homework-jianmu/src/util/inc/hash.h

165 lines
3.9 KiB
C

/*
* Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
*
* This program is free software: you can use, redistribute, and/or modify
* it under the terms of the GNU Affero General Public License, version 3
* or later ("AGPL"), 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.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef TDENGINE_HASH_H
#define TDENGINE_HASH_H
#ifdef __cplusplus
extern "C" {
#endif
#include "hashfunc.h"
#define HASH_MAX_CAPACITY (1024 * 1024 * 16)
#define HASH_DEFAULT_LOAD_FACTOR (0.75)
#define HASH_INDEX(v, c) ((v) & ((c)-1))
typedef void (*_hash_free_fn_t)(void *param);
typedef struct SHashNode {
char *key;
struct SHashNode *prev;
struct SHashNode *next;
uint32_t hashVal; // the hash value of key, if hashVal == HASH_VALUE_IN_TRASH, this node is moved to trash
uint32_t keyLen; // length of the key
char *data;
} SHashNode;
typedef struct SHashObj {
SHashNode **hashList;
size_t capacity; // number of slots
size_t size; // number of elements in hash table
_hash_fn_t hashFp; // hash function
_hash_free_fn_t freeFp; // hash node free callback function
bool enableUpdate; // enable update
#if defined(LINUX)
pthread_rwlock_t *lock;
#else
pthread_mutex_t *lock;
#endif
} SHashObj;
typedef struct SHashMutableIterator {
SHashObj * pHashObj;
int32_t entryIndex;
SHashNode *pCur;
SHashNode *pNext; // current node can be deleted for mutable iterator, so keep the next one before return current
int32_t num; // already check number of elements in hash table
} SHashMutableIterator;
/**
* init the hash table
*
* @param capacity initial capacity of the hash table
* @param fn hash function to generate the hash value
* @param threadsafe thread safe or not
* @return
*/
SHashObj *taosHashInit(size_t capacity, _hash_fn_t fn, bool update, bool threadsafe);
/**
* return the size of hash table
* @param pHashObj
* @return
*/
size_t taosHashGetSize(const SHashObj *pHashObj);
/**
* put element into hash table, if the element with the same key exists, update it
* @param pHashObj
* @param key
* @param keyLen
* @param data
* @param size
* @return
*/
int32_t taosHashPut(SHashObj *pHashObj, const void *key, size_t keyLen, void *data, size_t size);
/**
* return the payload data with the specified key
*
* @param pHashObj
* @param key
* @param keyLen
* @return
*/
void *taosHashGet(SHashObj *pHashObj, const void *key, size_t keyLen);
/**
* remove item with the specified key
* @param pHashObj
* @param key
* @param keyLen
*/
int32_t taosHashRemove(SHashObj *pHashObj, const void *key, size_t keyLen);
void* taosHashRemoveNode(SHashObj *pHashObj, const void *key, size_t keyLen);
/**
* clean up hash table
* @param handle
*/
void taosHashCleanup(SHashObj *pHashObj);
/**
* Set the free callback function
* This function if set will be invoked right before freeing each hash node
* @param pHashObj
*/
void taosHashSetFreecb(SHashObj *pHashObj, _hash_free_fn_t freeFp);
/**
*
* @param pHashObj
* @return
*/
SHashMutableIterator* taosHashCreateIter(SHashObj *pHashObj);
/**
*
* @param iter
* @return
*/
bool taosHashIterNext(SHashMutableIterator *iter);
/**
*
* @param iter
* @return
*/
void *taosHashIterGet(SHashMutableIterator *iter);
/**
*
* @param iter
* @return
*/
void* taosHashDestroyIter(SHashMutableIterator* iter);
/**
*
* @param pHashObj
* @return
*/
int32_t taosHashGetMaxOverflowLinkLength(const SHashObj *pHashObj);
#ifdef __cplusplus
}
#endif
#endif // TDENGINE_HASH_H