diff options
Diffstat (limited to 'src/core/channel/compress_filter.c')
| -rw-r--r-- | src/core/channel/compress_filter.c | 190 |
1 files changed, 190 insertions, 0 deletions
diff --git a/src/core/channel/compress_filter.c b/src/core/channel/compress_filter.c new file mode 100644 index 0000000000..5da82edb3c --- /dev/null +++ b/src/core/channel/compress_filter.c @@ -0,0 +1,190 @@ +/* + * + * 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 <string.h> + +#include "src/core/channel/compress_filter.h" +#include "src/core/channel/channel_args.h" +#include "src/core/compression/message_compress.h" +#include <grpc/compression.h> +#include <grpc/support/log.h> +#include <grpc/support/slice_buffer.h> + +typedef struct call_data { + gpr_slice_buffer slices; + int remaining_slice_bytes; + int dont_compress; /**< whether skip compression for this specific call */ +} call_data; + +typedef struct channel_data { + grpc_compression_algorithm compress_algorithm; +} channel_data; + +static void compress_send_sb(grpc_compression_algorithm algorithm, + gpr_slice_buffer *slices) { + gpr_slice_buffer tmp; + gpr_slice_buffer_init(&tmp); + if (!grpc_msg_compress(algorithm, slices, &tmp)) { + gpr_log(GPR_INFO, "Not compressed!"); + } + gpr_slice_buffer_swap(slices, &tmp); + gpr_slice_buffer_destroy(&tmp); +} + +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, j; + /* buffer up slices until we've processed all the expected ones (as given by + * GRPC_OP_BEGIN_MESSAGE) */ + for (i = 0; i < send_ops->nops; ++i) { + grpc_stream_op *sop = &send_ops->ops[i]; + switch (sop->type) { + case GRPC_OP_BEGIN_MESSAGE: + calld->remaining_slice_bytes = sop->data.begin_message.length; + calld->dont_compress = + !!(sop->data.begin_message.flags & GRPC_WRITE_NO_COMPRESS); + break; + case GRPC_OP_SLICE: + if (calld->dont_compress) return; + GPR_ASSERT(calld->remaining_slice_bytes > 0); + /* add to calld->slices */ + gpr_slice_buffer_add(&calld->slices, sop->data.slice); + calld->remaining_slice_bytes -= GPR_SLICE_LENGTH(sop->data.slice); + if (calld->remaining_slice_bytes == 0) { + /* compress */ + compress_send_sb(channeld->compress_algorithm, &calld->slices); + } + break; + case GRPC_NO_OP: + case GRPC_OP_METADATA: + ; /* fallthrough, ignore */ + } + } + + /* at this point, calld->slices contains the *compressed* slices from + * send_ops->ops[*]->data.slice. We now replace these input slices with the + * compressed ones. */ + for (i = 0, j = 0; i < send_ops->nops; ++i) { + grpc_stream_op *sop = &send_ops->ops[i]; + GPR_ASSERT(j < calld->slices.count); + switch (sop->type) { + case GRPC_OP_SLICE: + gpr_slice_unref(sop->data.slice); + sop->data.slice = gpr_slice_ref(calld->slices.slices[j++]); + break; + case GRPC_OP_BEGIN_MESSAGE: + case GRPC_NO_OP: + case GRPC_OP_METADATA: + ; /* fallthrough, ignore */ + } + } +} + +/* 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_op(grpc_call_element *elem, + grpc_transport_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); +} + +/* Called on special channel events, such as disconnection or new incoming + calls on the server */ +static void channel_op(grpc_channel_element *elem, + grpc_channel_element *from_elem, grpc_channel_op *op) { + switch (op->type) { + default: + grpc_channel_next_op(elem, op); + break; + } +} + +/* Constructor for call_data */ +static void init_call_elem(grpc_call_element *elem, + const void *server_transport_data, + grpc_transport_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); + + 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, + const grpc_channel_args *args, grpc_mdctx *mdctx, + int is_first, int is_last) { + channel_data *channeld = elem->channel_data; + channeld->compress_algorithm = grpc_compression_algorithm_for_level( + grpc_channel_args_get_compression_level(args)); + /*We shouldn't be in this filter if compression is disabled. */ + GPR_ASSERT(channeld->compress_algorithm != GRPC_COMPRESS_NONE); + + /* The first and the last filters tend to be implemented differently to + handle the case that there's no 'next' filter to call on the up or down + path */ + GPR_ASSERT(!is_first); + GPR_ASSERT(!is_last); +} + +/* Destructor for channel data */ +static void destroy_channel_elem(grpc_channel_element *elem) { + /* empty for now */ +} + +const grpc_channel_filter grpc_compress_filter = { + compress_start_transport_op, channel_op, sizeof(call_data), init_call_elem, + destroy_call_elem, sizeof(channel_data), init_channel_elem, + destroy_channel_elem, "compress"}; |