BLI_ghash.c

Go to the documentation of this file.

/*
 * ***** BEGIN GPL LICENSE BLOCK *****
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * The Original Code is Copyright (C) 2001-2002 by NaN Holding BV.
 * All rights reserved.
 *
 * The Original Code is: all of this file.
 *
 * Contributor(s): none yet.
 *
 * ***** END GPL LICENSE BLOCK *****
 * A general (pointer -> pointer) hash table ADT
 */

#include <string.h>
#include <stdlib.h>


#include "MEM_guardedalloc.h"



// #include "BLI_blenlib.h"

#include "BLI_mempool.h"
#include "BLI_utildefines.h"
#include "BLI_ghash.h"

#include "BLO_sys_types.h" // for intptr_t support
/***/

static unsigned int hashsizes[]= {
    5, 11, 17, 37, 67, 131, 257, 521, 1031, 2053, 4099, 8209, 
    16411, 32771, 65537, 131101, 262147, 524309, 1048583, 2097169, 
    4194319, 8388617, 16777259, 33554467, 67108879, 134217757, 
    268435459
};

/***/

GHash *BLI_ghash_new(GHashHashFP hashfp, GHashCmpFP cmpfp, const char *info)
{
    GHash *gh= MEM_mallocN(sizeof(*gh), info);
    gh->hashfp= hashfp;
    gh->cmpfp= cmpfp;
    gh->entrypool = BLI_mempool_create(sizeof(Entry), 64, 64, FALSE, FALSE);

    gh->cursize= 0;
    gh->nentries= 0;
    gh->nbuckets= hashsizes[gh->cursize];
    
    gh->buckets= MEM_mallocN(gh->nbuckets*sizeof(*gh->buckets), "buckets");
    memset(gh->buckets, 0, gh->nbuckets*sizeof(*gh->buckets));
    
    return gh;
}

int BLI_ghash_size(GHash *gh)
{
    return gh->nentries;
}

void BLI_ghash_insert(GHash *gh, void *key, void *val)
{
    unsigned int hash= gh->hashfp(key)%gh->nbuckets;
    Entry *e= (Entry*) BLI_mempool_alloc(gh->entrypool);

    e->key= key;
    e->val= val;
    e->next= gh->buckets[hash];
    gh->buckets[hash]= e;

    if (++gh->nentries>(float)gh->nbuckets/2) {
        Entry **old= gh->buckets;
        int i, nold= gh->nbuckets;

        gh->nbuckets= hashsizes[++gh->cursize];
        gh->buckets= (Entry**)MEM_mallocN(gh->nbuckets*sizeof(*gh->buckets), "buckets");
        memset(gh->buckets, 0, gh->nbuckets*sizeof(*gh->buckets));

        for (i=0; i<nold; i++) {
            for (e= old[i]; e;) {
                Entry *n= e->next;

                hash= gh->hashfp(e->key)%gh->nbuckets;
                e->next= gh->buckets[hash];
                gh->buckets[hash]= e;

                e= n;
            }
        }

        MEM_freeN(old);
    }
}

void *BLI_ghash_lookup(GHash *gh, const void *key)
{
    if(gh) {
        unsigned int hash= gh->hashfp(key)%gh->nbuckets;
        Entry *e;

        for (e= gh->buckets[hash]; e; e= e->next)
            if (gh->cmpfp(key, e->key)==0)
                return e->val;
    }
    return NULL;
}

int BLI_ghash_remove (GHash *gh, void *key, GHashKeyFreeFP keyfreefp, GHashValFreeFP valfreefp)
{
    unsigned int hash= gh->hashfp(key)%gh->nbuckets;
    Entry *e;
    Entry *p = NULL;

    for (e= gh->buckets[hash]; e; e= e->next) {
        if (gh->cmpfp(key, e->key)==0) {
            Entry *n= e->next;

            if (keyfreefp) keyfreefp(e->key);
            if (valfreefp) valfreefp(e->val);
            BLI_mempool_free(gh->entrypool, e);

            /* correct but 'e' isnt used before return */
            /* e= n; */ /*UNUSED*/
            if (p)
                p->next = n;
            else
                gh->buckets[hash] = n;

            --gh->nentries;
            return 1;
        }
        p = e;
    }

    return 0;
}

int BLI_ghash_haskey(GHash *gh, void *key)
{
    unsigned int hash= gh->hashfp(key)%gh->nbuckets;
    Entry *e;

    for (e= gh->buckets[hash]; e; e= e->next)
        if (gh->cmpfp(key, e->key)==0)
            return 1;

    return 0;
}

void BLI_ghash_free(GHash *gh, GHashKeyFreeFP keyfreefp, GHashValFreeFP valfreefp)
{
    int i;
    
    if (keyfreefp || valfreefp) {
        for (i=0; i<gh->nbuckets; i++) {
            Entry *e;
            
            for (e= gh->buckets[i]; e; ) {
                Entry *n= e->next;
                
                if (keyfreefp) keyfreefp(e->key);
                if (valfreefp) valfreefp(e->val);

                e= n;
            }
        }
    }
    
    MEM_freeN(gh->buckets);
    BLI_mempool_destroy(gh->entrypool);
    gh->buckets = NULL;
    gh->nentries = 0;
    gh->nbuckets = 0;
    MEM_freeN(gh);
}

/***/

GHashIterator *BLI_ghashIterator_new(GHash *gh)
{
    GHashIterator *ghi= MEM_mallocN(sizeof(*ghi), "ghash iterator");
    ghi->gh= gh;
    ghi->curEntry= NULL;
    ghi->curBucket= -1;
    while (!ghi->curEntry) {
        ghi->curBucket++;
        if (ghi->curBucket==ghi->gh->nbuckets)
            break;
        ghi->curEntry= ghi->gh->buckets[ghi->curBucket];
    }
    return ghi;
}
void BLI_ghashIterator_init(GHashIterator *ghi, GHash *gh)
{
    ghi->gh= gh;
    ghi->curEntry= NULL;
    ghi->curBucket= -1;
    while (!ghi->curEntry) {
        ghi->curBucket++;
        if (ghi->curBucket==ghi->gh->nbuckets)
            break;
        ghi->curEntry= ghi->gh->buckets[ghi->curBucket];
    }
}
void BLI_ghashIterator_free(GHashIterator *ghi)
{
    MEM_freeN(ghi);
}

void *BLI_ghashIterator_getKey(GHashIterator *ghi)
{
    return ghi->curEntry?ghi->curEntry->key:NULL;
}
void *BLI_ghashIterator_getValue(GHashIterator *ghi)
{
    return ghi->curEntry?ghi->curEntry->val:NULL;
}

void BLI_ghashIterator_step(GHashIterator *ghi)
{
    if (ghi->curEntry) {
        ghi->curEntry= ghi->curEntry->next;
        while (!ghi->curEntry) {
            ghi->curBucket++;
            if (ghi->curBucket==ghi->gh->nbuckets)
                break;
            ghi->curEntry= ghi->gh->buckets[ghi->curBucket];
        }
    }
}
int BLI_ghashIterator_isDone(GHashIterator *ghi)
{
    return !ghi->curEntry;
}

/***/

unsigned int BLI_ghashutil_ptrhash(const void *key)
{
    return (unsigned int)(intptr_t)key;
}
int BLI_ghashutil_ptrcmp(const void *a, const void *b)
{
    if (a==b)
        return 0;
    else
        return (a<b)?-1:1;
}

unsigned int BLI_ghashutil_inthash(const void *ptr)
{
    uintptr_t key = (uintptr_t)ptr;

    key += ~(key << 16);
    key ^=  (key >>  5);
    key +=  (key <<  3);
    key ^=  (key >> 13);
    key += ~(key <<  9);
    key ^=  (key >> 17);

    return (unsigned int)(key & 0xffffffff);
}

int BLI_ghashutil_intcmp(const void *a, const void *b)
{
    if (a==b)
        return 0;
    else
        return (a<b)?-1:1;
}

unsigned int BLI_ghashutil_strhash(const void *ptr)
{
    const char *s= ptr;
    unsigned int i= 0;
    unsigned char c;
    
    while ( (c= *s++) )
        i= i*37 + c;
        
    return i;
}
int BLI_ghashutil_strcmp(const void *a, const void *b)
{
    return strcmp(a, b);
}

GHashPair *BLI_ghashutil_pairalloc(const void *first, int second)
{
    GHashPair *pair = MEM_mallocN(sizeof(GHashPair), "GHashPair");
    pair->first = first;
    pair->second = second;
    return pair;
}

unsigned int BLI_ghashutil_pairhash(const void *ptr)
{
    const GHashPair *pair = ptr;
    unsigned int hash = BLI_ghashutil_ptrhash(pair->first);
    return hash ^ BLI_ghashutil_inthash(SET_INT_IN_POINTER(pair->second));
}

int BLI_ghashutil_paircmp(const void *a, const void *b)
{
    const GHashPair *A = a;
    const GHashPair *B = b;

    int cmp = BLI_ghashutil_ptrcmp(A->first, B->first);
    if(cmp == 0)
        return BLI_ghashutil_intcmp(SET_INT_IN_POINTER(A->second), SET_INT_IN_POINTER(B->second));
    return cmp;
}

void BLI_ghashutil_pairfree(void *ptr)
{
    MEM_freeN((void*)ptr);
}