gecko-dev/xpcom/glue/nsHashKeys.h
Ryan VanderMeulen a6f60ceb1e Bug 606070 - warning C4244: 'return' : conversion from 'const PRUint64' to 'PLDHashNumber' in nsHashKeys.h r,a=bzbarsky
--HG--
extra : rebase_source : e0f4a753c9408c85165a9d3047be00e6c8ca757c
2010-11-06 14:53:37 +00:00

442 lines
12 KiB
C++

/* -*- 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 C++ hashtable templates.
*
* The Initial Developer of the Original Code is
* Benjamin Smedberg.
* Portions created by the Initial Developer are Copyright (C) 2002
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the terms of
* either 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 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 <stdlib.h>
#include <string.h>
/** @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
* nsPtrHashkey
* nsClearingPtrHashKey
* nsVoidPtrHashKey
* nsClearingVoidPtrHashKey
* nsISupportsHashKey
* nsIDHashKey
* nsDepCharHashKey
* nsCharPtrHashKey
* nsUnicharPtrHashKey
* nsHashableHashKey
*/
NS_COM_GLUE PRUint32 HashString(const nsAString& aStr);
NS_COM_GLUE PRUint32 HashString(const nsACString& aStr);
NS_COM_GLUE PRUint32 HashString(const char* aKey);
NS_COM_GLUE PRUint32 HashString(const PRUnichar* aKey);
/**
* 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; }
PRBool KeyEquals(const KeyTypePointer aKey) const
{
return mStr.Equals(*aKey);
}
static KeyTypePointer KeyToPointer(KeyType aKey) { return &aKey; }
static PLDHashNumber HashKey(const KeyTypePointer aKey)
{
return HashString(*aKey);
}
enum { ALLOW_MEMMOVE = PR_TRUE };
private:
const nsString mStr;
};
/**
* 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; }
PRBool KeyEquals(KeyTypePointer aKey) const { return mStr.Equals(*aKey); }
static KeyTypePointer KeyToPointer(KeyType aKey) { return &aKey; }
static PLDHashNumber HashKey(KeyTypePointer aKey)
{
return HashString(*aKey);
}
enum { ALLOW_MEMMOVE = PR_TRUE };
private:
const nsCString mStr;
};
/**
* hashkey wrapper using PRUint32 KeyType
*
* @see nsTHashtable::EntryType for specification
*/
class nsUint32HashKey : public PLDHashEntryHdr
{
public:
typedef const PRUint32& KeyType;
typedef const PRUint32* KeyTypePointer;
nsUint32HashKey(KeyTypePointer aKey) : mValue(*aKey) { }
nsUint32HashKey(const nsUint32HashKey& toCopy) : mValue(toCopy.mValue) { }
~nsUint32HashKey() { }
KeyType GetKey() const { return mValue; }
PRBool KeyEquals(KeyTypePointer aKey) const { return *aKey == mValue; }
static KeyTypePointer KeyToPointer(KeyType aKey) { return &aKey; }
static PLDHashNumber HashKey(KeyTypePointer aKey) { return *aKey; }
enum { ALLOW_MEMMOVE = PR_TRUE };
private:
const PRUint32 mValue;
};
/**
* hashkey wrapper using PRUint64 KeyType
*
* @see nsTHashtable::EntryType for specification
*/
class nsUint64HashKey : public PLDHashEntryHdr
{
public:
typedef const PRUint64& KeyType;
typedef const PRUint64* KeyTypePointer;
nsUint64HashKey(KeyTypePointer aKey) : mValue(*aKey) { }
nsUint64HashKey(const nsUint64HashKey& toCopy) : mValue(toCopy.mValue) { }
~nsUint64HashKey() { }
KeyType GetKey() const { return mValue; }
PRBool 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 = PR_TRUE };
private:
const PRUint64 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; }
PRBool 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 = PR_TRUE };
private:
nsCOMPtr<nsISupports> mSupports;
};
/**
* 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; }
PRBool 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 = PR_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 = nsnull; }
};
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; }
PRBool KeyEquals(KeyTypePointer aKey) const { return aKey->Equals(mID); }
static KeyTypePointer KeyToPointer(KeyType aKey) { return &aKey; }
static PLDHashNumber HashKey(KeyTypePointer aKey);
enum { ALLOW_MEMMOVE = PR_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; }
PRBool 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 HashString(aKey); }
enum { ALLOW_MEMMOVE = PR_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; }
PRBool KeyEquals(KeyTypePointer aKey) const
{
return !strcmp(mKey, aKey);
}
static KeyTypePointer KeyToPointer(KeyType aKey) { return aKey; }
static PLDHashNumber HashKey(KeyTypePointer aKey) { return HashString(aKey); }
enum { ALLOW_MEMMOVE = PR_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; }
PRBool KeyEquals(KeyTypePointer aKey) const
{
return !NS_strcmp(mKey, aKey);
}
static KeyTypePointer KeyToPointer(KeyType aKey) { return aKey; }
static PLDHashNumber HashKey(KeyTypePointer aKey) { return HashString(aKey); }
enum { ALLOW_MEMMOVE = PR_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; }
PRBool KeyEquals(const nsIHashable* aKey) const {
PRBool eq;
if (NS_SUCCEEDED(mKey->Equals(const_cast<nsIHashable*>(aKey), &eq))) {
return eq;
}
return PR_FALSE;
}
static const nsIHashable* KeyToPointer(nsIHashable* aKey) { return aKey; }
static PLDHashNumber HashKey(const nsIHashable* aKey) {
PRUint32 code = 8888; // magic number if GetHashCode fails :-(
#ifdef NS_DEBUG
nsresult rv =
#endif
const_cast<nsIHashable*>(aKey)->GetHashCode(&code);
NS_ASSERTION(NS_SUCCEEDED(rv), "GetHashCode should not throw!");
return code;
}
enum { ALLOW_MEMMOVE = PR_TRUE };
private:
nsCOMPtr<nsIHashable> mKey;
};
#endif // nsTHashKeys_h__