Add 'flog' service implementation.

services/flog/flog_logger_impl.cc

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "base/logging.h"
+#include "services/flog/flog_logger_impl.h"
+
+namespace mojo {
+namespace flog {
+
+// static
+std::shared_ptr<FlogLoggerImpl> FlogLoggerImpl::Create(
+    InterfaceRequest<FlogLogger> request,
+    uint32_t log_id,
+    const std::string& label,
+    std::shared_ptr<FlogDirectory> directory,
+    FlogServiceImpl* owner) {
+  return std::shared_ptr<FlogLoggerImpl>(
+      new FlogLoggerImpl(request.Pass(), log_id, label, directory, owner));
+}
+
+FlogLoggerImpl::FlogLoggerImpl(InterfaceRequest<FlogLogger> request,
+                               uint32_t log_id,
+                               const std::string& label,
+                               std::shared_ptr<FlogDirectory> directory,
+                               FlogServiceImpl* owner)
+    : FlogServiceImpl::ProductBase(owner),
+      file_(directory->GetFile(log_id, label, true)) {
+  mojo::internal::MessageValidatorList validators;
+  router_.reset(new mojo::internal::Router(
+      request.PassMessagePipe(), std::move(validators),
+      Environment::GetDefaultAsyncWaiter()));
+  router_->set_incoming_receiver(this);
+  router_->set_connection_error_handler([this]() { ReleaseFromOwner(); });
+}
+
+FlogLoggerImpl::~FlogLoggerImpl() {}
+
+bool FlogLoggerImpl::Accept(Message* message) {
+  DCHECK(message != nullptr);
+  DCHECK(message->data_num_bytes() > 0);
+  DCHECK(message->data() != nullptr);
+
+  uint32_t message_size = message->data_num_bytes();
+
+  WriteData(sizeof(message_size), &message_size);
+  WriteData(message_size, message->data());
+
+  return true;
+}
+
+bool FlogLoggerImpl::AcceptWithResponder(Message* message,
+                                         MessageReceiverWithStatus* responder) {
+  DCHECK(false) << "FlogLogger has no methods with responses";
+  abort();
+}
+
+void FlogLoggerImpl::WriteData(uint32_t data_size, const void* data) {
+  DCHECK(data_size > 0);
+  DCHECK(data != nullptr);
+  DCHECK(file_);
+
+  Array<uint8_t> bytes_to_write = Array<uint8_t>::New(data_size);
+  memcpy(bytes_to_write.data(), data, data_size);
+  file_->Write(bytes_to_write.Pass(), 0, files::Whence::FROM_CURRENT,
+               [data_size](files::Error error, uint32 bytes_written) {
+                 DCHECK(error == files::Error::OK);
+                 DCHECK(bytes_written == data_size);
+                 // TODO(dalesat): Handle error.
+               });
+}
+
+}  // namespace flog
+}  // namespace mojo