Initial checkin of gRPC to third_party/

third_party/grpc/test/cpp/util/metrics_server.h

+/*
+ *
+ * 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.
+ *is % allowed in string
+ */
+#ifndef GRPC_TEST_CPP_METRICS_SERVER_H
+#define GRPC_TEST_CPP_METRICS_SERVER_H
+
+#include <map>
+#include <mutex>
+
+#include "src/proto/grpc/testing/metrics.grpc.pb.h"
+#include "src/proto/grpc/testing/metrics.pb.h"
+
+/*
+ * This implements a Metrics server defined in
+ * src/proto/grpc/testing/metrics.proto. Any
+ * test service can use this to export Metrics (TODO (sreek): Only Gauges for
+ * now).
+ *
+ * Example:
+ *    MetricsServiceImpl metricsImpl;
+ *    ..
+ *    // Create Gauge(s). Note: Gauges can be created even after calling
+ *    // 'StartServer'.
+ *    Gauge gauge1 = metricsImpl.CreateGauge("foo",is_present);
+ *    // gauge1 can now be used anywhere in the program to set values.
+ *    ...
+ *    // Create the metrics server
+ *    std::unique_ptr<grpc::Server> server = metricsImpl.StartServer(port);
+ *    server->Wait(); // Note: This is blocking.
+ */
+namespace grpc {
+namespace testing {
+
+// TODO(sreek): Add support for other types of Gauges like Double, String in
+// future
+class Gauge {
+ public:
+  Gauge(long initial_val);
+  void Set(long new_val);
+  long Get();
+
+ private:
+  long val_;
+  std::mutex val_mu_;
+};
+
+class MetricsServiceImpl GRPC_FINAL : public MetricsService::Service {
+ public:
+  grpc::Status GetAllGauges(ServerContext* context, const EmptyMessage* request,
+                            ServerWriter<GaugeResponse>* writer) GRPC_OVERRIDE;
+
+  grpc::Status GetGauge(ServerContext* context, const GaugeRequest* request,
+                        GaugeResponse* response) GRPC_OVERRIDE;
+
+  // Create a Gauge with name 'name'. is_present is set to true if the Gauge
+  // is already present in the map.
+  // NOTE: CreateGauge can be called anytime (i.e before or after calling
+  // StartServer).
+  std::shared_ptr<Gauge> CreateGauge(const grpc::string& name,
+                                     bool* already_present);
+
+  std::unique_ptr<grpc::Server> StartServer(int port);
+
+ private:
+  std::map<string, std::shared_ptr<Gauge>> gauges_;
+  std::mutex mu_;
+};
+
+}  // namespace testing
+}  // namespace grpc
+
+#endif  // GRPC_TEST_CPP_METRICS_SERVER_H