cdb_make.c

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/*
   +----------------------------------------------------------------------+
   | Copyright (c) The PHP Group                                          |
   +----------------------------------------------------------------------+
   | This source file is subject to version 3.01 of the PHP license,      |
   | that is bundled with this package in the file LICENSE, and is        |
   | available through the world-wide-web at the following url:           |
   | https://www.php.net/license/3_01.txt                                 |
   | If you did not receive a copy of the PHP license and are unable to   |
   | obtain it through the world-wide-web, please send a note to          |
   | license@php.net so we can mail you a copy immediately.               |
   +----------------------------------------------------------------------+
   | Author: Marcus Boerger <helly@php.net>                               |
   +----------------------------------------------------------------------+
 */
 
/* $Id: 570e3625b0cea5c29455cecf40fdfd491c0eb3c6 $ */
 
/* incorporated from D.J.Bernstein's cdb-0.75 (http://cr.yp.to/cdb.html)*/
 
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
 
#include "php.h"
 
#include <sys/types.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include "cdb.h"
#include "cdb_make.h"
#include "uint32.h"
 
/* {{{ cdb_make_write */
static int cdb_make_write(struct cdb_make *c, char *buf, uint32 sz) {
    return php_stream_write(c->fp, buf, sz) == sz ? 0 : -1;
}
 
/* {{{ cdb_posplus */
static int cdb_posplus(struct cdb_make *c, uint32 len)
{
    uint32 newpos = c->pos + len;
    if (newpos < len) {
        errno = ENOMEM;
        return -1;
    }
    c->pos = newpos;
    return 0;
}
/* }}} */
 
/* {{{ cdb_make_start */
int cdb_make_start(struct cdb_make *c, php_stream * f)
{
    c->head = 0;
    c->split = 0;
    c->hash = 0;
    c->numentries = 0;
    c->fp = f;
    c->pos = sizeof(c->final);
    if (php_stream_seek(f, c->pos, SEEK_SET) == -1) {
        php_error_docref(NULL, E_NOTICE, "Fseek failed");
        return -1;
    }
    return php_stream_tell(c->fp);
}
/* }}} */
 
/* {{{ cdb_make_addend */
int cdb_make_addend(struct cdb_make *c, unsigned int keylen, unsigned int datalen, uint32 h)
{
    struct cdb_hplist *head;
 
    head = c->head;
    if (!head || (head->num >= CDB_HPLIST)) {
        head = (struct cdb_hplist *) emalloc(sizeof(struct cdb_hplist));
        if (!head)
            return -1;
        head->num = 0;
        head->next = c->head;
        c->head = head;
    }
    head->hp[head->num].h = h;
    head->hp[head->num].p = c->pos;
    ++head->num;
    ++c->numentries;
    if (cdb_posplus(c,8) == -1)
        return -1;
    if (cdb_posplus(c, keylen) == -1)
        return -1;
    if (cdb_posplus(c, datalen) == -1)
        return -1;
    return 0;
}
/* }}} */
 
/* {{{ cdb_make_addbegin */
int cdb_make_addbegin(struct cdb_make *c, unsigned int keylen, unsigned int datalen)
{
    char buf[8];
 
    if (keylen > 0xffffffff) {
        errno = ENOMEM;
        return -1;
    }
    if (datalen > 0xffffffff) {
        errno = ENOMEM;
        return -1;
    }
 
    uint32_pack(buf, keylen);
    uint32_pack(buf + 4, datalen);
    if (cdb_make_write(c, buf, 8) != 0)
        return -1;
    return 0;
}
 
/* {{{ cdb_make_add */
int cdb_make_add(struct cdb_make *c,char *key,unsigned int keylen,char *data,unsigned int datalen)
{
    if (cdb_make_addbegin(c, keylen, datalen) == -1)
        return -1;
    if (cdb_make_write(c, key, keylen) != 0)
        return -1;
    if (cdb_make_write(c, data, datalen) != 0)
        return -1;
    return cdb_make_addend(c, keylen, datalen, cdb_hash(key, keylen));
}
/* }}} */
 
/* {{{ cdb_make_finish */
int cdb_make_finish(struct cdb_make *c)
{
    char buf[8];
    int i;
    uint32 len;
    uint32 u;
    uint32 memsize;
    uint32 count;
    uint32 where;
    struct cdb_hplist *x;
    struct cdb_hp *hp;
 
    for (i = 0;i < 256;++i)
    c->count[i] = 0;
 
    for (x = c->head; x; x = x->next) {
        i = x->num;
        while (i--)
        ++c->count[255 & x->hp[i].h];
    }
 
    memsize = 1;
    for (i = 0;i < 256;++i) {
        u = c->count[i] * 2;
        if (u > memsize)
        memsize = u;
    }
 
    memsize += c->numentries; /* no overflow possible up to now */
    u = (uint32) 0 - (uint32) 1;
    u /= sizeof(struct cdb_hp);
    if (memsize > u) {
        errno = ENOMEM;
        return -1;
    }
 
    c->split = (struct cdb_hp *) safe_emalloc(memsize, sizeof(struct cdb_hp), 0);
    if (!c->split)
        return -1;
 
    c->hash = c->split + c->numentries;
 
    u = 0;
    for (i = 0;i < 256;++i) {
        u += c->count[i]; /* bounded by numentries, so no overflow */
        c->start[i] = u;
    }
 
    for (x = c->head; x; x = x->next) {
        i = x->num;
        while (i--)
        c->split[--c->start[255 & x->hp[i].h]] = x->hp[i];
    }
 
    for (i = 0;i < 256;++i) {
        count = c->count[i];
 
        len = count + count; /* no overflow possible */
        uint32_pack(c->final + 8 * i,c->pos);
        uint32_pack(c->final + 8 * i + 4,len);
 
        for (u = 0;u < len;++u)
            c->hash[u].h = c->hash[u].p = 0;
 
        hp = c->split + c->start[i];
        for (u = 0;u < count;++u) {
            where = (hp->h >> 8) % len;
            while (c->hash[where].p)
                if (++where == len)
                    where = 0;
            c->hash[where] = *hp++;
        }
 
        for (u = 0;u < len;++u) {
            uint32_pack(buf, c->hash[u].h);
            uint32_pack(buf + 4, c->hash[u].p);
            if (cdb_make_write(c, buf, 8) != 0)
                return -1;
            if (cdb_posplus(c, 8) == -1)
                return -1;
        }
    }
 
    if (c->split)
        efree(c->split);
 
    for (x = c->head; x; c->head = x) {
        x = x->next;
        efree(c->head);
    }
 
    if (php_stream_flush(c->fp) != 0)
        return -1;
    php_stream_rewind(c->fp);
    if (php_stream_tell(c->fp) != 0)
        return -1;
    if (cdb_make_write(c, c->final, sizeof(c->final)) != 0)
        return -1;
    return php_stream_flush(c->fp);
}
/* }}} */
 
/* {{{ cdb_make_version */
const char *cdb_make_version(void)
{
    return "0.75, $Id: 570e3625b0cea5c29455cecf40fdfd491c0eb3c6 $";
}