amxmodx/public/sm_stringhashmap.h

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2014-05-03 11:22:48 +00:00
/**
* vim: set ts=4 sw=4 tw=99 noet :
* =============================================================================
* SourceMod
* Copyright (C) 2004-2008 AlliedModders LLC. All rights reserved.
* =============================================================================
*
* This program is free software; you can redistribute it and/or modify it under
* the terms of the GNU General Public License, version 3.0, as published by the
* Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License along with
* this program. If not, see <http://www.gnu.org/licenses/>.
*
* As a special exception, AlliedModders LLC gives you permission to link the
* code of this program (as well as its derivative works) to "Half-Life 2," the
* "Source Engine," the "SourcePawn JIT," and any Game MODs that run on software
* by the Valve Corporation. You must obey the GNU General Public License in
* all respects for all other code used. Additionally, AlliedModders LLC grants
* this exception to all derivative works. AlliedModders LLC defines further
* exceptions, found in LICENSE.txt (as of this writing, version JULY-31-2007),
* or <http://www.sourcemod.net/license.php>.
*
* Version: $Id$
*/
#ifndef _include_sourcemod_hashtable_h_
#define _include_sourcemod_hashtable_h_
/**
* @file sm_stringhashmap.h
*
* @brief Generic Key -> Value map class, based on a hash table. The Key, in
* this case, is always an ASCII string, and the value type is a template
* parameter. This class is intended as a drop-in replacement for KTrie
* (though the retrieve() signature has been improved).
*
* If your Value type already contains the key string, consider using
* NameHashSet instead.
*/
#include <am-allocator-policies.h>
#include <am-hashmap.h>
#include <am-string.h>
#include <am-moveable.h>
#include <string.h>
namespace SourceMod
{
namespace detail
{
class CharsAndLength
{
public:
CharsAndLength(const char *str)
: str_(str),
length_(0)
{
int c;
uint32_t hash = 0;
while ((c = *str++))
hash = c + (hash << 6) + (hash << 16) - hash;
hash_ = hash;
length_ = str - str_ - 1;
}
uint32_t hash() const {
return hash_;
}
const char *chars() const {
return str_;
}
size_t length() const {
return length_;
}
private:
const char *str_;
size_t length_;
uint32_t hash_;
};
struct StringHashMapPolicy
{
static inline bool matches(const CharsAndLength &lookup, const ke::AString &key) {
return lookup.length() == key.length() &&
memcmp(lookup.chars(), key.chars(), key.length()) == 0;
}
static inline uint32_t hash(const CharsAndLength &key) {
return key.hash();
}
};
}
template <typename T>
class StringHashMap
{
typedef detail::CharsAndLength CharsAndLength;
typedef ke::HashMap<ke::AString, T, detail::StringHashMapPolicy> Internal;
public:
StringHashMap()
: internal_(ke::SystemAllocatorPolicy()),
memory_used_(0)
{
if (!internal_.init())
internal_.reportOutOfMemory();
}
typedef typename Internal::Result Result;
typedef typename Internal::Insert Insert;
typedef typename Internal::iterator iterator;
// Some KTrie-like helper functions.
bool retrieve(const char *aKey, T *aResult = NULL)
{
CharsAndLength key(aKey);
Result r = internal_.find(key);
if (!r.found())
return false;
if (aResult)
*aResult = r->value;
return true;
}
Result find(const char *aKey)
{
CharsAndLength key(aKey);
return internal_.find(key);
}
bool contains(const char *aKey)
{
CharsAndLength key(aKey);
Result r = internal_.find(key);
return r.found();
}
bool replace(const char *aKey, const T &value)
{
CharsAndLength key(aKey);
Insert i = internal_.findForAdd(key);
if (!i.found())
{
memory_used_ += key.length() + 1;
if (!internal_.add(i))
return false;
i->key = aKey;
}
i->value = value;
return true;
}
bool insert(const char *aKey, const T &value)
{
CharsAndLength key(aKey);
Insert i = internal_.findForAdd(key);
if (i.found())
return false;
if (!internal_.add(i))
return false;
memory_used_ += key.length() + 1;
i->key = aKey;
i->value = value;
return true;
}
bool remove(const char *aKey)
{
CharsAndLength key(aKey);
Result r = internal_.find(key);
if (!r.found())
return false;
memory_used_ -= key.length() + 1;
internal_.remove(r);
return true;
}
void remove(Result &r)
{
internal_.remove(r);
}
void clear()
{
internal_.clear();
}
iterator iter()
{
return internal_.iter();
}
size_t mem_usage() const
{
return internal_.estimateMemoryUse() + memory_used_;
}
size_t elements() const
{
return internal_.elements();
}
Insert findForAdd(const char *aKey)
{
CharsAndLength key(aKey);
return internal_.findForAdd(key);
}
// Note that |i->key| must be set after calling this, and the key must
// be the same as used with findForAdd(). It is best to avoid these two
// functions as the combined variants above are safer.
bool add(Insert &i)
{
return internal_.add(i);
}
// Only value needs to be set after.
bool add(Insert &i, const char *aKey)
{
if (!internal_.add(i))
return false;
i->key = aKey;
return true;
}
private:
Internal internal_;
size_t memory_used_;
};
}
#endif // _include_sourcemod_hashtable_h_