/**
* Copyright (C) 2008 Happy Fish / YuQing
*
* FastDFS may be copied only under the terms of the GNU General
* Public License V3, which may be found in the FastDFS source kit.
* Please visit the FastDFS Home Page http://www.csource.org/ for more detail.
**/

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include "pthread_func.h"
#include "hash.h"

static unsigned int prime_array[] = {
    1,              /* 0 */
    3,              /* 1 */
    17,             /* 2 */
    37,             /* 3 */
    79,             /* 4 */
    163,            /* 5 */
    331,            /* 6 */
    673,            /* 7 */
    1361,           /* 8 */
    2729,           /* 9 */
    5471,           /* 10 */
    10949,          /* 11 */
    21911,          /* 12 */
    43853,          /* 13 */
    87719,          /* 14 */
    175447,         /* 15 */
    350899,         /* 16 */
    701819,         /* 17 */
    1403641,        /* 18 */
    2807303,        /* 19 */
    5614657,        /* 20 */
    11229331,       /* 21 */
    22458671,       /* 22 */
    44917381,       /* 23 */
    89834777,       /* 24 */
    179669557,      /* 25 */
    359339171,      /* 26 */
    718678369,      /* 27 */
    1437356741,     /* 28 */
    2147483647      /* 29 (largest signed int prime) */
};

#define PRIME_ARRAY_SIZE  30

static int _hash_alloc_buckets(HashArray *pHash, const unsigned int old_capacity)
{
	size_t bytes;

	bytes = sizeof(HashData *) * (*pHash->capacity);
	if (pHash->max_bytes > 0 && pHash->bytes_used+bytes > pHash->max_bytes)
	{
		return ENOSPC;
	}

	pHash->buckets = (HashData **)malloc(bytes);
	if (pHash->buckets == NULL)
	{
		return ENOMEM;
	}

	memset(pHash->buckets, 0, bytes);
	pHash->bytes_used += bytes - sizeof(HashData *) * old_capacity;

	return 0;
}

int hash_init_ex(HashArray *pHash, HashFunc hash_func, \
		const unsigned int capacity, const double load_factor, \
		const int64_t max_bytes, const bool bMallocValue)
{
	unsigned int *pprime;
	unsigned int *prime_end;
	int result;

	memset(pHash, 0, sizeof(HashArray));
	prime_end = prime_array + PRIME_ARRAY_SIZE;
	for (pprime = prime_array; pprime!=prime_end; pprime++)
	{
		if (*pprime > capacity)
		{
			pHash->capacity = pprime;
			break;
		}
	}

	if (pHash->capacity == NULL)
	{
		return EINVAL;
	}

	if ((result=_hash_alloc_buckets(pHash, 0)) != 0)
	{
		return result;
	}

	pHash->hash_func = hash_func;
	pHash->max_bytes = max_bytes;
	pHash->is_malloc_value = bMallocValue;

	if (load_factor >= 0.00 && load_factor <= 1.00)
	{
		pHash->load_factor = load_factor;
	}
	else
	{
		pHash->load_factor = 0.50;
	}

	return 0;
}

int hash_set_locks(HashArray *pHash, const int lock_count)
{
	size_t bytes;
	pthread_mutex_t *lock;
	pthread_mutex_t *lock_end;

	if (pHash->locks != NULL)
	{
		return EEXIST;
	}

	if (lock_count <= 0)
	{
		return EINVAL;
	}

	if (pHash->load_factor >= 0.10)
	{
		return EINVAL;
	}

	bytes = sizeof(pthread_mutex_t) * lock_count;
	pHash->locks = (pthread_mutex_t *)malloc(bytes);
	if (pHash->locks == NULL)
	{
		return ENOMEM;
	}

	pHash->lock_count = lock_count;
	lock_end = pHash->locks + lock_count;
	for (lock=pHash->locks; lock<lock_end; lock++)
	{
		init_pthread_lock(lock);
	}

	return 0;
}

void hash_destroy(HashArray *pHash)
{
	HashData **ppBucket;
	HashData **bucket_end;
	HashData *pNode;
	HashData *pDelete;

	if (pHash == NULL || pHash->buckets == NULL)
	{
		return;
	}

	bucket_end = pHash->buckets + (*pHash->capacity);
	for (ppBucket=pHash->buckets; ppBucket<bucket_end; ppBucket++)
	{
		pNode = *ppBucket;
		while (pNode != NULL)
		{
			pDelete = pNode;
			pNode = pNode->next;
			free(pDelete);
		}
	}

	free(pHash->buckets);
	pHash->buckets = NULL;
	if (pHash->is_malloc_capacity)
	{
		free(pHash->capacity);
		pHash->capacity = NULL;
		pHash->is_malloc_capacity = false;
	}

	pHash->item_count = 0;
	pHash->bytes_used = 0;
}

#define ADD_TO_BUCKET(pHash, ppBucket, hash_data) \
	hash_data->next = *ppBucket; \
	*ppBucket = hash_data; \
	pHash->item_count++;


#define DELETE_FROM_BUCKET(pHash, ppBucket, previous, hash_data) \
	if (previous == NULL) \
	{ \
		*ppBucket = hash_data->next; \
	} \
	else \
	{ \
		previous->next = hash_data->next; \
	} \
	pHash->item_count--; \
	pHash->bytes_used -= CALC_NODE_MALLOC_BYTES(hash_data->key_len, \
				hash_data->malloc_value_size); \
	free(hash_data);

#define HASH_LOCK(pHash, index) \
	if (pHash->lock_count > 0) \
	{ \
		pthread_mutex_lock(pHash->locks + (index) % pHash->lock_count); \
	}

#define HASH_UNLOCK(pHash, index) \
	if (pHash->lock_count > 0) \
	{ \
		pthread_mutex_unlock(pHash->locks + (index) % pHash->lock_count); \
	}


int hash_stat(HashArray *pHash, HashStat *pStat, \
		int *stat_by_lens, const int stat_size)
{
	HashData **ppBucket;
	HashData **bucket_end;
	HashData *hash_data;
	int totalLength;
	int last;
	int count;
	int i;

	memset(stat_by_lens, 0, sizeof(int) * stat_size);
	pStat->bucket_max_length = 0;
	pStat->bucket_used = 0;
	last = stat_size - 1;
	bucket_end = pHash->buckets + (*pHash->capacity);
	for (ppBucket=pHash->buckets; ppBucket<bucket_end; ppBucket++)
	{
		if (*ppBucket == NULL)
		{
			continue;
		}

		count = 0;
		hash_data = *ppBucket;
		while (hash_data != NULL)
		{
			count++;
			hash_data = hash_data->next;
		}

		pStat->bucket_used++;
		if (count > last)
		{
			return ENOSPC;
		}
		stat_by_lens[count]++;

		if (count > pStat->bucket_max_length)
		{
			pStat->bucket_max_length = count;
		}
	}

	totalLength = 0;
	for (i=0; i<=pStat->bucket_max_length; i++)
	{
		if (stat_by_lens[i] > 0)
		{
			totalLength += i * stat_by_lens[i];
		}
	}

	pStat->capacity = *(pHash->capacity);
	pStat->item_count = pHash->item_count;
	pStat->bucket_avg_length = pStat->bucket_used > 0 ? \
		(double)totalLength / (double)pStat->bucket_used : 0.00;

	return 0;
}

void hash_stat_print(HashArray *pHash)
{
#define STAT_MAX_NUM  64
	HashStat hs;
	int stats[STAT_MAX_NUM];

	if (hash_stat(pHash, &hs, stats, STAT_MAX_NUM) != 0)
	{
		printf("hash max length exceeds %d!\n", STAT_MAX_NUM);
		return;
	}

	/*
	printf("collision stat:\n");
	for (i=0; i<last; i++)
	{
		if (stats[i] > 0) printf("%d: %d\n", i+1, stats[i]);
	}
	if (stats[i] > 0) printf(">=%d: %d\n", i+1, stats[i]);
	*/

	printf("capacity: %d, item_count=%d, bucket_used: %d, " \
		"avg length: %.4f, max length: %d, bucket / item = %.2f%%\n", 
		hs.capacity, hs.item_count, hs.bucket_used,
		hs.bucket_avg_length, hs.bucket_max_length, 
		(double)hs.bucket_used*100.00/(double)hs.capacity);
}

static int _rehash1(HashArray *pHash, const int old_capacity, \
		unsigned int *new_capacity)
{
	HashData **old_buckets;
	HashData **ppBucket;
	HashData **bucket_end;
	HashData *hash_data;
	HashData *pNext;
	int result;

	old_buckets = pHash->buckets;
	pHash->capacity = new_capacity;
	if ((result=_hash_alloc_buckets(pHash, old_capacity)) != 0)
	{
		pHash->buckets = old_buckets;
		return result;
	}

	//printf("old: %d, new: %d\n", old_capacity, *pHash->capacity);

	pHash->item_count = 0;
	bucket_end = old_buckets + old_capacity;
	for (ppBucket=old_buckets; ppBucket<bucket_end; ppBucket++)
	{
		if (*ppBucket == NULL)
		{
			continue;
		}

		hash_data = *ppBucket;
		while (hash_data != NULL)
		{
			pNext = hash_data->next;

			ADD_TO_BUCKET(pHash, (pHash->buckets + \
				(HASH_CODE(pHash, hash_data) % \
				(*pHash->capacity))), hash_data)

			hash_data = pNext;
		}
	}

	free(old_buckets);
	return 0;
}

static int _rehash(HashArray *pHash)
{
	int result;
	unsigned int *pOldCapacity;

	pOldCapacity = pHash->capacity;
	if (pHash->is_malloc_capacity)
	{
		unsigned int *pprime;
		unsigned int *prime_end;

		pHash->capacity = NULL;

		prime_end = prime_array + PRIME_ARRAY_SIZE;
		for (pprime = prime_array; pprime!=prime_end; pprime++)
		{
			if (*pprime > *pOldCapacity)
			{
				pHash->capacity = pprime;
				break;
			}
		}
	}
	else
	{
		pHash->capacity++;
	}

	if ((result=_rehash1(pHash, *pOldCapacity, pHash->capacity)) != 0)
	{
		pHash->capacity = pOldCapacity;  //rollback
	}
	else
	{
		if (pHash->is_malloc_capacity)
		{
			free(pOldCapacity);
			pHash->is_malloc_capacity = false;
		}
	}

	/*printf("rehash, old_capacity=%d, new_capacity=%d\n", \
		old_capacity, *pHash->capacity);
	*/
	return result;
}

static int _hash_conflict_count(HashArray *pHash)
{
	HashData **ppBucket;
	HashData **bucket_end;
	HashData *hash_data;
	HashData *pNext;
	int conflicted;
	int conflict_count;

	bucket_end = pHash->buckets + (*pHash->capacity);
	conflict_count = 0;
	for (ppBucket=pHash->buckets; ppBucket<bucket_end; ppBucket++)
	{
		if (*ppBucket == NULL || (*ppBucket)->next == NULL)
		{
			continue;
		}

		conflicted = 0;
		hash_data = *ppBucket;
		while (hash_data != NULL)
		{
			pNext = hash_data->next;
			while (pNext != NULL)
			{
				if (HASH_CODE(pHash, hash_data) != \
					HASH_CODE(pHash, pNext))
				{
					conflicted = 1;
					break;
				}

				pNext = pNext->next;
			}

			if (conflicted)
			{
				break;
			}

			hash_data = hash_data->next;
		}

		conflict_count += conflicted;
	}

	return conflict_count;
}

int hash_best_op(HashArray *pHash, const int suggest_capacity)
{
	int old_capacity;
	int conflict_count;
	unsigned int *new_capacity;
	int result;

	if ((conflict_count=_hash_conflict_count(pHash)) == 0)
	{
		return 0;
	}

	old_capacity = *pHash->capacity;
	new_capacity = (unsigned int *)malloc(sizeof(unsigned int));
	if (new_capacity == NULL)
	{
		return -ENOMEM;
	}

	if ((suggest_capacity > 2) && (suggest_capacity >= pHash->item_count))
	{
		*new_capacity = suggest_capacity - 2;
		if (*new_capacity % 2 == 0)
		{
			++(*new_capacity);
		}
	}
	else
	{
		*new_capacity = 2 * (pHash->item_count - 1) + 1;
	}

	do
	{
		do
		{
			*new_capacity += 2;
		} while ((*new_capacity % 3 == 0) || (*new_capacity % 5 == 0) \
			 || (*new_capacity % 7 == 0));

		if ((result=_rehash1(pHash, old_capacity, new_capacity)) != 0)
		{
			pHash->is_malloc_capacity = \
					(pHash->capacity == new_capacity);
			*pHash->capacity = old_capacity;
			return -1 * result;
		}

		old_capacity = *new_capacity;
		/*printf("rehash, conflict_count=%d, old_capacity=%d, " \
			"new_capacity=%d\n", conflict_count, \
			old_capacity, *new_capacity);
		*/
	} while ((conflict_count=_hash_conflict_count(pHash)) > 0);

	pHash->is_malloc_capacity = true;

	//hash_stat_print(pHash);
	return 1;
}

static HashData *_chain_find_entry(HashData **ppBucket, const void *key, \
		const int key_len, const unsigned int hash_code)
{
	HashData *hash_data;

	hash_data = *ppBucket;
	while (hash_data != NULL)
	{
		if (key_len == hash_data->key_len && \
			memcmp(key, hash_data->key, key_len) == 0)
		{
			return hash_data;
		}

		hash_data = hash_data->next;
	}

	return NULL;
}

HashData *hash_find_ex(HashArray *pHash, const void *key, const int key_len)
{
	unsigned int hash_code;
	HashData **ppBucket;
	HashData *hash_data;

	hash_code = pHash->hash_func(key, key_len);
	ppBucket = pHash->buckets + (hash_code % (*pHash->capacity));

	HASH_LOCK(pHash, ppBucket - pHash->buckets)
	hash_data = _chain_find_entry(ppBucket, key, key_len, hash_code);
	HASH_UNLOCK(pHash, ppBucket - pHash->buckets)

	return hash_data;
}

void *hash_find(HashArray *pHash, const void *key, const int key_len)
{
	unsigned int hash_code;
	HashData **ppBucket;
	HashData *hash_data;

	hash_code = pHash->hash_func(key, key_len);
	ppBucket = pHash->buckets + (hash_code % (*pHash->capacity));

	HASH_LOCK(pHash, ppBucket - pHash->buckets)
	hash_data = _chain_find_entry(ppBucket, key, key_len, hash_code);
	HASH_UNLOCK(pHash, ppBucket - pHash->buckets)

	if (hash_data != NULL)
	{
		return hash_data->value;
	}
	else
	{
		return NULL;
	}
}

int hash_get(HashArray *pHash, const void *key, const int key_len,
	void *value, int *value_len)
{
	unsigned int hash_code;
	int result;
	HashData **ppBucket;
	HashData *hash_data;

	hash_code = pHash->hash_func(key, key_len);
	ppBucket = pHash->buckets + (hash_code % (*pHash->capacity));

	HASH_LOCK(pHash, ppBucket - pHash->buckets)
	hash_data = _chain_find_entry(ppBucket, key, key_len, hash_code);
	if (hash_data != NULL)
	{
		if (hash_data->value_len <= *value_len)
		{
			*value_len = hash_data->value_len;
			memcpy(value, hash_data->value, hash_data->value_len);
			result = 0;
		}
		else
		{
			result = ENOSPC;
		}
	}
	else
	{
		result = ENOENT;
	}
	HASH_UNLOCK(pHash, ppBucket - pHash->buckets)
	return result;
}

int hash_insert_ex(HashArray *pHash, const void *key, const int key_len, \
		void *value, const int value_len, const bool needLock)
{
	unsigned int hash_code;
	HashData **ppBucket;
	HashData *hash_data;
	HashData *previous;
	char *pBuff;
	int bytes;
	int malloc_value_size;

	hash_code = pHash->hash_func(key, key_len);
	ppBucket = pHash->buckets + (hash_code % (*pHash->capacity));

	previous = NULL;

	if (needLock)
	{
		HASH_LOCK(pHash, ppBucket - pHash->buckets)
	}

	hash_data = *ppBucket;
	while (hash_data != NULL)
	{
		if (key_len == hash_data->key_len && \
			memcmp(key, hash_data->key, key_len) == 0)
		{
			break;
		}

		previous = hash_data;
		hash_data = hash_data->next;
	}

	if (hash_data != NULL) //exists
	{
		if (!pHash->is_malloc_value)
		{
			hash_data->value_len = value_len;
			hash_data->value = (char *)value;
			if (needLock)
			{
				HASH_UNLOCK(pHash, ppBucket - pHash->buckets)
			}
			return 0;
		}
		else
		{
			if (hash_data->malloc_value_size >= value_len && \
				(hash_data->malloc_value_size <= 128 ||
				 hash_data->malloc_value_size / 2 < value_len))
			{
				hash_data->value_len = value_len;
				memcpy(hash_data->value, value, value_len);
				if (needLock)
				{
					HASH_UNLOCK(pHash, ppBucket - pHash->buckets)
				}
				return 0;
			}

			DELETE_FROM_BUCKET(pHash, ppBucket, previous, hash_data)
		}
	}
	if (needLock)
	{
		HASH_UNLOCK(pHash, ppBucket - pHash->buckets)
	}

	if (!pHash->is_malloc_value)
	{
		malloc_value_size = 0;
	}
	else
	{
		malloc_value_size = MEM_ALIGN(value_len);
	}

	bytes = CALC_NODE_MALLOC_BYTES(key_len, malloc_value_size);
	if (pHash->max_bytes > 0 && pHash->bytes_used+bytes > pHash->max_bytes)
	{
		return -ENOSPC;
	}

	pBuff = (char *)malloc(bytes);
	if (pBuff == NULL)
	{
		return -ENOMEM;
	}

	pHash->bytes_used += bytes;

	hash_data = (HashData *)pBuff;
	hash_data->malloc_value_size = malloc_value_size;

	hash_data->key_len = key_len;
	memcpy(hash_data->key, key, key_len);
#ifdef HASH_STORE_HASH_CODE
	hash_data->hash_code = hash_code;
#endif
	hash_data->value_len = value_len;

	if (!pHash->is_malloc_value)
	{
		hash_data->value = (char *)value;
	}
	else
	{
		hash_data->value = hash_data->key + hash_data->key_len;
		memcpy(hash_data->value, value, value_len);
	}

	if (needLock)
	{
		HASH_LOCK(pHash, ppBucket - pHash->buckets)
		ADD_TO_BUCKET(pHash, ppBucket, hash_data)
		HASH_UNLOCK(pHash, ppBucket - pHash->buckets)
	}
	else
	{
		ADD_TO_BUCKET(pHash, ppBucket, hash_data)
	}

	if (pHash->load_factor >= 0.10 && (double)pHash->item_count /
		(double)*pHash->capacity >= pHash->load_factor)
	{
		_rehash(pHash);
	}

	return 1;
}

int64_t hash_inc_value(const HashData *old_data, const int inc,
	char *new_value, int *new_value_len, void *arg)
{
	int64_t n;
	if (old_data != NULL)
	{
		if (old_data->value_len < *new_value_len)
		{
			memcpy(new_value, old_data->value, old_data->value_len);
                        new_value[old_data->value_len] = '\0';
                        n = strtoll(new_value, NULL, 10);
                        n += inc;
		}
		else
		{
			n = inc;
		}
		*new_value_len = sprintf(new_value, INT64_PRINTF_FORMAT, n);
	}
	else
	{
		n = inc;
		*new_value_len = sprintf(new_value, INT64_PRINTF_FORMAT, n);
	}

	return n;
}

int hash_inc_ex(HashArray *pHash, const void *key, const int key_len,
		const int inc, char *value, int *value_len,
		ConvertValueFunc convert_func, void *arg)
{
	unsigned int hash_code;
	int result;
	HashData **ppBucket;
	HashData *hash_data;

	hash_code = pHash->hash_func(key, key_len);
	ppBucket = pHash->buckets + (hash_code % (*pHash->capacity));

	HASH_LOCK(pHash, ppBucket - pHash->buckets)
	hash_data = _chain_find_entry(ppBucket, key, key_len, hash_code);
	convert_func(hash_data, inc, value, value_len, arg);
	if (hash_data != NULL)
	{
		if (!pHash->is_malloc_value)
		{
			hash_data->value_len = *value_len;
			hash_data->value = (char *)value;
			HASH_UNLOCK(pHash, ppBucket - pHash->buckets)
			return 0;
		}
		else
		{
			if (hash_data->malloc_value_size >= *value_len)
			{
				hash_data->value_len = *value_len;
				memcpy(hash_data->value, value, *value_len);
				HASH_UNLOCK(pHash, ppBucket - pHash->buckets)
				return 0;
			}
		}
	}
	result = hash_insert_ex(pHash, key, key_len, value, *value_len, false);
	if (result < 0)
	{
		*value = '\0';
		*value_len = 0;
		result *= -1;
	}
	else
	{
		result = 0;
	}
	HASH_UNLOCK(pHash, ppBucket - pHash->buckets)

	return result;
}

int hash_partial_set(HashArray *pHash, const void *key, const int key_len,
		const char *value, const int offset, const int value_len)
{
	unsigned int hash_code;
	int result;
	HashData **ppBucket;
	HashData *hash_data;
	char *pNewBuff;

	hash_code = pHash->hash_func(key, key_len);
	ppBucket = pHash->buckets + (hash_code % (*pHash->capacity));

	HASH_LOCK(pHash, ppBucket - pHash->buckets)
	hash_data = _chain_find_entry(ppBucket, key, key_len, hash_code);
	do
	{
		if (hash_data != NULL)
		{
			if (offset < 0 || offset >= hash_data->value_len)
			{
				result = EINVAL;
				break;
			}
			if (offset + value_len <= hash_data->value_len)
			{
				memcpy(hash_data->value+offset, value, value_len);
				result = 0;
				break;
			}

			pNewBuff = (char *)malloc(offset + value_len);
			if (pNewBuff == NULL)
			{
				result = errno != 0 ? errno : ENOMEM;
				break;
			}

			if (offset > 0)
			{
				memcpy(pNewBuff, hash_data->value, offset);
			}
			memcpy(pNewBuff + offset, value, value_len);
			result = hash_insert_ex(pHash, key, key_len, pNewBuff,
				offset + value_len, false);
			free(pNewBuff);
		}
		else
		{
			if (offset != 0)
			{
				result = ENOENT;
				break;
			}
			result = hash_insert_ex(pHash, key, key_len, (void *)value,
				value_len, false);
		}

		if (result < 0)
		{
			result *= -1;
		}
		else
		{
			result = 0;
		}
	} while (0);

	HASH_UNLOCK(pHash, ppBucket - pHash->buckets)
	return result;
}

int hash_delete(HashArray *pHash, const void *key, const int key_len)
{
	HashData **ppBucket;
	HashData *hash_data;
	HashData *previous;
	unsigned int hash_code;
	int result;

	hash_code = pHash->hash_func(key, key_len);
	ppBucket = pHash->buckets + (hash_code % (*pHash->capacity));

	result = ENOENT;
	previous = NULL;
	HASH_LOCK(pHash, ppBucket - pHash->buckets)
	hash_data = *ppBucket;
	while (hash_data != NULL)
	{
		if (key_len == hash_data->key_len && \
			memcmp(key, hash_data->key, key_len) == 0)
		{
			DELETE_FROM_BUCKET(pHash, ppBucket, previous, hash_data)
			result = 0;
			break;
		}

		previous = hash_data;
		hash_data = hash_data->next;
	}
	HASH_UNLOCK(pHash, ppBucket - pHash->buckets)

	return result;
}

int hash_walk(HashArray *pHash, HashWalkFunc walkFunc, void *args)
{
	HashData **ppBucket;
	HashData **bucket_end;
	HashData *hash_data;
	int index;
	int result;

	index = 0;
	bucket_end = pHash->buckets + (*pHash->capacity);
	for (ppBucket=pHash->buckets; ppBucket<bucket_end; ppBucket++)
	{
		hash_data = *ppBucket;
		while (hash_data != NULL)
		{
			result = walkFunc(index, hash_data, args);
			if (result != 0)
			{
				return result;
			}

			index++;
			hash_data = hash_data->next;
		}
	}

	return 0;
}

int hash_count(HashArray *pHash)
{
	return pHash->item_count;
}

int hash_bucket_lock(HashArray *pHash, const unsigned int bucket_index)
{
	if (pHash->lock_count <= 0)
	{
		return 0;
	}

	return pthread_mutex_lock(pHash->locks + bucket_index %
			pHash->lock_count);
}

int hash_bucket_unlock(HashArray *pHash, const unsigned int bucket_index)
{
	if (pHash->lock_count <= 0)
	{
		return 0;
	}

	return pthread_mutex_unlock(pHash->locks + bucket_index %
			pHash->lock_count);
}

// RS Hash Function
int RSHash(const void *key, const int key_len)
{
    unsigned char *pKey;
    unsigned char *pEnd;
    int a = 63689;
    int hash = 0;

    pEnd = (unsigned char *)key + key_len;
    for (pKey = (unsigned char *)key; pKey != pEnd; pKey++)
    {
        hash = hash * a + (*pKey);
        a *= 378551;
    }

    return hash;
} 
 
#define JS_HASH_FUNC(init_value) \
    unsigned char *pKey; \
    unsigned char *pEnd; \
    int hash; \
 \
    hash = init_value; \
    pEnd = (unsigned char *)key + key_len; \
    for (pKey = (unsigned char *)key; pKey != pEnd; pKey++) \
    { \
        hash ^= ((hash << 5) + (*pKey) + (hash >> 2)); \
    } \
 \
    return hash; \


// JS Hash Function
int JSHash(const void *key, const int key_len)
{
	JS_HASH_FUNC(1315423911)
}
 
int JSHash_ex(const void *key, const int key_len, \
	const int init_value)
{
	JS_HASH_FUNC(init_value)
}
 
#define BITS_IN_UNIGNED_INT (int)(sizeof(int) * 8)
#define THREE_QUARTERS      (int)((BITS_IN_UNIGNED_INT * 3) / 4)
#define HASH_ONE_EIGHTH     (int)(BITS_IN_UNIGNED_INT / 8)
#define HASH_HIGH_BITS      (int)((unsigned int)(0xFFFFFFFF) << \
				(BITS_IN_UNIGNED_INT - HASH_ONE_EIGHTH))

#define PJW_HASH_FUNC(init_value) \
    unsigned char *pKey; \
    unsigned char *pEnd; \
    int hash; \
    int test; \
 \
    hash = init_value; \
    pEnd = (unsigned char *)key + key_len; \
    for (pKey = (unsigned char *)key; pKey != pEnd; pKey++) \
    { \
        hash = (hash << HASH_ONE_EIGHTH) + (*(pKey)); \
        if ((test = hash & HASH_HIGH_BITS) != 0) \
        { \
            hash = ((hash ^ (test >> THREE_QUARTERS)) & (~HASH_HIGH_BITS)); \
        } \
    } \
 \
    return hash; \


// P.J.Weinberger Hash Function, same as ELF Hash
int PJWHash(const void *key, const int key_len)
{
	PJW_HASH_FUNC(0)
}
 
int PJWHash_ex(const void *key, const int key_len, \
	const int init_value)
{
	PJW_HASH_FUNC(init_value)
}
 
#define ELF_HASH_FUNC(init_value) \
    unsigned char *pKey; \
    unsigned char *pEnd; \
    int hash; \
    int x; \
 \
    hash = init_value; \
    pEnd = (unsigned char *)key + key_len; \
    for (pKey = (unsigned char *)key; pKey != pEnd; pKey++) \
    { \
        hash = (hash << 4) + (*pKey); \
        if ((x = hash & 0xF0000000) != 0) \
        { \
            hash ^= (x >> 24); \
            hash &= ~x; \
        } \
    } \
 \
    return hash; \


// ELF Hash Function, same as PJW Hash
int ELFHash(const void *key, const int key_len)
{
	ELF_HASH_FUNC(0)
}

int ELFHash_ex(const void *key, const int key_len, \
	const int init_value)
{
	ELF_HASH_FUNC(init_value)
}

#define BKDR_HASH_FUNC(init_value) \
    unsigned char *pKey; \
    unsigned char *pEnd; \
    int seed = 131;  /* 31 131 1313 13131 131313 etc..*/ \
    int hash; \
 \
    hash = init_value; \
    pEnd = (unsigned char *)key + key_len; \
    for (pKey = (unsigned char *)key; pKey != pEnd; pKey++) \
    { \
        hash = hash * seed + (*pKey); \
    } \
 \
    return hash; \


// BKDR Hash Function
int BKDRHash(const void *key, const int key_len)
{
	BKDR_HASH_FUNC(0)
}

int BKDRHash_ex(const void *key, const int key_len, \
	const int init_value)
{
	BKDR_HASH_FUNC(init_value)
}

#define SDBM_HASH_FUNC(init_value) \
    unsigned char *pKey; \
    unsigned char *pEnd; \
    int hash; \
 \
    hash = init_value; \
    pEnd = (unsigned char *)key + key_len; \
    for (pKey = (unsigned char *)key; pKey != pEnd; pKey++) \
    { \
        hash = (*pKey) + (hash << 6) + (hash << 16) - hash; \
    } \
 \
    return hash; \


// SDBM Hash Function
int SDBMHash(const void *key, const int key_len)
{
	SDBM_HASH_FUNC(0)
}

int SDBMHash_ex(const void *key, const int key_len, \
	const int init_value)
{
	SDBM_HASH_FUNC(init_value)
}

#define TIME33_HASH_FUNC(init_value) \
	int nHash; \
	unsigned char *pKey; \
	unsigned char *pEnd; \
 \
	nHash = init_value; \
	pEnd = (unsigned char *)key + key_len; \
	for (pKey = (unsigned char *)key; pKey != pEnd; pKey++) \
	{ \
		nHash += (nHash << 5) + (*pKey); \
	} \
 \
	return nHash; \


int Time33Hash(const void *key, const int key_len)
{
	TIME33_HASH_FUNC(0)
}

int Time33Hash_ex(const void *key, const int key_len, \
	const int init_value)
{
	TIME33_HASH_FUNC(init_value)
}

#define DJB_HASH_FUNC(init_value) \
    unsigned char *pKey; \
    unsigned char *pEnd; \
    int hash; \
 \
    hash = init_value; \
    pEnd = (unsigned char *)key + key_len; \
    for (pKey = (unsigned char *)key; pKey != pEnd; pKey++) \
    { \
        hash += (hash << 5) + (*pKey); \
    } \
 \
    return hash; \


// DJB Hash Function
int DJBHash(const void *key, const int key_len)
{
	DJB_HASH_FUNC(5381)
}

int DJBHash_ex(const void *key, const int key_len, \
	const int init_value)
{
	DJB_HASH_FUNC(init_value)
}

#define AP_HASH_FUNC(init_value) \
    unsigned char *pKey; \
    unsigned char *pEnd; \
    int i; \
    int hash; \
 \
    hash = init_value; \
 \
    pEnd = (unsigned char *)key + key_len; \
    for (pKey = (unsigned char *)key, i=0; pKey != pEnd; pKey++, i++) \
    { \
        if ((i & 1) == 0) \
        { \
            hash ^= ((hash << 7) ^ (*pKey) ^ (hash >> 3)); \
        } \
        else \
        { \
            hash ^= (~((hash << 11) ^ (*pKey) ^ (hash >> 5))); \
        } \
    } \
 \
    return hash; \


// AP Hash Function
int APHash(const void *key, const int key_len)
{
	AP_HASH_FUNC(0)
}

int APHash_ex(const void *key, const int key_len, \
	const int init_value)
{
	AP_HASH_FUNC(init_value)
}

int calc_hashnr (const void* key, const int key_len)
{
  unsigned char *pKey;
  unsigned char *pEnd;
  int nr = 1, nr2 = 4;

  pEnd = (unsigned char *)key + key_len;
  for (pKey = (unsigned char *)key; pKey != pEnd; pKey++)
  {
      nr ^= (((nr & 63) + nr2) * (*pKey)) + (nr << 8);
      nr2 += 3;
  }

  return nr;

}

#define CALC_HASHNR1_FUNC(init_value) \
  unsigned char *pKey; \
  unsigned char *pEnd; \
  int hash; \
 \
  hash = init_value; \
  pEnd = (unsigned char *)key + key_len; \
  for (pKey = (unsigned char *)key; pKey != pEnd; pKey++) \
  { \
    hash *= 16777619; \
    hash ^= *pKey; \
  } \
  return hash; \

int calc_hashnr1(const void* key, const int key_len)
{
	CALC_HASHNR1_FUNC(0)
}

int calc_hashnr1_ex(const void* key, const int key_len, \
	const int init_value)
{
	CALC_HASHNR1_FUNC(init_value)
}

#define SIMPLE_HASH_FUNC(init_value) \
  int h; \
  unsigned char *p; \
  unsigned char *pEnd; \
 \
  h = init_value; \
  pEnd = (unsigned char *)key + key_len; \
  for (p = (unsigned char *)key; p!= pEnd; p++) \
  { \
    h = 31 * h + *p; \
  } \
 \
  return h; \

int simple_hash(const void* key, const int key_len)
{
	SIMPLE_HASH_FUNC(0)
}

int simple_hash_ex(const void* key, const int key_len, \
	const int init_value)
{
	SIMPLE_HASH_FUNC(init_value)
}

static unsigned int crc_table[256] = {
	0x00000000, 0x77073096, 0xEE0E612C, 0x990951BA,
	0x076DC419, 0x706AF48F, 0xE963A535, 0x9E6495A3,
	0x0EDB8832, 0x79DCB8A4, 0xE0D5E91E, 0x97D2D988,
	0x09B64C2B, 0x7EB17CBD, 0xE7B82D07, 0x90BF1D91,
	0x1DB71064, 0x6AB020F2, 0xF3B97148, 0x84BE41DE,
	0x1ADAD47D, 0x6DDDE4EB, 0xF4D4B551, 0x83D385C7,
	0x136C9856, 0x646BA8C0, 0xFD62F97A, 0x8A65C9EC,
	0x14015C4F, 0x63066CD9, 0xFA0F3D63, 0x8D080DF5,
	0x3B6E20C8, 0x4C69105E, 0xD56041E4, 0xA2677172,
	0x3C03E4D1, 0x4B04D447, 0xD20D85FD, 0xA50AB56B,
	0x35B5A8FA, 0x42B2986C, 0xDBBBC9D6, 0xACBCF940,
	0x32D86CE3, 0x45DF5C75, 0xDCD60DCF, 0xABD13D59,
	0x26D930AC, 0x51DE003A, 0xC8D75180, 0xBFD06116,
	0x21B4F4B5, 0x56B3C423, 0xCFBA9599, 0xB8BDA50F,
	0x2802B89E, 0x5F058808, 0xC60CD9B2, 0xB10BE924,
	0x2F6F7C87, 0x58684C11, 0xC1611DAB, 0xB6662D3D,
	0x76DC4190, 0x01DB7106, 0x98D220BC, 0xEFD5102A,
	0x71B18589, 0x06B6B51F, 0x9FBFE4A5, 0xE8B8D433,
	0x7807C9A2, 0x0F00F934, 0x9609A88E, 0xE10E9818,
	0x7F6A0DBB, 0x086D3D2D, 0x91646C97, 0xE6635C01,
	0x6B6B51F4, 0x1C6C6162, 0x856530D8, 0xF262004E,
	0x6C0695ED, 0x1B01A57B, 0x8208F4C1, 0xF50FC457,
	0x65B0D9C6, 0x12B7E950, 0x8BBEB8EA, 0xFCB9887C,
	0x62DD1DDF, 0x15DA2D49, 0x8CD37CF3, 0xFBD44C65,
	0x4DB26158, 0x3AB551CE, 0xA3BC0074, 0xD4BB30E2,
	0x4ADFA541, 0x3DD895D7, 0xA4D1C46D, 0xD3D6F4FB,
	0x4369E96A, 0x346ED9FC, 0xAD678846, 0xDA60B8D0,
	0x44042D73, 0x33031DE5, 0xAA0A4C5F, 0xDD0D7CC9,
	0x5005713C, 0x270241AA, 0xBE0B1010, 0xC90C2086,
	0x5768B525, 0x206F85B3, 0xB966D409, 0xCE61E49F,
	0x5EDEF90E, 0x29D9C998, 0xB0D09822, 0xC7D7A8B4,
	0x59B33D17, 0x2EB40D81, 0xB7BD5C3B, 0xC0BA6CAD,
	0xEDB88320, 0x9ABFB3B6, 0x03B6E20C, 0x74B1D29A,
	0xEAD54739, 0x9DD277AF, 0x04DB2615, 0x73DC1683,
	0xE3630B12, 0x94643B84, 0x0D6D6A3E, 0x7A6A5AA8,
	0xE40ECF0B, 0x9309FF9D, 0x0A00AE27, 0x7D079EB1,
	0xF00F9344, 0x8708A3D2, 0x1E01F268, 0x6906C2FE,
	0xF762575D, 0x806567CB, 0x196C3671, 0x6E6B06E7,
	0xFED41B76, 0x89D32BE0, 0x10DA7A5A, 0x67DD4ACC,
	0xF9B9DF6F, 0x8EBEEFF9, 0x17B7BE43, 0x60B08ED5,
	0xD6D6A3E8, 0xA1D1937E, 0x38D8C2C4, 0x4FDFF252,
	0xD1BB67F1, 0xA6BC5767, 0x3FB506DD, 0x48B2364B,
	0xD80D2BDA, 0xAF0A1B4C, 0x36034AF6, 0x41047A60,
	0xDF60EFC3, 0xA867DF55, 0x316E8EEF, 0x4669BE79,
	0xCB61B38C, 0xBC66831A, 0x256FD2A0, 0x5268E236,
	0xCC0C7795, 0xBB0B4703, 0x220216B9, 0x5505262F,
	0xC5BA3BBE, 0xB2BD0B28, 0x2BB45A92, 0x5CB36A04,
	0xC2D7FFA7, 0xB5D0CF31, 0x2CD99E8B, 0x5BDEAE1D,
	0x9B64C2B0, 0xEC63F226, 0x756AA39C, 0x026D930A,
	0x9C0906A9, 0xEB0E363F, 0x72076785, 0x05005713,
	0x95BF4A82, 0xE2B87A14, 0x7BB12BAE, 0x0CB61B38,
	0x92D28E9B, 0xE5D5BE0D, 0x7CDCEFB7, 0x0BDBDF21,
	0x86D3D2D4, 0xF1D4E242, 0x68DDB3F8, 0x1FDA836E,
	0x81BE16CD, 0xF6B9265B, 0x6FB077E1, 0x18B74777,
	0x88085AE6, 0xFF0F6A70, 0x66063BCA, 0x11010B5C,
	0x8F659EFF, 0xF862AE69, 0x616BFFD3, 0x166CCF45,
	0xA00AE278, 0xD70DD2EE, 0x4E048354, 0x3903B3C2,
	0xA7672661, 0xD06016F7, 0x4969474D, 0x3E6E77DB,
	0xAED16A4A, 0xD9D65ADC, 0x40DF0B66, 0x37D83BF0,
	0xA9BCAE53, 0xDEBB9EC5, 0x47B2CF7F, 0x30B5FFE9,
	0xBDBDF21C, 0xCABAC28A, 0x53B39330, 0x24B4A3A6,
	0xBAD03605, 0xCDD70693, 0x54DE5729, 0x23D967BF,
	0xB3667A2E, 0xC4614AB8, 0x5D681B02, 0x2A6F2B94,
	0xB40BBE37, 0xC30C8EA1, 0x5A05DF1B, 0x2D02EF8D
};

#define CRC32_BODY(init_value) \
	unsigned char *pKey; \
	unsigned char *pEnd; \
	int crc; \
 \
	crc = init_value; \
	pEnd = (unsigned char *)key + key_len; \
	for (pKey = (unsigned char *)key; pKey != pEnd; pKey++) \
	{ \
		crc = crc_table[(crc ^ *pKey) & 0xFF] ^ (crc >> 8); \
	} \

int CRC32(void *key, const int key_len)
{
	CRC32_BODY(CRC32_XINIT)

	return crc ^ CRC32_XOROT;
}

int CRC32_ex(void *key, const int key_len, \
	const int init_value)
{
	CRC32_BODY(init_value)

	return crc;
}