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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "cairoint.h"
#include "cairo-error-private.h"
#include "cairo-output-stream-private.h"
#include <zlib.h>
#define BUFFER_SIZE 16384
typedef struct _cairo_deflate_stream {
cairo_output_stream_t base;
cairo_output_stream_t *output;
z_stream zlib_stream;
unsigned char input_buf[BUFFER_SIZE];
unsigned char output_buf[BUFFER_SIZE];
} cairo_deflate_stream_t;
static void
cairo_deflate_stream_deflate (cairo_deflate_stream_t *stream, cairo_bool_t flush)
{
int ret;
cairo_bool_t finished;
do {
ret = deflate (&stream->zlib_stream, flush ? Z_FINISH : Z_NO_FLUSH);
if (flush || stream->zlib_stream.avail_out == 0)
{
_cairo_output_stream_write (stream->output,
stream->output_buf,
BUFFER_SIZE - stream->zlib_stream.avail_out);
stream->zlib_stream.next_out = stream->output_buf;
stream->zlib_stream.avail_out = BUFFER_SIZE;
}
finished = TRUE;
if (stream->zlib_stream.avail_in != 0)
finished = FALSE;
if (flush && ret != Z_STREAM_END)
finished = FALSE;
} while (!finished);
stream->zlib_stream.next_in = stream->input_buf;
}
static cairo_status_t
_cairo_deflate_stream_write (cairo_output_stream_t *base,
const unsigned char *data,
unsigned int length)
{
cairo_deflate_stream_t *stream = (cairo_deflate_stream_t *) base;
unsigned int count;
const unsigned char *p = data;
while (length) {
count = length;
if (count > BUFFER_SIZE - stream->zlib_stream.avail_in)
count = BUFFER_SIZE - stream->zlib_stream.avail_in;
memcpy (stream->input_buf + stream->zlib_stream.avail_in, p, count);
p += count;
stream->zlib_stream.avail_in += count;
length -= count;
if (stream->zlib_stream.avail_in == BUFFER_SIZE)
cairo_deflate_stream_deflate (stream, FALSE);
}
return _cairo_output_stream_get_status (stream->output);
}
static cairo_status_t
_cairo_deflate_stream_close (cairo_output_stream_t *base)
{
cairo_deflate_stream_t *stream = (cairo_deflate_stream_t *) base;
cairo_deflate_stream_deflate (stream, TRUE);
deflateEnd (&stream->zlib_stream);
return _cairo_output_stream_get_status (stream->output);
}
cairo_output_stream_t *
_cairo_deflate_stream_create (cairo_output_stream_t *output)
{
cairo_deflate_stream_t *stream;
if (output->status)
return _cairo_output_stream_create_in_error (output->status);
stream = malloc (sizeof (cairo_deflate_stream_t));
if (unlikely (stream == NULL)) {
_cairo_error_throw (CAIRO_STATUS_NO_MEMORY);
return (cairo_output_stream_t *) &_cairo_output_stream_nil;
}
_cairo_output_stream_init (&stream->base,
_cairo_deflate_stream_write,
NULL,
_cairo_deflate_stream_close);
stream->output = output;
stream->zlib_stream.zalloc = Z_NULL;
stream->zlib_stream.zfree = Z_NULL;
stream->zlib_stream.opaque = Z_NULL;
if (deflateInit (&stream->zlib_stream, Z_DEFAULT_COMPRESSION) != Z_OK) {
free (stream);
return (cairo_output_stream_t *) &_cairo_output_stream_nil;
}
stream->zlib_stream.next_in = stream->input_buf;
stream->zlib_stream.avail_in = 0;
stream->zlib_stream.next_out = stream->output_buf;
stream->zlib_stream.avail_out = BUFFER_SIZE;
return &stream->base;
}
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