examples/peerconnection/server/peer_channel.cc - src - Git at Google

 /*
  *  Copyright 2011 The WebRTC Project Authors. All rights reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */

 #include "examples/peerconnection/server/peer_channel.h"

 #include <assert.h>
 #include <stdio.h>
 #include <stdlib.h>

 #include <algorithm>

 #include "examples/peerconnection/server/data_socket.h"
 #include "examples/peerconnection/server/utils.h"

 // Set to the peer id of the originator when messages are being
 // exchanged between peers, but set to the id of the receiving peer
 // itself when notifications are sent from the server about the state
 // of other peers.
 //
 // WORKAROUND: Since support for CORS varies greatly from one browser to the
 // next, we don't use a custom name for our peer-id header (originally it was
 // "X-Peer-Id: ").  Instead, we use a "simple header", "Pragma" which should
 // always be exposed to CORS requests.  There is a special CORS header devoted
 // to exposing proprietary headers (Access-Control-Expose-Headers), however
 // at this point it is not working correctly in some popular browsers.
 static const char kPeerIdHeader[] = "Pragma: ";

 static const char* kRequestPaths[] = {
     "/wait",
     "/sign_out",
     "/message",
 };

 enum RequestPathIndex {
   kWait,
   kSignOut,
   kMessage,
 };

 const size_t kMaxNameLength = 512;

 //
 // ChannelMember
 //

 int ChannelMember::s_member_id_ = 0;

 ChannelMember::ChannelMember(DataSocket* socket)
     : waiting_socket_(NULL),
       id_(++s_member_id_),
       connected_(true),
       timestamp_(time(NULL)) {
   assert(socket);
   assert(socket->method() == DataSocket::GET);
   assert(socket->PathEquals("/sign_in"));
   name_ = socket->request_arguments();
   if (name_.empty())
     name_ = "peer_" + int2str(id_);
   else if (name_.length() > kMaxNameLength)
     name_.resize(kMaxNameLength);

   std::replace(name_.begin(), name_.end(), ',', '_');
 }

 ChannelMember::~ChannelMember() {}

 bool ChannelMember::is_wait_request(DataSocket* ds) const {
   return ds && ds->PathEquals(kRequestPaths[kWait]);
 }

 bool ChannelMember::TimedOut() {
   return waiting_socket_ == NULL && (time(NULL) - timestamp_) > 30;
 }

 std::string ChannelMember::GetPeerIdHeader() const {
   std::string ret(kPeerIdHeader + int2str(id_) + "\r\n");
   return ret;
 }

 bool ChannelMember::NotifyOfOtherMember(const ChannelMember& other) {
   assert(&other != this);
   QueueResponse("200 OK", "text/plain", GetPeerIdHeader(), other.GetEntry());
   return true;
 }

 // Returns a string in the form "name,id,connected\n".
 std::string ChannelMember::GetEntry() const {
   assert(name_.length() <= kMaxNameLength);

   // name, 11-digit int, 1-digit bool, newline, null
   char entry[kMaxNameLength + 15];
   snprintf(entry, sizeof(entry), "%s,%d,%d\n",
            name_.substr(0, kMaxNameLength).c_str(), id_, connected_);
   return entry;
 }

 void ChannelMember::ForwardRequestToPeer(DataSocket* ds, ChannelMember* peer) {
   assert(peer);
   assert(ds);

   std::string extra_headers(GetPeerIdHeader());

   if (peer == this) {
     ds->Send("200 OK", true, ds->content_type(), extra_headers, ds->data());
   } else {
     printf("Client %s sending to %s\n", name_.c_str(), peer->name().c_str());
     peer->QueueResponse("200 OK", ds->content_type(), extra_headers,
                         ds->data());
     ds->Send("200 OK", true, "text/plain", "", "");
   }
 }

 void ChannelMember::OnClosing(DataSocket* ds) {
   if (ds == waiting_socket_) {
     waiting_socket_ = NULL;
     timestamp_ = time(NULL);
   }
 }

 void ChannelMember::QueueResponse(const std::string& status,
                                   const std::string& content_type,
                                   const std::string& extra_headers,
                                   const std::string& data) {
   if (waiting_socket_) {
     assert(queue_.empty());
     assert(waiting_socket_->method() == DataSocket::GET);
     bool ok =
         waiting_socket_->Send(status, true, content_type, extra_headers, data);
     if (!ok) {
       printf("Failed to deliver data to waiting socket\n");
     }
     waiting_socket_ = NULL;
     timestamp_ = time(NULL);
   } else {
     QueuedResponse qr;
     qr.status = status;
     qr.content_type = content_type;
     qr.extra_headers = extra_headers;
     qr.data = data;
     queue_.push(qr);
   }
 }

 void ChannelMember::SetWaitingSocket(DataSocket* ds) {
   assert(ds->method() == DataSocket::GET);
   if (ds && !queue_.empty()) {
     assert(waiting_socket_ == NULL);
     const QueuedResponse& response = queue_.front();
     ds->Send(response.status, true, response.content_type,
              response.extra_headers, response.data);
     queue_.pop();
   } else {
     waiting_socket_ = ds;
   }
 }

 //
 // PeerChannel
 //

 // static
 bool PeerChannel::IsPeerConnection(const DataSocket* ds) {
   assert(ds);
   return (ds->method() == DataSocket::POST && ds->content_length() > 0) ||
          (ds->method() == DataSocket::GET && ds->PathEquals("/sign_in"));
 }

 ChannelMember* PeerChannel::Lookup(DataSocket* ds) const {
   assert(ds);

   if (ds->method() != DataSocket::GET && ds->method() != DataSocket::POST)
     return NULL;

   size_t i = 0;
   for (; i < ARRAYSIZE(kRequestPaths); ++i) {
     if (ds->PathEquals(kRequestPaths[i]))
       break;
   }

   if (i == ARRAYSIZE(kRequestPaths))
     return NULL;

   std::string args(ds->request_arguments());
   static const char kPeerId[] = "peer_id=";
   size_t found = args.find(kPeerId);
   if (found == std::string::npos)
     return NULL;

   int id = atoi(&args[found + ARRAYSIZE(kPeerId) - 1]);
   Members::const_iterator iter = members_.begin();
   for (; iter != members_.end(); ++iter) {
     if (id == (*iter)->id()) {
       if (i == kWait)
         (*iter)->SetWaitingSocket(ds);
       if (i == kSignOut)
         (*iter)->set_disconnected();
       return *iter;
     }
   }

   return NULL;
 }

 ChannelMember* PeerChannel::IsTargetedRequest(const DataSocket* ds) const {
   assert(ds);
   // Regardless of GET or POST, we look for the peer_id parameter
   // only in the request_path.
   const std::string& path = ds->request_path();
   size_t args = path.find('?');
   if (args == std::string::npos)
     return NULL;
   size_t found;
   const char kTargetPeerIdParam[] = "to=";
   do {
     found = path.find(kTargetPeerIdParam, args);
     if (found == std::string::npos)
       return NULL;
     if (found == (args + 1) || path[found - 1] == '&') {
       found += ARRAYSIZE(kTargetPeerIdParam) - 1;
       break;
     }
     args = found + ARRAYSIZE(kTargetPeerIdParam) - 1;
   } while (true);
   int id = atoi(&path[found]);
   Members::const_iterator i = members_.begin();
   for (; i != members_.end(); ++i) {
     if ((*i)->id() == id) {
       return *i;
     }
   }
   return NULL;
 }

 bool PeerChannel::AddMember(DataSocket* ds) {
   assert(IsPeerConnection(ds));
   ChannelMember* new_guy = new ChannelMember(ds);
   Members failures;
   BroadcastChangedState(*new_guy, &failures);
   HandleDeliveryFailures(&failures);
   members_.push_back(new_guy);

   printf("New member added (total=%s): %s\n",
          size_t2str(members_.size()).c_str(), new_guy->name().c_str());

   // Let the newly connected peer know about other members of the channel.
   std::string content_type;
   std::string response = BuildResponseForNewMember(*new_guy, &content_type);
   ds->Send("200 Added", true, content_type, new_guy->GetPeerIdHeader(),
            response);
   return true;
 }

 void PeerChannel::CloseAll() {
   Members::const_iterator i = members_.begin();
   for (; i != members_.end(); ++i) {
     (*i)->QueueResponse("200 OK", "text/plain", "", "Server shutting down");
   }
   DeleteAll();
 }

 void PeerChannel::OnClosing(DataSocket* ds) {
   for (Members::iterator i = members_.begin(); i != members_.end(); ++i) {
     ChannelMember* m = (*i);
     m->OnClosing(ds);
     if (!m->connected()) {
       i = members_.erase(i);
       Members failures;
       BroadcastChangedState(*m, &failures);
       HandleDeliveryFailures(&failures);
       delete m;
       if (i == members_.end())
         break;
     }
   }
   printf("Total connected: %s\n", size_t2str(members_.size()).c_str());
 }

 void PeerChannel::CheckForTimeout() {
   for (Members::iterator i = members_.begin(); i != members_.end(); ++i) {
     ChannelMember* m = (*i);
     if (m->TimedOut()) {
       printf("Timeout: %s\n", m->name().c_str());
       m->set_disconnected();
       i = members_.erase(i);
       Members failures;
       BroadcastChangedState(*m, &failures);
       HandleDeliveryFailures(&failures);
       delete m;
       if (i == members_.end())
         break;
     }
   }
 }

 void PeerChannel::DeleteAll() {
   for (Members::iterator i = members_.begin(); i != members_.end(); ++i)
     delete (*i);
   members_.clear();
 }

 void PeerChannel::BroadcastChangedState(const ChannelMember& member,
                                         Members* delivery_failures) {
   // This function should be called prior to DataSocket::Close().
   assert(delivery_failures);

   if (!member.connected()) {
     printf("Member disconnected: %s\n", member.name().c_str());
   }

   Members::iterator i = members_.begin();
   for (; i != members_.end(); ++i) {
     if (&member != (*i)) {
       if (!(*i)->NotifyOfOtherMember(member)) {
         (*i)->set_disconnected();
         delivery_failures->push_back(*i);
         i = members_.erase(i);
         if (i == members_.end())
           break;
       }
     }
   }
 }

 void PeerChannel::HandleDeliveryFailures(Members* failures) {
   assert(failures);

   while (!failures->empty()) {
     Members::iterator i = failures->begin();
     ChannelMember* member = *i;
     assert(!member->connected());
     failures->erase(i);
     BroadcastChangedState(*member, failures);
     delete member;
   }
 }

 // Builds a simple list of "name,id\n" entries for each member.
 std::string PeerChannel::BuildResponseForNewMember(const ChannelMember& member,
                                                    std::string* content_type) {
   assert(content_type);

   *content_type = "text/plain";
   // The peer itself will always be the first entry.
   std::string response(member.GetEntry());
   for (Members::iterator i = members_.begin(); i != members_.end(); ++i) {
     if (member.id() != (*i)->id()) {
       assert((*i)->connected());
       response += (*i)->GetEntry();
     }
   }

   return response;
 }
	/*
	* Copyright 2011 The WebRTC Project Authors. All rights reserved.
	*
	* Use of this source code is governed by a BSD-style license
	* that can be found in the LICENSE file in the root of the source
	* tree. An additional intellectual property rights grant can be found
	* in the file PATENTS. All contributing project authors may
	* be found in the AUTHORS file in the root of the source tree.
	*/

	#include "examples/peerconnection/server/peer_channel.h"

	#include <assert.h>
	#include <stdio.h>
	#include <stdlib.h>

	#include <algorithm>

	#include "examples/peerconnection/server/data_socket.h"
	#include "examples/peerconnection/server/utils.h"

	// Set to the peer id of the originator when messages are being
	// exchanged between peers, but set to the id of the receiving peer
	// itself when notifications are sent from the server about the state
	// of other peers.
	//
	// WORKAROUND: Since support for CORS varies greatly from one browser to the
	// next, we don't use a custom name for our peer-id header (originally it was
	// "X-Peer-Id: "). Instead, we use a "simple header", "Pragma" which should
	// always be exposed to CORS requests. There is a special CORS header devoted
	// to exposing proprietary headers (Access-Control-Expose-Headers), however
	// at this point it is not working correctly in some popular browsers.
	static const char kPeerIdHeader[] = "Pragma: ";

	static const char* kRequestPaths[] = {
	"/wait",
	"/sign_out",
	"/message",
	};

	enum RequestPathIndex {
	kWait,
	kSignOut,
	kMessage,
	};

	const size_t kMaxNameLength = 512;

	//
	// ChannelMember
	//

	int ChannelMember::s_member_id_ = 0;

	ChannelMember::ChannelMember(DataSocket* socket)
	: waiting_socket_(NULL),
	id_(++s_member_id_),
	connected_(true),
	timestamp_(time(NULL)) {
	assert(socket);
	assert(socket->method() == DataSocket::GET);
	assert(socket->PathEquals("/sign_in"));
	name_ = socket->request_arguments();
	if (name_.empty())
	name_ = "peer_" + int2str(id_);
	else if (name_.length() > kMaxNameLength)
	name_.resize(kMaxNameLength);

	std::replace(name_.begin(), name_.end(), ',', '_');
	}

	ChannelMember::~ChannelMember() {}

	bool ChannelMember::is_wait_request(DataSocket* ds) const {
	return ds && ds->PathEquals(kRequestPaths[kWait]);
	}

	bool ChannelMember::TimedOut() {
	return waiting_socket_ == NULL && (time(NULL) - timestamp_) > 30;
	}

	std::string ChannelMember::GetPeerIdHeader() const {
	std::string ret(kPeerIdHeader + int2str(id_) + "\r\n");
	return ret;
	}

	bool ChannelMember::NotifyOfOtherMember(const ChannelMember& other) {
	assert(&other != this);
	QueueResponse("200 OK", "text/plain", GetPeerIdHeader(), other.GetEntry());
	return true;
	}

	// Returns a string in the form "name,id,connected\n".
	std::string ChannelMember::GetEntry() const {
	assert(name_.length() <= kMaxNameLength);

	// name, 11-digit int, 1-digit bool, newline, null
	char entry[kMaxNameLength + 15];
	snprintf(entry, sizeof(entry), "%s,%d,%d\n",
	name_.substr(0, kMaxNameLength).c_str(), id_, connected_);
	return entry;
	}

	void ChannelMember::ForwardRequestToPeer(DataSocket* ds, ChannelMember* peer) {
	assert(peer);
	assert(ds);

	std::string extra_headers(GetPeerIdHeader());

	if (peer == this) {
	ds->Send("200 OK", true, ds->content_type(), extra_headers, ds->data());
	} else {
	printf("Client %s sending to %s\n", name_.c_str(), peer->name().c_str());
	peer->QueueResponse("200 OK", ds->content_type(), extra_headers,
	ds->data());
	ds->Send("200 OK", true, "text/plain", "", "");
	}
	}

	void ChannelMember::OnClosing(DataSocket* ds) {
	if (ds == waiting_socket_) {
	waiting_socket_ = NULL;
	timestamp_ = time(NULL);
	}
	}

	void ChannelMember::QueueResponse(const std::string& status,
	const std::string& content_type,
	const std::string& extra_headers,
	const std::string& data) {
	if (waiting_socket_) {
	assert(queue_.empty());
	assert(waiting_socket_->method() == DataSocket::GET);
	bool ok =
	waiting_socket_->Send(status, true, content_type, extra_headers, data);
	if (!ok) {
	printf("Failed to deliver data to waiting socket\n");
	}
	waiting_socket_ = NULL;
	timestamp_ = time(NULL);
	} else {
	QueuedResponse qr;
	qr.status = status;
	qr.content_type = content_type;
	qr.extra_headers = extra_headers;
	qr.data = data;
	queue_.push(qr);
	}
	}

	void ChannelMember::SetWaitingSocket(DataSocket* ds) {
	assert(ds->method() == DataSocket::GET);
	if (ds && !queue_.empty()) {
	assert(waiting_socket_ == NULL);
	const QueuedResponse& response = queue_.front();
	ds->Send(response.status, true, response.content_type,
	response.extra_headers, response.data);
	queue_.pop();
	} else {
	waiting_socket_ = ds;
	}
	}

	//
	// PeerChannel
	//

	// static
	bool PeerChannel::IsPeerConnection(const DataSocket* ds) {
	assert(ds);
	return (ds->method() == DataSocket::POST && ds->content_length() > 0) \|\|
	(ds->method() == DataSocket::GET && ds->PathEquals("/sign_in"));
	}

	ChannelMember* PeerChannel::Lookup(DataSocket* ds) const {
	assert(ds);

	if (ds->method() != DataSocket::GET && ds->method() != DataSocket::POST)
	return NULL;

	size_t i = 0;
	for (; i < ARRAYSIZE(kRequestPaths); ++i) {
	if (ds->PathEquals(kRequestPaths[i]))
	break;
	}

	if (i == ARRAYSIZE(kRequestPaths))
	return NULL;

	std::string args(ds->request_arguments());
	static const char kPeerId[] = "peer_id=";
	size_t found = args.find(kPeerId);
	if (found == std::string::npos)
	return NULL;

	int id = atoi(&args[found + ARRAYSIZE(kPeerId) - 1]);
	Members::const_iterator iter = members_.begin();
	for (; iter != members_.end(); ++iter) {
	if (id == (*iter)->id()) {
	if (i == kWait)
	(*iter)->SetWaitingSocket(ds);
	if (i == kSignOut)
	(*iter)->set_disconnected();
	return *iter;
	}
	}

	return NULL;
	}

	ChannelMember* PeerChannel::IsTargetedRequest(const DataSocket* ds) const {
	assert(ds);
	// Regardless of GET or POST, we look for the peer_id parameter
	// only in the request_path.
	const std::string& path = ds->request_path();
	size_t args = path.find('?');
	if (args == std::string::npos)
	return NULL;
	size_t found;
	const char kTargetPeerIdParam[] = "to=";
	do {
	found = path.find(kTargetPeerIdParam, args);
	if (found == std::string::npos)
	return NULL;
	if (found == (args + 1) \|\| path[found - 1] == '&') {
	found += ARRAYSIZE(kTargetPeerIdParam) - 1;
	break;
	}
	args = found + ARRAYSIZE(kTargetPeerIdParam) - 1;
	} while (true);
	int id = atoi(&path[found]);
	Members::const_iterator i = members_.begin();
	for (; i != members_.end(); ++i) {
	if ((*i)->id() == id) {
	return *i;
	}
	}
	return NULL;
	}

	bool PeerChannel::AddMember(DataSocket* ds) {
	assert(IsPeerConnection(ds));
	ChannelMember* new_guy = new ChannelMember(ds);
	Members failures;
	BroadcastChangedState(*new_guy, &failures);
	HandleDeliveryFailures(&failures);
	members_.push_back(new_guy);

	printf("New member added (total=%s): %s\n",
	size_t2str(members_.size()).c_str(), new_guy->name().c_str());

	// Let the newly connected peer know about other members of the channel.
	std::string content_type;
	std::string response = BuildResponseForNewMember(*new_guy, &content_type);
	ds->Send("200 Added", true, content_type, new_guy->GetPeerIdHeader(),
	response);
	return true;
	}

	void PeerChannel::CloseAll() {
	Members::const_iterator i = members_.begin();
	for (; i != members_.end(); ++i) {
	(*i)->QueueResponse("200 OK", "text/plain", "", "Server shutting down");
	}
	DeleteAll();
	}

	void PeerChannel::OnClosing(DataSocket* ds) {
	for (Members::iterator i = members_.begin(); i != members_.end(); ++i) {
	ChannelMember* m = (*i);
	m->OnClosing(ds);
	if (!m->connected()) {
	i = members_.erase(i);
	Members failures;
	BroadcastChangedState(*m, &failures);
	HandleDeliveryFailures(&failures);
	delete m;
	if (i == members_.end())
	break;
	}
	}
	printf("Total connected: %s\n", size_t2str(members_.size()).c_str());
	}

	void PeerChannel::CheckForTimeout() {
	for (Members::iterator i = members_.begin(); i != members_.end(); ++i) {
	ChannelMember* m = (*i);
	if (m->TimedOut()) {
	printf("Timeout: %s\n", m->name().c_str());
	m->set_disconnected();
	i = members_.erase(i);
	Members failures;
	BroadcastChangedState(*m, &failures);
	HandleDeliveryFailures(&failures);
	delete m;
	if (i == members_.end())
	break;
	}
	}
	}

	void PeerChannel::DeleteAll() {
	for (Members::iterator i = members_.begin(); i != members_.end(); ++i)
	delete (*i);
	members_.clear();
	}

	void PeerChannel::BroadcastChangedState(const ChannelMember& member,
	Members* delivery_failures) {
	// This function should be called prior to DataSocket::Close().
	assert(delivery_failures);

	if (!member.connected()) {
	printf("Member disconnected: %s\n", member.name().c_str());
	}

	Members::iterator i = members_.begin();
	for (; i != members_.end(); ++i) {
	if (&member != (*i)) {
	if (!(*i)->NotifyOfOtherMember(member)) {
	(*i)->set_disconnected();
	delivery_failures->push_back(*i);
	i = members_.erase(i);
	if (i == members_.end())
	break;
	}
	}
	}
	}

	void PeerChannel::HandleDeliveryFailures(Members* failures) {
	assert(failures);

	while (!failures->empty()) {
	Members::iterator i = failures->begin();
	ChannelMember* member = *i;
	assert(!member->connected());
	failures->erase(i);
	BroadcastChangedState(*member, failures);
	delete member;
	}
	}

	// Builds a simple list of "name,id\n" entries for each member.
	std::string PeerChannel::BuildResponseForNewMember(const ChannelMember& member,
	std::string* content_type) {
	assert(content_type);

	*content_type = "text/plain";
	// The peer itself will always be the first entry.
	std::string response(member.GetEntry());
	for (Members::iterator i = members_.begin(); i != members_.end(); ++i) {
	if (member.id() != (*i)->id()) {
	assert((*i)->connected());
	response += (*i)->GetEntry();
	}
	}

	return response;
	}