src/cpp/common/call.cc

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#include <google/protobuf/message.h>
#include <grpc/support/alloc.h>
#include <grpc++/impl/call.h>
#include <grpc++/client_context.h>
#include <grpc++/channel_interface.h>

#include "src/cpp/proto/proto_utils.h"

namespace grpc {

void CallOpBuffer::Reset(void* next_return_tag) {
  return_tag_ = next_return_tag;

  send_initial_metadata_ = false;
  initial_metadata_count_ = 0;
  gpr_free(initial_metadata_);

  recv_initial_metadata_ = nullptr;
  recv_initial_metadata_arr_.count = 0;

  send_message_ = nullptr;
  if (send_message_buf_) {
    grpc_byte_buffer_destroy(send_message_buf_);
    send_message_buf_ = nullptr;
  }

  recv_message_ = nullptr;
  got_message = false;
  if (recv_message_buf_) {
    grpc_byte_buffer_destroy(recv_message_buf_);
    recv_message_buf_ = nullptr;
  }

  client_send_close_ = false;

  recv_trailing_metadata_ = nullptr;
  recv_status_ = nullptr;
  recv_trailing_metadata_arr_.count = 0;

  status_code_ = GRPC_STATUS_OK;

  send_status_ = nullptr;
  trailing_metadata_count_ = 0;
  trailing_metadata_ = nullptr;

  recv_closed_ = nullptr;
}

CallOpBuffer::~CallOpBuffer() {
  gpr_free(status_details_);
  gpr_free(recv_initial_metadata_arr_.metadata);
  gpr_free(recv_trailing_metadata_arr_.metadata);
  if (recv_message_buf_) {
    grpc_byte_buffer_destroy(recv_message_buf_);
  }
  if (send_message_buf_) {
    grpc_byte_buffer_destroy(send_message_buf_);
  }
}

namespace {
// TODO(yangg) if the map is changed before we send, the pointers will be a
// mess. Make sure it does not happen.
grpc_metadata* FillMetadataArray(
    std::multimap<grpc::string, grpc::string>* metadata) {
  if (metadata->empty()) {
    return nullptr;
  }
  grpc_metadata* metadata_array =
      (grpc_metadata*)gpr_malloc(metadata->size() * sizeof(grpc_metadata));
  size_t i = 0;
  for (auto iter = metadata->cbegin(); iter != metadata->cend(); ++iter, ++i) {
    metadata_array[i].key = iter->first.c_str();
    metadata_array[i].value = iter->second.c_str();
    metadata_array[i].value_length = iter->second.size();
  }
  return metadata_array;
}

void FillMetadataMap(grpc_metadata_array* arr,
                     std::multimap<grpc::string, grpc::string>* metadata) {
  for (size_t i = 0; i < arr->count; i++) {
    // TODO(yangg) handle duplicates?
    metadata->insert(std::pair<grpc::string, grpc::string>(
        arr->metadata[i].key,
        {arr->metadata[i].value, arr->metadata[i].value_length}));
  }
  grpc_metadata_array_destroy(arr);
  grpc_metadata_array_init(arr);
}
}  // namespace

void CallOpBuffer::AddSendInitialMetadata(
    std::multimap<grpc::string, grpc::string>* metadata) {
  send_initial_metadata_ = true;
  initial_metadata_count_ = metadata->size();
  initial_metadata_ = FillMetadataArray(metadata);
}

void CallOpBuffer::AddRecvInitialMetadata(ClientContext* ctx) {
  ctx->initial_metadata_received_ = true;
  recv_initial_metadata_ = &ctx->recv_initial_metadata_;
}

void CallOpBuffer::AddSendInitialMetadata(ClientContext* ctx) {
  AddSendInitialMetadata(&ctx->send_initial_metadata_);
}

void CallOpBuffer::AddSendMessage(const google::protobuf::Message& message) {
  send_message_ = &message;
}

void CallOpBuffer::AddRecvMessage(google::protobuf::Message* message) {
  recv_message_ = message;
  recv_message_->Clear();
}

void CallOpBuffer::AddClientSendClose() { client_send_close_ = true; }

void CallOpBuffer::AddServerRecvClose(bool* cancelled) {
  recv_closed_ = cancelled;
}

void CallOpBuffer::AddClientRecvStatus(ClientContext* context, Status* status) {
  recv_trailing_metadata_ = &context->trailing_metadata_;
  recv_status_ = status;
}

void CallOpBuffer::AddServerSendStatus(
    std::multimap<grpc::string, grpc::string>* metadata, const Status& status) {
  if (metadata != NULL) {
    trailing_metadata_count_ = metadata->size();
    trailing_metadata_ = FillMetadataArray(metadata);
  } else {
    trailing_metadata_count_ = 0;
  }
  send_status_ = &status;
}

void CallOpBuffer::FillOps(grpc_op* ops, size_t* nops) {
  *nops = 0;
  if (send_initial_metadata_) {
    ops[*nops].op = GRPC_OP_SEND_INITIAL_METADATA;
    ops[*nops].data.send_initial_metadata.count = initial_metadata_count_;
    ops[*nops].data.send_initial_metadata.metadata = initial_metadata_;
    (*nops)++;
  }
  if (recv_initial_metadata_) {
    ops[*nops].op = GRPC_OP_RECV_INITIAL_METADATA;
    ops[*nops].data.recv_initial_metadata = &recv_initial_metadata_arr_;
    (*nops)++;
  }
  if (send_message_) {
    bool success = SerializeProto(*send_message_, &send_message_buf_);
    if (!success) {
      abort();
      // TODO handle parse failure
    }
    ops[*nops].op = GRPC_OP_SEND_MESSAGE;
    ops[*nops].data.send_message = send_message_buf_;
    (*nops)++;
  }
  if (recv_message_) {
    ops[*nops].op = GRPC_OP_RECV_MESSAGE;
    ops[*nops].data.recv_message = &recv_message_buf_;
    (*nops)++;
  }
  if (client_send_close_) {
    ops[*nops].op = GRPC_OP_SEND_CLOSE_FROM_CLIENT;
    (*nops)++;
  }
  if (recv_status_) {
    ops[*nops].op = GRPC_OP_RECV_STATUS_ON_CLIENT;
    ops[*nops].data.recv_status_on_client.trailing_metadata =
        &recv_trailing_metadata_arr_;
    ops[*nops].data.recv_status_on_client.status = &status_code_;
    ops[*nops].data.recv_status_on_client.status_details = &status_details_;
    ops[*nops].data.recv_status_on_client.status_details_capacity =
        &status_details_capacity_;
    (*nops)++;
  }
  if (send_status_) {
    ops[*nops].op = GRPC_OP_SEND_STATUS_FROM_SERVER;
    ops[*nops].data.send_status_from_server.trailing_metadata_count =
        trailing_metadata_count_;
    ops[*nops].data.send_status_from_server.trailing_metadata =
        trailing_metadata_;
    ops[*nops].data.send_status_from_server.status =
        static_cast<grpc_status_code>(send_status_->code());
    ops[*nops].data.send_status_from_server.status_details =
        send_status_->details().c_str();
    (*nops)++;
  }
  if (recv_closed_) {
    ops[*nops].op = GRPC_OP_RECV_CLOSE_ON_SERVER;
    ops[*nops].data.recv_close_on_server.cancelled = &cancelled_buf_;
    (*nops)++;
  }
}

bool CallOpBuffer::FinalizeResult(void** tag, bool* status) {
  // Release send buffers.
  if (send_message_buf_) {
    grpc_byte_buffer_destroy(send_message_buf_);
    send_message_buf_ = nullptr;
  }
  if (initial_metadata_) {
    gpr_free(initial_metadata_);
    initial_metadata_ = nullptr;
  }
  if (trailing_metadata_count_) {
    gpr_free(trailing_metadata_);
    trailing_metadata_ = nullptr;
  }
  // Set user-facing tag.
  *tag = return_tag_;
  // Process received initial metadata
  if (recv_initial_metadata_) {
    FillMetadataMap(&recv_initial_metadata_arr_, recv_initial_metadata_);
  }
  // Parse received message if any.
  if (recv_message_) {
    if (recv_message_buf_) {
      got_message = *status;
      *status = *status && DeserializeProto(recv_message_buf_, recv_message_);
      grpc_byte_buffer_destroy(recv_message_buf_);
      recv_message_buf_ = nullptr;
    } else {
      // Read failed
      got_message = false;
      *status = false;
    }
  }
  // Parse received status.
  if (recv_status_) {
    FillMetadataMap(&recv_trailing_metadata_arr_, recv_trailing_metadata_);
    *recv_status_ = Status(
        static_cast<StatusCode>(status_code_),
        status_details_ ? grpc::string(status_details_) : grpc::string());
  }
  if (recv_closed_) {
    *recv_closed_ = cancelled_buf_ != 0;
  }
  return true;
}

Call::Call(grpc_call* call, CallHook* call_hook, CompletionQueue* cq)
    : call_hook_(call_hook), cq_(cq), call_(call) {}

void Call::PerformOps(CallOpBuffer* buffer) {
  call_hook_->PerformOpsOnCall(buffer, this);
}

}  // namespace grpc