diff options
Diffstat (limited to 'src/core/lib/compression/message_compress.cc')
| -rw-r--r-- | src/core/lib/compression/message_compress.cc | 189 |
1 files changed, 189 insertions, 0 deletions
diff --git a/src/core/lib/compression/message_compress.cc b/src/core/lib/compression/message_compress.cc new file mode 100644 index 0000000000..c051e28864 --- /dev/null +++ b/src/core/lib/compression/message_compress.cc @@ -0,0 +1,189 @@ +/* + * + * Copyright 2015 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 "src/core/lib/compression/message_compress.h" + +#include <string.h> + +#include <grpc/support/alloc.h> +#include <grpc/support/log.h> + +#include <zlib.h> + +#include "src/core/lib/slice/slice_internal.h" + +#define OUTPUT_BLOCK_SIZE 1024 + +static int zlib_body(grpc_exec_ctx* exec_ctx, z_stream* zs, + grpc_slice_buffer* input, grpc_slice_buffer* output, + int (*flate)(z_stream* zs, int flush)) { + int r; + int flush; + size_t i; + grpc_slice outbuf = GRPC_SLICE_MALLOC(OUTPUT_BLOCK_SIZE); + const uInt uint_max = ~(uInt)0; + + GPR_ASSERT(GRPC_SLICE_LENGTH(outbuf) <= uint_max); + zs->avail_out = (uInt)GRPC_SLICE_LENGTH(outbuf); + zs->next_out = GRPC_SLICE_START_PTR(outbuf); + flush = Z_NO_FLUSH; + for (i = 0; i < input->count; i++) { + if (i == input->count - 1) flush = Z_FINISH; + GPR_ASSERT(GRPC_SLICE_LENGTH(input->slices[i]) <= uint_max); + zs->avail_in = (uInt)GRPC_SLICE_LENGTH(input->slices[i]); + zs->next_in = GRPC_SLICE_START_PTR(input->slices[i]); + do { + if (zs->avail_out == 0) { + grpc_slice_buffer_add_indexed(output, outbuf); + outbuf = GRPC_SLICE_MALLOC(OUTPUT_BLOCK_SIZE); + GPR_ASSERT(GRPC_SLICE_LENGTH(outbuf) <= uint_max); + zs->avail_out = (uInt)GRPC_SLICE_LENGTH(outbuf); + zs->next_out = GRPC_SLICE_START_PTR(outbuf); + } + r = flate(zs, flush); + if (r < 0 && r != Z_BUF_ERROR /* not fatal */) { + gpr_log(GPR_INFO, "zlib error (%d)", r); + goto error; + } + } while (zs->avail_out == 0); + if (zs->avail_in) { + gpr_log(GPR_INFO, "zlib: not all input consumed"); + goto error; + } + } + + GPR_ASSERT(outbuf.refcount); + outbuf.data.refcounted.length -= zs->avail_out; + grpc_slice_buffer_add_indexed(output, outbuf); + + return 1; + +error: + grpc_slice_unref_internal(exec_ctx, outbuf); + return 0; +} + +static void* zalloc_gpr(void* opaque, unsigned int items, unsigned int size) { + return gpr_malloc(items * size); +} + +static void zfree_gpr(void* opaque, void* address) { gpr_free(address); } + +static int zlib_compress(grpc_exec_ctx* exec_ctx, grpc_slice_buffer* input, + grpc_slice_buffer* output, int gzip) { + z_stream zs; + int r; + size_t i; + size_t count_before = output->count; + size_t length_before = output->length; + memset(&zs, 0, sizeof(zs)); + zs.zalloc = zalloc_gpr; + zs.zfree = zfree_gpr; + r = deflateInit2(&zs, Z_DEFAULT_COMPRESSION, Z_DEFLATED, 15 | (gzip ? 16 : 0), + 8, Z_DEFAULT_STRATEGY); + GPR_ASSERT(r == Z_OK); + r = zlib_body(exec_ctx, &zs, input, output, deflate) && + output->length < input->length; + if (!r) { + for (i = count_before; i < output->count; i++) { + grpc_slice_unref_internal(exec_ctx, output->slices[i]); + } + output->count = count_before; + output->length = length_before; + } + deflateEnd(&zs); + return r; +} + +static int zlib_decompress(grpc_exec_ctx* exec_ctx, grpc_slice_buffer* input, + grpc_slice_buffer* output, int gzip) { + z_stream zs; + int r; + size_t i; + size_t count_before = output->count; + size_t length_before = output->length; + memset(&zs, 0, sizeof(zs)); + zs.zalloc = zalloc_gpr; + zs.zfree = zfree_gpr; + r = inflateInit2(&zs, 15 | (gzip ? 16 : 0)); + GPR_ASSERT(r == Z_OK); + r = zlib_body(exec_ctx, &zs, input, output, inflate); + if (!r) { + for (i = count_before; i < output->count; i++) { + grpc_slice_unref_internal(exec_ctx, output->slices[i]); + } + output->count = count_before; + output->length = length_before; + } + inflateEnd(&zs); + return r; +} + +static int copy(grpc_slice_buffer* input, grpc_slice_buffer* output) { + size_t i; + for (i = 0; i < input->count; i++) { + grpc_slice_buffer_add(output, grpc_slice_ref_internal(input->slices[i])); + } + return 1; +} + +static int compress_inner(grpc_exec_ctx* exec_ctx, + grpc_compression_algorithm algorithm, + grpc_slice_buffer* input, grpc_slice_buffer* output) { + switch (algorithm) { + case GRPC_COMPRESS_NONE: + /* the fallback path always needs to be send uncompressed: we simply + rely on that here */ + return 0; + case GRPC_COMPRESS_DEFLATE: + return zlib_compress(exec_ctx, input, output, 0); + case GRPC_COMPRESS_GZIP: + return zlib_compress(exec_ctx, input, output, 1); + case GRPC_COMPRESS_ALGORITHMS_COUNT: + break; + } + gpr_log(GPR_ERROR, "invalid compression algorithm %d", algorithm); + return 0; +} + +int grpc_msg_compress(grpc_exec_ctx* exec_ctx, + grpc_compression_algorithm algorithm, + grpc_slice_buffer* input, grpc_slice_buffer* output) { + if (!compress_inner(exec_ctx, algorithm, input, output)) { + copy(input, output); + return 0; + } + return 1; +} + +int grpc_msg_decompress(grpc_exec_ctx* exec_ctx, + grpc_compression_algorithm algorithm, + grpc_slice_buffer* input, grpc_slice_buffer* output) { + switch (algorithm) { + case GRPC_COMPRESS_NONE: + return copy(input, output); + case GRPC_COMPRESS_DEFLATE: + return zlib_decompress(exec_ctx, input, output, 0); + case GRPC_COMPRESS_GZIP: + return zlib_decompress(exec_ctx, input, output, 1); + case GRPC_COMPRESS_ALGORITHMS_COUNT: + break; + } + gpr_log(GPR_ERROR, "invalid compression algorithm %d", algorithm); + return 0; +} |