Fixed bug in hash.c
A bug in the delete function in hash.c was preventing the unit test of the new set ID API functions from running properly. In fixing this bug the entire hash table code was refactored to make it look more like the mempool service routines. Also the need to copy the string passed into the table's insert function was eliminated.
This commit is contained in:
Lew Rossman
269
src/hash.c
269
src/hash.c
@@ -1,21 +1,20 @@
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/*-----------------------------------------------------------------------------
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** hash.c
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**
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** Implementation of a simple Hash Table for string storage & retrieval
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** Implementation of a simple Hash Table that uses a string pointer
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** as a key and an associated integer as data.
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**
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** Written by L. Rossman
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** Last Updated on 6/19/03
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** Last Updated on 10/17/18
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**
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** The hash table data structure (HTable) is defined in "hash.h".
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** Interface Functions:
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** HTcreate() - creates a hash table
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** HTinsert() - inserts a string & its index value into a hash table
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** HTfind() - retrieves the index value of a string from a table
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** HTfree() - frees a hash table
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** hashtable_create - creates a hash table
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** hashtable_insert - inserts a string & its data value into a table
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** hashtable_find - retrieves the data value associated with a string
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** hashtable_findkey - retrieves the key associated with a data value
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** hashtable_delete - deletes an entry from a table
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** hashtable_free - frees a hash table
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**
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*********************************************************************
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** NOTE: This is a modified version of the original HASH.C module.
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*********************************************************************
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*/
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#ifndef __APPLE__
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@@ -26,144 +25,148 @@
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#include <string.h>
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#include "hash.h"
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unsigned int _enHash(char *str);
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unsigned int _enHash(char *str)
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{
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unsigned int hash = 5381;
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unsigned int retHash;
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int c;
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while ((c = *str++)) {
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hash = ((hash << 5) + hash) + c; /* hash * 33 + c */
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}
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retHash = hash % ENHASHTABLEMAXSIZE;
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return retHash;
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}
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#define HASHTABLEMAXSIZE 128000
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ENHashTable *ENHashTableCreate()
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typedef struct DataEntryStruct
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{
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int i;
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ENHashTable *ht = (ENHashTable *) calloc(ENHASHTABLEMAXSIZE, sizeof(ENHashTable));
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if (ht != NULL) {
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for (i=0; i<ENHASHTABLEMAXSIZE; i++) {
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ht[i] = NULL;
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char *key;
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int data;
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struct DataEntryStruct *next;
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} DataEntry;
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unsigned int gethash(char *str)
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{
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unsigned int hash = 5381;
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unsigned int retHash;
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int c;
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while ((c = *str++))
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{
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hash = ((hash << 5) + hash) + c; /* hash * 33 + c */
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}
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}
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return(ht);
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retHash = hash % HASHTABLEMAXSIZE;
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return retHash;
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}
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int ENHashTableInsert(ENHashTable *ht, char *key, int data)
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HashTable *hashtable_create()
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{
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size_t len;
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unsigned int i = _enHash(key);
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ENHashEntry *entry;
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if ( i >= ENHASHTABLEMAXSIZE ) {
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return(0);
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}
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entry = (ENHashEntry *) malloc(sizeof(ENHashEntry));
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if (entry == NULL) {
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return(0);
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}
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len = strlen(key) + 1;
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entry->key = calloc(len, sizeof(char));
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strncpy(entry->key, key, len);
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entry->data = data;
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entry->next = ht[i];
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ht[i] = entry;
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return(1);
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}
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/* Abel Heinsbroek: Added function to update the hash table value for a given key */
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int ENHashTableUpdate(ENHashTable *ht, char *key, int new_data)
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{
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unsigned int i = _enHash(key);
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ENHashEntry *entry;
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if ( i >= ENHASHTABLEMAXSIZE ) {
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return(NOTFOUND);
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}
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entry = ht[i];
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while (entry != NULL)
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{
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if ( strcmp(entry->key,key) == 0 ) {
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entry->data = new_data;
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return(1);
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int i;
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HashTable *ht = (HashTable *) calloc(HASHTABLEMAXSIZE, sizeof(HashTable));
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if (ht != NULL)
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{
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for (i = 0; i < HASHTABLEMAXSIZE; i++) ht[i] = NULL;
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}
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entry = entry->next;
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}
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return(NOTFOUND);
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return ht;
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}
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int ENHashTableDelete(ENHashTable *ht, char *key) {
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unsigned int i = _enHash(key);
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ENHashEntry *entry;
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if ( i >= ENHASHTABLEMAXSIZE ) {
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return(NOTFOUND);
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}
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entry = ht[i];
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while (entry != NULL)
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{
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if (strcmp(entry->key, key) == 0) {
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entry->key = "";
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return(1);
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}
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entry = entry->next;
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}
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return(NOTFOUND);
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}
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int ENHashTableFind(ENHashTable *ht, char *key)
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int hashtable_insert(HashTable *ht, char *key, int data)
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{
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unsigned int i = _enHash(key);
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ENHashEntry *entry;
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if ( i >= ENHASHTABLEMAXSIZE ) {
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return(NOTFOUND);
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}
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entry = ht[i];
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while (entry != NULL)
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{
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if ( strcmp(entry->key,key) == 0 ) {
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return(entry->data);
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}
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entry = entry->next;
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}
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return(NOTFOUND);
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unsigned int i = gethash(key);
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DataEntry *entry;
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if ( i >= HASHTABLEMAXSIZE ) return 0;
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entry = (DataEntry *) malloc(sizeof(DataEntry));
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if (entry == NULL) return(0);
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entry->key = key;
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entry->data = data;
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entry->next = ht[i];
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ht[i] = entry;
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return 1;
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}
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char *ENHashTableFindKey(ENHashTable *ht, char *key)
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int hashtable_update(HashTable *ht, char *key, int new_data)
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{
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unsigned int i = _enHash(key);
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ENHashEntry *entry;
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if ( i >= ENHASHTABLEMAXSIZE ) {
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return(NULL);
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}
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entry = ht[i];
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while (entry != NULL)
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{
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if ( strcmp(entry->key,key) == 0 ) {
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return(entry->key);
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}
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entry = entry->next;
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}
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return(NULL);
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}
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void ENHashTableFree(ENHashTable *ht)
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{
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ENHashEntry *entry, *nextentry;
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int i;
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for (i=0; i<ENHASHTABLEMAXSIZE; i++)
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{
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unsigned int i = gethash(key);
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DataEntry *entry;
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if ( i >= HASHTABLEMAXSIZE ) return NOTFOUND;
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entry = ht[i];
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while (entry != NULL)
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{
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nextentry = entry->next;
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free(entry->key);
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free(entry);
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entry = nextentry;
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if ( strcmp(entry->key, key) == 0 )
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{
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entry->data = new_data;
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return 1;
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}
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entry = entry->next;
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}
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}
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free(ht);
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return NOTFOUND;
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}
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int hashtable_delete(HashTable *ht, char *key)
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{
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unsigned int i = gethash(key);
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DataEntry *entry, *preventry;
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if ( i >= HASHTABLEMAXSIZE ) return NOTFOUND;
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// Check if first entry in bucket i to be deleted
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entry = ht[i];
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if (strcmp(entry->key, key) == 0)
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{
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ht[i] = entry->next;
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free(entry);
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return 1;
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}
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// Check remaining entries in bucket i
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preventry = ht[i];
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entry = ht[i]->next;
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while (entry != NULL)
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{
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if (strcmp(entry->key, key) == 0)
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{
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preventry->next = entry->next;
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free(entry);
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return 1;
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}
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preventry = entry;
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entry = entry->next;
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}
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return NOTFOUND;
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}
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int hashtable_find(HashTable *ht, char *key)
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{
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unsigned int i = gethash(key);
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DataEntry *entry;
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if ( i >= HASHTABLEMAXSIZE ) return NOTFOUND;
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entry = ht[i];
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while (entry != NULL)
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{
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if ( strcmp(entry->key, key) == 0 )
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{
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return entry->data;
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}
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entry = entry->next;
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}
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return NOTFOUND;
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}
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char *hashtable_findkey(HashTable *ht, char *key)
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{
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unsigned int i = gethash(key);
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DataEntry *entry;
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if ( i >= HASHTABLEMAXSIZE ) return NULL;
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entry = ht[i];
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while (entry != NULL)
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{
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if ( strcmp(entry->key, key) == 0 ) return entry->key;
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entry = entry->next;
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}
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return NULL;
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}
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void hashtable_free(HashTable *ht)
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{
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DataEntry *entry, *nextentry;
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int i;
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for (i = 0; i < HASHTABLEMAXSIZE; i++)
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{
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entry = ht[i];
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while (entry != NULL)
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{
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nextentry = entry->next;
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free(entry);
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entry = nextentry;
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}
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}
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free(ht);
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}
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