/*
 *
 * Copyright 2017, 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.
 *
 */

/* This benchmark exists to ensure that the benchmark integration is
 * working */

#include <benchmark/benchmark.h>
#include <string.h>
#include <sstream>

#include <grpc++/channel.h>
#include <grpc++/support/channel_arguments.h>
#include <grpc/grpc.h>
#include <grpc/support/alloc.h>
#include <grpc/support/string_util.h>

extern "C" {
#include "src/core/ext/filters/client_channel/client_channel.h"
#include "src/core/ext/filters/load_reporting/load_reporting_filter.h"
#include "src/core/lib/channel/channel_stack.h"
#include "src/core/lib/channel/compress_filter.h"
#include "src/core/lib/channel/connected_channel.h"
#include "src/core/lib/channel/deadline_filter.h"
#include "src/core/lib/channel/http_client_filter.h"
#include "src/core/lib/channel/http_server_filter.h"
#include "src/core/lib/channel/message_size_filter.h"
#include "src/core/lib/profiling/timers.h"
#include "src/core/lib/surface/channel.h"
#include "src/core/lib/transport/transport_impl.h"
}

#include "src/cpp/client/create_channel_internal.h"
#include "src/proto/grpc/testing/echo.grpc.pb.h"
#include "test/cpp/microbenchmarks/helpers.h"

auto &force_library_initialization = Library::get();

void BM_Zalloc(benchmark::State &state) {
  // speed of light for call creation is zalloc, so benchmark a few interesting
  // sizes
  size_t sz = state.range(0);
  while (state.KeepRunning()) {
    gpr_free(gpr_zalloc(sz));
  }
}
BENCHMARK(BM_Zalloc)
    ->Arg(64)
    ->Arg(128)
    ->Arg(256)
    ->Arg(512)
    ->Arg(1024)
    ->Arg(1536)
    ->Arg(2048)
    ->Arg(3072)
    ->Arg(4096)
    ->Arg(5120)
    ->Arg(6144)
    ->Arg(7168);

////////////////////////////////////////////////////////////////////////////////
// Benchmarks creating full stacks

class BaseChannelFixture {
 public:
  BaseChannelFixture(grpc_channel *channel) : channel_(channel) {}
  ~BaseChannelFixture() { grpc_channel_destroy(channel_); }

  grpc_channel *channel() const { return channel_; }

 private:
  grpc_channel *const channel_;
};

class InsecureChannel : public BaseChannelFixture {
 public:
  InsecureChannel()
      : BaseChannelFixture(
            grpc_insecure_channel_create("localhost:1234", NULL, NULL)) {}
};

class LameChannel : public BaseChannelFixture {
 public:
  LameChannel()
      : BaseChannelFixture(grpc_lame_client_channel_create(
            "localhost:1234", GRPC_STATUS_UNAUTHENTICATED, "blah")) {}
};

template <class Fixture>
static void BM_CallCreateDestroy(benchmark::State &state) {
  TrackCounters track_counters;
  Fixture fixture;
  grpc_completion_queue *cq = grpc_completion_queue_create(NULL);
  gpr_timespec deadline = gpr_inf_future(GPR_CLOCK_MONOTONIC);
  void *method_hdl =
      grpc_channel_register_call(fixture.channel(), "/foo/bar", NULL, NULL);
  while (state.KeepRunning()) {
    grpc_call_destroy(grpc_channel_create_registered_call(
        fixture.channel(), NULL, GRPC_PROPAGATE_DEFAULTS, cq, method_hdl,
        deadline, NULL));
  }
  grpc_completion_queue_destroy(cq);
  track_counters.Finish(state);
}

BENCHMARK_TEMPLATE(BM_CallCreateDestroy, InsecureChannel);
BENCHMARK_TEMPLATE(BM_CallCreateDestroy, LameChannel);

////////////////////////////////////////////////////////////////////////////////
// Benchmarks isolating individual filters

static void *tag(int i) {
  return reinterpret_cast<void *>(static_cast<intptr_t>(i));
}

static void BM_LameChannelCallCreateCpp(benchmark::State &state) {
  TrackCounters track_counters;
  auto stub =
      grpc::testing::EchoTestService::NewStub(grpc::CreateChannelInternal(
          "", grpc_lame_client_channel_create(
                  "localhost:1234", GRPC_STATUS_UNAUTHENTICATED, "blah")));
  grpc::CompletionQueue cq;
  grpc::testing::EchoRequest send_request;
  grpc::testing::EchoResponse recv_response;
  grpc::Status recv_status;
  while (state.KeepRunning()) {
    GPR_TIMER_SCOPE("BenchmarkCycle", 0);
    grpc::ClientContext cli_ctx;
    auto reader = stub->AsyncEcho(&cli_ctx, send_request, &cq);
    reader->Finish(&recv_response, &recv_status, tag(0));
    void *t;
    bool ok;
    GPR_ASSERT(cq.Next(&t, &ok));
    GPR_ASSERT(ok);
  }
  track_counters.Finish(state);
}
BENCHMARK(BM_LameChannelCallCreateCpp);

static void do_nothing(void *ignored) {}

static void BM_LameChannelCallCreateCore(benchmark::State &state) {
  TrackCounters track_counters;

  grpc_channel *channel;
  grpc_completion_queue *cq;
  grpc_metadata_array initial_metadata_recv;
  grpc_metadata_array trailing_metadata_recv;
  grpc_byte_buffer *response_payload_recv = NULL;
  grpc_status_code status;
  grpc_slice details;
  grpc::testing::EchoRequest send_request;
  grpc_slice send_request_slice =
      grpc_slice_new(&send_request, sizeof(send_request), do_nothing);

  channel = grpc_lame_client_channel_create(
      "localhost:1234", GRPC_STATUS_UNAUTHENTICATED, "blah");
  cq = grpc_completion_queue_create(NULL);
  void *rc = grpc_channel_register_call(
      channel, "/grpc.testing.EchoTestService/Echo", NULL, NULL);
  while (state.KeepRunning()) {
    GPR_TIMER_SCOPE("BenchmarkCycle", 0);
    grpc_call *call = grpc_channel_create_registered_call(
        channel, NULL, GRPC_PROPAGATE_DEFAULTS, cq, rc,
        gpr_inf_future(GPR_CLOCK_REALTIME), NULL);
    grpc_metadata_array_init(&initial_metadata_recv);
    grpc_metadata_array_init(&trailing_metadata_recv);
    grpc_byte_buffer *request_payload_send =
        grpc_raw_byte_buffer_create(&send_request_slice, 1);

    // Fill in call ops
    grpc_op ops[6];
    memset(ops, 0, sizeof(ops));
    grpc_op *op = ops;
    op->op = GRPC_OP_SEND_INITIAL_METADATA;
    op->data.send_initial_metadata.count = 0;
    op++;
    op->op = GRPC_OP_SEND_MESSAGE;
    op->data.send_message.send_message = request_payload_send;
    op++;
    op->op = GRPC_OP_SEND_CLOSE_FROM_CLIENT;
    op++;
    op->op = GRPC_OP_RECV_INITIAL_METADATA;
    op->data.recv_initial_metadata.recv_initial_metadata =
        &initial_metadata_recv;
    op++;
    op->op = GRPC_OP_RECV_MESSAGE;
    op->data.recv_message.recv_message = &response_payload_recv;
    op++;
    op->op = GRPC_OP_RECV_STATUS_ON_CLIENT;
    op->data.recv_status_on_client.trailing_metadata = &trailing_metadata_recv;
    op->data.recv_status_on_client.status = &status;
    op->data.recv_status_on_client.status_details = &details;
    op++;

    GPR_ASSERT(GRPC_CALL_OK == grpc_call_start_batch(call, ops,
                                                     (size_t)(op - ops),
                                                     (void *)1, NULL));
    grpc_event ev = grpc_completion_queue_next(
        cq, gpr_inf_future(GPR_CLOCK_REALTIME), NULL);
    GPR_ASSERT(ev.type != GRPC_QUEUE_SHUTDOWN);
    GPR_ASSERT(ev.success != 0);
    grpc_call_destroy(call);
    grpc_byte_buffer_destroy(request_payload_send);
    grpc_byte_buffer_destroy(response_payload_recv);
    grpc_metadata_array_destroy(&initial_metadata_recv);
    grpc_metadata_array_destroy(&trailing_metadata_recv);
  }
  grpc_channel_destroy(channel);
  grpc_completion_queue_destroy(cq);
  grpc_slice_unref(send_request_slice);
  track_counters.Finish(state);
}
BENCHMARK(BM_LameChannelCallCreateCore);

static void FilterDestroy(grpc_exec_ctx *exec_ctx, void *arg,
                          grpc_error *error) {
  gpr_free(arg);
}

static void DoNothing(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error) {}

class FakeClientChannelFactory : public grpc_client_channel_factory {
 public:
  FakeClientChannelFactory() { vtable = &vtable_; }

 private:
  static void NoRef(grpc_client_channel_factory *factory) {}
  static void NoUnref(grpc_exec_ctx *exec_ctx,
                      grpc_client_channel_factory *factory) {}
  static grpc_subchannel *CreateSubchannel(grpc_exec_ctx *exec_ctx,
                                           grpc_client_channel_factory *factory,
                                           const grpc_subchannel_args *args) {
    return nullptr;
  }
  static grpc_channel *CreateClientChannel(grpc_exec_ctx *exec_ctx,
                                           grpc_client_channel_factory *factory,
                                           const char *target,
                                           grpc_client_channel_type type,
                                           const grpc_channel_args *args) {
    return nullptr;
  }

  static const grpc_client_channel_factory_vtable vtable_;
};

const grpc_client_channel_factory_vtable FakeClientChannelFactory::vtable_ = {
    NoRef, NoUnref, CreateSubchannel, CreateClientChannel};

static grpc_arg StringArg(const char *key, const char *value) {
  grpc_arg a;
  a.type = GRPC_ARG_STRING;
  a.key = const_cast<char *>(key);
  a.value.string = const_cast<char *>(value);
  return a;
}

enum FixtureFlags : uint32_t {
  CHECKS_NOT_LAST = 1,
  REQUIRES_TRANSPORT = 2,
};

template <const grpc_channel_filter *kFilter, uint32_t kFlags>
struct Fixture {
  const grpc_channel_filter *filter = kFilter;
  const uint32_t flags = kFlags;
};

namespace dummy_filter {

static void StartTransportStreamOp(grpc_exec_ctx *exec_ctx,
                                   grpc_call_element *elem,
                                   grpc_transport_stream_op_batch *op) {}

static void StartTransportOp(grpc_exec_ctx *exec_ctx,
                             grpc_channel_element *elem,
                             grpc_transport_op *op) {}

static grpc_error *InitCallElem(grpc_exec_ctx *exec_ctx,
                                grpc_call_element *elem,
                                const grpc_call_element_args *args) {
  return GRPC_ERROR_NONE;
}

static void SetPollsetOrPollsetSet(grpc_exec_ctx *exec_ctx,
                                   grpc_call_element *elem,
                                   grpc_polling_entity *pollent) {}

static void DestroyCallElem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
                            const grpc_call_final_info *final_info,
                            grpc_closure *then_sched_closure) {}

grpc_error *InitChannelElem(grpc_exec_ctx *exec_ctx, grpc_channel_element *elem,
                            grpc_channel_element_args *args) {
  return GRPC_ERROR_NONE;
}

void DestroyChannelElem(grpc_exec_ctx *exec_ctx, grpc_channel_element *elem) {}

char *GetPeer(grpc_exec_ctx *exec_ctx, grpc_call_element *elem) {
  return gpr_strdup("peer");
}

void GetChannelInfo(grpc_exec_ctx *exec_ctx, grpc_channel_element *elem,
                    const grpc_channel_info *channel_info) {}

static const grpc_channel_filter dummy_filter = {StartTransportStreamOp,
                                                 StartTransportOp,
                                                 0,
                                                 InitCallElem,
                                                 SetPollsetOrPollsetSet,
                                                 DestroyCallElem,
                                                 0,
                                                 InitChannelElem,
                                                 DestroyChannelElem,
                                                 GetPeer,
                                                 GetChannelInfo,
                                                 "dummy_filter"};

}  // namespace dummy_filter

namespace dummy_transport {

/* Memory required for a single stream element - this is allocated by upper
   layers and initialized by the transport */
size_t sizeof_stream; /* = sizeof(transport stream) */

/* name of this transport implementation */
const char *name;

/* implementation of grpc_transport_init_stream */
int InitStream(grpc_exec_ctx *exec_ctx, grpc_transport *self,
               grpc_stream *stream, grpc_stream_refcount *refcount,
               const void *server_data, gpr_arena *arena) {
  return 0;
}

/* implementation of grpc_transport_set_pollset */
void SetPollset(grpc_exec_ctx *exec_ctx, grpc_transport *self,
                grpc_stream *stream, grpc_pollset *pollset) {}

/* implementation of grpc_transport_set_pollset */
void SetPollsetSet(grpc_exec_ctx *exec_ctx, grpc_transport *self,
                   grpc_stream *stream, grpc_pollset_set *pollset_set) {}

/* implementation of grpc_transport_perform_stream_op */
void PerformStreamOp(grpc_exec_ctx *exec_ctx, grpc_transport *self,
                     grpc_stream *stream, grpc_transport_stream_op_batch *op) {
  grpc_closure_sched(exec_ctx, op->on_complete, GRPC_ERROR_NONE);
}

/* implementation of grpc_transport_perform_op */
void PerformOp(grpc_exec_ctx *exec_ctx, grpc_transport *self,
               grpc_transport_op *op) {}

/* implementation of grpc_transport_destroy_stream */
void DestroyStream(grpc_exec_ctx *exec_ctx, grpc_transport *self,
                   grpc_stream *stream, grpc_closure *then_sched_closure) {}

/* implementation of grpc_transport_destroy */
void Destroy(grpc_exec_ctx *exec_ctx, grpc_transport *self) {}

/* implementation of grpc_transport_get_peer */
char *GetPeer(grpc_exec_ctx *exec_ctx, grpc_transport *self) {
  return gpr_strdup("transport_peer");
}

/* implementation of grpc_transport_get_endpoint */
grpc_endpoint *GetEndpoint(grpc_exec_ctx *exec_ctx, grpc_transport *self) {
  return nullptr;
}

static const grpc_transport_vtable dummy_transport_vtable = {
    0,          "dummy_http2", InitStream,
    SetPollset, SetPollsetSet, PerformStreamOp,
    PerformOp,  DestroyStream, Destroy,
    GetPeer,    GetEndpoint};

static grpc_transport dummy_transport = {&dummy_transport_vtable};

}  // namespace dummy_transport

class NoOp {
 public:
  class Op {
   public:
    Op(grpc_exec_ctx *exec_ctx, NoOp *p, grpc_call_stack *s) {}
    void Finish(grpc_exec_ctx *exec_ctx) {}
  };
};

class SendEmptyMetadata {
 public:
  SendEmptyMetadata() {
    memset(&op_, 0, sizeof(op_));
    op_.on_complete = grpc_closure_init(&closure_, DoNothing, nullptr,
                                        grpc_schedule_on_exec_ctx);
    op_.send_initial_metadata = true;
    op_.payload = &op_payload_;
  }

  class Op {
   public:
    Op(grpc_exec_ctx *exec_ctx, SendEmptyMetadata *p, grpc_call_stack *s) {
      grpc_metadata_batch_init(&batch_);
      p->op_payload_.send_initial_metadata.send_initial_metadata = &batch_;
    }
    void Finish(grpc_exec_ctx *exec_ctx) {
      grpc_metadata_batch_destroy(exec_ctx, &batch_);
    }

   private:
    grpc_metadata_batch batch_;
  };

 private:
  const gpr_timespec deadline_ = gpr_inf_future(GPR_CLOCK_MONOTONIC);
  const gpr_timespec start_time_ = gpr_now(GPR_CLOCK_MONOTONIC);
  const grpc_slice method_ = grpc_slice_from_static_string("/foo/bar");
  grpc_transport_stream_op_batch op_;
  grpc_transport_stream_op_batch_payload op_payload_;
  grpc_closure closure_;
};

// Test a filter in isolation. Fixture specifies the filter under test (use the
// Fixture<> template to specify this), and TestOp defines some unit of work to
// perform on said filter.
template <class Fixture, class TestOp>
static void BM_IsolatedFilter(benchmark::State &state) {
  TrackCounters track_counters;
  Fixture fixture;
  std::ostringstream label;

  std::vector<grpc_arg> args;
  FakeClientChannelFactory fake_client_channel_factory;
  args.push_back(grpc_client_channel_factory_create_channel_arg(
      &fake_client_channel_factory));
  args.push_back(StringArg(GRPC_ARG_SERVER_URI, "localhost"));

  grpc_channel_args channel_args = {args.size(), &args[0]};

  std::vector<const grpc_channel_filter *> filters;
  if (fixture.filter != nullptr) {
    filters.push_back(fixture.filter);
  }
  if (fixture.flags & CHECKS_NOT_LAST) {
    filters.push_back(&dummy_filter::dummy_filter);
    label << " #has_dummy_filter";
  }

  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
  size_t channel_size = grpc_channel_stack_size(&filters[0], filters.size());
  grpc_channel_stack *channel_stack =
      static_cast<grpc_channel_stack *>(gpr_zalloc(channel_size));
  GPR_ASSERT(GRPC_LOG_IF_ERROR(
      "channel_stack_init",
      grpc_channel_stack_init(&exec_ctx, 1, FilterDestroy, channel_stack,
                              &filters[0], filters.size(), &channel_args,
                              fixture.flags & REQUIRES_TRANSPORT
                                  ? &dummy_transport::dummy_transport
                                  : nullptr,
                              "CHANNEL", channel_stack)));
  grpc_exec_ctx_flush(&exec_ctx);
  grpc_call_stack *call_stack = static_cast<grpc_call_stack *>(
      gpr_zalloc(channel_stack->call_stack_size));
  gpr_timespec deadline = gpr_inf_future(GPR_CLOCK_MONOTONIC);
  gpr_timespec start_time = gpr_now(GPR_CLOCK_MONOTONIC);
  grpc_slice method = grpc_slice_from_static_string("/foo/bar");
  grpc_call_final_info final_info;
  TestOp test_op_data;
  grpc_call_element_args call_args;
  call_args.call_stack = call_stack;
  call_args.server_transport_data = NULL;
  call_args.context = NULL;
  call_args.path = method;
  call_args.start_time = start_time;
  call_args.deadline = deadline;
  const int kArenaSize = 4096;
  call_args.arena = gpr_arena_create(kArenaSize);
  while (state.KeepRunning()) {
    GPR_TIMER_SCOPE("BenchmarkCycle", 0);
    GRPC_ERROR_UNREF(grpc_call_stack_init(&exec_ctx, channel_stack, 1,
                                          DoNothing, NULL, &call_args));
    typename TestOp::Op op(&exec_ctx, &test_op_data, call_stack);
    grpc_call_stack_destroy(&exec_ctx, call_stack, &final_info, NULL);
    op.Finish(&exec_ctx);
    grpc_exec_ctx_flush(&exec_ctx);
    // recreate arena every 64k iterations to avoid oom
    if (0 == (state.iterations() & 0xffff)) {
      gpr_arena_destroy(call_args.arena);
      call_args.arena = gpr_arena_create(kArenaSize);
    }
  }
  gpr_arena_destroy(call_args.arena);
  grpc_channel_stack_destroy(&exec_ctx, channel_stack);
  grpc_exec_ctx_finish(&exec_ctx);
  gpr_free(channel_stack);
  gpr_free(call_stack);

  state.SetLabel(label.str());
  track_counters.Finish(state);
}

typedef Fixture<nullptr, 0> NoFilter;
BENCHMARK_TEMPLATE(BM_IsolatedFilter, NoFilter, NoOp);
typedef Fixture<&dummy_filter::dummy_filter, 0> DummyFilter;
BENCHMARK_TEMPLATE(BM_IsolatedFilter, DummyFilter, NoOp);
BENCHMARK_TEMPLATE(BM_IsolatedFilter, DummyFilter, SendEmptyMetadata);
typedef Fixture<&grpc_client_channel_filter, 0> ClientChannelFilter;
BENCHMARK_TEMPLATE(BM_IsolatedFilter, ClientChannelFilter, NoOp);
typedef Fixture<&grpc_compress_filter, CHECKS_NOT_LAST> CompressFilter;
BENCHMARK_TEMPLATE(BM_IsolatedFilter, CompressFilter, NoOp);
BENCHMARK_TEMPLATE(BM_IsolatedFilter, CompressFilter, SendEmptyMetadata);
typedef Fixture<&grpc_client_deadline_filter, CHECKS_NOT_LAST>
    ClientDeadlineFilter;
BENCHMARK_TEMPLATE(BM_IsolatedFilter, ClientDeadlineFilter, NoOp);
BENCHMARK_TEMPLATE(BM_IsolatedFilter, ClientDeadlineFilter, SendEmptyMetadata);
typedef Fixture<&grpc_server_deadline_filter, CHECKS_NOT_LAST>
    ServerDeadlineFilter;
BENCHMARK_TEMPLATE(BM_IsolatedFilter, ServerDeadlineFilter, NoOp);
BENCHMARK_TEMPLATE(BM_IsolatedFilter, ServerDeadlineFilter, SendEmptyMetadata);
typedef Fixture<&grpc_http_client_filter, CHECKS_NOT_LAST | REQUIRES_TRANSPORT>
    HttpClientFilter;
BENCHMARK_TEMPLATE(BM_IsolatedFilter, HttpClientFilter, NoOp);
BENCHMARK_TEMPLATE(BM_IsolatedFilter, HttpClientFilter, SendEmptyMetadata);
typedef Fixture<&grpc_http_server_filter, CHECKS_NOT_LAST> HttpServerFilter;
BENCHMARK_TEMPLATE(BM_IsolatedFilter, HttpServerFilter, NoOp);
BENCHMARK_TEMPLATE(BM_IsolatedFilter, HttpServerFilter, SendEmptyMetadata);
typedef Fixture<&grpc_message_size_filter, CHECKS_NOT_LAST> MessageSizeFilter;
BENCHMARK_TEMPLATE(BM_IsolatedFilter, MessageSizeFilter, NoOp);
BENCHMARK_TEMPLATE(BM_IsolatedFilter, MessageSizeFilter, SendEmptyMetadata);
typedef Fixture<&grpc_load_reporting_filter, CHECKS_NOT_LAST>
    LoadReportingFilter;
BENCHMARK_TEMPLATE(BM_IsolatedFilter, LoadReportingFilter, NoOp);
BENCHMARK_TEMPLATE(BM_IsolatedFilter, LoadReportingFilter, SendEmptyMetadata);

////////////////////////////////////////////////////////////////////////////////
// Benchmarks isolating grpc_call

namespace isolated_call_filter {

static void StartTransportStreamOp(grpc_exec_ctx *exec_ctx,
                                   grpc_call_element *elem,
                                   grpc_transport_stream_op_batch *op) {
  if (op->recv_initial_metadata) {
    grpc_closure_sched(
        exec_ctx,
        op->payload->recv_initial_metadata.recv_initial_metadata_ready,
        GRPC_ERROR_NONE);
  }
  if (op->recv_message) {
    grpc_closure_sched(exec_ctx, op->payload->recv_message.recv_message_ready,
                       GRPC_ERROR_NONE);
  }
  grpc_closure_sched(exec_ctx, op->on_complete, GRPC_ERROR_NONE);
}

static void StartTransportOp(grpc_exec_ctx *exec_ctx,
                             grpc_channel_element *elem,
                             grpc_transport_op *op) {
  if (op->disconnect_with_error != GRPC_ERROR_NONE) {
    GRPC_ERROR_UNREF(op->disconnect_with_error);
  }
  grpc_closure_sched(exec_ctx, op->on_consumed, GRPC_ERROR_NONE);
}

static grpc_error *InitCallElem(grpc_exec_ctx *exec_ctx,
                                grpc_call_element *elem,
                                const grpc_call_element_args *args) {
  return GRPC_ERROR_NONE;
}

static void SetPollsetOrPollsetSet(grpc_exec_ctx *exec_ctx,
                                   grpc_call_element *elem,
                                   grpc_polling_entity *pollent) {}

static void DestroyCallElem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
                            const grpc_call_final_info *final_info,
                            grpc_closure *then_sched_closure) {
  grpc_closure_sched(exec_ctx, then_sched_closure, GRPC_ERROR_NONE);
}

grpc_error *InitChannelElem(grpc_exec_ctx *exec_ctx, grpc_channel_element *elem,
                            grpc_channel_element_args *args) {
  return GRPC_ERROR_NONE;
}

void DestroyChannelElem(grpc_exec_ctx *exec_ctx, grpc_channel_element *elem) {}

char *GetPeer(grpc_exec_ctx *exec_ctx, grpc_call_element *elem) {
  return gpr_strdup("peer");
}

void GetChannelInfo(grpc_exec_ctx *exec_ctx, grpc_channel_element *elem,
                    const grpc_channel_info *channel_info) {}

static const grpc_channel_filter isolated_call_filter = {
    StartTransportStreamOp,
    StartTransportOp,
    0,
    InitCallElem,
    SetPollsetOrPollsetSet,
    DestroyCallElem,
    0,
    InitChannelElem,
    DestroyChannelElem,
    GetPeer,
    GetChannelInfo,
    "isolated_call_filter"};
}  // namespace isolated_call_filter

class IsolatedCallFixture : public TrackCounters {
 public:
  IsolatedCallFixture() {
    grpc_channel_stack_builder *builder = grpc_channel_stack_builder_create();
    grpc_channel_stack_builder_set_name(builder, "dummy");
    grpc_channel_stack_builder_set_target(builder, "dummy_target");
    GPR_ASSERT(grpc_channel_stack_builder_append_filter(
        builder, &isolated_call_filter::isolated_call_filter, NULL, NULL));
    {
      grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
      channel_ = grpc_channel_create_with_builder(&exec_ctx, builder,
                                                  GRPC_CLIENT_CHANNEL);
      grpc_exec_ctx_finish(&exec_ctx);
    }
    cq_ = grpc_completion_queue_create(NULL);
  }

  void Finish(benchmark::State &state) {
    grpc_completion_queue_destroy(cq_);
    grpc_channel_destroy(channel_);
    TrackCounters::Finish(state);
  }

  grpc_channel *channel() const { return channel_; }
  grpc_completion_queue *cq() const { return cq_; }

 private:
  grpc_completion_queue *cq_;
  grpc_channel *channel_;
};

static void BM_IsolatedCall_NoOp(benchmark::State &state) {
  IsolatedCallFixture fixture;
  gpr_timespec deadline = gpr_inf_future(GPR_CLOCK_MONOTONIC);
  void *method_hdl =
      grpc_channel_register_call(fixture.channel(), "/foo/bar", NULL, NULL);
  while (state.KeepRunning()) {
    GPR_TIMER_SCOPE("BenchmarkCycle", 0);
    grpc_call_destroy(grpc_channel_create_registered_call(
        fixture.channel(), nullptr, GRPC_PROPAGATE_DEFAULTS, fixture.cq(),
        method_hdl, deadline, NULL));
  }
  fixture.Finish(state);
}
BENCHMARK(BM_IsolatedCall_NoOp);

static void BM_IsolatedCall_Unary(benchmark::State &state) {
  IsolatedCallFixture fixture;
  gpr_timespec deadline = gpr_inf_future(GPR_CLOCK_MONOTONIC);
  void *method_hdl =
      grpc_channel_register_call(fixture.channel(), "/foo/bar", NULL, NULL);
  grpc_slice slice = grpc_slice_from_static_string("hello world");
  grpc_byte_buffer *send_message = grpc_raw_byte_buffer_create(&slice, 1);
  grpc_byte_buffer *recv_message = NULL;
  grpc_status_code status_code;
  grpc_slice status_details = grpc_empty_slice();
  grpc_metadata_array recv_initial_metadata;
  grpc_metadata_array_init(&recv_initial_metadata);
  grpc_metadata_array recv_trailing_metadata;
  grpc_metadata_array_init(&recv_trailing_metadata);
  grpc_op ops[6];
  memset(ops, 0, sizeof(ops));
  ops[0].op = GRPC_OP_SEND_INITIAL_METADATA;
  ops[1].op = GRPC_OP_SEND_MESSAGE;
  ops[1].data.send_message.send_message = send_message;
  ops[2].op = GRPC_OP_SEND_CLOSE_FROM_CLIENT;
  ops[3].op = GRPC_OP_RECV_INITIAL_METADATA;
  ops[3].data.recv_initial_metadata.recv_initial_metadata =
      &recv_initial_metadata;
  ops[4].op = GRPC_OP_RECV_MESSAGE;
  ops[4].data.recv_message.recv_message = &recv_message;
  ops[5].op = GRPC_OP_RECV_STATUS_ON_CLIENT;
  ops[5].data.recv_status_on_client.status = &status_code;
  ops[5].data.recv_status_on_client.status_details = &status_details;
  ops[5].data.recv_status_on_client.trailing_metadata = &recv_trailing_metadata;
  while (state.KeepRunning()) {
    GPR_TIMER_SCOPE("BenchmarkCycle", 0);
    grpc_call *call = grpc_channel_create_registered_call(
        fixture.channel(), nullptr, GRPC_PROPAGATE_DEFAULTS, fixture.cq(),
        method_hdl, deadline, NULL);
    grpc_call_start_batch(call, ops, 6, tag(1), NULL);
    grpc_completion_queue_next(fixture.cq(),
                               gpr_inf_future(GPR_CLOCK_MONOTONIC), NULL);
    grpc_call_destroy(call);
  }
  fixture.Finish(state);
  grpc_metadata_array_destroy(&recv_initial_metadata);
  grpc_metadata_array_destroy(&recv_trailing_metadata);
  grpc_byte_buffer_destroy(send_message);
}
BENCHMARK(BM_IsolatedCall_Unary);

static void BM_IsolatedCall_StreamingSend(benchmark::State &state) {
  IsolatedCallFixture fixture;
  gpr_timespec deadline = gpr_inf_future(GPR_CLOCK_MONOTONIC);
  void *method_hdl =
      grpc_channel_register_call(fixture.channel(), "/foo/bar", NULL, NULL);
  grpc_slice slice = grpc_slice_from_static_string("hello world");
  grpc_byte_buffer *send_message = grpc_raw_byte_buffer_create(&slice, 1);
  grpc_metadata_array recv_initial_metadata;
  grpc_metadata_array_init(&recv_initial_metadata);
  grpc_metadata_array recv_trailing_metadata;
  grpc_metadata_array_init(&recv_trailing_metadata);
  grpc_op ops[2];
  memset(ops, 0, sizeof(ops));
  ops[0].op = GRPC_OP_SEND_INITIAL_METADATA;
  ops[1].op = GRPC_OP_RECV_INITIAL_METADATA;
  ops[1].data.recv_initial_metadata.recv_initial_metadata =
      &recv_initial_metadata;
  grpc_call *call = grpc_channel_create_registered_call(
      fixture.channel(), nullptr, GRPC_PROPAGATE_DEFAULTS, fixture.cq(),
      method_hdl, deadline, NULL);
  grpc_call_start_batch(call, ops, 2, tag(1), NULL);
  grpc_completion_queue_next(fixture.cq(), gpr_inf_future(GPR_CLOCK_MONOTONIC),
                             NULL);
  memset(ops, 0, sizeof(ops));
  ops[0].op = GRPC_OP_SEND_MESSAGE;
  ops[0].data.send_message.send_message = send_message;
  while (state.KeepRunning()) {
    GPR_TIMER_SCOPE("BenchmarkCycle", 0);
    grpc_call_start_batch(call, ops, 1, tag(2), NULL);
    grpc_completion_queue_next(fixture.cq(),
                               gpr_inf_future(GPR_CLOCK_MONOTONIC), NULL);
  }
  grpc_call_destroy(call);
  fixture.Finish(state);
  grpc_metadata_array_destroy(&recv_initial_metadata);
  grpc_metadata_array_destroy(&recv_trailing_metadata);
  grpc_byte_buffer_destroy(send_message);
}
BENCHMARK(BM_IsolatedCall_StreamingSend);

BENCHMARK_MAIN();