diff options
Diffstat (limited to 'src/core/compression/message_compress.c')
| -rw-r--r-- | src/core/compression/message_compress.c | 193 |
1 files changed, 193 insertions, 0 deletions
diff --git a/src/core/compression/message_compress.c b/src/core/compression/message_compress.c new file mode 100644 index 0000000000..1787ccd7d8 --- /dev/null +++ b/src/core/compression/message_compress.c @@ -0,0 +1,193 @@ +/* + * + * Copyright 2014, Google Inc. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: + * + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following disclaimer + * in the documentation and/or other materials provided with the + * distribution. + * * Neither the name of Google Inc. nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + */ + +#include "src/core/compression/message_compress.h" + +#include <string.h> + +#include <grpc/support/alloc.h> +#include <grpc/support/log.h> + +#include <zlib.h> + +#define OUTPUT_BLOCK_SIZE 1024 + +static int zlib_body(z_stream *zs, gpr_slice_buffer *input, + gpr_slice_buffer *output, + int (*flate)(z_stream *zs, int flush)) { + int r; + int flush; + size_t i; + size_t output_bytes = 0; + gpr_slice outbuf = gpr_slice_malloc(OUTPUT_BLOCK_SIZE); + + zs->avail_out = GPR_SLICE_LENGTH(outbuf); + zs->next_out = GPR_SLICE_START_PTR(outbuf); + flush = Z_NO_FLUSH; + for (i = 0; i < input->count; i++) { + if (i == input->count - 1) flush = Z_FINISH; + zs->avail_in = GPR_SLICE_LENGTH(input->slices[i]); + zs->next_in = GPR_SLICE_START_PTR(input->slices[i]); + do { + if (zs->avail_out == 0) { + output_bytes += GPR_SLICE_LENGTH(outbuf); + gpr_slice_buffer_add_indexed(output, outbuf); + outbuf = gpr_slice_malloc(OUTPUT_BLOCK_SIZE); + zs->avail_out = GPR_SLICE_LENGTH(outbuf); + zs->next_out = GPR_SLICE_START_PTR(outbuf); + } + r = flate(zs, flush); + if (r == Z_STREAM_ERROR) { + gpr_log(GPR_INFO, "zlib: stream error"); + 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; + output_bytes += GPR_SLICE_LENGTH(outbuf); + gpr_slice_buffer_add_indexed(output, outbuf); + + return 1; + +error: + gpr_slice_unref(outbuf); + return 0; +} + +static int zlib_compress(gpr_slice_buffer *input, gpr_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)); + r = deflateInit2(&zs, Z_DEFAULT_COMPRESSION, Z_DEFLATED, 15 | (gzip ? 16 : 0), + 8, Z_DEFAULT_STRATEGY); + if (r != Z_OK) { + gpr_log(GPR_ERROR, "deflateInit2 returns %d", r); + return 0; + } + r = zlib_body(&zs, input, output, deflate) && output->length < input->length; + if (!r) { + for (i = count_before; i < output->count; i++) { + gpr_slice_unref(output->slices[i]); + } + output->count = count_before; + output->length = length_before; + } + deflateEnd(&zs); + return r; +} + +static int zlib_decompress(gpr_slice_buffer *input, gpr_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)); + r = inflateInit2(&zs, 15 | (gzip ? 16 : 0)); + if (r != Z_OK) { + gpr_log(GPR_ERROR, "inflateInit2 returns %d", r); + return 0; + } + r = zlib_body(&zs, input, output, inflate); + if (!r) { + for (i = count_before; i < output->count; i++) { + gpr_slice_unref(output->slices[i]); + } + output->count = count_before; + output->length = length_before; + } + inflateEnd(&zs); + return r; +} + +static int copy(gpr_slice_buffer *input, gpr_slice_buffer *output) { + size_t i; + for (i = 0; i < input->count; i++) { + gpr_slice_buffer_add(output, gpr_slice_ref(input->slices[i])); + } + return 1; +} + +int compress_inner(grpc_compression_algorithm algorithm, + gpr_slice_buffer *input, gpr_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(input, output, 0); + case GRPC_COMPRESS_GZIP: + return zlib_compress(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_compression_algorithm algorithm, + gpr_slice_buffer *input, gpr_slice_buffer *output) { + if (!compress_inner(algorithm, input, output)) { + copy(input, output); + return 0; + } + return 1; +} + +int grpc_msg_decompress(grpc_compression_algorithm algorithm, + gpr_slice_buffer *input, gpr_slice_buffer *output) { + switch (algorithm) { + case GRPC_COMPRESS_NONE: + return copy(input, output); + case GRPC_COMPRESS_DEFLATE: + return zlib_decompress(input, output, 0); + case GRPC_COMPRESS_GZIP: + return zlib_decompress(input, output, 1); + case GRPC_COMPRESS_ALGORITHMS_COUNT: + break; + } + gpr_log(GPR_ERROR, "invalid compression algorithm %d", algorithm); + return 0; +} |