsString mStr;
+};
+
+#endif
+
+/**
+ * hashkey wrapper using nsACString KeyType
+ *
+ * @see nsTHashtable::EntryType for specification
+ */
+class nsCStringHashKey : public PLDHashEntryHdr
+{
+public:
+  typedef const nsACString& KeyType;
+  typedef const nsACString* KeyTypePointer;
+
+  explicit nsCStringHashKey(const nsACString* aStr) : mStr(*aStr) {}
+  nsCStringHashKey(const nsCStringHashKey& aToCopy) : mStr(aToCopy.mStr) {}
+  ~nsCStringHashKey() {}
+
+  KeyType GetKey() const { return mStr; }
+  bool KeyEquals(KeyTypePointer aKey) const { return mStr.Equals(*aKey); }
+
+  static KeyTypePointer KeyToPointer(KeyType aKey) { return &aKey; }
+  static PLDHashNumber HashKey(KeyTypePointer aKey)
+  {
+    return mozilla::HashString(*aKey);
+  }
+
+#ifdef MOZILLA_INTERNAL_API
+  // To avoid double-counting, only measure the string if it is unshared.
+  size_t SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const
+  {
+    return GetKey().SizeOfExcludingThisIfUnshared(aMallocSizeOf);
+  }
+#endif
+
+  enum { ALLOW_MEMMOVE = true };
+
+private:
+  const nsCString mStr;
+};
+
+/**
+ * hashkey wrapper using uint32_t KeyType
+ *
+ * @see nsTHashtable::EntryType for specification
+ */
+class nsUint32HashKey : public PLDHashEntryHdr
+{
+public:
+  typedef const uint32_t& KeyType;
+  typedef const uint32_t* KeyTypePointer;
+
+  explicit nsUint32HashKey(KeyTypePointer aKey) : mValue(*aKey) {}
+  nsUint32HashKey(const nsUint32HashKey& aToCopy) : mValue(aToCopy.mValue) {}
+  ~nsUint32HashKey() {}
+
+  KeyType GetKey() const { return mValue; }
+  bool KeyEquals(KeyTypePointer aKey) const { return *aKey == mValue; }
+
+  static KeyTypePointer KeyToPointer(KeyType aKey) { return &aKey; }
+  static PLDHashNumber HashKey(KeyTypePointer aKey) { return *aKey; }
+  enum { ALLOW_MEMMOVE = true };
+
+private:
+  const uint32_t mValue;
+};
+
+/**
+ * hashkey wrapper using uint64_t KeyType
+ *
+ * @see nsTHashtable::EntryType for specification
+ */
+class nsUint64HashKey : public PLDHashEntryHdr
+{
+public:
+  typedef const uint64_t& KeyType;
+  typedef const uint64_t* KeyTypePointer;
+
+  explicit nsUint64HashKey(KeyTypePointer aKey) : mValue(*aKey) {}
+  nsUint64HashKey(const nsUint64HashKey& aToCopy) : mValue(aToCopy.mValue) {}
+  ~nsUint64HashKey() {}
+
+  KeyType GetKey() const { return mValue; }
+  bool KeyEquals(KeyTypePointer aKey) const { return *aKey == mValue; }
+
+  static KeyTypePointer KeyToPointer(KeyType aKey) { return &aKey; }
+  static PLDHashNumber HashKey(KeyTypePointer aKey)
+  {
+    return PLDHashNumber(*aKey);
+  }
+  enum { ALLOW_MEMMOVE = true };
+
+private:
+  const uint64_t mValue;
+};
+
+/**
+ * hashkey wrapper using float KeyType
+ *
+ * @see nsTHashtable::EntryType for specification
+ */
+class nsFloatHashKey : public PLDHashEntryHdr
+{
+public:
+  typedef const float& KeyType;
+  typedef const float* KeyTypePointer;
+
+  explicit nsFloatHashKey(KeyTypePointer aKey) : mValue(*aKey) {}
+  nsFloatHashKey(const nsFloatHashKey& aToCopy) : mValue(aToCopy.mValue) {}
+  ~nsFloatHashKey() {}
+
+  KeyType GetKey() const { return mValue; }
+  bool KeyEquals(KeyTypePointer aKey) const { return *aKey == mValue; }
+
+  static KeyTypePointer KeyToPointer(KeyType aKey) { return &aKey; }
+  static PLDHashNumber HashKey(KeyTypePointer aKey)
+  {
+    return *reinterpret_cast<const uint32_t*>(aKey);
+  }
+  enum { ALLOW_MEMMOVE = true };
+
+private:
+  const float mValue;
+};
+
+/**
+ * hashkey wrapper using nsISupports* KeyType
+ *
+ * @see nsTHashtable::EntryType for specification
+ */
+class nsISupportsHashKey : public PLDHashEntryHdr
+{
+public:
+  typedef nsISupports* KeyType;
+  typedef const nsISupports* KeyTypePointer;
+
+  explicit nsISupportsHashKey(const nsISupports* aKey)
+    : mSupports(const_cast<nsISupports*>(aKey))
+  {
+  }
+  nsISupportsHashKey(const nsISupportsHashKey& aToCopy)
+    : mSupports(aToCopy.mSupports)
+  {
+  }
+  ~nsISupportsHashKey() {}
+
+  KeyType GetKey() const { return mSupports; }
+  bool KeyEquals(KeyTypePointer aKey) const { return aKey == mSupports; }
+
+  static KeyTypePointer KeyToPointer(KeyType aKey) { return aKey; }
+  static PLDHashNumber HashKey(KeyTypePointer aKey)
+  {
+    return NS_PTR_TO_UINT32(aKey) >> 2;
+  }
+  enum { ALLOW_MEMMOVE = true };
+
+private:
+  nsCOMPtr<nsISupports> mSupports;
+};
+
+/**
+ * hashkey wrapper using refcounted * KeyType
+ *
+ * @see nsTHashtable::EntryType for specification
+ */
+template<class T>
+class nsRefPtrHashKey : public PLDHashEntryHdr
+{
+public:
+  typedef T* KeyType;
+  typedef const T* KeyTypePointer;
+
+  explicit nsRefPtrHashKey(const T* aKey) : mKey(const_cast<T*>(aKey)) {}
+  nsRefPtrHashKey(const nsRefPtrHashKey& aToCopy) : mKey(aToCopy.mKey) {}
+  ~nsRefPtrHashKey() {}
+
+  KeyType GetKey() const { return mKey; }
+  bool KeyEquals(KeyTypePointer aKey) const { return aKey == mKey; }
+
+  static KeyTypePointer KeyToPointer(KeyType aKey) { return aKey; }
+  static PLDHashNumber HashKey(KeyTypePointer aKey)
+  {
+    return NS_PTR_TO_UINT32(aKey) >> 2;
+  }
+  enum { ALLOW_MEMMOVE = true };
+
+private:
+  RefPtr<T> mKey;
+};
+
+template<class T>
+inline void
+ImplCycleCollectionTraverse(nsCycleCollectionTraversalCallback& aCallback,
+                            nsRefPtrHashKey<T>& aField,
+                            const char* aName,
+                            uint32_t aFlags = 0)
+{
+  CycleCollectionNoteChild(aCallback, aField.GetKey(), aName, aFlags);
+}
+
+/**
+ * hashkey wrapper using T* KeyType that sets key to nullptr upon
+ * destruction. Relevant only in cases where a memory pointer-scanner
+ * like valgrind might get confused about stale references.
+ *
+ * @see nsTHashtable::EntryType for specification
+ */
+
+template<class T>
+class nsClearingPtrHashKey : public nsPtrHashKey<T>
+{
+public:
+  explicit nsClearingPtrHashKey(const T* aKey) : nsPtrHashKey<T>(aKey) {}
+  nsClearingPtrHashKey(const nsClearingPtrHashKey<T>& aToCopy)
+    : nsPtrHashKey<T>(aToCopy)
+  {
+  }
+  ~nsClearingPtrHashKey() { nsPtrHashKey<T>::mKey = nullptr; }
+};
+
+typedef nsClearingPtrHashKey<const void> nsClearingVoidPtrHashKey;
+
+/**
+ * hashkey wrapper using a function pointer KeyType
+ *
+ * @see nsTHashtable::EntryType for specification
+ */
+template<class T>
+class nsFuncPtrHashKey : public PLDHashEntryHdr
+{
+public:
+  typedef T& KeyType;
+  typedef const T* KeyTypePointer;
+
+  explicit nsFuncPtrHashKey(const T* aKey) : mKey(*const_cast<T*>(aKey)) {}
+  nsFuncPtrHashKey(const nsFuncPtrHashKey<T>& aToCopy) : mKey(aToCopy.mKey) {}
+  ~nsFuncPtrHashKey() {}
+
+  KeyType GetKey() const { return const_cast<T&>(mKey); }
+  bool KeyEquals(KeyTypePointer aKey) const { return *aKey == mKey; }
+
+  static KeyTypePointer KeyToPointer(KeyType aKey) { return &aKey; }
+  static PLDHashNumber HashKey(KeyTypePointer aKey)
+  {
+    return NS_PTR_TO_UINT32(*aKey) >> 2;
+  }
+  enum { ALLOW_MEMMOVE = true };
+
+protected:
+  T mKey;
+};
+
+/**
+ * hashkey wrapper using nsID KeyType
+ *
+ * @see nsTHashtable::EntryType for specification
+ */
+class nsIDHashKey : public PLDHashEntryHdr
+{
+public:
+  typedef const nsID& KeyType;
+  typedef const nsID* KeyTypePointer;
+
+  explicit nsIDHashKey(const nsID* aInID) : mID(*aInID) {}
+  nsIDHashKey(const nsIDHashKey& aToCopy) : mID(aToCopy.mID) {}
+  ~nsIDHashKey() {}
+
+  KeyType GetKey() const { return mID; }
+  bool KeyEquals(KeyTypePointer aKey) const { return aKey->Equals(mID); }
+
+  static KeyTypePointer KeyToPointer(KeyType aKey) { return &aKey; }
+  static PLDHashNumber HashKey(KeyTypePointer aKey)
+  {
+    // Hash the nsID object's raw bytes.
+    return mozilla::HashBytes(aKey, sizeof(KeyType));
+  }
+
+  enum { ALLOW_MEMMOVE = true };
+
+private:
+  const nsID mID;
+};
+
+/**
+ * hashkey wrapper for "dependent" const char*; this class does not "own"
+ * its string pointer.
+ *
+ * This class must only be used if the strings have a lifetime longer than
+ * the hashtable they occupy. This normally occurs only for static
+ * strings or strings that have been arena-allocated.
+ *
+ * @see nsTHashtable::EntryType for specification
+ */
+class nsDepCharHashKey : public PLDHashEntryHdr
+{
+public:
+  typedef const char* KeyType;
+  typedef const char* KeyTypePointer;
+
+  explicit nsDepCharHashKey(const char* aKey) : mKey(aKey) {}
+  nsDepCharHashKey(const nsDepCharHashKey& aToCopy) : mKey(aToCopy.mKey) {}
+  ~nsDepCharHashKey() {}
+
+  const char* GetKey() const { return mKey; }
+  bool KeyEquals(const char* aKey) const { return !strcmp(mKey, aKey); }
+
+  static const char* KeyToPointer(const char* aKey) { return aKey; }
+  static PLDHashNumber HashKey(const char* aKey)
+  {
+    return mozilla::HashString(aKey);
+  }
+  enum { ALLOW_MEMMOVE = true };
+
+private:
+  const char* mKey;
+};
+
+/**
+ * hashkey wrapper for const char*; at construction, this class duplicates
+ * a string pointed to by the pointer so that it doesn't matter whether or not
+ * the string lives longer than the hash table.
+ */
+class nsCharPtrHashKey : public PLDHashEntryHdr
+{
+public:
+  typedef const char* KeyType;
+  typedef const char* KeyTypePointer;
+
+  explicit nsCharPtrHashKey(const char* aKey) : mKey(strdup(aKey)) {}
+  nsCharPtrHashKey(const nsCharPtrHashKey& aToCopy)
+    : mKey(strdup(aToCopy.mKey))
+  {
+  }
+
+  nsCharPtrHashKey(nsCharPtrHashKey&& aOther)
+    : mKey(aOther.mKey)
+  {
+    aOther.mKey = nullptr;
+  }
+
+  ~nsCharPtrHashKey()
+  {
+    if (mKey) {
+      free(const_cast<char*>(mKey));
+    }
+  }
+
+  const char* GetKey() const { return mKey; }
+  bool KeyEquals(KeyTypePointer aKey) const { return !strcmp(mKey, aKey); }
+
+  static KeyTypePointer KeyToPointer(KeyType aKey) { return aKey; }
+  static PLDHashNumber HashKey(KeyTypePointer aKey)
+  {
+    return mozilla::HashString(aKey);
+  }
+
+  size_t SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const
+  {
+    return aMallocSizeOf(mKey);
+  }
+
+  enum { ALLOW_MEMMOVE = true };
+
+private:
+  const char* mKey;
+};
+
+/**
+ * hashkey wrapper for const char16_t*; at construction, this class duplicates
+ * a string pointed to by the pointer so that it doesn't matter whether or not
+ * the string lives longer than the hash table.
+ */
+class nsUnicharPtrHashKey : public PLDHashEntryHdr
+{
+public:
+  typedef const char16_t* KeyType;
+  typedef const char16_t* KeyTypePointer;
+
+  explicit nsUnicharPtrHashKey(const char16_t* aKey) : mKey(NS_strdup(aKey)) {}
+  nsUnicharPtrHashKey(const nsUnicharPtrHashKey& aToCopy)
+    : mKey(NS_strdup(aToCopy.mKey))
+  {
+  }
+
+  nsUnicharPtrHashKey(nsUnicharPtrHashKey&& aOther)
+    : mKey(aOther.mKey)
+  {
+    aOther.mKey = nullptr;
+  }
+
+  ~nsUnicharPtrHashKey()
+  {
+    if (mKey) {
+      NS_Free(const_cast<char16_t*>(mKey));
+    }
+  }
+
+  const char16_t* GetKey() const { return mKey; }
+  bool KeyEquals(KeyTypePointer aKey) const { return !NS_strcmp(mKey, aKey); }
+
+  static KeyTypePointer KeyToPointer(KeyType aKey) { return aKey; }
+  static PLDHashNumber HashKey(KeyTypePointer aKey)
+  {
+    return mozilla::HashString(aKey);
+  }
+
+  size_t SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const
+  {
+    return aMallocSizeOf(mKey);
+  }
+
+  enum { ALLOW_MEMMOVE = true };
+
+private:
+  const char16_t* mKey;
+};
+
+/**
+ * Hashtable key class to use with objects that support nsIHashable
+ */
+class nsHashableHashKey : public PLDHashEntryHdr
+{
+public:
+  typedef nsIHashable* KeyType;
+  typedef const nsIHashable* KeyTypePointer;
+
+  explicit nsHashableHashKey(const nsIHashable* aKey)
+    : mKey(const_cast<nsIHashable*>(aKey))
+  {
+  }
+  nsHashableHashKey(const nsHashableHashKey& aToCopy) : mKey(aToCopy.mKey) {}
+  ~nsHashableHashKey() {}
+
+  nsIHashable* GetKey() const { return mKey; }
+
+  bool KeyEquals(const nsIHashable* aKey) const
+  {
+    bool eq;
+    if (NS_SUCCEEDED(mKey->Equals(const_cast<nsIHashable*>(aKey), &eq))) {
+      return eq;
+    }
+    return false;
+  }
+
+  static const nsIHashable* KeyToPointer(nsIHashable* aKey) { return aKey; }
+  static PLDHashNumber HashKey(const nsIHashable* aKey)
+  {
+    uint32_t code = 8888; // magic number if GetHashCode fails :-(
+#ifdef DEBUG
+    nsresult rv =
+#endif
+      const_cast<nsIHashable*>(aKey)->GetHashCode(&code);
+    NS_ASSERTION(NS_SUCCEEDED(rv), "GetHashCode should not throw!");
+    return code;
+  }
+
+  enum { ALLOW_MEMMOVE = true };
+
+private:
+  nsCOMPtr<nsIHashable> mKey;
+};
+
+namespace mozilla {
+
+template <typename T>
+PLDHashNumber
+Hash(const T& aValue)
+{
+  return aValue.Hash();
+}
+
+} // namespace mozilla
+
+/**
+ * Hashtable key class to use with objects for which Hash() and operator==()
+ * are defined.
+ */
+template<typename T>
+class nsGenericHashKey : public PLDHashEntryHdr
+{
+public:
+  typedef const T& KeyType;
+  typedef const T* KeyTypePointer;
+
+  explicit nsGenericHashKey(KeyTypePointer aKey) : mKey(*aKey) {}
+  nsGenericHashKey(const nsGenericHashKey<T>& aOther) : mKey(aOther.mKey) {}
+
+  KeyType GetKey() const { return mKey; }
+  bool KeyEquals(KeyTypePointer aKey) const { return *aKey == mKey; }
+
+  static KeyTypePointer KeyToPointer(KeyType aKey) { return &aKey; }
+  static PLDHashNumber HashKey(KeyTypePointer aKey) { return ::mozilla::Hash(*aKey); }
+  enum { ALLOW_MEMMOVE = true };
+
+private:
+  T mKey;
+};
+
+#endif // nsTHashKeys_h__