/**

 * \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);