rpm/lib/rpmhash.H

175 lines
4.7 KiB
C

/**
* \file lib/rpmhash.h
* Hash table implemenation.
*/
#include <string.h>
// Hackery to make sure that macros get expanded
#define __JOIN(a,b) a##b
#define JOIN(a,b) __JOIN(a,b)
#define HASHPREFIX(name) JOIN(HASHTYPE,name)
#define HASHSTRUCT JOIN(HASHTYPE,_s)
typedef struct HASHSTRUCT * HASHTYPE;
/* function pointer types to deal with the datatypes the hash works with */
#define hashFunctionType JOIN(HASHTYPE,HashFunctionType)
#define hashEqualityType JOIN(HASHTYPE,HashEqualityType)
#define hashFreeKey JOIN(HASHTYPE,FreeKey)
typedef unsigned int (*hashFunctionType) (HTKEYTYPE string);
typedef int (*hashEqualityType) (HTKEYTYPE key1, HTKEYTYPE key2);
typedef HTKEYTYPE (*hashFreeKey) (HTKEYTYPE);
#ifdef HTDATATYPE
#define hashFreeData JOIN(HASHTYPE,FreeData)
typedef HTDATATYPE (*hashFreeData) (HTDATATYPE);
#endif
/**
* 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 fn function to generate hash value for key
* @param eq function to compare hash keys for equality
* @param freeKey function to free the keys or NULL
* @param freeData function to free the data or NULL
* @return pointer to initialized hash table
*/
RPM_GNUC_INTERNAL
HASHTYPE HASHPREFIX(Create)(int numBuckets,
hashFunctionType fn, hashEqualityType eq,
hashFreeKey freeKey
#ifdef HTDATATYPE
, hashFreeData freeData
#endif
);
/**
* Destroy hash table.
* @param ht pointer to hash table
* @return NULL always
*/
RPM_GNUC_INTERNAL
HASHTYPE HASHPREFIX(Free)( HASHTYPE ht);
/**
* Remove all entries from the hash table.
* @param ht pointer to hash table
*/
RPM_GNUC_INTERNAL
void HASHPREFIX(Empty)(HASHTYPE ht);
/**
* Calculate hash for key.
* @param @ht pointer to hash table
* @param @key key
*/
RPM_GNUC_INTERNAL
unsigned int HASHPREFIX(KeyHash)(HASHTYPE ht, HTKEYTYPE key);
/**
* Add item to hash table.
* @param ht pointer to hash table
* @param key key
* @param data data value
*/
RPM_GNUC_INTERNAL
void HASHPREFIX(AddEntry)(HASHTYPE ht, HTKEYTYPE key
#ifdef HTDATATYPE
, HTDATATYPE data
#endif
);
/* Add item to hash table with precalculated key hash. */
RPM_GNUC_INTERNAL
void HASHPREFIX(AddHEntry)(HASHTYPE ht, HTKEYTYPE key, unsigned int keyHash
#ifdef HTDATATYPE
, HTDATATYPE data
#endif
);
/**
* Retrieve item from hash table.
* @param ht pointer to hash table
* @param key 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 1 on success, 0 if the item is not found.
*/
RPM_GNUC_INTERNAL
int HASHPREFIX(GetEntry)(HASHTYPE ht, HTKEYTYPE key,
#ifdef HTDATATYPE
HTDATATYPE** data,
int * dataCount,
#endif
HTKEYTYPE* tableKey);
/* Retrieve item from hash table with precalculated key hash. */
RPM_GNUC_INTERNAL
int HASHPREFIX(GetHEntry)(HASHTYPE ht, HTKEYTYPE key, unsigned int keyHash,
#ifdef HTDATATYPE
HTDATATYPE** data,
int * dataCount,
#endif
HTKEYTYPE* tableKey);
/**
* Check for key in hash table.
* @param ht pointer to hash table
* @param key key value
* @return 1 if the key is present, 0 otherwise
*/
RPM_GNUC_INTERNAL
int HASHPREFIX(HasEntry)(HASHTYPE ht, HTKEYTYPE key);
/* Check for key in hash table with precalculated key hash. */
RPM_GNUC_INTERNAL
int HASHPREFIX(HasHEntry)(HASHTYPE ht, HTKEYTYPE key, unsigned int keyHash);
/**
* How many buckets are currently allocated (result is implementation
* dependent)
* @param ht pointer to hash table
* @result number of buckets allocated
*/
RPM_GNUC_INTERNAL
unsigned int HASHPREFIX(NumBuckets)(HASHTYPE ht);
/**
* How many buckets are used (result is implementation dependent)
* @param ht pointer to hash table
* @result number of buckets used
*/
RPM_GNUC_INTERNAL
unsigned int HASHPREFIX(UsedBuckets)(HASHTYPE ht);
/**
* How many (unique) keys have been added to the hash table
* @param ht pointer to hash table
* @result number of unique keys
*/
RPM_GNUC_INTERNAL
unsigned int HASHPREFIX(NumKeys)(HASHTYPE ht);
#ifdef HTDATATYPE
/**
* How many data entries have been added to the hash table
* @param ht pointer to hash table
* @result number of data entries
*/
RPM_GNUC_INTERNAL
unsigned int HASHPREFIX(NumData)(HASHTYPE ht);
#endif
/**
* Print statistics about the hash to stderr
* This is for debugging only
* @param ht pointer to hash table
*/
RPM_GNUC_INTERNAL
void HASHPREFIX(PrintStats)(HASHTYPE ht);