The Windows portion of Native Messagaing

chrome/browser/extensions/api/messaging/native_message_process_host_win.cc

 // Copyright (c) 2012 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 "chrome/browser/extensions/api/messaging/native_message_process_host.h"
 
 #include <windows.h>
 
 #include "base/logging.h"
 #include "base/message_pump_win.h"
 #include "base/platform_file.h"
 #include "base/process_util.h"
 #include "content/public/browser/browser_thread.h"
 
+namespace {
+
+void AddToOverlappedOffset(OVERLAPPED* overlapped, uint32 to_add) {
+  uint64 full_offset =
+      static_cast<uint64>(overlapped->OffsetHigh) << 32 | overlapped->Offset;
+  full_offset += to_add;
+  overlapped->Offset = full_offset & 0x00000000ffffffff;
+  overlapped->OffsetHigh = full_offset >> 32;
+}
+
+}  // namespace
+
 namespace extensions {
 
+void NativeMessageProcessHost::ReadNowForTesting() {
+}
+
 void NativeMessageProcessHost::OnIOCompleted(
     MessageLoopForIO::IOContext* context,
     DWORD bytes_transfered,
     DWORD error) {
-  NOTREACHED();
+  if (error != 0) {
+    if (native_process_handle_ != base::kNullProcessHandle &&
+        base::GetTerminationStatus(native_process_handle_, NULL) !=
+            base::TERMINATION_STATUS_STILL_RUNNING) {
+      // Notify the message service that the channel should close.
+      content::BrowserThread::PostTask(content::BrowserThread::UI, FROM_HERE,
+          base::Bind(&Client::CloseChannel, weak_client_ui_,
+                     destination_port_, true));
+    }
+    return;
+  }
+
+  if (context == read_context_.get()) {
+    switch (read_state) {
+      case READ_STATE_INVALID:
+        // This could be the case on destruction.
+        return;
+      case READ_STATE_WAITING_FOR_META:
+        {

[Matt Perry, 2012/10/24 23:40:31]

nit: common chrome style is to put the { on the same line as the case.

[eaugusti, 2012/10/30 22:03:12]

Done.

+          AddToOverlappedOffset(&read_context_->overlapped, bytes_transfered);
+
+          MessageType type;
+          uint32 message_length = 0;
+          if (!VerifyMessageMetaData(pending_message_meta_data_, &type,
+                                     &message_length)) {
+            return;
+          }
+          pending_message_.resize(message_length, '\0');
+          // Try to read the full message.
+          read_state = READ_STATE_WAITING_FOR_MESSGAE;
+          ::ReadFile(read_file_, &(pending_message_)[0], message_length, NULL,
+                     &read_context_->overlapped);
+          return;
+        }
+      case READ_STATE_WAITING_FOR_MESSGAE:
+        AddToOverlappedOffset(&read_context_->overlapped, bytes_transfered);
+
+        // Verify that the entire message was read.
+        if (bytes_transfered != pending_message_.size()) {

[Matt Perry, 2012/10/24 23:40:31]

Are you guaranteed that the entire contents is read in one go?

[eaugusti, 2012/10/30 22:03:12]

According to the documentation, it should be. But, I am going to bring in a
windows expert.

+          LOG(ERROR) << "Could not read entire message.";
+          return;
+        }
+        // Send the current message
+        content::BrowserThread::PostTask(content::BrowserThread::UI, FROM_HERE,
+            base::Bind(&Client::PostMessageFromNativeProcess, weak_client_ui_,
+                       destination_port_, pending_message_));
+        // Do not try to read another message if this is only a
+        // sendNativeMessage().
+        if (is_send_message_) {
+          read_state = READ_STATE_INVALID;
+        } else {
+          // Start the read for the next message.
+          read_state = READ_STATE_WAITING_FOR_META;
+          ::ReadFile(read_file_, &pending_message_meta_data_, 8, NULL,
+                     &read_context_->overlapped);
+        }
+        return;
+      default:
+        NOTREACHED();
+        return;
+    }
+  } else {
+    DCHECK(context == write_context_.get());
+  }
 }
 
 void NativeMessageProcessHost::InitIO() {
-  NOTREACHED();
+  read_context_.reset(new MessageLoopForIO::IOContext());
+  write_context_.reset(new MessageLoopForIO::IOContext());
+
+  memset(&read_context_->overlapped, 0, sizeof(read_context_->overlapped));
+  memset(&write_context_->overlapped, 0, sizeof(write_context_->overlapped));
+
+  read_context_->handler = this;
+  write_context_->handler = this;
+
+  MessageLoopForIO::current()->RegisterIOHandler(read_file_, this);
+
+  // Make a request for the type and length of the first message.
+  read_state = READ_STATE_WAITING_FOR_META;
+  ::ReadFile(read_file_, &pending_message_meta_data_, 8, NULL,
+             &read_context_->overlapped);
+}
+
+void NativeMessageProcessHost::StopIO() {
+  read_state = READ_STATE_INVALID;
+
+  ::CancelIo(read_file_);
+  ::CancelIo(write_file_);
+
+  MessageLoopForIO::current()->WaitForIOCompletion(INFINITE, this);

[Matt Perry, 2012/10/24 23:40:31]

We generally don't want to block any thread. Is this call necessary?

[eaugusti, 2012/10/30 22:03:12]

Yeah, I think it is. ipc_channel_win does it and it is suggested in
message_loop_win.

+
+  read_context_->handler = NULL;
+  write_context_->handler = NULL;
+
+  read_context_.reset();
+  write_context_.reset();
+
+  // Because of possible overlapped IO, the handles may not close cleanly but
+  // with a non-zero status. We have to circumvent ScopedHandle::Close().

[Matt Perry, 2012/10/24 23:40:31]

I don't follow this comment.

[eaugusti, 2012/10/30 22:03:12]

Done.

+  ::CloseHandle(scoped_read_file_.Take());
+  ::CloseHandle(scoped_write_file_.Take());
 }
 
 bool NativeMessageProcessHost::WriteData(FileHandle file,
                                          const char* data,
                                          size_t bytes_to_write) {
-  NOTREACHED();
-  return false;
+  DWORD bytes_written = 0;
+  ::SetLastError(0);
+  BOOL result = ::WriteFile(file, data, bytes_to_write, &bytes_written,
+                            &write_context_->overlapped);
+
+  return result || ::GetLastError() == ERROR_IO_PENDING;
 }
 
 bool NativeMessageProcessHost::ReadData(FileHandle file,
                                         char* data,
                                         size_t bytes_to_read) {
+  // Not used by win.

[Matt Perry, 2012/10/24 23:40:31]

Then why not #ifdef it out in the header? ReadMessage seems unused on win as
well.

[eaugusti, 2012/10/30 22:03:12]

Done.

   NOTREACHED();
   return false;
 }
 
 }  // namespace extensions