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			439 lines
		
	
	
		
			10 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			439 lines
		
	
	
		
			10 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * The Python Imaging Library
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|  * $Id$
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|  *
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|  * hash tables used by the image quantizer
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|  *
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|  * history:
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|  * 98-09-10 tjs  Contributed
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|  * 98-12-29 fl   Added to PIL 1.0b1
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|  *
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|  * Written by Toby J Sargeant <tjs@longford.cs.monash.edu.au>.
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|  *
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|  * Copyright (c) 1998 by Toby J Sargeant
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|  * Copyright (c) 1998 by Secret Labs AB
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|  *
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|  * See the README file for information on usage and redistribution.
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|  */
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| 
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| #include <stdio.h>
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| #include <stdlib.h>
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| #include <string.h>
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| #include <math.h>
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| 
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| #include "QuantHash.h"
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| 
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| typedef struct _HashNode {
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|    struct _HashNode *next;
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|    HashKey_t key;
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|    HashVal_t value;
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| } HashNode;
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| 
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| struct _HashTable {
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|    HashNode **table;
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|    uint32_t length;
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|    uint32_t count;
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|    HashFunc hashFunc;
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|    HashCmpFunc cmpFunc;
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|    KeyDestroyFunc keyDestroyFunc;
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|    ValDestroyFunc valDestroyFunc;
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|    void *userData;
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| };
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| 
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| #define MIN_LENGTH 11
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| #define RESIZE_FACTOR 3
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| 
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| static int _hashtable_insert_node(HashTable *,HashNode *,int,int,CollisionFunc);
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| 
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| HashTable *hashtable_new(HashFunc hf,HashCmpFunc cf) {
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|    HashTable *h;
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|    h=malloc(sizeof(HashTable));
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|    if (!h) { return NULL; }
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|    h->hashFunc=hf;
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|    h->cmpFunc=cf;
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|    h->keyDestroyFunc=NULL;
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|    h->valDestroyFunc=NULL;
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|    h->length=MIN_LENGTH;
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|    h->count=0;
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|    h->userData=NULL;
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|    h->table=malloc(sizeof(HashNode *)*h->length);
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|    if (!h->table) { free(h); return NULL; }
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|    memset (h->table,0,sizeof(HashNode *)*h->length);
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|    return h;
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| }
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| 
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| static void _hashtable_destroy(const HashTable *h,const HashKey_t key,const HashVal_t val,void *u) {
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|    if (h->keyDestroyFunc) {
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|       h->keyDestroyFunc(h,key);
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|    }
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|    if (h->valDestroyFunc) {
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|       h->valDestroyFunc(h,val);
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|    }
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| }
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| 
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| static uint32_t _findPrime(uint32_t start,int dir) {
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|    static int unit[]={0,1,0,1,0,0,0,1,0,1,0,1,0,1,0,0};
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|    uint32_t t;
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|    while (start>1) {
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|       if (!unit[start&0x0f]) {
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|          start+=dir;
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|          continue;
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|       }
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|       for (t=2;t<sqrt((double)start);t++) {
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|          if (!start%t) break;
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|       }
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|       if (t>=sqrt((double)start)) {
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|          break;
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|       }
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|       start+=dir;
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|    }
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|    return start;
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| }
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| 
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| static void _hashtable_rehash(HashTable *h,CollisionFunc cf,uint32_t newSize) {
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|    HashNode **oldTable=h->table;
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|    uint32_t i;
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|    HashNode *n,*nn;
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|    uint32_t oldSize;
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|    oldSize=h->length;
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|    h->table=malloc(sizeof(HashNode *)*newSize);
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|    if (!h->table) {
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|       h->table=oldTable;
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|       return;
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|    }
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|    h->length=newSize;
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|    h->count=0;
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|    memset (h->table,0,sizeof(HashNode *)*h->length);
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|    for (i=0;i<oldSize;i++) {
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|       for (n=oldTable[i];n;n=nn) {
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|          nn=n->next;
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|          _hashtable_insert_node(h,n,0,0,cf);
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|       }
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|    }
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|    free(oldTable);
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| }
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| 
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| static void _hashtable_resize(HashTable *h) {
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|    uint32_t newSize;
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|    uint32_t oldSize;
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|    oldSize=h->length;
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|    newSize=oldSize;
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|    if (h->count*RESIZE_FACTOR<h->length) {
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|       newSize=_findPrime(h->length/2-1,-1);
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|    } else  if (h->length*RESIZE_FACTOR<h->count) {
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|       newSize=_findPrime(h->length*2+1,+1);
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|    }
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|    if (newSize<MIN_LENGTH) { newSize=oldSize; }
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|    if (newSize!=oldSize) {
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|       _hashtable_rehash(h,NULL,newSize);
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|    }
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| }
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| 
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| static int _hashtable_insert_node(HashTable *h,HashNode *node,int resize,int update,CollisionFunc cf) {
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|    uint32_t hash=h->hashFunc(h,node->key)%h->length;
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|    HashNode **n,*nv;
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|    int i;
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| 
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|    for (n=&(h->table[hash]);*n;n=&((*n)->next)) {
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|       nv=*n;
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|       i=h->cmpFunc(h,nv->key,node->key);
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|       if (!i) {
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|          if (cf) {
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|             nv->key=node->key;
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|             cf(h,&(nv->key),&(nv->value),node->key,node->value);
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|             free(node);
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|             return 1;
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|          } else {
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|             if (h->valDestroyFunc) {
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|                h->valDestroyFunc(h,nv->value);
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|             }
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|             if (h->keyDestroyFunc) {
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|                h->keyDestroyFunc(h,nv->key);
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|             }
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|             nv->key=node->key;
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|             nv->value=node->value;
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|             free(node);
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|             return 1;
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|          }
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|       } else if (i>0) {
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|          break;
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|       }
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|    }
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|    if (!update) {
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|       node->next=*n;
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|       *n=node;
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|       h->count++;
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|       if (resize) _hashtable_resize(h);
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|       return 1;
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|    } else {
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|       return 0;
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|    }
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| }
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| 
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| static int _hashtable_insert(HashTable *h,HashKey_t key,HashVal_t val,int resize,int update) {
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|    HashNode **n,*nv;
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|    HashNode *t;
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|    int i;
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|    uint32_t hash=h->hashFunc(h,key)%h->length;
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| 
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|    for (n=&(h->table[hash]);*n;n=&((*n)->next)) {
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|       nv=*n;
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|       i=h->cmpFunc(h,nv->key,key);
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|       if (!i) {
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|          if (h->valDestroyFunc) { h->valDestroyFunc(h,nv->value); }
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|          nv->value=val;
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|          return 1;
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|       } else if (i>0) {
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|          break;
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|       }
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|    }
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|    if (!update) {
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|       t=malloc(sizeof(HashNode));
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|       if (!t) return 0;
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|       t->next=*n;
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|       *n=t;
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|       t->key=key;
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|       t->value=val;
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|       h->count++;
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|       if (resize) _hashtable_resize(h);
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|       return 1;
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|    } else {
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|       return 0;
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|    }
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| }
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| 
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| static int _hashtable_lookup_or_insert(HashTable *h,HashKey_t key,HashVal_t *retVal,HashVal_t newVal,int resize) {
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|    HashNode **n,*nv;
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|    HashNode *t;
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|    int i;
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|    uint32_t hash=h->hashFunc(h,key)%h->length;
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| 
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|    for (n=&(h->table[hash]);*n;n=&((*n)->next)) {
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|       nv=*n;
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|       i=h->cmpFunc(h,nv->key,key);
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|       if (!i) {
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|          *retVal=nv->value;
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|          return 1;
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|       } else if (i>0) {
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|          break;
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|       }
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|    }
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|    t=malloc(sizeof(HashNode));
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|    if (!t) return 0;
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|    t->next=*n;
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|    *n=t;
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|    t->key=key;
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|    t->value=newVal;
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|    *retVal=newVal;
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|    h->count++;
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|    if (resize) _hashtable_resize(h);
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|    return 1;
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| }
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| 
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| int hashtable_insert_or_update_computed(HashTable *h,
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|                                         HashKey_t key,
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|                                         ComputeFunc newFunc,
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|                                         ComputeFunc existsFunc) {
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|    HashNode **n,*nv;
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|    HashNode *t;
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|    int i;
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|    uint32_t hash=h->hashFunc(h,key)%h->length;
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| 
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|    for (n=&(h->table[hash]);*n;n=&((*n)->next)) {
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|       nv=*n;
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|       i=h->cmpFunc(h,nv->key,key);
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|       if (!i) {
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|          HashVal_t old=nv->value;
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|          if (existsFunc) {
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|             existsFunc(h,nv->key,&(nv->value));
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|             if (nv->value!=old) {
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|                if (h->valDestroyFunc) {
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|                   h->valDestroyFunc(h,old);
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|                }
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|             }
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|          } else {
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|             return 0;
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|          }
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|          return 1;
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|       } else if (i>0) {
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|          break;
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|       }
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|    }
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|    t=malloc(sizeof(HashNode));
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|    if (!t) return 0;
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|    t->key=key;
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|    t->next=*n;
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|    *n=t;
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|    if (newFunc) {
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|       newFunc(h,t->key,&(t->value));
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|    } else {
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|       free(t);
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|       return 0;
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|    }
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|    h->count++;
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|    _hashtable_resize(h);
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|    return 1;
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| }
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| 
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| int hashtable_update(HashTable *h,HashKey_t key,HashVal_t val) {
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|    return _hashtable_insert(h,key,val,1,0);
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| }
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| 
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| int hashtable_insert(HashTable *h,HashKey_t key,HashVal_t val) {
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|    return _hashtable_insert(h,key,val,1,0);
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| }
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| 
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| void hashtable_foreach_update(HashTable *h,IteratorUpdateFunc i,void *u) {
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|    HashNode *n;
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|    uint32_t x;
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| 
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|    if (h->table) {
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|       for (x=0;x<h->length;x++) {
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|          for (n=h->table[x];n;n=n->next) {
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|             i(h,n->key,&(n->value),u);
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|          }
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|       }
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|    }
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| }
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| 
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| void hashtable_foreach(HashTable *h,IteratorFunc i,void *u) {
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|    HashNode *n;
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|    uint32_t x;
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| 
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|    if (h->table) {
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|       for (x=0;x<h->length;x++) {
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|          for (n=h->table[x];n;n=n->next) {
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|             i(h,n->key,n->value,u);
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|          }
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|       }
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|    }
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| }
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| 
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| void hashtable_free(HashTable *h) {
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|    HashNode *n,*nn;
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|    uint32_t i;
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| 
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|    if (h->table) {
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|       if (h->keyDestroyFunc || h->keyDestroyFunc) {
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|          hashtable_foreach(h,_hashtable_destroy,NULL);
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|       }
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|       for (i=0;i<h->length;i++) {
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|          for (n=h->table[i];n;n=nn) {
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|             nn=n->next;
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|             free(n);
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|          }
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|       }
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|       free(h->table);
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|    }
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|    free(h);
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| }
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| 
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| ValDestroyFunc hashtable_set_value_destroy_func(HashTable *h,ValDestroyFunc d) {
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|    ValDestroyFunc r=h->valDestroyFunc;
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|    h->valDestroyFunc=d;
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|    return r;
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| }
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| 
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| KeyDestroyFunc hashtable_set_key_destroy_func(HashTable *h,KeyDestroyFunc d) {
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|    KeyDestroyFunc r=h->keyDestroyFunc;
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|    h->keyDestroyFunc=d;
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|    return r;
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| }
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| 
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| static int _hashtable_remove(HashTable *h,
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|                              const HashKey_t key,
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|                              HashKey_t *keyRet,
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|                              HashVal_t *valRet,
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|                              int resize) {
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|    uint32_t hash=h->hashFunc(h,key)%h->length;
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|    HashNode *n,*p;
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|    int i;
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| 
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|    for (p=NULL,n=h->table[hash];n;p=n,n=n->next) {
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|       i=h->cmpFunc(h,n->key,key);
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|       if (!i) {
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|          if (p) p=n->next; else h->table[hash]=n->next;
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|          *keyRet=n->key;
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|          *valRet=n->value;
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|          free(n);
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|          h->count++;
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|          return 1;
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|       } else if (i>0) {
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|          break;
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|       }
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|    }
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|    return 0;
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| }
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| 
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| static int _hashtable_delete(HashTable *h,const HashKey_t key,int resize) {
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|    uint32_t hash=h->hashFunc(h,key)%h->length;
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|    HashNode *n,*p;
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|    int i;
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| 
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|    for (p=NULL,n=h->table[hash];n;p=n,n=n->next) {
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|       i=h->cmpFunc(h,n->key,key);
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|       if (!i) {
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|          if (p) p=n->next; else h->table[hash]=n->next;
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|          if (h->valDestroyFunc) { h->valDestroyFunc(h,n->value); }
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|          if (h->keyDestroyFunc) { h->keyDestroyFunc(h,n->key); }
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|          free(n);
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|          h->count++;
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|          return 1;
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|       } else if (i>0) {
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|          break;
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|       }
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|    }
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|    return 0;
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| }
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| 
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| int hashtable_remove(HashTable *h,const HashKey_t key,HashKey_t *keyRet,HashVal_t *valRet) {
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|    return _hashtable_remove(h,key,keyRet,valRet,1);
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| }
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| 
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| int hashtable_delete(HashTable *h,const HashKey_t key) {
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|    return _hashtable_delete(h,key,1);
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| }
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| 
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| void hashtable_rehash_compute(HashTable *h,CollisionFunc cf) {
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|    _hashtable_rehash(h,cf,h->length);
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| }
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| 
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| void hashtable_rehash(HashTable *h) {
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|    _hashtable_rehash(h,NULL,h->length);
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| }
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| 
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| int hashtable_lookup_or_insert(HashTable *h,HashKey_t key,HashVal_t *valp,HashVal_t val) {
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|    return _hashtable_lookup_or_insert(h,key,valp,val,1);
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| }
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| 
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| int hashtable_lookup(const HashTable *h,const HashKey_t key,HashVal_t *valp) {
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|    uint32_t hash=h->hashFunc(h,key)%h->length;
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|    HashNode *n;
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|    int i;
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| 
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|    for (n=h->table[hash];n;n=n->next) {
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|       i=h->cmpFunc(h,n->key,key);
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|       if (!i) {
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|          *valp=n->value;
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|          return 1;
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|       } else if (i>0) {
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|          break;
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|       }
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|    }
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|    return 0;
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| }
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| 
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| uint32_t hashtable_get_count(const HashTable *h) {
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|    return h->count;
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| }
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| 
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| void *hashtable_get_user_data(const HashTable *h) {
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|    return h->userData;
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| }
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| 
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| void *hashtable_set_user_data(HashTable *h,void *data) {
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|    void *r=h->userData;
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|    h->userData=data;
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|    return r;
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| }
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