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/*
*
* Copyright 2017 gRPC authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
#include <grpc/support/alloc.h>
#include <grpc/support/log.h>
#include "src/core/lib/compression/stream_compression_gzip.h"
#include "src/core/lib/iomgr/exec_ctx.h"
#include "src/core/lib/slice/slice_internal.h"
#define OUTPUT_BLOCK_SIZE (1024)
typedef struct grpc_stream_compression_context_gzip {
grpc_stream_compression_context base;
z_stream zs;
int (*flate)(z_stream* zs, int flush);
} grpc_stream_compression_context_gzip;
static bool gzip_flate(grpc_stream_compression_context_gzip* ctx,
grpc_slice_buffer* in, grpc_slice_buffer* out,
size_t* output_size, size_t max_output_size, int flush,
bool* end_of_context) {
GPR_ASSERT(flush == 0 || flush == Z_SYNC_FLUSH || flush == Z_FINISH);
/* Full flush is not allowed when inflating. */
GPR_ASSERT(!(ctx->flate == inflate && (flush == Z_FINISH)));
grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
int r;
bool eoc = false;
size_t original_max_output_size = max_output_size;
while (max_output_size > 0 && (in->length > 0 || flush) && !eoc) {
size_t slice_size = max_output_size < OUTPUT_BLOCK_SIZE ? max_output_size
: OUTPUT_BLOCK_SIZE;
grpc_slice slice_out = GRPC_SLICE_MALLOC(slice_size);
ctx->zs.avail_out = (uInt)slice_size;
ctx->zs.next_out = GRPC_SLICE_START_PTR(slice_out);
while (ctx->zs.avail_out > 0 && in->length > 0 && !eoc) {
grpc_slice slice = grpc_slice_buffer_take_first(in);
ctx->zs.avail_in = (uInt)GRPC_SLICE_LENGTH(slice);
ctx->zs.next_in = GRPC_SLICE_START_PTR(slice);
r = ctx->flate(&ctx->zs, Z_NO_FLUSH);
if (r < 0 && r != Z_BUF_ERROR) {
gpr_log(GPR_ERROR, "zlib error (%d)", r);
grpc_slice_unref_internal(&exec_ctx, slice_out);
grpc_exec_ctx_finish(&exec_ctx);
return false;
} else if (r == Z_STREAM_END && ctx->flate == inflate) {
eoc = true;
}
if (ctx->zs.avail_in > 0) {
grpc_slice_buffer_undo_take_first(
in,
grpc_slice_sub(slice, GRPC_SLICE_LENGTH(slice) - ctx->zs.avail_in,
GRPC_SLICE_LENGTH(slice)));
}
grpc_slice_unref_internal(&exec_ctx, slice);
}
if (flush != 0 && ctx->zs.avail_out > 0 && !eoc) {
GPR_ASSERT(in->length == 0);
r = ctx->flate(&ctx->zs, flush);
if (flush == Z_SYNC_FLUSH) {
switch (r) {
case Z_OK:
/* Maybe flush is not complete; just made some partial progress. */
if (ctx->zs.avail_out > 0) {
flush = 0;
}
break;
case Z_BUF_ERROR:
case Z_STREAM_END:
flush = 0;
break;
default:
gpr_log(GPR_ERROR, "zlib error (%d)", r);
grpc_slice_unref_internal(&exec_ctx, slice_out);
grpc_exec_ctx_finish(&exec_ctx);
return false;
}
} else if (flush == Z_FINISH) {
switch (r) {
case Z_OK:
case Z_BUF_ERROR:
/* Wait for the next loop to assign additional output space. */
GPR_ASSERT(ctx->zs.avail_out == 0);
break;
case Z_STREAM_END:
flush = 0;
break;
default:
gpr_log(GPR_ERROR, "zlib error (%d)", r);
grpc_slice_unref_internal(&exec_ctx, slice_out);
grpc_exec_ctx_finish(&exec_ctx);
return false;
}
}
}
if (ctx->zs.avail_out == 0) {
grpc_slice_buffer_add(out, slice_out);
} else if (ctx->zs.avail_out < slice_size) {
slice_out.data.refcounted.length -= ctx->zs.avail_out;
grpc_slice_buffer_add(out, slice_out);
} else {
grpc_slice_unref_internal(&exec_ctx, slice_out);
}
max_output_size -= (slice_size - ctx->zs.avail_out);
}
grpc_exec_ctx_finish(&exec_ctx);
if (end_of_context) {
*end_of_context = eoc;
}
if (output_size) {
*output_size = original_max_output_size - max_output_size;
}
return true;
}
static bool grpc_stream_compress_gzip(grpc_stream_compression_context* ctx,
grpc_slice_buffer* in,
grpc_slice_buffer* out,
size_t* output_size,
size_t max_output_size,
grpc_stream_compression_flush flush) {
if (ctx == NULL) {
return false;
}
grpc_stream_compression_context_gzip* gzip_ctx =
(grpc_stream_compression_context_gzip*)ctx;
GPR_ASSERT(gzip_ctx->flate == deflate);
int gzip_flush;
switch (flush) {
case GRPC_STREAM_COMPRESSION_FLUSH_NONE:
gzip_flush = 0;
break;
case GRPC_STREAM_COMPRESSION_FLUSH_SYNC:
gzip_flush = Z_SYNC_FLUSH;
break;
case GRPC_STREAM_COMPRESSION_FLUSH_FINISH:
gzip_flush = Z_FINISH;
break;
default:
gzip_flush = 0;
}
return gzip_flate(gzip_ctx, in, out, output_size, max_output_size, gzip_flush,
NULL);
}
static bool grpc_stream_decompress_gzip(grpc_stream_compression_context* ctx,
grpc_slice_buffer* in,
grpc_slice_buffer* out,
size_t* output_size,
size_t max_output_size,
bool* end_of_context) {
if (ctx == NULL) {
return false;
}
grpc_stream_compression_context_gzip* gzip_ctx =
(grpc_stream_compression_context_gzip*)ctx;
GPR_ASSERT(gzip_ctx->flate == inflate);
return gzip_flate(gzip_ctx, in, out, output_size, max_output_size,
Z_SYNC_FLUSH, end_of_context);
}
static grpc_stream_compression_context*
grpc_stream_compression_context_create_gzip(
grpc_stream_compression_method method) {
GPR_ASSERT(method == GRPC_STREAM_COMPRESSION_GZIP_COMPRESS ||
method == GRPC_STREAM_COMPRESSION_GZIP_DECOMPRESS);
grpc_stream_compression_context_gzip* gzip_ctx =
(grpc_stream_compression_context_gzip*)gpr_zalloc(
sizeof(grpc_stream_compression_context_gzip));
int r;
if (gzip_ctx == NULL) {
return NULL;
}
if (method == GRPC_STREAM_COMPRESSION_GZIP_DECOMPRESS) {
r = inflateInit2(&gzip_ctx->zs, 0x1F);
gzip_ctx->flate = inflate;
} else {
r = deflateInit2(&gzip_ctx->zs, Z_DEFAULT_COMPRESSION, Z_DEFLATED, 0x1F, 8,
Z_DEFAULT_STRATEGY);
gzip_ctx->flate = deflate;
}
if (r != Z_OK) {
gpr_free(gzip_ctx);
return NULL;
}
gzip_ctx->base.vtable = &grpc_stream_compression_gzip_vtable;
return (grpc_stream_compression_context*)gzip_ctx;
}
static void grpc_stream_compression_context_destroy_gzip(
grpc_stream_compression_context* ctx) {
if (ctx == NULL) {
return;
}
grpc_stream_compression_context_gzip* gzip_ctx =
(grpc_stream_compression_context_gzip*)ctx;
if (gzip_ctx->flate == inflate) {
inflateEnd(&gzip_ctx->zs);
} else {
deflateEnd(&gzip_ctx->zs);
}
gpr_free(ctx);
}
const grpc_stream_compression_vtable grpc_stream_compression_gzip_vtable = {
grpc_stream_compress_gzip, grpc_stream_decompress_gzip,
grpc_stream_compression_context_create_gzip,
grpc_stream_compression_context_destroy_gzip};
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