avs_stream_abstract_t *
_avs_http_create_decompressor(http_compression_format_t format,
int window_bits,
size_t input_buffer_size,
size_t output_buffer_size) {
int result;
zlib_stream_t *stream = zlib_stream_init(&decompressor_vtable,
input_buffer_size,
output_buffer_size);
if (!stream) {
return NULL;
}
stream->zlib.opaque = &decompressor_flush_holder;
result = inflateInit2(
&stream->zlib,
window_bits + (format == HTTP_COMPRESSION_GZIP ? 16 : 0));
if (result != Z_OK) {
LOG(ERROR, "could not initialize zlib (%d): %s",
result, get_zlib_msg(stream));
avs_free(stream);
return NULL;
}
reset_fields(stream);
return (avs_stream_abstract_t *) stream;
}
/**
* Creates an incremental zlib deflater for `len' bytes starting at `data',
* with specified compression `level'.
*
* @param data data to compress; if NULL, will be incrementally given
* @param len length of data to compress (if data not NULL) or estimation
* @param dest where compressed data should go, or NULL if allocated
* @param destlen length of supplied output buffer, if dest != NULL
* @param level compression level, between 0 and 9.
*
* @return new deflater, or NULL if error.
*/
static zlib_deflater_t *
zlib_deflater_alloc(
const void *data, size_t len, void *dest, size_t destlen, int level)
{
zlib_deflater_t *zd;
z_streamp outz;
int ret;
g_assert(size_is_non_negative(len));
g_assert(size_is_non_negative(destlen));
g_assert(level == Z_DEFAULT_COMPRESSION || (level >= 0 && level <= 9));
WALLOC(outz);
outz->zalloc = zlib_alloc_func;
outz->zfree = zlib_free_func;
outz->opaque = NULL;
ret = deflateInit(outz, level);
if (ret != Z_OK) {
WFREE(outz);
g_carp("%s(): unable to initialize compressor: %s",
G_STRFUNC, zlib_strerror(ret));
return NULL;
}
WALLOC0(zd);
zd->zs.magic = ZLIB_DEFLATER_MAGIC;
zd->zs.z = outz;
zd->zs.closed = FALSE;
zlib_stream_init(&zd->zs, data, len, dest, destlen);
return zd;
}
/**
* Reset an incremental zlib stream.
*
* The compression parameters remain the same as the ones used when the
* deflater was initially created. Only the input/output settings change.
*
* @param zd the zlib deflater to reset
* @param data data to compress; if NULL, will be incrementally given
* @param len length of data to compress (if data not NULL) or estimation
* @param dest where compressed data should go, or NULL if allocated
* @param destlen length of supplied output buffer, if dest != NULL
*/
static void
zlib_stream_reset_into(zlib_stream_t *zs,
const void *data, size_t len, void *dest, size_t destlen)
{
g_assert(zs->z != NULL); /* Stream not closed yet */
zs->closed = FALSE;
switch (zs->magic) {
case ZLIB_INFLATER_MAGIC:
inflateReset(zs->z);
break;
case ZLIB_DEFLATER_MAGIC:
deflateReset(zs->z);
break;
}
zlib_stream_init(zs, data, len, dest, destlen);
}