| /* |
| * |
| * 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 <assert.h> |
| #include <string.h> |
| |
| #include <grpc/compression.h> |
| #include <grpc/support/log.h> |
| #include <grpc/support/slice_buffer.h> |
| |
| #include "src/core/channel/compress_filter.h" |
| #include "src/core/channel/channel_args.h" |
| #include "src/core/compression/message_compress.h" |
| |
| typedef struct call_data { |
| gpr_slice_buffer slices; /**< Buffers up input slices to be compressed */ |
| grpc_linked_mdelem compression_algorithm_storage; |
| int remaining_slice_bytes; /**< Input data to be read, as per BEGIN_MESSAGE */ |
| int written_initial_metadata; /**< Already processed initial md? */ |
| /** Compression algorithm we'll try to use. It may be given by incoming |
| * metadata, or by the channel's default compression settings. */ |
| grpc_compression_algorithm compression_algorithm; |
| /** If true, contents of \a compression_algorithm are authoritative */ |
| int has_compression_algorithm; |
| } call_data; |
| |
| typedef struct channel_data { |
| /** Metadata key for the incoming (requested) compression algorithm */ |
| grpc_mdstr *mdstr_request_compression_algorithm_key; |
| /** Metadata key for the outgoing (used) compression algorithm */ |
| grpc_mdstr *mdstr_outgoing_compression_algorithm_key; |
| /** Precomputed metadata elements for all available compression algorithms */ |
| grpc_mdelem *mdelem_compression_algorithms[GRPC_COMPRESS_ALGORITHMS_COUNT]; |
| /** The default, channel-level, compression algorithm */ |
| grpc_compression_algorithm default_compression_algorithm; |
| } channel_data; |
| |
| /** Compress \a slices in place using \a algorithm. Returns 1 if compression did |
| * actually happen, 0 otherwise (for example if the compressed output size was |
| * larger than the raw input). |
| * |
| * Returns 1 if the data was actually compress and 0 otherwise. */ |
| static int compress_send_sb(grpc_compression_algorithm algorithm, |
| gpr_slice_buffer *slices) { |
| int did_compress; |
| gpr_slice_buffer tmp; |
| gpr_slice_buffer_init(&tmp); |
| did_compress = grpc_msg_compress(algorithm, slices, &tmp); |
| if (did_compress) { |
| gpr_slice_buffer_swap(slices, &tmp); |
| } |
| gpr_slice_buffer_destroy(&tmp); |
| return did_compress; |
| } |
| |
| /** For each \a md element from the incoming metadata, filter out the entry for |
| * "grpc-encoding", using its value to populate the call data's |
| * compression_algorithm field. */ |
| static grpc_mdelem* compression_md_filter(void *user_data, grpc_mdelem *md) { |
| grpc_call_element *elem = user_data; |
| call_data *calld = elem->call_data; |
| channel_data *channeld = elem->channel_data; |
| |
| if (md->key == channeld->mdstr_request_compression_algorithm_key) { |
| const char *md_c_str = grpc_mdstr_as_c_string(md->value); |
| if (!grpc_compression_algorithm_parse(md_c_str, |
| &calld->compression_algorithm)) { |
| gpr_log(GPR_ERROR, "Invalid compression algorithm: '%s'. Ignoring.", |
| md_c_str); |
| calld->compression_algorithm = GRPC_COMPRESS_NONE; |
| } |
| calld->has_compression_algorithm = 1; |
| return NULL; |
| } |
| |
| return md; |
| } |
| |
| static int skip_compression(channel_data *channeld, call_data *calld) { |
| if (calld->has_compression_algorithm) { |
| if (calld->compression_algorithm == GRPC_COMPRESS_NONE) { |
| return 1; |
| } |
| return 0; /* we have an actual call-specific algorithm */ |
| } |
| /* no per-call compression override */ |
| return channeld->default_compression_algorithm == GRPC_COMPRESS_NONE; |
| } |
| |
| /** Assembles a new grpc_stream_op_buffer with the compressed slices, modifying |
| * the associated GRPC_OP_BEGIN_MESSAGE accordingly (new compressed length, |
| * flags indicating compression is in effect) and replaces \a send_ops with it. |
| * */ |
| static void finish_compressed_sopb(grpc_stream_op_buffer *send_ops, |
| grpc_call_element *elem) { |
| size_t i; |
| call_data *calld = elem->call_data; |
| int new_slices_added = 0; /* GPR_FALSE */ |
| grpc_metadata_batch metadata; |
| grpc_stream_op_buffer new_send_ops; |
| grpc_sopb_init(&new_send_ops); |
| |
| for (i = 0; i < send_ops->nops; i++) { |
| grpc_stream_op *sop = &send_ops->ops[i]; |
| switch (sop->type) { |
| case GRPC_OP_BEGIN_MESSAGE: |
| grpc_sopb_add_begin_message( |
| &new_send_ops, calld->slices.length, |
| sop->data.begin_message.flags | GRPC_WRITE_INTERNAL_COMPRESS); |
| break; |
| case GRPC_OP_SLICE: |
| /* Once we reach the slices section of the original buffer, simply add |
| * all the new (compressed) slices. We obviously want to do this only |
| * once, hence the "new_slices_added" guard. */ |
| if (!new_slices_added) { |
| size_t j; |
| for (j = 0; j < calld->slices.count; ++j) { |
| grpc_sopb_add_slice(&new_send_ops, |
| gpr_slice_ref(calld->slices.slices[j])); |
| } |
| new_slices_added = 1; /* GPR_TRUE */ |
| } |
| break; |
| case GRPC_OP_METADATA: |
| /* move the metadata to the new buffer. */ |
| grpc_metadata_batch_move(&metadata, &sop->data.metadata); |
| grpc_sopb_add_metadata(&new_send_ops, metadata); |
| break; |
| case GRPC_NO_OP: |
| break; |
| } |
| } |
| grpc_sopb_swap(send_ops, &new_send_ops); |
| grpc_sopb_destroy(&new_send_ops); |
| } |
| |
| /** Filter's "main" function, called for any incoming grpc_transport_stream_op |
| * instance that holds a non-zero number of send operations, accesible to this |
| * function in \a send_ops. */ |
| static void process_send_ops(grpc_call_element *elem, |
| grpc_stream_op_buffer *send_ops) { |
| call_data *calld = elem->call_data; |
| channel_data *channeld = elem->channel_data; |
| size_t i; |
| int did_compress = 0; |
| |
| /* In streaming calls, we need to reset the previously accumulated slices */ |
| gpr_slice_buffer_reset_and_unref(&calld->slices); |
| for (i = 0; i < send_ops->nops; ++i) { |
| grpc_stream_op *sop = &send_ops->ops[i]; |
| switch (sop->type) { |
| case GRPC_OP_BEGIN_MESSAGE: |
| /* buffer up slices until we've processed all the expected ones (as |
| * given by GRPC_OP_BEGIN_MESSAGE) */ |
| calld->remaining_slice_bytes = sop->data.begin_message.length; |
| if (sop->data.begin_message.flags & GRPC_WRITE_NO_COMPRESS) { |
| calld->has_compression_algorithm = 1; /* GPR_TRUE */ |
| calld->compression_algorithm = GRPC_COMPRESS_NONE; |
| } |
| break; |
| case GRPC_OP_METADATA: |
| if (!calld->written_initial_metadata) { |
| /* Parse incoming request for compression. If any, it'll be available |
| * at calld->compression_algorithm */ |
| grpc_metadata_batch_filter(&(sop->data.metadata), |
| compression_md_filter, elem); |
| if (!calld->has_compression_algorithm) { |
| /* If no algorithm was found in the metadata and we aren't |
| * exceptionally skipping compression, fall back to the channel |
| * default */ |
| calld->compression_algorithm = |
| channeld->default_compression_algorithm; |
| calld->has_compression_algorithm = 1; /* GPR_TRUE */ |
| } |
| grpc_metadata_batch_add_tail( |
| &(sop->data.metadata), &calld->compression_algorithm_storage, |
| grpc_mdelem_ref(channeld->mdelem_compression_algorithms |
| [calld->compression_algorithm])); |
| calld->written_initial_metadata = 1; /* GPR_TRUE */ |
| } |
| break; |
| case GRPC_OP_SLICE: |
| if (skip_compression(channeld, calld)) continue; |
| GPR_ASSERT(calld->remaining_slice_bytes > 0); |
| /* Increase input ref count, gpr_slice_buffer_add takes ownership. */ |
| gpr_slice_buffer_add(&calld->slices, gpr_slice_ref(sop->data.slice)); |
| calld->remaining_slice_bytes -= GPR_SLICE_LENGTH(sop->data.slice); |
| if (calld->remaining_slice_bytes == 0) { |
| did_compress = |
| compress_send_sb(calld->compression_algorithm, &calld->slices); |
| } |
| break; |
| case GRPC_NO_OP: |
| break; |
| } |
| } |
| |
| /* Modify the send_ops stream_op_buffer depending on whether compression was |
| * carried out */ |
| if (did_compress) { |
| finish_compressed_sopb(send_ops, elem); |
| } |
| } |
| |
| /* Called either: |
| - in response to an API call (or similar) from above, to send something |
| - a network event (or similar) from below, to receive something |
| op contains type and call direction information, in addition to the data |
| that is being sent or received. */ |
| static void compress_start_transport_stream_op(grpc_call_element *elem, |
| grpc_transport_stream_op *op) { |
| if (op->send_ops && op->send_ops->nops > 0) { |
| process_send_ops(elem, op->send_ops); |
| } |
| |
| /* pass control down the stack */ |
| grpc_call_next_op(elem, op); |
| } |
| |
| /* Constructor for call_data */ |
| static void init_call_elem(grpc_call_element *elem, |
| const void *server_transport_data, |
| grpc_transport_stream_op *initial_op) { |
| /* grab pointers to our data from the call element */ |
| call_data *calld = elem->call_data; |
| |
| /* initialize members */ |
| gpr_slice_buffer_init(&calld->slices); |
| calld->has_compression_algorithm = 0; |
| calld->written_initial_metadata = 0; /* GPR_FALSE */ |
| |
| if (initial_op) { |
| if (initial_op->send_ops && initial_op->send_ops->nops > 0) { |
| process_send_ops(elem, initial_op->send_ops); |
| } |
| } |
| } |
| |
| /* Destructor for call_data */ |
| static void destroy_call_elem(grpc_call_element *elem) { |
| /* grab pointers to our data from the call element */ |
| call_data *calld = elem->call_data; |
| gpr_slice_buffer_destroy(&calld->slices); |
| } |
| |
| /* Constructor for channel_data */ |
| static void init_channel_elem(grpc_channel_element *elem, grpc_channel *master, |
| const grpc_channel_args *args, grpc_mdctx *mdctx, |
| int is_first, int is_last) { |
| channel_data *channeld = elem->channel_data; |
| grpc_compression_algorithm algo_idx; |
| |
| channeld->default_compression_algorithm = |
| grpc_channel_args_get_compression_algorithm(args); |
| |
| channeld->mdstr_request_compression_algorithm_key = |
| grpc_mdstr_from_string(mdctx, GRPC_COMPRESS_REQUEST_ALGORITHM_KEY); |
| |
| channeld->mdstr_outgoing_compression_algorithm_key = |
| grpc_mdstr_from_string(mdctx, "grpc-encoding"); |
| |
| for (algo_idx = 0; algo_idx < GRPC_COMPRESS_ALGORITHMS_COUNT; ++algo_idx) { |
| char *algorith_name; |
| GPR_ASSERT(grpc_compression_algorithm_name(algo_idx, &algorith_name) != 0); |
| channeld->mdelem_compression_algorithms[algo_idx] = |
| grpc_mdelem_from_metadata_strings( |
| mdctx, |
| grpc_mdstr_ref(channeld->mdstr_outgoing_compression_algorithm_key), |
| grpc_mdstr_from_string(mdctx, algorith_name)); |
| } |
| |
| GPR_ASSERT(!is_last); |
| } |
| |
| /* Destructor for channel data */ |
| static void destroy_channel_elem(grpc_channel_element *elem) { |
| channel_data *channeld = elem->channel_data; |
| grpc_compression_algorithm algo_idx; |
| |
| grpc_mdstr_unref(channeld->mdstr_request_compression_algorithm_key); |
| grpc_mdstr_unref(channeld->mdstr_outgoing_compression_algorithm_key); |
| for (algo_idx = 0; algo_idx < GRPC_COMPRESS_ALGORITHMS_COUNT; |
| ++algo_idx) { |
| grpc_mdelem_unref(channeld->mdelem_compression_algorithms[algo_idx]); |
| } |
| } |
| |
| const grpc_channel_filter grpc_compress_filter = { |
| compress_start_transport_stream_op, |
| grpc_channel_next_op, |
| sizeof(call_data), |
| init_call_elem, |
| destroy_call_elem, |
| sizeof(channel_data), |
| init_channel_elem, |
| destroy_channel_elem, |
| grpc_call_next_get_peer, |
| "compress"}; |