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/*
*
* Copyright 2014, 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/cpp/client/channel.h"
#include <chrono>
#include <string>
#include <grpc/grpc.h>
#include <grpc/support/log.h>
#include <grpc/support/slice.h>
#include <grpc/support/time.h>
#include "src/cpp/rpc_method.h"
#include "src/cpp/proto/proto_utils.h"
#include "src/cpp/stream/stream_context.h"
#include "src/cpp/util/time.h"
#include <grpc++/config.h>
#include <google/protobuf/message.h>
#include <grpc++/client_context.h>
#include <grpc++/status.h>
namespace grpc {
Channel::Channel(const grpc::string& target) : target_(target) {
c_channel_ = grpc_channel_create(target_.c_str(), nullptr);
}
Channel::~Channel() { grpc_channel_destroy(c_channel_); }
namespace {
// Poll one event from the compeletion queue. Return false when an error
// occured or the polled type is not expected. If a finished event has been
// polled, set finished and set status if it has not been set.
bool NextEvent(grpc_completion_queue* cq, grpc_completion_type expected_type,
bool* finished, bool* status_set, Status* status,
google::protobuf::Message* result) {
// We rely on the c layer to enforce deadline and thus do not use deadline
// here.
grpc_event* ev = grpc_completion_queue_next(cq, gpr_inf_future);
if (!ev) {
return false;
}
bool ret = ev->type == expected_type;
switch (ev->type) {
case GRPC_INVOKE_ACCEPTED:
ret = ret && (ev->data.invoke_accepted == GRPC_OP_OK);
break;
case GRPC_READ:
ret = ret && (ev->data.read != nullptr);
if (ret && !DeserializeProto(ev->data.read, result)) {
*status_set = true;
*status =
Status(StatusCode::DATA_LOSS, "Failed to parse response proto.");
ret = false;
}
break;
case GRPC_WRITE_ACCEPTED:
ret = ret && (ev->data.write_accepted == GRPC_OP_OK);
break;
case GRPC_FINISH_ACCEPTED:
ret = ret && (ev->data.finish_accepted == GRPC_OP_OK);
break;
case GRPC_CLIENT_METADATA_READ:
break;
case GRPC_FINISHED:
*finished = true;
if (!*status_set) {
*status_set = true;
StatusCode error_code = static_cast<StatusCode>(ev->data.finished.code);
grpc::string details(
ev->data.finished.details ? ev->data.finished.details : "");
*status = Status(error_code, details);
}
break;
default:
gpr_log(GPR_ERROR, "Dropping unhandled event with type %d", ev->type);
break;
}
grpc_event_finish(ev);
return ret;
}
// If finished is not true, get final status by polling until a finished
// event is obtained.
void GetFinalStatus(grpc_completion_queue* cq, bool status_set, bool finished,
Status* status) {
while (!finished) {
NextEvent(cq, GRPC_FINISHED, &finished, &status_set, status, nullptr);
}
}
} // namespace
// TODO(yangg) more error handling
Status Channel::StartBlockingRpc(const RpcMethod& method,
ClientContext* context,
const google::protobuf::Message& request,
google::protobuf::Message* result) {
Status status;
bool status_set = false;
bool finished = false;
gpr_timespec absolute_deadline;
AbsoluteDeadlineTimepoint2Timespec(context->absolute_deadline(),
&absolute_deadline);
grpc_call* call = grpc_channel_create_call(c_channel_, method.name(),
// FIXME(yangg)
"localhost", absolute_deadline);
context->set_call(call);
grpc_completion_queue* cq = grpc_completion_queue_create();
context->set_cq(cq);
// add_metadata from context
//
// invoke
GPR_ASSERT(grpc_call_start_invoke(call, cq, call, call, call,
GRPC_WRITE_BUFFER_HINT) == GRPC_CALL_OK);
if (!NextEvent(cq, GRPC_INVOKE_ACCEPTED, &status_set, &finished, &status,
nullptr)) {
GetFinalStatus(cq, finished, status_set, &status);
return status;
}
// write request
grpc_byte_buffer* write_buffer = nullptr;
bool success = SerializeProto(request, &write_buffer);
if (!success) {
grpc_call_cancel(call);
status_set = true;
status =
Status(StatusCode::DATA_LOSS, "Failed to serialize request proto.");
GetFinalStatus(cq, finished, status_set, &status);
return status;
}
GPR_ASSERT(grpc_call_start_write(call, write_buffer, call,
GRPC_WRITE_BUFFER_HINT) == GRPC_CALL_OK);
grpc_byte_buffer_destroy(write_buffer);
if (!NextEvent(cq, GRPC_WRITE_ACCEPTED, &finished, &status_set, &status,
nullptr)) {
GetFinalStatus(cq, finished, status_set, &status);
return status;
}
// writes done
GPR_ASSERT(grpc_call_writes_done(call, call) == GRPC_CALL_OK);
if (!NextEvent(cq, GRPC_FINISH_ACCEPTED, &finished, &status_set, &status,
nullptr)) {
GetFinalStatus(cq, finished, status_set, &status);
return status;
}
// start read metadata
//
if (!NextEvent(cq, GRPC_CLIENT_METADATA_READ, &finished, &status_set, &status,
nullptr)) {
GetFinalStatus(cq, finished, status_set, &status);
return status;
}
// start read
GPR_ASSERT(grpc_call_start_read(call, call) == GRPC_CALL_OK);
if (!NextEvent(cq, GRPC_READ, &finished, &status_set, &status, result)) {
GetFinalStatus(cq, finished, status_set, &status);
return status;
}
// wait status
GetFinalStatus(cq, finished, status_set, &status);
return status;
}
StreamContextInterface* Channel::CreateStream(const RpcMethod& method,
ClientContext* context,
const google::protobuf::Message* request,
google::protobuf::Message* result) {
gpr_timespec absolute_deadline;
AbsoluteDeadlineTimepoint2Timespec(context->absolute_deadline(),
&absolute_deadline);
grpc_call* call = grpc_channel_create_call(c_channel_, method.name(),
// FIXME(yangg)
"localhost", absolute_deadline);
context->set_call(call);
grpc_completion_queue* cq = grpc_completion_queue_create();
context->set_cq(cq);
return new StreamContext(method, context, request, result);
}
} // namespace grpc
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