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-rw-r--r--src/core/lib/compression/algorithm_metadata.h53
-rw-r--r--src/core/lib/compression/compression_algorithm.c203
-rw-r--r--src/core/lib/compression/message_compress.c198
-rw-r--r--src/core/lib/compression/message_compress.h52
4 files changed, 506 insertions, 0 deletions
diff --git a/src/core/lib/compression/algorithm_metadata.h b/src/core/lib/compression/algorithm_metadata.h
new file mode 100644
index 0000000000..1f9cc15f23
--- /dev/null
+++ b/src/core/lib/compression/algorithm_metadata.h
@@ -0,0 +1,53 @@
+/*
+ *
+ * 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.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_COMPRESSION_ALGORITHM_METADATA_H
+#define GRPC_CORE_LIB_COMPRESSION_ALGORITHM_METADATA_H
+
+#include <grpc/compression.h>
+#include "src/core/lib/transport/metadata.h"
+
+/** Return compression algorithm based metadata value */
+grpc_mdstr *grpc_compression_algorithm_mdstr(
+ grpc_compression_algorithm algorithm);
+
+/** Return compression algorithm based metadata element (grpc-encoding: xxx) */
+grpc_mdelem *grpc_compression_encoding_mdelem(
+ grpc_compression_algorithm algorithm);
+
+/** Find compression algorithm based on passed in mdstr - returns
+ * GRPC_COMPRESS_ALGORITHM_COUNT on failure */
+grpc_compression_algorithm grpc_compression_algorithm_from_mdstr(
+ grpc_mdstr *str);
+
+#endif /* GRPC_CORE_LIB_COMPRESSION_ALGORITHM_METADATA_H */
diff --git a/src/core/lib/compression/compression_algorithm.c b/src/core/lib/compression/compression_algorithm.c
new file mode 100644
index 0000000000..7039364b7b
--- /dev/null
+++ b/src/core/lib/compression/compression_algorithm.c
@@ -0,0 +1,203 @@
+/*
+ *
+ * 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(const char *name, size_t name_length,
+ 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) */
+ GRPC_API_TRACE(
+ "grpc_compression_algorithm_parse("
+ "name=%*.*s, name_length=%lu, algorithm=%p)",
+ 5, ((int)name_length, (int)name_length, name, (unsigned long)name_length,
+ algorithm));
+ if (name_length == 0) {
+ return 0;
+ }
+ if (strncmp(name, "identity", name_length) == 0) {
+ *algorithm = GRPC_COMPRESS_NONE;
+ } else if (strncmp(name, "gzip", name_length) == 0) {
+ *algorithm = GRPC_COMPRESS_GZIP;
+ } else if (strncmp(name, "deflate", name_length) == 0) {
+ *algorithm = GRPC_COMPRESS_DEFLATE;
+ } else {
+ return 0;
+ }
+ return 1;
+}
+
+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_mdstr(
+ grpc_mdstr *str) {
+ if (str == GRPC_MDSTR_IDENTITY) return GRPC_COMPRESS_NONE;
+ if (str == GRPC_MDSTR_DEFLATE) return GRPC_COMPRESS_DEFLATE;
+ if (str == GRPC_MDSTR_GZIP) return GRPC_COMPRESS_GZIP;
+ return GRPC_COMPRESS_ALGORITHMS_COUNT;
+}
+
+grpc_mdstr *grpc_compression_algorithm_mdstr(
+ 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 NULL;
+ }
+ return NULL;
+}
+
+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 NULL;
+}
+
+/* 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();
+ };
+}
+
+void grpc_compression_options_init(grpc_compression_options *opts) {
+ opts->enabled_algorithms_bitset = (1u << GRPC_COMPRESS_ALGORITHMS_COUNT) - 1;
+ opts->default_compression_algorithm = GRPC_COMPRESS_NONE;
+}
+
+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);
+}
diff --git a/src/core/lib/compression/message_compress.c b/src/core/lib/compression/message_compress.c
new file mode 100644
index 0000000000..cbe0b5a285
--- /dev/null
+++ b/src/core/lib/compression/message_compress.c
@@ -0,0 +1,198 @@
+/*
+ *
+ * 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 "src/core/lib/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;
+ gpr_slice outbuf = gpr_slice_malloc(OUTPUT_BLOCK_SIZE);
+ const uInt uint_max = ~(uInt)0;
+
+ GPR_ASSERT(GPR_SLICE_LENGTH(outbuf) <= uint_max);
+ zs->avail_out = (uInt)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;
+ GPR_ASSERT(GPR_SLICE_LENGTH(input->slices[i]) <= uint_max);
+ zs->avail_in = (uInt)GPR_SLICE_LENGTH(input->slices[i]);
+ zs->next_in = GPR_SLICE_START_PTR(input->slices[i]);
+ do {
+ if (zs->avail_out == 0) {
+ gpr_slice_buffer_add_indexed(output, outbuf);
+ outbuf = gpr_slice_malloc(OUTPUT_BLOCK_SIZE);
+ GPR_ASSERT(GPR_SLICE_LENGTH(outbuf) <= uint_max);
+ zs->avail_out = (uInt)GPR_SLICE_LENGTH(outbuf);
+ zs->next_out = GPR_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;
+ gpr_slice_buffer_add_indexed(output, outbuf);
+
+ return 1;
+
+error:
+ gpr_slice_unref(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(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));
+ 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(&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));
+ zs.zalloc = zalloc_gpr;
+ zs.zfree = zfree_gpr;
+ r = inflateInit2(&zs, 15 | (gzip ? 16 : 0));
+ GPR_ASSERT(r == Z_OK);
+ 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;
+}
+
+static 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;
+}
diff --git a/src/core/lib/compression/message_compress.h b/src/core/lib/compression/message_compress.h
new file mode 100644
index 0000000000..c69eaaf006
--- /dev/null
+++ b/src/core/lib/compression/message_compress.h
@@ -0,0 +1,52 @@
+/*
+ *
+ * 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.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_COMPRESSION_MESSAGE_COMPRESS_H
+#define GRPC_CORE_LIB_COMPRESSION_MESSAGE_COMPRESS_H
+
+#include <grpc/compression.h>
+#include <grpc/support/slice_buffer.h>
+
+/* compress 'input' to 'output' using 'algorithm'.
+ On success, appends compressed slices to output and returns 1.
+ On failure, appends uncompressed slices to output and returns 0. */
+int grpc_msg_compress(grpc_compression_algorithm algorithm,
+ gpr_slice_buffer* input, gpr_slice_buffer* output);
+
+/* decompress 'input' to 'output' using 'algorithm'.
+ On success, appends slices to output and returns 1.
+ On failure, output is unchanged, and returns 0. */
+int grpc_msg_decompress(grpc_compression_algorithm algorithm,
+ gpr_slice_buffer* input, gpr_slice_buffer* output);
+
+#endif /* GRPC_CORE_LIB_COMPRESSION_MESSAGE_COMPRESS_H */