Refactoring: Move MessagePipeReader subclasess out from ChannelMojo

ipc/mojo/ipc_channel_mojo.cc

Index: ipc/mojo/ipc_channel_mojo.cc
diff --git a/ipc/mojo/ipc_channel_mojo.cc b/ipc/mojo/ipc_channel_mojo.cc
index cdb928175dabcfda3104553ad88846b026b952b6..086b420cc52071ef90c7b53cf77249714efd67be 100644
--- a/ipc/mojo/ipc_channel_mojo.cc
+++ b/ipc/mojo/ipc_channel_mojo.cc
@@ -8,6 +8,7 @@
 #include "base/bind_helpers.h"
 #include "base/lazy_instance.h"
 #include "ipc/ipc_listener.h"
+#include "ipc/mojo/ipc_channel_mojo_readers.h"
 #include "mojo/embedder/embedder.h"
 
 #if defined(OS_POSIX) && !defined(OS_NACL)
@@ -82,371 +83,10 @@ mojo::embedder::PlatformHandle ToPlatformHandle(
 #endif
 }
 
-//------------------------------------------------------------------------------
-
-// TODO(morrita): This should be built using higher-level Mojo construct
-// for clarity and extensibility.
-class HelloMessage {
- public:
-  static Pickle CreateRequest(int32 pid) {
-    Pickle request;
-    request.WriteString(kHelloRequestMagic);
-    request.WriteInt(pid);
-    return request;
-  }
-
-  static bool ReadRequest(Pickle& pickle, int32* pid) {
-    PickleIterator iter(pickle);
-    std::string hello;
-    if (!iter.ReadString(&hello)) {
-      DLOG(WARNING) << "Failed to Read magic string.";
-      return false;
-    }
-
-    if (hello != kHelloRequestMagic) {
-      DLOG(WARNING) << "Magic mismatch:" << hello;
-      return false;
-    }
-
-    int read_pid;
-    if (!iter.ReadInt(&read_pid)) {
-      DLOG(WARNING) << "Failed to Read PID.";
-      return false;
-    }
-
-    *pid = read_pid;
-    return true;
-  }
-
-  static Pickle CreateResponse(int32 pid) {
-    Pickle request;
-    request.WriteString(kHelloResponseMagic);
-    request.WriteInt(pid);
-    return request;
-  }
-
-  static bool ReadResponse(Pickle& pickle, int32* pid) {
-    PickleIterator iter(pickle);
-    std::string hello;
-    if (!iter.ReadString(&hello)) {
-      DLOG(WARNING) << "Failed to read magic string.";
-      return false;
-    }
-
-    if (hello != kHelloResponseMagic) {
-      DLOG(WARNING) << "Magic mismatch:" << hello;
-      return false;
-    }
-
-    int read_pid;
-    if (!iter.ReadInt(&read_pid)) {
-      DLOG(WARNING) << "Failed to read PID.";
-      return false;
-    }
-
-    *pid = read_pid;
-    return true;
-  }
-
- private:
-  static const char* kHelloRequestMagic;
-  static const char* kHelloResponseMagic;
-};
-
-const char* HelloMessage::kHelloRequestMagic = "MREQ";
-const char* HelloMessage::kHelloResponseMagic = "MRES";
-
 } // namespace
 
 //------------------------------------------------------------------------------
 
-// A MessagePipeReader implemenation for IPC::Message communication.
-class ChannelMojo::MessageReader : public internal::MessagePipeReader {
- public:
-  MessageReader(mojo::ScopedMessagePipeHandle pipe, ChannelMojo* owner)
-      : internal::MessagePipeReader(pipe.Pass()),
-        owner_(owner) {}
-
-  bool Send(scoped_ptr<Message> message);
-  virtual void OnMessageReceived() OVERRIDE;
-  virtual void OnPipeClosed() OVERRIDE;
-  virtual void OnPipeError(MojoResult error) OVERRIDE;
-
- private:
-  ChannelMojo* owner_;
-};
-
-void ChannelMojo::MessageReader::OnMessageReceived() {
-  Message message(data_buffer().empty() ? "" : &data_buffer()[0],
-                  static_cast<uint32>(data_buffer().size()));
-
-  std::vector<MojoHandle> handle_buffer;
-  TakeHandleBuffer(&handle_buffer);
-#if defined(OS_POSIX) && !defined(OS_NACL)
-  for (size_t i = 0; i < handle_buffer.size(); ++i) {
-    mojo::embedder::ScopedPlatformHandle platform_handle;
-    MojoResult unwrap_result = mojo::embedder::PassWrappedPlatformHandle(
-        handle_buffer[i], &platform_handle);
-    if (unwrap_result != MOJO_RESULT_OK) {
-      DLOG(WARNING) << "Pipe failed to covert handles. Closing: "
-                    << unwrap_result;
-      CloseWithError(unwrap_result);
-      return;
-    }
-
-    bool ok = message.file_descriptor_set()->Add(platform_handle.release().fd);
-    DCHECK(ok);
-  }
-#else
-  DCHECK(handle_buffer.empty());
-#endif
-
-  message.TraceMessageEnd();
-  owner_->OnMessageReceived(message);
-}
-
-void ChannelMojo::MessageReader::OnPipeClosed() {
-  if (!owner_)
-    return;
-  owner_->OnPipeClosed(this);
-  owner_ = NULL;
-}
-
-void ChannelMojo::MessageReader::OnPipeError(MojoResult error) {
-  if (!owner_)
-    return;
-  owner_->OnPipeError(this);
-}
-
-bool ChannelMojo::MessageReader::Send(scoped_ptr<Message> message) {
-  DCHECK(IsValid());
-
-  message->TraceMessageBegin();
-  std::vector<MojoHandle> handles;
-#if defined(OS_POSIX) && !defined(OS_NACL)
-  // We dup() the handles in IPC::Message to transmit.
-  // IPC::FileDescriptorSet has intricate lifecycle semantics
-  // of FDs, so just to dup()-and-own them is the safest option.
-  if (message->HasFileDescriptors()) {
-    FileDescriptorSet* fdset = message->file_descriptor_set();
-    for (size_t i = 0; i < fdset->size(); ++i) {
-      int fd_to_send = dup(fdset->GetDescriptorAt(i));
-      if (-1 == fd_to_send) {
-        DPLOG(WARNING) << "Failed to dup FD to transmit.";
-        std::for_each(handles.begin(), handles.end(), &MojoClose);
-        CloseWithError(MOJO_RESULT_UNKNOWN);
-        return false;
-      }
-
-      MojoHandle wrapped_handle;
-      MojoResult wrap_result = CreatePlatformHandleWrapper(
-          mojo::embedder::ScopedPlatformHandle(
-              mojo::embedder::PlatformHandle(fd_to_send)),
-          &wrapped_handle);
-      if (MOJO_RESULT_OK != wrap_result) {
-        DLOG(WARNING) << "Pipe failed to wrap handles. Closing: "
-                      << wrap_result;
-        std::for_each(handles.begin(), handles.end(), &MojoClose);
-        CloseWithError(wrap_result);
-        return false;
-      }
-
-      handles.push_back(wrapped_handle);
-    }
-  }
-#endif
-  MojoResult write_result = MojoWriteMessage(
-      handle(),
-      message->data(), static_cast<uint32>(message->size()),
-      handles.empty() ? NULL : &handles[0],
-      static_cast<uint32>(handles.size()),
-      MOJO_WRITE_MESSAGE_FLAG_NONE);
-  if (MOJO_RESULT_OK != write_result) {
-    std::for_each(handles.begin(), handles.end(), &MojoClose);
-    CloseWithError(write_result);
-    return false;
-  }
-
-  return true;
-}
-
-//------------------------------------------------------------------------------
-
-// MessagePipeReader implementation for control messages.
-// Actual message handling is implemented by sublcasses.
-class ChannelMojo::ControlReader : public internal::MessagePipeReader {
- public:
-  ControlReader(mojo::ScopedMessagePipeHandle pipe, ChannelMojo* owner)
-      : internal::MessagePipeReader(pipe.Pass()),
-        owner_(owner) {}
-
-  virtual bool Connect() { return true; }
-  virtual void OnPipeClosed() OVERRIDE;
-  virtual void OnPipeError(MojoResult error) OVERRIDE;
-
- protected:
-  ChannelMojo* owner_;
-};
-
-void ChannelMojo::ControlReader::OnPipeClosed() {
-  if (!owner_)
-    return;
-  owner_->OnPipeClosed(this);
-  owner_ = NULL;
-}
-
-void ChannelMojo::ControlReader::OnPipeError(MojoResult error) {
-  if (!owner_)
-    return;
-  owner_->OnPipeError(this);
-}
-
-//------------------------------------------------------------------------------
-
-// ControlReader for server-side ChannelMojo.
-class ChannelMojo::ServerControlReader : public ChannelMojo::ControlReader {
- public:
-  ServerControlReader(mojo::ScopedMessagePipeHandle pipe, ChannelMojo* owner)
-      : ControlReader(pipe.Pass(), owner) { }
-
-  virtual bool Connect() OVERRIDE;
-  virtual void OnMessageReceived() OVERRIDE;
-
- private:
-  MojoResult SendHelloRequest();
-  MojoResult RespondHelloResponse();
-
-  mojo::ScopedMessagePipeHandle message_pipe_;
-};
-
-bool ChannelMojo::ServerControlReader::Connect() {
-  MojoResult result = SendHelloRequest();
-  if (result != MOJO_RESULT_OK) {
-    CloseWithError(result);
-    return false;
-  }
-
-  return true;
-}
-
-MojoResult ChannelMojo::ServerControlReader::SendHelloRequest() {
-  DCHECK(IsValid());
-  DCHECK(!message_pipe_.is_valid());
-
-  mojo::ScopedMessagePipeHandle self;
-  mojo::ScopedMessagePipeHandle peer;
-  MojoResult create_result = mojo::CreateMessagePipe(
-      NULL, &message_pipe_, &peer);
-  if (MOJO_RESULT_OK != create_result) {
-    DLOG(WARNING) << "mojo::CreateMessagePipe failed: " << create_result;
-    return create_result;
-  }
-
-  MojoHandle peer_to_send = peer.get().value();
-  Pickle request = HelloMessage::CreateRequest(owner_->GetSelfPID());
-  MojoResult write_result = MojoWriteMessage(
-      handle(),
-      request.data(), static_cast<uint32>(request.size()),
-      &peer_to_send, 1,
-      MOJO_WRITE_MESSAGE_FLAG_NONE);
-  if (MOJO_RESULT_OK != write_result) {
-    DLOG(WARNING) << "Writing Hello request failed: " << create_result;
-    return write_result;
-  }
-
-  // |peer| is sent and no longer owned by |this|.
-  (void)peer.release();
-  return MOJO_RESULT_OK;
-}
-
-MojoResult ChannelMojo::ServerControlReader::RespondHelloResponse() {
-  Pickle request(data_buffer().empty() ? "" : &data_buffer()[0],
-                 static_cast<uint32>(data_buffer().size()));
-
-  int32 read_pid = 0;
-  if (!HelloMessage::ReadResponse(request, &read_pid)) {
-    DLOG(ERROR) << "Failed to parse Hello response.";
-    return MOJO_RESULT_UNKNOWN;
-  }
-
-  base::ProcessId pid = static_cast<base::ProcessId>(read_pid);
-  owner_->set_peer_pid(pid);
-  owner_->OnConnected(message_pipe_.Pass());
-  return MOJO_RESULT_OK;
-}
-
-void ChannelMojo::ServerControlReader::OnMessageReceived() {
-  MojoResult result = RespondHelloResponse();
-  if (result != MOJO_RESULT_OK)
-    CloseWithError(result);
-}
-
-//------------------------------------------------------------------------------
-
-// ControlReader for client-side ChannelMojo.
-class ChannelMojo::ClientControlReader : public ChannelMojo::ControlReader {
- public:
-  ClientControlReader(mojo::ScopedMessagePipeHandle pipe, ChannelMojo* owner)
-      : ControlReader(pipe.Pass(), owner) {}
-
-  virtual void OnMessageReceived() OVERRIDE;
-
- private:
-  MojoResult RespondHelloRequest(MojoHandle message_channel);
-};
-
-MojoResult ChannelMojo::ClientControlReader::RespondHelloRequest(
-    MojoHandle message_channel) {
-  DCHECK(IsValid());
-
-  mojo::ScopedMessagePipeHandle received_pipe(
-      (mojo::MessagePipeHandle(message_channel)));
-
-  int32 read_request = 0;
-  Pickle request(data_buffer().empty() ? "" : &data_buffer()[0],
-                 static_cast<uint32>(data_buffer().size()));
-  if (!HelloMessage::ReadRequest(request, &read_request)) {
-    DLOG(ERROR) << "Hello request has wrong magic.";
-    return MOJO_RESULT_UNKNOWN;
-  }
-
-  base::ProcessId pid = read_request;
-  Pickle response = HelloMessage::CreateResponse(owner_->GetSelfPID());
-  MojoResult write_result = MojoWriteMessage(
-      handle(),
-      response.data(), static_cast<uint32>(response.size()),
-      NULL, 0,
-      MOJO_WRITE_MESSAGE_FLAG_NONE);
-  if (MOJO_RESULT_OK != write_result) {
-    DLOG(ERROR) << "Writing Hello response failed: " << write_result;
-    return write_result;
-  }
-
-  owner_->set_peer_pid(pid);
-  owner_->OnConnected(received_pipe.Pass());
-  return MOJO_RESULT_OK;
-}
-
-void ChannelMojo::ClientControlReader::OnMessageReceived() {
-  std::vector<MojoHandle> handle_buffer;
-  TakeHandleBuffer(&handle_buffer);
-  if (handle_buffer.size() != 1) {
-    DLOG(ERROR) << "Hello request doesn't contains required handle: "
-                << handle_buffer.size();
-    CloseWithError(MOJO_RESULT_UNKNOWN);
-    return;
-  }
-
-  MojoResult result = RespondHelloRequest(handle_buffer[0]);
-  if (result != MOJO_RESULT_OK) {
-    DLOG(ERROR) << "Failed to respond Hello request. Closing: "
-                << result;
-    CloseWithError(result);
-  }
-}
-
-//------------------------------------------------------------------------------
-
 void ChannelMojo::ChannelInfoDeleter::operator()(
     mojo::embedder::ChannelInfo* ptr) const {
   mojo::embedder::DestroyChannelOnIOThread(ptr);
@@ -458,9 +98,8 @@ void ChannelMojo::ChannelInfoDeleter::operator()(
 scoped_ptr<ChannelMojo> ChannelMojo::Create(
     const ChannelHandle &channel_handle, Mode mode, Listener* listener,
     scoped_refptr<base::TaskRunner> io_thread_task_runner) {
-  return make_scoped_ptr(new ChannelMojo(
-      Channel::Create(channel_handle, mode, g_null_listener.Pointer()),
-      mode, listener, io_thread_task_runner));
+  return make_scoped_ptr(
+      new ChannelMojo(channel_handle, mode, listener, io_thread_task_runner));
 }
 
 // static
@@ -473,11 +112,14 @@ scoped_ptr<ChannelFactory> ChannelMojo::CreateFactory(
           io_thread_task_runner)).PassAs<ChannelFactory>();
 }
 
-ChannelMojo::ChannelMojo(
-    scoped_ptr<Channel> bootstrap, Mode mode, Listener* listener,
-    scoped_refptr<base::TaskRunner> io_thread_task_runner)
-    : bootstrap_(bootstrap.Pass()),
-      mode_(mode), listener_(listener),
+ChannelMojo::ChannelMojo(const ChannelHandle& channel_handle,
+                         Mode mode,
+                         Listener* listener,
+                         scoped_refptr<base::TaskRunner> io_thread_task_runner)
+    : bootstrap_(
+          Channel::Create(channel_handle, mode, g_null_listener.Pointer())),
+      mode_(mode),
+      listener_(listener),
       peer_pid_(base::kNullProcessId),
       weak_factory_(this) {
   if (base::MessageLoopProxy::current() == io_thread_task_runner.get()) {
@@ -504,10 +146,12 @@ void ChannelMojo::InitOnIOThread() {
 
   switch (mode_) {
     case MODE_SERVER:
-      control_reader_.reset(new ServerControlReader(control_pipe.Pass(), this));
+      control_reader_.reset(
+          new internal::ServerControlReader(control_pipe.Pass(), this));
       break;
     case MODE_CLIENT:
-      control_reader_.reset(new ClientControlReader(control_pipe.Pass(), this));
+      control_reader_.reset(
+          new internal::ClientControlReader(control_pipe.Pass(), this));
       break;
     default:
       NOTREACHED();
@@ -527,7 +171,8 @@ void ChannelMojo::Close() {
 }
 
 void ChannelMojo::OnConnected(mojo::ScopedMessagePipeHandle pipe) {
-  message_reader_ = make_scoped_ptr(new MessageReader(pipe.Pass(), this));
+  message_reader_ =
+      make_scoped_ptr(new internal::MessageReader(pipe.Pass(), this));
 
   for (size_t i = 0; i < pending_messages_.size(); ++i) {
     message_reader_->Send(make_scoped_ptr(pending_messages_[i]));
@@ -583,6 +228,62 @@ int ChannelMojo::GetClientFileDescriptor() const {
 int ChannelMojo::TakeClientFileDescriptor() {
   return bootstrap_->TakeClientFileDescriptor();
 }
+
+// static
+MojoResult ChannelMojo::WriteToFileDescriptorSet(
+    const std::vector<MojoHandle>& handle_buffer,
+    Message* message) {
+  for (size_t i = 0; i < handle_buffer.size(); ++i) {
+    mojo::embedder::ScopedPlatformHandle platform_handle;
+    MojoResult unwrap_result = mojo::embedder::PassWrappedPlatformHandle(
+        handle_buffer[i], &platform_handle);
+    if (unwrap_result != MOJO_RESULT_OK) {
+      DLOG(WARNING) << "Pipe failed to covert handles. Closing: "
+                    << unwrap_result;
+      return unwrap_result;
+    }
+
+    bool ok = message->file_descriptor_set()->Add(platform_handle.release().fd);
+    DCHECK(ok);
+  }
+
+  return MOJO_RESULT_OK;
+}
+
+// static
+MojoResult ChannelMojo::ReadFromFileDescriptorSet(
+    const Message& message,
+    std::vector<MojoHandle>* handles) {
+  // We dup() the handles in IPC::Message to transmit.
+  // IPC::FileDescriptorSet has intricate lifecycle semantics
+  // of FDs, so just to dup()-and-own them is the safest option.
+  if (message.HasFileDescriptors()) {
+    const FileDescriptorSet* fdset = message.file_descriptor_set();
+    for (size_t i = 0; i < fdset->size(); ++i) {
+      int fd_to_send = dup(fdset->GetDescriptorAt(i));
+      if (-1 == fd_to_send) {
+        DPLOG(WARNING) << "Failed to dup FD to transmit.";
+        return MOJO_RESULT_UNKNOWN;
+      }
+
+      MojoHandle wrapped_handle;
+      MojoResult wrap_result = CreatePlatformHandleWrapper(
+          mojo::embedder::ScopedPlatformHandle(
+              mojo::embedder::PlatformHandle(fd_to_send)),
+          &wrapped_handle);
+      if (MOJO_RESULT_OK != wrap_result) {
+        DLOG(WARNING) << "Pipe failed to wrap handles. Closing: "
+                      << wrap_result;
+        return wrap_result;
+      }
+
+      handles->push_back(wrapped_handle);
+    }
+  }
+
+  return MOJO_RESULT_OK;
+}
+
 #endif  // defined(OS_POSIX) && !defined(OS_NACL)
 
 }  // namespace IPC