zlibmem.c

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/*====================================================================*
 -  Copyright (C) 2001 Leptonica.  All rights reserved.
 -
 -  Redistribution and use in source and binary forms, with or without
 -  modification, are permitted provided that the following conditions
 -  are met:
 -  1. Redistributions of source code must retain the above copyright
 -     notice, this list of conditions and the following disclaimer.
 -  2. Redistributions in binary form must reproduce the above
 -     copyright notice, this list of conditions and the following
 -     disclaimer in the documentation and/or other materials
 -     provided with the distribution.
 -
 -  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 -  ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 -  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 -  A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL ANY
 -  CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 -  EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 -  PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 -  PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 -  OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 -  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 -  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *====================================================================*/


#ifdef HAVE_CONFIG_H
#include "config_auto.h"
#endif  /* HAVE_CONFIG_H */

#include "allheaders.h"

/* --------------------------------------------*/
#if  HAVE_LIBZ   /* defined in environ.h */
/* --------------------------------------------*/

#include "zlib.h"

static const l_int32  L_BUF_SIZE = 32768;
static const l_int32  ZLIB_COMPRESSION_LEVEL = 6;

#ifndef  NO_CONSOLE_IO
#define  DEBUG     0
#endif  /* ~NO_CONSOLE_IO */


l_uint8 *
zlibCompress(l_uint8  *datain,
             size_t    nin,
             size_t   *pnout)
{
l_uint8    *dataout;
l_int32     status, success;
l_int32     flush;
size_t      nbytes;
l_uint8    *bufferin, *bufferout;
L_BBUFFER  *bbin, *bbout;
z_stream    z;

    PROCNAME("zlibCompress");

    if (!datain)
        return (l_uint8 *)ERROR_PTR("datain not defined", procName, NULL);

        /* Set up fixed size buffers used in z_stream */
    bufferin = (l_uint8 *)LEPT_CALLOC(L_BUF_SIZE, sizeof(l_uint8));
    bufferout = (l_uint8 *)LEPT_CALLOC(L_BUF_SIZE, sizeof(l_uint8));

        /* Set up bbuffers and load bbin with the data */
    bbin = bbufferCreate(datain, nin);
    bbout = bbufferCreate(NULL, 0);

    success = TRUE;
    if (!bufferin || !bufferout || !bbin || !bbout) {
        L_ERROR("calloc fail for buffer\n", procName);
        success = FALSE;
        goto cleanup_arrays;
    }

    z.zalloc = (alloc_func)0;
    z.zfree = (free_func)0;
    z.opaque = (voidpf)0;

    z.next_in = bufferin;
    z.avail_in = 0;
    z.next_out = bufferout;
    z.avail_out = L_BUF_SIZE;

    status = deflateInit(&z, ZLIB_COMPRESSION_LEVEL);
    if (status != Z_OK) {
        L_ERROR("deflateInit failed\n", procName);
        success = FALSE;
        goto cleanup_arrays;
    }

    do {
        if (z.avail_in == 0) {
            z.next_in = bufferin;
            bbufferWrite(bbin, bufferin, L_BUF_SIZE, &nbytes);
#if DEBUG
            fprintf(stderr, " wrote %lu bytes to bufferin\n",
                    (unsigned long)nbytes);
#endif  /* DEBUG */
            z.avail_in = nbytes;
        }
        flush = (bbin->n) ? Z_SYNC_FLUSH : Z_FINISH;
        status = deflate(&z, flush);
#if DEBUG
        fprintf(stderr, " status is %d, bytesleft = %u, totalout = %lu\n",
                  status, z.avail_out, z.total_out);
#endif  /* DEBUG */
        nbytes = L_BUF_SIZE - z.avail_out;
        if (nbytes) {
            bbufferRead(bbout, bufferout, nbytes);
#if DEBUG
            fprintf(stderr, " read %lu bytes from bufferout\n",
                    (unsigned long)nbytes);
#endif  /* DEBUG */
        }
        z.next_out = bufferout;
        z.avail_out = L_BUF_SIZE;
    } while (flush != Z_FINISH);

    deflateEnd(&z);

cleanup_arrays:
    if (success) {
        dataout = bbufferDestroyAndSaveData(&bbout, pnout);
    } else {
        dataout = NULL;
        bbufferDestroy(&bbout);
    }
    bbufferDestroy(&bbin);
    LEPT_FREE(bufferin);
    LEPT_FREE(bufferout);
    return dataout;
}


l_uint8 *
zlibUncompress(l_uint8  *datain,
               size_t    nin,
               size_t   *pnout)
{
l_uint8    *dataout;
l_uint8    *bufferin, *bufferout;
l_int32     status, success;
size_t      nbytes;
L_BBUFFER  *bbin, *bbout;
z_stream    z;

    PROCNAME("zlibUncompress");

    if (!datain)
        return (l_uint8 *)ERROR_PTR("datain not defined", procName, NULL);

        /* Set up fixed size buffers used in z_stream */
    bufferin = (l_uint8 *)LEPT_CALLOC(L_BUF_SIZE, sizeof(l_uint8));
    bufferout = (l_uint8 *)LEPT_CALLOC(L_BUF_SIZE, sizeof(l_uint8));

        /* Set up bbuffers and load bbin with the data */
    bbin = bbufferCreate(datain, nin);
    bbout = bbufferCreate(NULL, 0);

    success = TRUE;
    if (!bufferin || !bufferout || !bbin || !bbout) {
        L_ERROR("calloc fail for buffer\n", procName);
        success = FALSE;
        goto cleanup_arrays;
    }

    z.zalloc = (alloc_func)0;
    z.zfree = (free_func)0;

    z.next_in = bufferin;
    z.avail_in = 0;
    z.next_out = bufferout;
    z.avail_out = L_BUF_SIZE;

    inflateInit(&z);


    for ( ; ; ) {
        if (z.avail_in == 0) {
            z.next_in = bufferin;
            bbufferWrite(bbin, bufferin, L_BUF_SIZE, &nbytes);
#if DEBUG
            fprintf(stderr, " wrote %d bytes to bufferin\n", nbytes);
#endif  /* DEBUG */
            z.avail_in = nbytes;
        }
        if (z.avail_in == 0)
            break;
        status = inflate(&z, Z_SYNC_FLUSH);
#if DEBUG
        fprintf(stderr, " status is %d, bytesleft = %d, totalout = %d\n",
                status, z.avail_out, z.total_out);
#endif  /* DEBUG */
        nbytes = L_BUF_SIZE - z.avail_out;
        if (nbytes) {
            bbufferRead(bbout, bufferout, nbytes);
#if DEBUG
            fprintf(stderr, " read %d bytes from bufferout\n", nbytes);
#endif  /* DEBUG */
        }
        z.next_out = bufferout;
        z.avail_out = L_BUF_SIZE;
    }

    inflateEnd(&z);

cleanup_arrays:
    if (success) {
        dataout = bbufferDestroyAndSaveData(&bbout, pnout);
    } else {
        dataout = NULL;
        bbufferDestroy(&bbout);
    }
    bbufferDestroy(&bbin);
    LEPT_FREE(bufferin);
    LEPT_FREE(bufferout);
    return dataout;
}

/* --------------------------------------------*/
#endif  /* HAVE_LIBZ */
/* --------------------------------------------*/