rpm/lib/rpmhash.h

97 lines
2.4 KiB
C

#ifndef H_RPMHASH
#define H_RPMHASH
/**
* \file lib/rpmhash.h
* Hash table implemenation.
*/
#ifdef __cplusplus
extern "C" {
#endif
/**
*/
typedef struct hashTable_s * hashTable;
/**
*/
typedef unsigned int (*hashFunctionType) (const void * string);
/**
*/
typedef int (*hashEqualityType) (const void * key1, const void * key2);
/**
* Return hash value of a string
* @param string string on which to calculate hash value
* @return hash value
*/
unsigned int hashFunctionString(const void * string);
/**
* Compare two hash table entries for equality.
* @param key1 entry 1
* @param key2 entry 2
* @return 0 if entries are equal
*/
int hashEqualityString(const void * key1, const void * key2);
/**
* Create hash table.
* If keySize > 0, the key is duplicated within the table (which costs
* memory, but may be useful anyway.
* @param numBuckets number of hash buckets
* @param keySize size of key (0 if unknown)
* @param freeData Should data be freed when table is destroyed?
* @param fn function to generate hash value for key
* @param eq function to compare hash keys for equality
* @return pointer to initialized hash table
*/
hashTable htCreate(int numBuckets, size_t keySize, int freeData,
hashFunctionType fn, hashEqualityType eq);
/**
* Destroy hash table.
* @param ht pointer to hash table
* @return NULL always
*/
hashTable htFree( hashTable ht);
/**
* Add item to hash table.
* @param ht pointer to hash table
* @param key pointer to key
* @param data pointer to data value
*/
void htAddEntry(hashTable ht, const void * key,
const void * data);
/**
* Retrieve item from hash table.
* @param ht pointer to hash table
* @param key pointer to key value
* @retval data address to store data value from bucket
* @retval dataCount address to store data value size from bucket
* @retval tableKey address to store key value from bucket (may be NULL)
* @return 0 on success, 1 if the item is not found.
*/
int htGetEntry(hashTable ht, const void * key,
const void *** data,
int * dataCount,
const void ** tableKey);
/**
* Check for key in hash table.
* @param ht pointer to hash table
* @param key pointer to key value
* @return 1 if the key is present, 0 otherwise
*/
int htHasEntry(hashTable ht, const void * key);
#ifdef __cplusplus
}
#endif
#endif