Rename compress_filter --> message_compress_filter

2 files changed, 420 insertions, 0 deletions

diff --git a/src/core/ext/filters/http/message_compress/message_compress_filter.c b/src/core/ext/filters/http/message_compress/message_compress_filter.c
new file mode 100644
index 0000000000..f110e7beb6
--- /dev/null
+++ b/src/core/ext/filters/http/message_compress/message_compress_filter.c
@@ -0,0 +1,353 @@
+/*
+ *
+ * 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/slice_buffer.h>
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+
+#include "src/core/ext/filters/http/message_compress/message_compress_filter.h"
+#include "src/core/lib/channel/channel_args.h"
+#include "src/core/lib/compression/algorithm_metadata.h"
+#include "src/core/lib/compression/message_compress.h"
+#include "src/core/lib/profiling/timers.h"
+#include "src/core/lib/slice/slice_internal.h"
+#include "src/core/lib/slice/slice_string_helpers.h"
+#include "src/core/lib/support/string.h"
+#include "src/core/lib/transport/static_metadata.h"
+
+int grpc_compression_trace = 0;
+
+typedef struct call_data {
+  grpc_slice_buffer slices; /**< Buffers up input slices to be compressed */
+  grpc_linked_mdelem compression_algorithm_storage;
+  grpc_linked_mdelem accept_encoding_storage;
+  uint32_t remaining_slice_bytes;
+  /** 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;
+
+  grpc_transport_stream_op_batch *send_op;
+  uint32_t send_length;
+  uint32_t send_flags;
+  grpc_slice incoming_slice;
+  grpc_slice_buffer_stream replacement_stream;
+  grpc_closure *post_send;
+  grpc_closure send_done;
+  grpc_closure got_slice;
+} call_data;
+
+typedef struct channel_data {
+  /** The default, channel-level, compression algorithm */
+  grpc_compression_algorithm default_compression_algorithm;
+  /** Bitset of enabled algorithms */
+  uint32_t enabled_algorithms_bitset;
+  /** Supported compression algorithms */
+  uint32_t supported_compression_algorithms;
+} channel_data;
+
+static int skip_compression(grpc_call_element *elem, uint32_t flags) {
+  call_data *calld = elem->call_data;
+  channel_data *channeld = elem->channel_data;
+
+  if (flags & (GRPC_WRITE_NO_COMPRESS | GRPC_WRITE_INTERNAL_COMPRESS)) {
+    return 1;
+  }
+  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;
+}
+
+/** Filter initial metadata */
+static grpc_error *process_send_initial_metadata(
+    grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
+    grpc_metadata_batch *initial_metadata) GRPC_MUST_USE_RESULT;
+static grpc_error *process_send_initial_metadata(
+    grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
+    grpc_metadata_batch *initial_metadata) {
+  call_data *calld = elem->call_data;
+  channel_data *channeld = elem->channel_data;
+  /* Parse incoming request for compression. If any, it'll be available
+   * at calld->compression_algorithm */
+  if (initial_metadata->idx.named.grpc_internal_encoding_request != NULL) {
+    grpc_mdelem md =
+        initial_metadata->idx.named.grpc_internal_encoding_request->md;
+    if (!grpc_compression_algorithm_parse(GRPC_MDVALUE(md),
+                                          &calld->compression_algorithm)) {
+      char *val = grpc_slice_to_c_string(GRPC_MDVALUE(md));
+      gpr_log(GPR_ERROR,
+              "Invalid compression algorithm: '%s' (unknown). Ignoring.", val);
+      gpr_free(val);
+      calld->compression_algorithm = GRPC_COMPRESS_NONE;
+    }
+    if (!GPR_BITGET(channeld->enabled_algorithms_bitset,
+                    calld->compression_algorithm)) {
+      char *val = grpc_slice_to_c_string(GRPC_MDVALUE(md));
+      gpr_log(GPR_ERROR,
+              "Invalid compression algorithm: '%s' (previously disabled). "
+              "Ignoring.",
+              val);
+      gpr_free(val);
+      calld->compression_algorithm = GRPC_COMPRESS_NONE;
+    }
+    calld->has_compression_algorithm = 1;
+
+    grpc_metadata_batch_remove(
+        exec_ctx, initial_metadata,
+        initial_metadata->idx.named.grpc_internal_encoding_request);
+  } else {
+    /* 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_error *error = GRPC_ERROR_NONE;
+  /* hint compression algorithm */
+  if (calld->compression_algorithm != GRPC_COMPRESS_NONE) {
+    error = grpc_metadata_batch_add_tail(
+        exec_ctx, initial_metadata, &calld->compression_algorithm_storage,
+        grpc_compression_encoding_mdelem(calld->compression_algorithm));
+  }
+
+  if (error != GRPC_ERROR_NONE) return error;
+
+  /* convey supported compression algorithms */
+  error = grpc_metadata_batch_add_tail(
+      exec_ctx, initial_metadata, &calld->accept_encoding_storage,
+      GRPC_MDELEM_ACCEPT_ENCODING_FOR_ALGORITHMS(
+          channeld->supported_compression_algorithms));
+
+  return error;
+}
+
+static void continue_send_message(grpc_exec_ctx *exec_ctx,
+                                  grpc_call_element *elem);
+
+static void send_done(grpc_exec_ctx *exec_ctx, void *elemp, grpc_error *error) {
+  grpc_call_element *elem = elemp;
+  call_data *calld = elem->call_data;
+  grpc_slice_buffer_reset_and_unref_internal(exec_ctx, &calld->slices);
+  calld->post_send->cb(exec_ctx, calld->post_send->cb_arg, error);
+}
+
+static void finish_send_message(grpc_exec_ctx *exec_ctx,
+                                grpc_call_element *elem) {
+  call_data *calld = elem->call_data;
+  int did_compress;
+  grpc_slice_buffer tmp;
+  grpc_slice_buffer_init(&tmp);
+  did_compress = grpc_msg_compress(exec_ctx, calld->compression_algorithm,
+                                   &calld->slices, &tmp);
+  if (did_compress) {
+    if (grpc_compression_trace) {
+      char *algo_name;
+      const size_t before_size = calld->slices.length;
+      const size_t after_size = tmp.length;
+      const float savings_ratio = 1.0f - (float)after_size / (float)before_size;
+      GPR_ASSERT(grpc_compression_algorithm_name(calld->compression_algorithm,
+                                                 &algo_name));
+      gpr_log(GPR_DEBUG, "Compressed[%s] %" PRIuPTR " bytes vs. %" PRIuPTR
+                         " bytes (%.2f%% savings)",
+              algo_name, before_size, after_size, 100 * savings_ratio);
+    }
+    grpc_slice_buffer_swap(&calld->slices, &tmp);
+    calld->send_flags |= GRPC_WRITE_INTERNAL_COMPRESS;
+  } else {
+    if (grpc_compression_trace) {
+      char *algo_name;
+      GPR_ASSERT(grpc_compression_algorithm_name(calld->compression_algorithm,
+                                                 &algo_name));
+      gpr_log(GPR_DEBUG,
+              "Algorithm '%s' enabled but decided not to compress. Input size: "
+              "%" PRIuPTR,
+              algo_name, calld->slices.length);
+    }
+  }
+
+  grpc_slice_buffer_destroy_internal(exec_ctx, &tmp);
+
+  grpc_slice_buffer_stream_init(&calld->replacement_stream, &calld->slices,
+                                calld->send_flags);
+  calld->send_op->payload->send_message.send_message =
+      &calld->replacement_stream.base;
+  calld->post_send = calld->send_op->on_complete;
+  calld->send_op->on_complete = &calld->send_done;
+
+  grpc_call_next_op(exec_ctx, elem, calld->send_op);
+}
+
+static void got_slice(grpc_exec_ctx *exec_ctx, void *elemp, grpc_error *error) {
+  grpc_call_element *elem = elemp;
+  call_data *calld = elem->call_data;
+  grpc_slice_buffer_add(&calld->slices, calld->incoming_slice);
+  if (calld->send_length == calld->slices.length) {
+    finish_send_message(exec_ctx, elem);
+  } else {
+    continue_send_message(exec_ctx, elem);
+  }
+}
+
+static void continue_send_message(grpc_exec_ctx *exec_ctx,
+                                  grpc_call_element *elem) {
+  call_data *calld = elem->call_data;
+  while (grpc_byte_stream_next(
+      exec_ctx, calld->send_op->payload->send_message.send_message,
+      &calld->incoming_slice, ~(size_t)0, &calld->got_slice)) {
+    grpc_slice_buffer_add(&calld->slices, calld->incoming_slice);
+    if (calld->send_length == calld->slices.length) {
+      finish_send_message(exec_ctx, elem);
+      break;
+    }
+  }
+}
+
+static void compress_start_transport_stream_op_batch(
+    grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
+    grpc_transport_stream_op_batch *op) {
+  call_data *calld = elem->call_data;
+
+  GPR_TIMER_BEGIN("compress_start_transport_stream_op_batch", 0);
+
+  if (op->send_initial_metadata) {
+    grpc_error *error = process_send_initial_metadata(
+        exec_ctx, elem,
+        op->payload->send_initial_metadata.send_initial_metadata);
+    if (error != GRPC_ERROR_NONE) {
+      grpc_transport_stream_op_batch_finish_with_failure(exec_ctx, op, error);
+      return;
+    }
+  }
+  if (op->send_message &&
+      !skip_compression(elem, op->payload->send_message.send_message->flags)) {
+    calld->send_op = op;
+    calld->send_length = op->payload->send_message.send_message->length;
+    calld->send_flags = op->payload->send_message.send_message->flags;
+    continue_send_message(exec_ctx, elem);
+  } else {
+    /* pass control down the stack */
+    grpc_call_next_op(exec_ctx, elem, op);
+  }
+
+  GPR_TIMER_END("compress_start_transport_stream_op_batch", 0);
+}
+
+/* Constructor for call_data */
+static grpc_error *init_call_elem(grpc_exec_ctx *exec_ctx,
+                                  grpc_call_element *elem,
+                                  const grpc_call_element_args *args) {
+  /* grab pointers to our data from the call element */
+  call_data *calld = elem->call_data;
+
+  /* initialize members */
+  grpc_slice_buffer_init(&calld->slices);
+  calld->has_compression_algorithm = 0;
+  grpc_closure_init(&calld->got_slice, got_slice, elem,
+                    grpc_schedule_on_exec_ctx);
+  grpc_closure_init(&calld->send_done, send_done, elem,
+                    grpc_schedule_on_exec_ctx);
+
+  return GRPC_ERROR_NONE;
+}
+
+/* Destructor for call_data */
+static void destroy_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
+                              const grpc_call_final_info *final_info,
+                              grpc_closure *ignored) {
+  /* grab pointers to our data from the call element */
+  call_data *calld = elem->call_data;
+  grpc_slice_buffer_destroy_internal(exec_ctx, &calld->slices);
+}
+
+/* Constructor for channel_data */
+static grpc_error *init_channel_elem(grpc_exec_ctx *exec_ctx,
+                                     grpc_channel_element *elem,
+                                     grpc_channel_element_args *args) {
+  channel_data *channeld = elem->channel_data;
+
+  channeld->enabled_algorithms_bitset =
+      grpc_channel_args_compression_algorithm_get_states(args->channel_args);
+
+  channeld->default_compression_algorithm =
+      grpc_channel_args_get_compression_algorithm(args->channel_args);
+  /* Make sure the default isn't disabled. */
+  if (!GPR_BITGET(channeld->enabled_algorithms_bitset,
+                  channeld->default_compression_algorithm)) {
+    gpr_log(GPR_DEBUG,
+            "compression algorithm %d not enabled: switching to none",
+            channeld->default_compression_algorithm);
+    channeld->default_compression_algorithm = GRPC_COMPRESS_NONE;
+  }
+
+  channeld->supported_compression_algorithms = 1; /* always support identity */
+  for (grpc_compression_algorithm algo_idx = 1;
+       algo_idx < GRPC_COMPRESS_ALGORITHMS_COUNT; ++algo_idx) {
+    /* skip disabled algorithms */
+    if (!GPR_BITGET(channeld->enabled_algorithms_bitset, algo_idx)) {
+      continue;
+    }
+    channeld->supported_compression_algorithms |= 1u << algo_idx;
+  }
+
+  GPR_ASSERT(!args->is_last);
+  return GRPC_ERROR_NONE;
+}
+
+/* Destructor for channel data */
+static void destroy_channel_elem(grpc_exec_ctx *exec_ctx,
+                                 grpc_channel_element *elem) {}
+
+const grpc_channel_filter grpc_compress_filter = {
+    compress_start_transport_stream_op_batch,
+    grpc_channel_next_op,
+    sizeof(call_data),
+    init_call_elem,
+    grpc_call_stack_ignore_set_pollset_or_pollset_set,
+    destroy_call_elem,
+    sizeof(channel_data),
+    init_channel_elem,
+    destroy_channel_elem,
+    grpc_call_next_get_peer,
+    grpc_channel_next_get_info,
+    "compress"};
diff --git a/src/core/ext/filters/http/message_compress/message_compress_filter.h b/src/core/ext/filters/http/message_compress/message_compress_filter.h
new file mode 100644
index 0000000000..68d2b8766a
--- /dev/null
+++ b/src/core/ext/filters/http/message_compress/message_compress_filter.h
@@ -0,0 +1,67 @@
+/*
+ *
+ * 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_EXT_FILTERS_HTTP_COMPRESS_COMPRESS_FILTER_H
+#define GRPC_CORE_EXT_FILTERS_HTTP_COMPRESS_COMPRESS_FILTER_H
+
+#include <grpc/impl/codegen/compression_types.h>
+
+#include "src/core/lib/channel/channel_stack.h"
+
+extern int grpc_compression_trace;
+
+/** Compression filter for outgoing data.
+ *
+ * See <grpc/compression.h> for the available compression settings.
+ *
+ * Compression settings may come from:
+ *  - Channel configuration, as established at channel creation time.
+ *  - The metadata accompanying the outgoing data to be compressed. This is
+ *    taken as a request only. We may choose not to honor it. The metadata key
+ *    is given by \a GRPC_COMPRESSION_REQUEST_ALGORITHM_MD_KEY.
+ *
+ * Compression can be disabled for concrete messages (for instance in order to
+ * prevent CRIME/BEAST type attacks) by having the GRPC_WRITE_NO_COMPRESS set in
+ * the BEGIN_MESSAGE flags.
+ *
+ * The attempted compression mechanism is added to the resulting initial
+ * metadata under the'grpc-encoding' key.
+ *
+ * If compression is actually performed, BEGIN_MESSAGE's flag is modified to
+ * incorporate GRPC_WRITE_INTERNAL_COMPRESS. Otherwise, and regardless of the
+ * aforementioned 'grpc-encoding' metadata value, data will pass through
+ * uncompressed. */
+
+extern const grpc_channel_filter grpc_compress_filter;
+
+#endif /* GRPC_CORE_EXT_FILTERS_HTTP_COMPRESS_COMPRESS_FILTER_H */