android13/external/libwebsockets/lib/roles/http/compression/deflate/deflate.c

114 lines
3.1 KiB
C

/*
* libwebsockets - small server side websockets and web server implementation
*
* Copyright (C) 2010 - 2019 Andy Green <andy@warmcat.com>
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to
* deal in the Software without restriction, including without limitation the
* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
* sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
#include "private-lib-core.h"
static int
lcs_init_compression_deflate(lws_comp_ctx_t *ctx, int decomp)
{
int n;
ctx->is_decompression = !!decomp;
ctx->u.deflate = lws_malloc(sizeof(*ctx->u.deflate), __func__);
if (!ctx->u.deflate)
return 2;
memset(ctx->u.deflate, 0, sizeof(*ctx->u.deflate));
if (!decomp &&
(n = deflateInit2(ctx->u.deflate, 1, Z_DEFLATED, -15, 8,
Z_DEFAULT_STRATEGY)) != Z_OK) {
lwsl_err("deflate init failed: %d\n", n);
lws_free_set_NULL(ctx->u.deflate);
return 1;
}
if (decomp &&
inflateInit2(ctx->u.deflate, 16 + 15) != Z_OK) {
lws_free_set_NULL(ctx->u.deflate);
return 1;
}
return 0;
}
static int
lcs_process_deflate(lws_comp_ctx_t *ctx, const void *in, size_t *ilen_iused,
void *out, size_t *olen_oused)
{
size_t olen_oused_in = *olen_oused;
int n;
ctx->u.deflate->next_in = (void *)in;
ctx->u.deflate->avail_in = (unsigned int)*ilen_iused;
ctx->u.deflate->next_out = out;
ctx->u.deflate->avail_out = (unsigned int)*olen_oused;
if (!ctx->is_decompression)
n = deflate(ctx->u.deflate, Z_SYNC_FLUSH);
else
n = inflate(ctx->u.deflate, Z_SYNC_FLUSH);
switch (n) {
case Z_NEED_DICT:
case Z_STREAM_ERROR:
case Z_DATA_ERROR:
case Z_MEM_ERROR:
lwsl_err("zlib error inflate %d\n", n);
return -1;
}
*ilen_iused -= ctx->u.deflate->avail_in;
*olen_oused -= ctx->u.deflate->avail_out;
/* it's ambiguous with zlib... */
ctx->may_have_more = (*olen_oused == olen_oused_in);
return n == Z_STREAM_END;
}
static void
lcs_destroy_deflate(lws_comp_ctx_t *ctx)
{
if (!ctx)
return;
if (!(*ctx).is_decompression)
deflateEnd((*ctx).u.deflate);
else
inflateEnd((*ctx).u.deflate);
lws_free_set_NULL(ctx->u.deflate);
}
struct lws_compression_support lcs_deflate = {
/* .encoding_name */ "deflate",
/* .init_compression */ lcs_init_compression_deflate,
/* .process */ lcs_process_deflate,
/* .destroy */ lcs_destroy_deflate,
};