gecko/xpcom/glue/nsHashKeys.h
2012-09-06 16:58:46 +12:00

532 lines
14 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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 "nsCOMPtr.h"
#include "pldhash.h"
#include NEW_H
#include "nsStringGlue.h"
#include "nsCRTGlue.h"
#include "nsUnicharUtils.h"
#include <stdlib.h>
#include <string.h>
#include "mozilla/HashFunctions.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
*/
/**
* hashkey wrapper using nsAString KeyType
*
* @see nsTHashtable::EntryType for specification
*/
class nsStringHashKey : public PLDHashEntryHdr
{
public:
typedef const nsAString& KeyType;
typedef const nsAString* KeyTypePointer;
nsStringHashKey(KeyTypePointer aStr) : mStr(*aStr) { }
nsStringHashKey(const nsStringHashKey& toCopy) : mStr(toCopy.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);
}
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;
nsStringCaseInsensitiveHashKey(KeyTypePointer aStr) : mStr(*aStr) { } //take it easy just deal HashKey
nsStringCaseInsensitiveHashKey(const nsStringCaseInsensitiveHashKey& toCopy) : mStr(toCopy.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 };
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;
nsCStringHashKey(const nsACString* aStr) : mStr(*aStr) { }
nsCStringHashKey(const nsCStringHashKey& toCopy) : mStr(toCopy.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);
}
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;
nsUint32HashKey(KeyTypePointer aKey) : mValue(*aKey) { }
nsUint32HashKey(const nsUint32HashKey& toCopy) : mValue(toCopy.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;
nsUint64HashKey(KeyTypePointer aKey) : mValue(*aKey) { }
nsUint64HashKey(const nsUint64HashKey& toCopy) : mValue(toCopy.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;
nsFloatHashKey(KeyTypePointer aKey) : mValue(*aKey) { }
nsFloatHashKey(const nsFloatHashKey& toCopy) : mValue(toCopy.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;
nsISupportsHashKey(const nsISupports* key) :
mSupports(const_cast<nsISupports*>(key)) { }
nsISupportsHashKey(const nsISupportsHashKey& toCopy) :
mSupports(toCopy.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_INT32(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;
nsRefPtrHashKey(const T* key) :
mKey(const_cast<T*>(key)) { }
nsRefPtrHashKey(const nsRefPtrHashKey& toCopy) :
mKey(toCopy.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_INT32(aKey) >>2;
}
enum { ALLOW_MEMMOVE = true };
private:
nsRefPtr<T> mKey;
};
/**
* hashkey wrapper using T* KeyType
*
* @see nsTHashtable::EntryType for specification
*/
template<class T>
class nsPtrHashKey : public PLDHashEntryHdr
{
public:
typedef T *KeyType;
typedef const T *KeyTypePointer;
nsPtrHashKey(const T *key) : mKey(const_cast<T*>(key)) {}
nsPtrHashKey(const nsPtrHashKey<T> &toCopy) : mKey(toCopy.mKey) {}
~nsPtrHashKey() {}
KeyType GetKey() const { return mKey; }
bool KeyEquals(KeyTypePointer key) const { return key == mKey; }
static KeyTypePointer KeyToPointer(KeyType key) { return key; }
static PLDHashNumber HashKey(KeyTypePointer key)
{
return NS_PTR_TO_INT32(key) >> 2;
}
enum { ALLOW_MEMMOVE = true };
protected:
T *mKey;
};
/**
* hashkey wrapper using T* KeyType that sets key to NULL 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:
nsClearingPtrHashKey(const T *key) : nsPtrHashKey<T>(key) {}
nsClearingPtrHashKey(const nsClearingPtrHashKey<T> &toCopy) :
nsPtrHashKey<T>(toCopy) {}
~nsClearingPtrHashKey() { nsPtrHashKey<T>::mKey = nullptr; }
};
typedef nsPtrHashKey<const void> nsVoidPtrHashKey;
typedef nsClearingPtrHashKey<const void> nsClearingVoidPtrHashKey;
/**
* hashkey wrapper using nsID KeyType
*
* @see nsTHashtable::EntryType for specification
*/
class nsIDHashKey : public PLDHashEntryHdr
{
public:
typedef const nsID& KeyType;
typedef const nsID* KeyTypePointer;
nsIDHashKey(const nsID* inID) : mID(*inID) { }
nsIDHashKey(const nsIDHashKey& toCopy) : mID(toCopy.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;
nsDepCharHashKey(const char* aKey) { mKey = aKey; }
nsDepCharHashKey(const nsDepCharHashKey& toCopy) { mKey = toCopy.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;
nsCharPtrHashKey(const char* aKey) : mKey(strdup(aKey)) { }
nsCharPtrHashKey(const nsCharPtrHashKey& toCopy) : mKey(strdup(toCopy.mKey)) { }
~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); }
enum { ALLOW_MEMMOVE = true };
private:
const char* mKey;
};
/**
* hashkey wrapper for const PRUnichar*; 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 PRUnichar* KeyType;
typedef const PRUnichar* KeyTypePointer;
nsUnicharPtrHashKey(const PRUnichar* aKey) : mKey(NS_strdup(aKey)) { }
nsUnicharPtrHashKey(const nsUnicharPtrHashKey& toCopy) : mKey(NS_strdup(toCopy.mKey)) { }
~nsUnicharPtrHashKey() { if (mKey) NS_Free(const_cast<PRUnichar *>(mKey)); }
const PRUnichar* 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); }
enum { ALLOW_MEMMOVE = true };
private:
const PRUnichar* mKey;
};
/**
* Hashtable key class to use with objects that support nsIHashable
*/
class nsHashableHashKey : public PLDHashEntryHdr
{
public:
typedef nsIHashable* KeyType;
typedef const nsIHashable* KeyTypePointer;
nsHashableHashKey(const nsIHashable* aKey) :
mKey(const_cast<nsIHashable*>(aKey)) { }
nsHashableHashKey(const nsHashableHashKey& toCopy) :
mKey(toCopy.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;
};
#endif // nsTHashKeys_h__