Replace libjingle's HttpPortAllocatorSession with Pepper's http client

remoting/client/plugin/pepper_port_allocator_session.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 "remoting/client/plugin/pepper_port_allocator_session.h"
+
+#include <map>
+
+#include "base/callback.h"
+#include "base/logging.h"
+#include "base/stringprintf.h"
+#include "base/synchronization/lock.h"
+#include "ppapi/c/pp_errors.h"
+#include "ppapi/c/trusted/ppb_url_loader_trusted.h"
+#include "ppapi/cpp/url_loader.h"
+#include "ppapi/cpp/url_request_info.h"
+#include "ppapi/cpp/url_response_info.h"
+#include "remoting/jingle_glue/http_port_allocator.h"
+#include "remoting/client/plugin/chromoting_instance.h"
+#include "remoting/client/plugin/pepper_entrypoints.h"
+#include "remoting/client/plugin/pepper_util.h"
+
+namespace {
+
+static const int kHostPort = 80;
+static const int kNumRetries = 5;
+static const std::string kCreateSessionURL = "/create_session";
+
+// Define a SessionFactory in the anonymouse namespace so we have a
+// shorter name.
+class SessionFactory : public remoting::PortAllocatorSessionFactory {

[Sergey Ulanov, 2011/03/07 12:58:45]

TODO to move this to a separate file?

[Alpha Left Google, 2011/03/07 18:02:29]

Done.

+ public:
+  SessionFactory(remoting::ChromotingInstance* instance,
+                 MessageLoop* message_loop)
+      : instance_(instance),
+        jingle_message_loop_(message_loop) {
+  }
+
+  virtual cricket::PortAllocatorSession* CreateSession(
+      cricket::BasicPortAllocator* allocator,
+      const std::string& name,
+      const std::string& session_type,
+      const std::vector<talk_base::SocketAddress>& stun_hosts,
+      const std::vector<std::string>& relay_hosts,
+      const std::string& relay,
+      const std::string& agent) {
+    return new remoting::PepperPortAllocatorSession(
+        instance_, jingle_message_loop_, allocator, name, session_type,
+        stun_hosts, relay_hosts, relay, agent);
+  }
+
+ private:
+  remoting::ChromotingInstance* instance_;
+
+  // Message loop that jingle runs on.
+  MessageLoop* jingle_message_loop_;
+
+  DISALLOW_COPY_AND_ASSIGN(SessionFactory);
+};
+
+typedef Callback3<bool, int, const std::string&>::Type FetchCallback;
+
+// Helper routine to remove whitespace from the ends of a string.
+void Trim(std::string& str) {

[Sergey Ulanov, 2011/03/07 12:58:45]

Can we use base::TrimString() instead?

[Alpha Left Google, 2011/03/07 18:02:29]

Done.

+  size_t first = str.find_first_not_of(" \t\r\n");
+  if (first == std::string::npos) {
+    str.clear();
+    return;
+  }
+
+  ASSERT(str.find_last_not_of(" \t\r\n") != std::string::npos);
+}
+
+// Parses the lines in the result of the HTTP request that are of the form
+// 'a=b' and returns them in a map.
+typedef std::map<std::string, std::string> StringMap;
+void ParseMap(const std::string& string, StringMap& map) {
+  size_t start_of_line = 0;
+  size_t end_of_line = 0;
+
+  for (;;) {  // for each line
+    start_of_line = string.find_first_not_of("\r\n", end_of_line);
+    if (start_of_line == std::string::npos)
+      break;
+
+    end_of_line = string.find_first_of("\r\n", start_of_line);

[Sergey Ulanov, 2011/03/07 12:58:45]

Could it be that the result we receive from the server contains Windows style
line ends? If yes, does this method parses them properly? If not, why should we
care about \r?

Also, Can we use base::Tokenize() to split the result lines?

[Alpha Left Google, 2011/03/07 18:02:29]

HTTP use \r\n as line breaks and this is from libjingle.

+    if (end_of_line == std::string::npos) {
+      end_of_line = string.length();
+    }
+
+    size_t equals = string.find('=', start_of_line);

[Sergey Ulanov, 2011/03/07 12:58:45]

equals_pos?

[Alpha Left Google, 2011/03/07 18:02:29]

I'm reluctant to change this at the moment since this is straight from
libjingle.

+    if ((equals >= end_of_line) || (equals == std::string::npos))
+      continue;
+
+    std::string key(string, start_of_line, equals - start_of_line);
+    std::string value(string, equals + 1, end_of_line - equals - 1);
+
+    Trim(key);

[Alpha Left Google, 2011/03/07 18:02:29]

I did change this to base::TrimString().

+    Trim(value);
+
+    if ((key.size() > 0) && (value.size() > 0))
+      map[key] = value;
+  }
+}
+
+}  // namespace
+
+namespace remoting {
+
+// A URL Fetcher using Pepper.
+class PepperURLFetcher {

[Sergey Ulanov, 2011/03/07 12:58:45]

TODO to move this to a separate file?

[Alpha Left Google, 2011/03/07 18:02:29]

Done.

+ public:
+  PepperURLFetcher() : fetch_callback_(NULL) {
+    callback_factory_.Initialize(this);
+  }
+
+  void Start(const pp::Instance& instance,
+             pp::URLRequestInfo request,
+             FetchCallback* fetch_callback) {
+    loader_ = pp::URLLoader(instance);
+
+    // Grant access to external origins.
+    const struct PPB_URLLoaderTrusted* trusted_loader_interface =
+        reinterpret_cast<const PPB_URLLoaderTrusted*>(
+            PPP_GetBrowserInterface(PPB_URLLOADERTRUSTED_INTERFACE));
+    trusted_loader_interface->GrantUniversalAccess(
+        loader_.pp_resource());
+
+    fetch_callback_.reset(fetch_callback);
+
+    pp::CompletionCallback callback =
+        callback_factory_.NewCallback(&PepperURLFetcher::DidOpen);
+    int rv = loader_.Open(request, callback);
+    if (rv != PP_ERROR_WOULDBLOCK)
+      callback.Run(rv);
+  }
+
+ private:
+  void ReadMore() {
+    pp::CompletionCallback callback =
+        callback_factory_.NewCallback(&PepperURLFetcher::DidRead);
+    int rv = loader_.ReadResponseBody(buf_, sizeof(buf_), callback);
+    if (rv != PP_ERROR_WOULDBLOCK)
+      callback.Run(rv);
+  }
+
+  void DidOpen(int32_t result) {
+    if (result == PP_OK) {
+      ReadMore();
+    } else {
+      DidFinish(result);
+    }
+  }
+
+  void DidRead(int32_t result) {
+    if (result > 0) {
+      data_.append(buf_, result);
+      ReadMore();
+    } else {
+      DidFinish(result);
+    }
+  }
+
+  void DidFinish(int32_t result) {
+    if (fetch_callback_.get()) {
+      bool success = result == PP_OK;
+      int status_code = 0;
+      if (success)
+        status_code = loader_.GetResponseInfo().GetStatusCode();
+      fetch_callback_->Run(success, status_code, data_);
+    }
+  }
+
+  pp::CompletionCallbackFactory<PepperURLFetcher> callback_factory_;
+  pp::URLLoader loader_;
+  scoped_ptr<FetchCallback> fetch_callback_;
+  char buf_[4096];
+  std::string data_;
+};
+
+// A helper class to do HTTP request on the pepper thread and then delegate the
+// result to PepperPortAllocatorSession on jingle thread safely.
+class PepperCreateSessionTask
+    : public base::RefCountedThreadSafe<PepperCreateSessionTask> {
+ public:
+  PepperCreateSessionTask(
+      MessageLoop* jingle_message_loop,
+      PepperPortAllocatorSession* allocator_session,
+      ChromotingInstance* instance,
+      const std::string& host,
+      int port,
+      const std::string& relay_token,
+      const std::string& session_type,
+      const std::string& name)
+      : jingle_message_loop_(jingle_message_loop),
+        allocator_session_(allocator_session),
+        instance_(instance),
+        host_(host),
+        port_(port),
+        relay_token_(relay_token),
+        session_type_(session_type),
+        name_(name) {
+  }
+
+  // Start doing the request. The request will start on the pepper thread.
+  void Start() {
+    if (!instance_->CurrentlyOnPluginThread()) {
+      RunTaskOnPluginThread(
+          NewRunnableMethod(this, &PepperCreateSessionTask::Start));
+      return;
+    }
+
+    // Perform the request here.
+    std::string url = base::StringPrintf("http://%s:%d/create_session",
+                                         host_.c_str(), port_);
+    pp::URLRequestInfo request(instance_);
+    request.SetURL(url.c_str());
+    request.SetMethod("GET");
+    request.SetHeaders(base::StringPrintf(
+        "X-Talk-Google-Relay-Auth: %s\r\n"
+        "X-Google-Relay-Auth: %s\r\n"
+        "X-Session-Type: %s\r\n"
+        "X-Stream-Type: %s\r\n",
+        relay_token_.c_str(), relay_token_.c_str(), session_type_.c_str(),
+        name_.c_str()));
+
+    url_fetcher_.reset(new PepperURLFetcher());
+    url_fetcher_->Start(
+        *instance_, request,
+        NewCallback(this, &PepperCreateSessionTask::OnRequestDone));
+  }
+
+  // Detach this task. This class will not access PepperPortAllocatorSession
+  // anymore.
+  void Detach() {
+    // Set the pointers to zero.
+    {
+      base::AutoLock auto_lock(lock_);
+      jingle_message_loop_ = NULL;
+      allocator_session_ = NULL;
+      instance_ = NULL;
+    }
+
+    // IMPORTANT!
+    // Post a dummy task so that we destruct this class and associated pepper
+    // resources on pepper thread.
+    RunTaskOnPluginThread(
+        NewRunnableMethod(this, &PepperCreateSessionTask::Dummy));

[Sergey Ulanov, 2011/03/07 12:58:45]

This doesn't guarantee that the object will be destroyed on that thread, does
it? Maybe replace Dummy with a method that explicitly destroys PepperURLFetcher
on that thread?

[Alpha Left Google, 2011/03/07 18:02:29]

sounds good.

+  }
+
+ private:
+  void OnRequestDone(bool success, int status_code,
+                     const std::string& response) {
+    // IMPORTANT!
+    // This method is called on the pepper thread and we want the response to
+    // be delegated to the jingle thread. However jignle thread might have
+    // been destroyed and |allocator_session_| might be dangling too. So we
+    // put a lock here to access |jingle_message_loop_| and then do the
+    // remaining work on the jingle thread.
+    base::AutoLock auto_lock(lock_);

[Sergey Ulanov, 2011/03/07 12:58:45]

Can we use MessageLoopProxy here? You would not need the lock?

[Alpha Left Google, 2011/03/07 18:02:29]

I believe we have to use message loop proxy everywhere in order to take
advantage of MessageLoopProxy. Right now using a lock does the same thing.

+    if (!jingle_message_loop_)
+      return;
+
+    jingle_message_loop_->PostTask(
+        FROM_HERE,
+        NewRunnableMethod(this, &PepperCreateSessionTask::DelegateRequestDone,
+                          success, status_code, response));
+  }
+
+  void DelegateRequestDone(bool success, int status_code,
+                           const std::string& response) {
+    if (!allocator_session_)
+      return;
+    allocator_session_->OnRequestDone(success, status_code, response);
+  }
+
+  // This is a dummy function just so that we can deref this class on pepper
+  // thread.
+  void Dummy() {}
+
+  // Protects |jingle_message_loop_|.
+  base::Lock lock_;
+
+  MessageLoop* jingle_message_loop_;
+  PepperPortAllocatorSession* allocator_session_;
+  ChromotingInstance* instance_;
+  std::string host_;
+  int port_;
+  std::string relay_token_;
+  std::string session_type_;
+  std::string name_;
+
+  // Pepper resources for URL fetching.
+  scoped_ptr<PepperURLFetcher> url_fetcher_;
+
+  DISALLOW_COPY_AND_ASSIGN(PepperCreateSessionTask);
+};
+
+PortAllocatorSessionFactory* PepperPortAllocatorSession::CreateFactory(
+    ChromotingInstance* instance) {
+  return new SessionFactory(instance, MessageLoop::current());
+}
+
+PepperPortAllocatorSession::PepperPortAllocatorSession(
+    ChromotingInstance* instance,
+    MessageLoop* message_loop,
+    cricket::BasicPortAllocator* allocator,
+    const std::string &name,
+    const std::string& session_type,
+    const std::vector<talk_base::SocketAddress>& stun_hosts,
+    const std::vector<std::string>& relay_hosts,
+    const std::string& relay_token,
+    const std::string& user_agent)
+    : BasicPortAllocatorSession(allocator, name, session_type),
+      instance_(instance), jingle_message_loop_(message_loop),
+      relay_hosts_(relay_hosts), stun_hosts_(stun_hosts),
+      relay_token_(relay_token), agent_(user_agent), attempts_(0) {
+}
+
+PepperPortAllocatorSession::~PepperPortAllocatorSession() {
+  if (create_session_task_) {
+    create_session_task_->Detach();
+    create_session_task_ = NULL;
+  }
+}
+
+void PepperPortAllocatorSession::GetPortConfigurations() {
+  // Creating relay sessions can take time and is done asynchronously.
+  // Creating stun sessions could also take time and could be done aysnc also,
+  // but for now is done here and added to the initial config.  Note any later
+  // configs will have unresolved stun ips and will be discarded by the
+  // AllocationSequence.
+  cricket::PortConfiguration* config =
+      new cricket::PortConfiguration(stun_hosts_[0], "", "", "");
+  ConfigReady(config);
+  TryCreateRelaySession();
+}
+
+void PepperPortAllocatorSession::TryCreateRelaySession() {
+  if (attempts_ == kNumRetries) {
+    LOG(ERROR) << "PepperPortAllocator: maximum number of requests reached; "
+               << "giving up on relay.";
+    return;
+  }
+
+  if (relay_hosts_.size() == 0) {
+    LOG(ERROR) << "PepperPortAllocator: no relay hosts configured.";
+    return;
+  }
+
+  // Choose the next host to try.
+  std::string host = relay_hosts_[attempts_ % relay_hosts_.size()];
+  attempts_++;
+  LOG(INFO) << "PepperPortAllocator: sending to relay host " << host;
+  if (relay_token_.empty()) {
+    LOG(WARNING) << "No relay auth token found.";
+  }
+
+  SendSessionRequest(host, kHostPort);
+}
+
+void PepperPortAllocatorSession::SendSessionRequest(const std::string& host,
+                                                    int port) {
+  // Destroy the old PepperCreateSessionTask first.
+  if (create_session_task_) {
+    create_session_task_->Detach();
+    create_session_task_ = NULL;
+  }
+
+  // Construct a new one and start it. OnRequestDone() will be called when
+  // task has completed.
+  create_session_task_ = new PepperCreateSessionTask(
+      jingle_message_loop_, this, instance_, host, port, relay_token_,
+      session_type(), name());
+  create_session_task_->Start();
+}
+
+void PepperPortAllocatorSession::OnRequestDone(bool success,
+                                               int status_code,
+                                               const std::string& response) {
+  DCHECK_EQ(jingle_message_loop_, MessageLoop::current());
+
+  if (!success || status_code != 200) {
+    LOG(WARNING) << "PepperPortAllocatorSession: failed.";
+    TryCreateRelaySession();
+    return;
+  }
+
+  LOG(INFO) << "PepperPortAllocatorSession: request succeeded.";
+  ReceiveSessionResponse(response);
+}
+
+void PepperPortAllocatorSession::ReceiveSessionResponse(
+    const std::string& response) {
+  StringMap map;
+  ParseMap(response, map);
+
+  std::string username = map["username"];
+  std::string password = map["password"];
+  std::string magic_cookie = map["magic_cookie"];
+
+  std::string relay_ip = map["relay.ip"];
+  std::string relay_udp_port = map["relay.udp_port"];
+  std::string relay_tcp_port = map["relay.tcp_port"];
+  std::string relay_ssltcp_port = map["relay.ssltcp_port"];
+
+  cricket::PortConfiguration* config =
+      new cricket::PortConfiguration(stun_hosts_[0], username,
+                                     password, magic_cookie);
+
+  cricket::PortConfiguration::PortList ports;
+  if (!relay_udp_port.empty()) {
+    talk_base::SocketAddress address(relay_ip, atoi(relay_udp_port.c_str()));
+    ports.push_back(cricket::ProtocolAddress(address, cricket::PROTO_UDP));
+  }
+  if (!relay_tcp_port.empty()) {
+    talk_base::SocketAddress address(relay_ip, atoi(relay_tcp_port.c_str()));
+    ports.push_back(cricket::ProtocolAddress(address, cricket::PROTO_TCP));
+  }
+  if (!relay_ssltcp_port.empty()) {
+    talk_base::SocketAddress address(relay_ip, atoi(relay_ssltcp_port.c_str()));
+    ports.push_back(cricket::ProtocolAddress(address, cricket::PROTO_SSLTCP));
+  }
+  config->AddRelay(ports, 0.0f);
+  ConfigReady(config);
+}
+
+}  // namespace remoting
+
+DISABLE_RUNNABLE_METHOD_REFCOUNT(remoting::PepperPortAllocatorSession);

[Sergey Ulanov, 2011/03/07 12:58:45]

I don't see why we would need this. Remove it?