Real (but naive) UDP socket sending.

chrome/browser/extensions/socket_api_controller.cc

+// Copyright (c) 2011 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/json/json_writer.h"
+#include "base/stl_util.h"
+#include "base/values.h"
+#include "chrome/browser/extensions/socket_api_constants.h"
+#include "chrome/browser/extensions/socket_api_controller.h"
+#include "chrome/browser/profiles/profile.h"
+#include "net/base/io_buffer.h"
+#include "net/base/net_errors.h"
+#include "net/base/rand_callback.h"
+#include "net/udp/datagram_socket.h"
+#include "net/udp/udp_client_socket.h"
+#include "net/udp/udp_socket.h"
+
+using namespace net;
+
+namespace constants = extensions::socket_api_constants;
+
+namespace extensions {
+
+Socket::Socket(const Profile* profile)
+    : profile_(profile),
+      src_id_(-1),
+      udp_client_socket_(new UDPClientSocket(
+          DatagramSocket::DEFAULT_BIND,
+          RandIntCallback(),
+          NULL,
+          NetLog::Source())),
+      is_connected_(false),
+      ALLOW_THIS_IN_INITIALIZER_LIST(
+          io_callback_(this, &Socket::OnIOComplete)) {}
+
+Socket::~Socket() {
+  if (is_connected_) {
+    Close();
+  }
+}
+
+void Socket::OnIOComplete(int result) {
+  // We don't need to do anything.
+}
+
+bool Socket::Connect(const net::IPEndPoint& ip_end_point) {
+  is_connected_ = udp_client_socket_->Connect(ip_end_point);
+  return is_connected_;
+}
+
+void Socket::Close() {
+  is_connected_ = false;
+  udp_client_socket_->Close();
+}
+
+int Socket::Write(const std::string message) {
+  int length = message.length();
+  scoped_refptr<StringIOBuffer> io_buffer(new StringIOBuffer(message));
+  scoped_refptr<DrainableIOBuffer> buffer(
+      new DrainableIOBuffer(io_buffer, length));
+
+  int bytes_sent = 0;
+  while (buffer->BytesRemaining()) {
+    int rv = udp_client_socket_->Write(buffer,
+                                       buffer->BytesRemaining(),
+                                       &io_callback_);
+    if (rv <= 0) {
+      // We pass all errors, including ERROR_IO_PENDING, back to the caller.

[Mihai Parparita -not on Chrome, 2011/12/01 23:39:32]

Based on my reading of
http://www.google.com/codesearch#OAMlx_jo-ck/src/net/socket/socket.h&l=35, if
ERROR_IO_PENDING returned, then the callback will be invoked when all bytes are
eventually written. It seems like we would want to give clients a way of getting
called for that too (or is this what you're planning on using events for?)

[miket_OOO, 2011/12/02 21:06:36]

Ugh, yeah, you're right. I thought we were supposed to call Write() again. Yes,
we're going to have to use events. So this CL is going to be basically broken at
this point, but still I think it's worth continuing this particular review as a
checkpoint, because I didn't want to bite off events in this one.

+      return bytes_sent > 0 ? bytes_sent : rv;
+    }
+    bytes_sent += rv;
+    buffer->DidConsume(rv);
+  }
+  return bytes_sent;
+}
+
+SocketController* SocketController::GetInstance() {
+  return Singleton<SocketController>::get();
+}
+
+SocketController::SocketController() : next_socket_id_(1) {}
+
+SocketController::~SocketController() {
+  STLDeleteValues(&socket_map_);
+}
+
+Socket* SocketController::GetSocket(int socket_id) {
+  // TODO(miket): we should verify that the extension asking for the
+  // socket is the same one that created it.
+  SocketMap::iterator i = socket_map_.find(socket_id);
+  if (i != socket_map_.end())
+    return i->second;
+  return NULL;
+}
+
+int SocketController::CreateUdp(const Profile* profile,
+                                const std::string& extension_id,
+                                const GURL& src_url) {
+  Socket* socket = new Socket(profile);
+  CHECK(socket);
+  socket->set_src_extension_id(extension_id);
+  socket->set_src_url(src_url);
+  socket_map_[next_socket_id_] = socket;

[Mihai Parparita -not on Chrome, 2011/12/01 23:39:32]

Should you also be setting the socket's src_id?

[miket_OOO, 2011/12/02 21:06:36]

No. I've removed src_id from this CL. I took it from TTS's Utterance class, and
I'm not convinced it's needed at this point. It has to do with events. I'm
leaving it out until I thoroughly understand events in a future CL.

+  return next_socket_id_++;
+}
+
+bool SocketController::DestroyUdp(int socket_id) {
+  Socket* socket = GetSocket(socket_id);
+  if (!socket)
+    return false;
+  delete socket;
+  socket_map_.erase(socket_id);
+  return true;
+}
+
+// TODO(miket): it *might* be nice to be able to resolve DNS. I am not putting
+// in interesting error reporting for this method because we clearly can't
+// leave experimental without DNS resolution.

[Mihai Parparita -not on Chrome, 2011/12/01 23:39:32]

It's customary to add a "// static" line in the comments for static class
functions:
http://www.google.com/codesearch#search&q=//.static+file:extensions&exact_pac...

[miket_OOO, 2011/12/02 21:06:36]

Done.

+bool SocketController::CreateIPEndPoint(const std::string address, int port,
+                                        net::IPEndPoint* ip_end_point) {
+  net::IPAddressNumber ip_number;
+  bool rv = net::ParseIPLiteralToNumber(address, &ip_number);
+  if (!rv)
+    return false;
+  *ip_end_point = net::IPEndPoint(ip_number, port);
+  return true;
+}
+
+bool SocketController::ConnectUdp(int socket_id, const std::string address,
+                                  int port) {
+  Socket* socket = GetSocket(socket_id);
+  if (!socket)
+    return false;
+  net::IPEndPoint ip_end_point;
+  if (!CreateIPEndPoint(address, port, &ip_end_point))
+    return false;
+  return socket->Connect(ip_end_point) == net::OK;
+}
+
+void SocketController::CloseUdp(int socket_id) {
+  Socket* socket = GetSocket(socket_id);
+  if (socket)
+    socket->Close();
+}
+
+int SocketController::WriteUdp(int socket_id, const std::string message) {
+  Socket* socket = GetSocket(socket_id);
+  if (!socket) {
+    return -1;
+  }
+  return socket->Write(message);
+}
+
+}  // namespace extensions