| /* |
| * |
| * Copyright 2015, 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 <stdlib.h> |
| #include <string.h> |
| |
| #include <grpc/compression.h> |
| #include <grpc/support/useful.h> |
| |
| #include "src/core/lib/compression/algorithm_metadata.h" |
| #include "src/core/lib/surface/api_trace.h" |
| #include "src/core/lib/transport/static_metadata.h" |
| |
| int grpc_compression_algorithm_parse(grpc_slice name, |
| grpc_compression_algorithm *algorithm) { |
| /* we use strncmp not only because it's safer (even though in this case it |
| * doesn't matter, given that we are comparing against string literals, but |
| * because this way we needn't have "name" nil-terminated (useful for slice |
| * data, for example) */ |
| if (grpc_slice_eq(name, GRPC_MDSTR_IDENTITY)) { |
| *algorithm = GRPC_COMPRESS_NONE; |
| return 1; |
| } else if (grpc_slice_eq(name, GRPC_MDSTR_GZIP)) { |
| *algorithm = GRPC_COMPRESS_GZIP; |
| return 1; |
| } else if (grpc_slice_eq(name, GRPC_MDSTR_DEFLATE)) { |
| *algorithm = GRPC_COMPRESS_DEFLATE; |
| return 1; |
| } else { |
| return 0; |
| } |
| } |
| |
| int grpc_compression_algorithm_name(grpc_compression_algorithm algorithm, |
| char **name) { |
| GRPC_API_TRACE("grpc_compression_algorithm_parse(algorithm=%d, name=%p)", 2, |
| ((int)algorithm, name)); |
| switch (algorithm) { |
| case GRPC_COMPRESS_NONE: |
| *name = "identity"; |
| return 1; |
| case GRPC_COMPRESS_DEFLATE: |
| *name = "deflate"; |
| return 1; |
| case GRPC_COMPRESS_GZIP: |
| *name = "gzip"; |
| return 1; |
| case GRPC_COMPRESS_ALGORITHMS_COUNT: |
| return 0; |
| } |
| return 0; |
| } |
| |
| grpc_compression_algorithm grpc_compression_algorithm_from_slice( |
| grpc_slice str) { |
| if (grpc_slice_eq(str, GRPC_MDSTR_IDENTITY)) return GRPC_COMPRESS_NONE; |
| if (grpc_slice_eq(str, GRPC_MDSTR_DEFLATE)) return GRPC_COMPRESS_DEFLATE; |
| if (grpc_slice_eq(str, GRPC_MDSTR_GZIP)) return GRPC_COMPRESS_GZIP; |
| return GRPC_COMPRESS_ALGORITHMS_COUNT; |
| } |
| |
| grpc_slice grpc_compression_algorithm_slice( |
| grpc_compression_algorithm algorithm) { |
| switch (algorithm) { |
| case GRPC_COMPRESS_NONE: |
| return GRPC_MDSTR_IDENTITY; |
| case GRPC_COMPRESS_DEFLATE: |
| return GRPC_MDSTR_DEFLATE; |
| case GRPC_COMPRESS_GZIP: |
| return GRPC_MDSTR_GZIP; |
| case GRPC_COMPRESS_ALGORITHMS_COUNT: |
| return grpc_empty_slice(); |
| } |
| return grpc_empty_slice(); |
| } |
| |
| grpc_mdelem grpc_compression_encoding_mdelem( |
| grpc_compression_algorithm algorithm) { |
| switch (algorithm) { |
| case GRPC_COMPRESS_NONE: |
| return GRPC_MDELEM_GRPC_ENCODING_IDENTITY; |
| case GRPC_COMPRESS_DEFLATE: |
| return GRPC_MDELEM_GRPC_ENCODING_DEFLATE; |
| case GRPC_COMPRESS_GZIP: |
| return GRPC_MDELEM_GRPC_ENCODING_GZIP; |
| default: |
| break; |
| } |
| return GRPC_MDNULL; |
| } |
| |
| void grpc_compression_options_init(grpc_compression_options *opts) { |
| memset(opts, 0, sizeof(*opts)); |
| /* all enabled by default */ |
| opts->enabled_algorithms_bitset = (1u << GRPC_COMPRESS_ALGORITHMS_COUNT) - 1; |
| } |
| |
| void grpc_compression_options_enable_algorithm( |
| grpc_compression_options *opts, grpc_compression_algorithm algorithm) { |
| GPR_BITSET(&opts->enabled_algorithms_bitset, algorithm); |
| } |
| |
| void grpc_compression_options_disable_algorithm( |
| grpc_compression_options *opts, grpc_compression_algorithm algorithm) { |
| GPR_BITCLEAR(&opts->enabled_algorithms_bitset, algorithm); |
| } |
| |
| int grpc_compression_options_is_algorithm_enabled( |
| const grpc_compression_options *opts, |
| grpc_compression_algorithm algorithm) { |
| return GPR_BITGET(opts->enabled_algorithms_bitset, algorithm); |
| } |
| |
| /* TODO(dgq): Add the ability to specify parameters to the individual |
| * compression algorithms */ |
| grpc_compression_algorithm grpc_compression_algorithm_for_level( |
| grpc_compression_level level, uint32_t accepted_encodings) { |
| GRPC_API_TRACE("grpc_compression_algorithm_for_level(level=%d)", 1, |
| ((int)level)); |
| if (level > GRPC_COMPRESS_LEVEL_HIGH) { |
| gpr_log(GPR_ERROR, "Unknown compression level %d.", (int)level); |
| abort(); |
| } |
| |
| const size_t num_supported = |
| GPR_BITCOUNT(accepted_encodings) - 1; /* discard NONE */ |
| if (level == GRPC_COMPRESS_LEVEL_NONE || num_supported == 0) { |
| return GRPC_COMPRESS_NONE; |
| } |
| |
| GPR_ASSERT(level > 0); |
| |
| /* Establish a "ranking" or compression algorithms in increasing order of |
| * compression. |
| * This is simplistic and we will probably want to introduce other dimensions |
| * in the future (cpu/memory cost, etc). */ |
| const grpc_compression_algorithm algos_ranking[] = {GRPC_COMPRESS_GZIP, |
| GRPC_COMPRESS_DEFLATE}; |
| |
| /* intersect algos_ranking with the supported ones keeping the ranked order */ |
| grpc_compression_algorithm |
| sorted_supported_algos[GRPC_COMPRESS_ALGORITHMS_COUNT]; |
| size_t algos_supported_idx = 0; |
| for (size_t i = 0; i < GPR_ARRAY_SIZE(algos_ranking); i++) { |
| const grpc_compression_algorithm alg = algos_ranking[i]; |
| for (size_t j = 0; j < num_supported; j++) { |
| if (GPR_BITGET(accepted_encodings, alg) == 1) { |
| /* if \a alg in supported */ |
| sorted_supported_algos[algos_supported_idx++] = alg; |
| break; |
| } |
| } |
| if (algos_supported_idx == num_supported) break; |
| } |
| |
| switch (level) { |
| case GRPC_COMPRESS_LEVEL_NONE: |
| abort(); /* should have been handled already */ |
| case GRPC_COMPRESS_LEVEL_LOW: |
| return sorted_supported_algos[0]; |
| case GRPC_COMPRESS_LEVEL_MED: |
| return sorted_supported_algos[num_supported / 2]; |
| case GRPC_COMPRESS_LEVEL_HIGH: |
| return sorted_supported_algos[num_supported - 1]; |
| default: |
| abort(); |
| }; |
| } |