Initial checkin of gRPC to third_party/

third_party/grpc/src/core/census/grpc_filter.c

Index: third_party/grpc/src/core/census/grpc_filter.c
diff --git a/third_party/grpc/src/core/census/grpc_filter.c b/third_party/grpc/src/core/census/grpc_filter.c
new file mode 100644
index 0000000000000000000000000000000000000000..c8aaf31e2d3a688717c669c0f9242f9f8814cfc8
--- /dev/null
+++ b/third_party/grpc/src/core/census/grpc_filter.c
@@ -0,0 +1,184 @@
+/*
+ *
+ * Copyright 2015-2016, 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/census/grpc_filter.h"
+
+#include <stdio.h>
+#include <string.h>
+
+#include <grpc/census.h>
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+#include <grpc/support/slice.h>
+#include <grpc/support/time.h>
+
+#include "src/core/channel/channel_stack.h"
+#include "src/core/statistics/census_interface.h"
+#include "src/core/statistics/census_rpc_stats.h"
+#include "src/core/transport/static_metadata.h"
+
+typedef struct call_data {
+  census_op_id op_id;
+  census_context *ctxt;
+  gpr_timespec start_ts;
+  int error;
+
+  /* recv callback */
+  grpc_metadata_batch *recv_initial_metadata;
+  grpc_closure *on_done_recv;
+  grpc_closure finish_recv;
+} call_data;
+
+typedef struct channel_data { uint8_t unused; } channel_data;
+
+static void extract_and_annotate_method_tag(grpc_metadata_batch *md,
+                                            call_data *calld,
+                                            channel_data *chand) {
+  grpc_linked_mdelem *m;
+  for (m = md->list.head; m != NULL; m = m->next) {
+    if (m->md->key == GRPC_MDSTR_PATH) {
+      gpr_log(GPR_DEBUG, "%s",
+              (const char *)GPR_SLICE_START_PTR(m->md->value->slice));
+      /* Add method tag here */
+    }
+  }
+}
+
+static void client_mutate_op(grpc_call_element *elem,
+                             grpc_transport_stream_op *op) {
+  call_data *calld = elem->call_data;
+  channel_data *chand = elem->channel_data;
+  if (op->send_initial_metadata) {
+    extract_and_annotate_method_tag(op->send_initial_metadata, calld, chand);
+  }
+}
+
+static void client_start_transport_op(grpc_exec_ctx *exec_ctx,
+                                      grpc_call_element *elem,
+                                      grpc_transport_stream_op *op) {
+  client_mutate_op(elem, op);
+  grpc_call_next_op(exec_ctx, elem, op);
+}
+
+static void server_on_done_recv(grpc_exec_ctx *exec_ctx, void *ptr,
+                                bool success) {
+  grpc_call_element *elem = ptr;
+  call_data *calld = elem->call_data;
+  channel_data *chand = elem->channel_data;
+  if (success) {
+    extract_and_annotate_method_tag(calld->recv_initial_metadata, calld, chand);
+  }
+  calld->on_done_recv->cb(exec_ctx, calld->on_done_recv->cb_arg, success);
+}
+
+static void server_mutate_op(grpc_call_element *elem,
+                             grpc_transport_stream_op *op) {
+  call_data *calld = elem->call_data;
+  if (op->recv_initial_metadata) {
+    /* substitute our callback for the op callback */
+    calld->recv_initial_metadata = op->recv_initial_metadata;
+    calld->on_done_recv = op->recv_initial_metadata_ready;
+    op->recv_initial_metadata_ready = &calld->finish_recv;
+  }
+}
+
+static void server_start_transport_op(grpc_exec_ctx *exec_ctx,
+                                      grpc_call_element *elem,
+                                      grpc_transport_stream_op *op) {
+  /* TODO(ctiller): this code fails. I don't know why. I expect it's
+                    incomplete, and someone should look at it soon.
+
+  call_data *calld = elem->call_data;
+  GPR_ASSERT((calld->op_id.upper != 0) || (calld->op_id.lower != 0)); */
+  server_mutate_op(elem, op);
+  grpc_call_next_op(exec_ctx, elem, op);
+}
+
+static void client_init_call_elem(grpc_exec_ctx *exec_ctx,
+                                  grpc_call_element *elem,
+                                  grpc_call_element_args *args) {
+  call_data *d = elem->call_data;
+  GPR_ASSERT(d != NULL);
+  memset(d, 0, sizeof(*d));
+  d->start_ts = gpr_now(GPR_CLOCK_REALTIME);
+}
+
+static void client_destroy_call_elem(grpc_exec_ctx *exec_ctx,
+                                     grpc_call_element *elem) {
+  call_data *d = elem->call_data;
+  GPR_ASSERT(d != NULL);
+  /* TODO(hongyu): record rpc client stats and census_rpc_end_op here */
+}
+
+static void server_init_call_elem(grpc_exec_ctx *exec_ctx,
+                                  grpc_call_element *elem,
+                                  grpc_call_element_args *args) {
+  call_data *d = elem->call_data;
+  GPR_ASSERT(d != NULL);
+  memset(d, 0, sizeof(*d));
+  d->start_ts = gpr_now(GPR_CLOCK_REALTIME);
+  /* TODO(hongyu): call census_tracing_start_op here. */
+  grpc_closure_init(&d->finish_recv, server_on_done_recv, elem);
+}
+
+static void server_destroy_call_elem(grpc_exec_ctx *exec_ctx,
+                                     grpc_call_element *elem) {
+  call_data *d = elem->call_data;
+  GPR_ASSERT(d != NULL);
+  /* TODO(hongyu): record rpc server stats and census_tracing_end_op here */
+}
+
+static void init_channel_elem(grpc_exec_ctx *exec_ctx,
+                              grpc_channel_element *elem,
+                              grpc_channel_element_args *args) {
+  channel_data *chand = elem->channel_data;
+  GPR_ASSERT(chand != NULL);
+}
+
+static void destroy_channel_elem(grpc_exec_ctx *exec_ctx,
+                                 grpc_channel_element *elem) {
+  channel_data *chand = elem->channel_data;
+  GPR_ASSERT(chand != NULL);
+}
+
+const grpc_channel_filter grpc_client_census_filter = {
+    client_start_transport_op, grpc_channel_next_op, sizeof(call_data),
+    client_init_call_elem, grpc_call_stack_ignore_set_pollset,
+    client_destroy_call_elem, sizeof(channel_data), init_channel_elem,
+    destroy_channel_elem, grpc_call_next_get_peer, "census-client"};
+
+const grpc_channel_filter grpc_server_census_filter = {
+    server_start_transport_op, grpc_channel_next_op, sizeof(call_data),
+    server_init_call_elem, grpc_call_stack_ignore_set_pollset,
+    server_destroy_call_elem, sizeof(channel_data), init_channel_elem,
+    destroy_channel_elem, grpc_call_next_get_peer, "census-server"};