1 files changed, 82 insertions, 0 deletions
diff --git a/src/core/ext/census/grpc_plugin.c b/src/core/ext/census/grpc_plugin.c
new file mode 100644
index 0000000000..e43ceafd0c
--- /dev/null
+++ b/src/core/ext/census/grpc_plugin.c
@@ -0,0 +1,82 @@
+/*
+ *
+ * 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 <limits.h>
+#include <string.h>
+
+#include <grpc/census.h>
+
+#include "src/core/ext/census/grpc_filter.h"
+#include "src/core/lib/channel/channel_stack_builder.h"
+#include "src/core/lib/surface/channel_init.h"
+
+static bool is_census_enabled(const grpc_channel_args *a) {
+  size_t i;
+  if (a == NULL) return 0;
+  for (i = 0; i < a->num_args; i++) {
+    if (0 == strcmp(a->args[i].key, GRPC_ARG_ENABLE_CENSUS)) {
+      return a->args[i].value.integer != 0 && census_enabled();
+    }
+  }
+  return census_enabled();
+}
+
+static bool maybe_add_census_filter(grpc_channel_stack_builder *builder,
+                                    void *arg) {
+  const grpc_channel_args *args =
+      grpc_channel_stack_builder_get_channel_arguments(builder);
+  if (is_census_enabled(args)) {
+    return grpc_channel_stack_builder_prepend_filter(
+        builder, (const grpc_channel_filter *)arg, NULL, NULL);
+  }
+  return true;
+}
+
+void census_grpc_plugin_init(void) {
+  /* Only initialize census if no one else has and some features are
+   * available. */
+  if (census_enabled() == CENSUS_FEATURE_NONE &&
+      census_supported() != CENSUS_FEATURE_NONE) {
+    if (census_initialize(census_supported())) { /* enable all features. */
+      gpr_log(GPR_ERROR, "Could not initialize census.");
+    }
+  }
+  grpc_channel_init_register_stage(GRPC_CLIENT_CHANNEL, INT_MAX,
+                                   maybe_add_census_filter,
+                                   (void *)&grpc_client_census_filter);
+  grpc_channel_init_register_stage(GRPC_SERVER_CHANNEL, INT_MAX,
+                                   maybe_add_census_filter,
+                                   (void *)&grpc_server_census_filter);
+}
+
+void census_grpc_plugin_shutdown(void) { census_shutdown(); }