source/libs/cairo/cairo-src/src/cairo-deflate-stream.c

   1 /* -*- Mode: c; c-basic-offset: 4; indent-tabs-mode: t; tab-width: 8; -*- */
   2 /* cairo - a vector graphics library with display and print output
   3  *
   4  * Copyright © 2006 Adrian Johnson
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it either under the terms of the GNU Lesser General Public
   8  * License version 2.1 as published by the Free Software Foundation
   9  * (the "LGPL") or, at your option, under the terms of the Mozilla
  10  * Public License Version 1.1 (the "MPL"). If you do not alter this
  11  * notice, a recipient may use your version of this file under either
  12  * the MPL or the LGPL.
  13  *
  14  * You should have received a copy of the LGPL along with this library
  15  * in the file COPYING-LGPL-2.1; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Suite 500, Boston, MA 02110-1335, USA
  17  * You should have received a copy of the MPL along with this library
  18  * in the file COPYING-MPL-1.1
  19  *
  20  * The contents of this file are subject to the Mozilla Public License
  21  * Version 1.1 (the "License"); you may not use this file except in
  22  * compliance with the License. You may obtain a copy of the License at
  23  * http://www.mozilla.org/MPL/
  24  *
  25  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY
  26  * OF ANY KIND, either express or implied. See the LGPL or the MPL for
  27  * the specific language governing rights and limitations.
  28  *
  29  * The Original Code is the cairo graphics library.
  30  *
  31  * The Initial Developer of the Original Code is Adrian Johnson.
  32  *
  33  * Author(s):
  34  *      Adrian Johnson <ajohnson@redneon.com>
  35  */
  36
  37 #include "cairoint.h"
  38
  39 #if CAIRO_HAS_DEFLATE_STREAM
  40
  41 #include "cairo-error-private.h"
  42 #include "cairo-output-stream-private.h"
  43 #include <zlib.h>
  44
  45 #define BUFFER_SIZE 16384
  46
  47 typedef struct _cairo_deflate_stream {
  48     cairo_output_stream_t  base;
  49     cairo_output_stream_t *output;
  50     z_stream               zlib_stream;
  51     unsigned char          input_buf[BUFFER_SIZE];
  52     unsigned char          output_buf[BUFFER_SIZE];
  53 } cairo_deflate_stream_t;
  54
  55 static void
  56 cairo_deflate_stream_deflate (cairo_deflate_stream_t *stream, cairo_bool_t flush)
  57 {
  58     int ret;
  59     cairo_bool_t finished;
  60
  61     do {
  62         ret = deflate (&stream->zlib_stream, flush ? Z_FINISH : Z_NO_FLUSH);
  63         if (flush || stream->zlib_stream.avail_out == 0)
  64         {
  65             _cairo_output_stream_write (stream->output,
  66                                         stream->output_buf,
  67                                         BUFFER_SIZE - stream->zlib_stream.avail_out);
  68             stream->zlib_stream.next_out = stream->output_buf;
  69             stream->zlib_stream.avail_out = BUFFER_SIZE;
  70         }
  71
  72         finished = TRUE;
  73         if (stream->zlib_stream.avail_in != 0)
  74             finished = FALSE;
  75         if (flush && ret != Z_STREAM_END)
  76             finished = FALSE;
  77
  78     } while (!finished);
  79
  80     stream->zlib_stream.next_in = stream->input_buf;
  81 }
  82
  83 static cairo_status_t
  84 _cairo_deflate_stream_write (cairo_output_stream_t *base,
  85                              const unsigned char   *data,
  86                              unsigned int           length)
  87 {
  88     cairo_deflate_stream_t *stream = (cairo_deflate_stream_t *) base;
  89     unsigned int count;
  90     const unsigned char *p = data;
  91
  92     while (length) {
  93         count = length;
  94         if (count > BUFFER_SIZE - stream->zlib_stream.avail_in)
  95             count = BUFFER_SIZE - stream->zlib_stream.avail_in;
  96         memcpy (stream->input_buf + stream->zlib_stream.avail_in, p, count);
  97         p += count;
  98         stream->zlib_stream.avail_in += count;
  99         length -= count;
 100
 101         if (stream->zlib_stream.avail_in == BUFFER_SIZE)
 102             cairo_deflate_stream_deflate (stream, FALSE);
 103     }
 104
 105     return _cairo_output_stream_get_status (stream->output);
 106 }
 107
 108 static cairo_status_t
 109 _cairo_deflate_stream_close (cairo_output_stream_t *base)
 110 {
 111     cairo_deflate_stream_t *stream = (cairo_deflate_stream_t *) base;
 112
 113     cairo_deflate_stream_deflate (stream, TRUE);
 114     deflateEnd (&stream->zlib_stream);
 115
 116     return _cairo_output_stream_get_status (stream->output);
 117 }
 118
 119 cairo_output_stream_t *
 120 _cairo_deflate_stream_create (cairo_output_stream_t *output)
 121 {
 122     cairo_deflate_stream_t *stream;
 123
 124     if (output->status)
 125         return _cairo_output_stream_create_in_error (output->status);
 126
 127     stream = malloc (sizeof (cairo_deflate_stream_t));
 128     if (unlikely (stream == NULL)) {
 129         _cairo_error_throw (CAIRO_STATUS_NO_MEMORY);
 130         return (cairo_output_stream_t *) &_cairo_output_stream_nil;
 131     }
 132
 133     _cairo_output_stream_init (&stream->base,
 134                                _cairo_deflate_stream_write,
 135                                NULL,
 136                                _cairo_deflate_stream_close);
 137     stream->output = output;
 138
 139     stream->zlib_stream.zalloc = Z_NULL;
 140     stream->zlib_stream.zfree  = Z_NULL;
 141     stream->zlib_stream.opaque  = Z_NULL;
 142
 143     if (deflateInit (&stream->zlib_stream, Z_DEFAULT_COMPRESSION) != Z_OK) {
 144         free (stream);
 145         return (cairo_output_stream_t *) &_cairo_output_stream_nil;
 146     }
 147
 148     stream->zlib_stream.next_in = stream->input_buf;
 149     stream->zlib_stream.avail_in = 0;
 150     stream->zlib_stream.next_out = stream->output_buf;
 151     stream->zlib_stream.avail_out = BUFFER_SIZE;
 152
 153     return &stream->base;
 154 }
 155
 156 #endif /* CAIRO_HAS_DEFLATE_STREAM */