rpm/misc/rpmhash.C

310 lines
6.6 KiB
C

/**
* \file lib/rpmhash.c
* Hash table implemenation
*/
#include "system.h"
#include <stdio.h>
#include "debug.h"
#define Bucket JOIN(HASHTYPE,Buket)
#define Bucket_s JOIN(HASHTYPE,Buket_s)
typedef struct Bucket_s * Bucket;
/**
*/
struct Bucket_s {
Bucket next; /*!< pointer to next item in bucket */
HTKEYTYPE key; /*!< hash key */
#ifdef HTDATATYPE
int dataCount; /*!< data entries */
HTDATATYPE data[1]; /*!< data - grows by resizing whole bucket */
#endif
};
/**
*/
struct HASHSTRUCT {
int numBuckets; /*!< number of hash buckets */
Bucket * buckets; /*!< hash bucket array */
hashFunctionType fn; /*!< generate hash value for key */
hashEqualityType eq; /*!< compare hash keys for equality */
hashFreeKey freeKey;
int bucketCount; /*!< number of used buckets */
int keyCount; /*!< number of keys */
#ifdef HTDATATYPE
int dataCount; /*!< number of data entries */
hashFreeData freeData;
#endif
};
/**
* Find entry in hash table.
* @param ht pointer to hash table
* @param key pointer to key value
* @param keyHash key hash
* @return pointer to hash bucket of key (or NULL)
*/
static
Bucket HASHPREFIX(findEntry)(HASHTYPE ht, HTKEYTYPE key, unsigned int keyHash)
{
unsigned int hash = keyHash % ht->numBuckets;
Bucket b = ht->buckets[hash];
while (b && ht->eq(b->key, key))
b = b->next;
return b;
}
HASHTYPE HASHPREFIX(Create)(int numBuckets,
hashFunctionType fn, hashEqualityType eq,
hashFreeKey freeKey
#ifdef HTDATATYPE
, hashFreeData freeData
#endif
)
{
HASHTYPE ht;
ht = xmalloc(sizeof(*ht));
ht->numBuckets = numBuckets > 11 ? numBuckets : 11;
ht->buckets = xcalloc(ht->numBuckets, sizeof(*ht->buckets));
ht->freeKey = freeKey;
#ifdef HTDATATYPE
ht->freeData = freeData;
ht->dataCount = 0;
#endif
ht->fn = fn;
ht->eq = eq;
ht->bucketCount = ht->keyCount = 0;
return ht;
}
static void HASHPREFIX(Resize)(HASHTYPE ht, int numBuckets) {
Bucket * buckets = xcalloc(numBuckets, sizeof(*ht->buckets));
for (int i=0; i<ht->numBuckets; i++) {
Bucket b = ht->buckets[i];
Bucket nextB;
while (b != NULL) {
unsigned int hash = ht->fn(b->key) % numBuckets;
nextB = b->next;
b->next = buckets[hash];
buckets[hash] = b;
b = nextB;
}
}
free(ht->buckets);
ht->buckets = buckets;
ht->numBuckets = numBuckets;
}
unsigned int HASHPREFIX(KeyHash)(HASHTYPE ht, HTKEYTYPE key)
{
return ht->fn(key);
}
void HASHPREFIX(AddHEntry)(HASHTYPE ht, HTKEYTYPE key, unsigned int keyHash
#ifdef HTDATATYPE
, HTDATATYPE data
#endif
)
{
unsigned int hash = keyHash % ht->numBuckets;
Bucket b = ht->buckets[hash];
#ifdef HTDATATYPE
Bucket * b_addr = ht->buckets + hash;
#endif
if (b == NULL) {
ht->bucketCount += 1;
}
while (b && ht->eq(b->key, key)) {
#ifdef HTDATATYPE
b_addr = &(b->next);
#endif
b = b->next;
}
if (b == NULL) {
ht->keyCount += 1;
b = xmalloc(sizeof(*b));
b->key = key;
#ifdef HTDATATYPE
b->dataCount = 1;
b->data[0] = data;
#endif
b->next = ht->buckets[hash];
ht->buckets[hash] = b;
}
#ifdef HTDATATYPE
else {
if (ht->freeKey)
ht->freeKey(key);
// resizing bucket TODO: increase exponentially
// Bucket_s already contains space for one dataset
b = *b_addr = xrealloc(
b, sizeof(*b) + sizeof(b->data[0]) * (b->dataCount));
// though increasing dataCount after the resize
b->data[b->dataCount++] = data;
}
ht->dataCount += 1;
#endif
if (ht->keyCount > ht->numBuckets) {
HASHPREFIX(Resize)(ht, ht->numBuckets * 2);
}
}
void HASHPREFIX(AddEntry)(HASHTYPE ht, HTKEYTYPE key
#ifdef HTDATATYPE
, HTDATATYPE data
#endif
)
{
#ifdef HTDATATYPE
HASHPREFIX(AddHEntry)(ht, key, ht->fn(key), data);
#else
HASHPREFIX(AddHEntry)(ht, key, ht->fn(key));
#endif
}
void HASHPREFIX(Empty)( HASHTYPE ht)
{
Bucket b, n;
int i;
if (ht->bucketCount == 0) return;
for (i = 0; i < ht->numBuckets; i++) {
b = ht->buckets[i];
if (b == NULL)
continue;
ht->buckets[i] = NULL;
do {
n = b->next;
if (ht->freeKey)
b->key = ht->freeKey(b->key);
#ifdef HTDATATYPE
if (ht->freeData) {
int j;
for (j=0; j < b->dataCount; j++ ) {
b->data[j] = ht->freeData(b->data[j]);
}
}
#endif
b = _free(b);
} while ((b = n) != NULL);
}
ht->bucketCount = 0;
ht->keyCount = 0;
#ifdef HTDATATYPE
ht->dataCount = 0;
#endif
}
HASHTYPE HASHPREFIX(Free)(HASHTYPE ht)
{
if (ht==NULL)
return ht;
HASHPREFIX(Empty)(ht);
ht->buckets = _free(ht->buckets);
ht = _free(ht);
return NULL;
}
int HASHPREFIX(HasHEntry)(HASHTYPE ht, HTKEYTYPE key, unsigned int keyHash)
{
Bucket b;
if (!(b = HASHPREFIX(findEntry)(ht, key, keyHash))) return 0; else return 1;
}
int HASHPREFIX(HasEntry)(HASHTYPE ht, HTKEYTYPE key)
{
return HASHPREFIX(HasHEntry)(ht, key, ht->fn(key));
}
int HASHPREFIX(GetHEntry)(HASHTYPE ht, HTKEYTYPE key, unsigned int keyHash,
#ifdef HTDATATYPE
HTDATATYPE** data, int * dataCount,
#endif
HTKEYTYPE* tableKey)
{
Bucket b;
int rc = ((b = HASHPREFIX(findEntry)(ht, key, keyHash)) != NULL);
#ifdef HTDATATYPE
if (data)
*data = rc ? b->data : NULL;
if (dataCount)
*dataCount = rc ? b->dataCount : 0;
#endif
if (tableKey && rc)
*tableKey = b->key;
return rc;
}
int HASHPREFIX(GetEntry)(HASHTYPE ht, HTKEYTYPE key,
#ifdef HTDATATYPE
HTDATATYPE** data, int * dataCount,
#endif
HTKEYTYPE* tableKey)
{
return HASHPREFIX(GetHEntry)(ht, key, ht->fn(key),
#ifdef HTDATATYPE
data, dataCount,
#endif
tableKey);
}
unsigned int HASHPREFIX(NumBuckets)(HASHTYPE ht) {
return ht->numBuckets;
}
unsigned int HASHPREFIX(UsedBuckets)(HASHTYPE ht) {
return ht->bucketCount;
}
unsigned int HASHPREFIX(NumKeys)(HASHTYPE ht) {
return ht->keyCount;
}
#ifdef HTDATATYPE
unsigned int HASHPREFIX(NumData)(HASHTYPE ht) {
return ht->dataCount;
}
#endif
void HASHPREFIX(PrintStats)(HASHTYPE ht) {
int i;
Bucket bucket;
int hashcnt=0, bucketcnt=0, datacnt=0;
int maxbuckets=0;
for (i=0; i<ht->numBuckets; i++) {
int buckets = 0;
for (bucket=ht->buckets[i]; bucket; bucket=bucket->next){
buckets++;
#ifdef HTDATATYPE
datacnt += bucket->dataCount;
#endif
}
if (maxbuckets < buckets) maxbuckets = buckets;
if (buckets) hashcnt++;
bucketcnt += buckets;
}
fprintf(stderr, "Hashsize: %i\n", ht->numBuckets);
fprintf(stderr, "Hashbuckets: %i\n", hashcnt);
fprintf(stderr, "Keys: %i\n", bucketcnt);
fprintf(stderr, "Values: %i\n", datacnt);
fprintf(stderr, "Max Keys/Bucket: %i\n", maxbuckets);
}