]> git.sesse.net Git - cubemap/blobdiff - server.cpp
Rename header_or_error to header_or_short_response, as it will soon be able to contai...
[cubemap] / server.cpp
index b5f58d4c56711968db64a8d6c63e7d9eb08d0e25..615e8fb31d48b137df3cdcb3acf8caa4cbf00c68 100644 (file)
 
 #include "accesslog.h"
 #include "log.h"
-#include "markpool.h"
-#include "metacube.h"
+#include "metacube2.h"
 #include "mutexlock.h"
 #include "parse.h"
 #include "server.h"
 #include "state.pb.h"
 #include "stream.h"
+#include "util.h"
+
+#ifndef SO_MAX_PACING_RATE
+#define SO_MAX_PACING_RATE 47
+#endif
 
 using namespace std;
 
 extern AccessLogThread *access_log;
 
+namespace {
+
+inline bool is_equal(timespec a, timespec b)
+{
+       return a.tv_sec == b.tv_sec &&
+              a.tv_nsec == b.tv_nsec;
+}
+
+inline bool is_earlier(timespec a, timespec b)
+{
+       if (a.tv_sec != b.tv_sec)
+               return a.tv_sec < b.tv_sec;
+       return a.tv_nsec < b.tv_nsec;
+}
+
+}  // namespace
+
 Server::Server()
 {
        pthread_mutex_init(&mutex, NULL);
-       pthread_mutex_init(&queued_data_mutex, NULL);
+       pthread_mutex_init(&queued_clients_mutex, NULL);
 
        epoll_fd = epoll_create(1024);  // Size argument is ignored.
        if (epoll_fd == -1) {
@@ -45,20 +66,11 @@ Server::Server()
 
 Server::~Server()
 {
-       for (map<string, Stream *>::iterator stream_it = streams.begin();
-            stream_it != streams.end();
-            ++stream_it) {
-               delete stream_it->second;
+       for (size_t i = 0; i < streams.size(); ++i) {   
+               delete streams[i];
        }
 
-       int ret;
-       do {
-               ret = close(epoll_fd);
-       } while (ret == -1 && errno == EINTR);
-
-       if (ret == -1) {
-               log_perror("close(epoll_fd)");
-       }
+       safe_close(epoll_fd);
 }
 
 vector<ClientStats> Server::get_client_stats() const
@@ -76,15 +88,17 @@ vector<ClientStats> Server::get_client_stats() const
 
 void Server::do_work()
 {
-       for ( ;; ) {
-               int nfds = epoll_wait(epoll_fd, events, EPOLL_MAX_EVENTS, EPOLL_TIMEOUT_MS);
-               if (nfds == -1 && errno == EINTR) {
-                       if (should_stop) {
-                               return;
-                       }
-                       continue;
-               }
-               if (nfds == -1) {
+       while (!should_stop()) {
+               // Wait until there's activity on at least one of the fds,
+               // or 20 ms (about one frame at 50 fps) has elapsed.
+               //
+               // We could in theory wait forever and rely on wakeup()
+               // from add_client_deferred() and add_data_deferred(),
+               // but wakeup is a pretty expensive operation, and the
+               // two threads might end up fighting over a lock, so it's
+               // seemingly (much) more efficient to just have a timeout here.
+               int nfds = epoll_pwait(epoll_fd, events, EPOLL_MAX_EVENTS, EPOLL_TIMEOUT_MS, &sigset_without_usr1_block);
+               if (nfds == -1 && errno != EINTR) {
                        log_perror("epoll_wait");
                        exit(1);
                }
@@ -93,6 +107,7 @@ void Server::do_work()
        
                process_queued_data();
 
+               // Process each client where we have socket activity.
                for (int i = 0; i < nfds; ++i) {
                        Client *client = reinterpret_cast<Client *>(events[i].data.u64);
 
@@ -104,18 +119,57 @@ void Server::do_work()
                        process_client(client);
                }
 
-               for (map<string, Stream *>::iterator stream_it = streams.begin();
-                    stream_it != streams.end();
-                    ++stream_it) {
+               // Process each client where its stream has new data,
+               // even if there was no socket activity.
+               for (size_t i = 0; i < streams.size(); ++i) {   
                        vector<Client *> to_process;
-                       swap(stream_it->second->to_process, to_process);
+                       swap(streams[i]->to_process, to_process);
                        for (size_t i = 0; i < to_process.size(); ++i) {
                                process_client(to_process[i]);
                        }
                }
 
-               if (should_stop) {
-                       return;
+               // Finally, go through each client to see if it's timed out
+               // in the READING_REQUEST state. (Seemingly there are clients
+               // that can hold sockets up for days at a time without sending
+               // anything at all.)
+               timespec timeout_time;
+               if (clock_gettime(CLOCK_MONOTONIC_COARSE, &timeout_time) == -1) {
+                       log_perror("clock_gettime(CLOCK_MONOTONIC_COARSE)");
+                       continue;
+               }
+               timeout_time.tv_sec -= REQUEST_READ_TIMEOUT_SEC;
+               while (!clients_ordered_by_connect_time.empty()) {
+                       const pair<timespec, int> &connect_time_and_fd = clients_ordered_by_connect_time.front();
+
+                       // See if we have reached the end of clients to process.
+                       if (is_earlier(timeout_time, connect_time_and_fd.first)) {
+                               break;
+                       }
+
+                       // If this client doesn't exist anymore, just ignore it
+                       // (it was deleted earlier).
+                       map<int, Client>::iterator client_it = clients.find(connect_time_and_fd.second);
+                       if (client_it == clients.end()) {
+                               clients_ordered_by_connect_time.pop();
+                               continue;
+                       }
+                       Client *client = &client_it->second;
+                       if (!is_equal(client->connect_time, connect_time_and_fd.first)) {
+                               // Another client has taken this fd in the meantime.
+                               clients_ordered_by_connect_time.pop();
+                               continue;
+                       }
+
+                       if (client->state != Client::READING_REQUEST) {
+                               // Only READING_REQUEST can time out.
+                               clients_ordered_by_connect_time.pop();
+                               continue;
+                       }
+
+                       // OK, it timed out.
+                       close_client(client);
+                       clients_ordered_by_connect_time.pop();
                }
        }
 }
@@ -125,23 +179,34 @@ CubemapStateProto Server::serialize()
        // We don't serialize anything queued, so empty the queues.
        process_queued_data();
 
+       // Set all clients in a consistent state before serializing
+       // (ie., they have no remaining lost data). Otherwise, increasing
+       // the backlog could take clients into a newly valid area of the backlog,
+       // sending a stream of zeros instead of skipping the data as it should.
+       //
+       // TODO: Do this when clients are added back from serialized state instead;
+       // it would probably be less wasteful.
+       for (map<int, Client>::iterator client_it = clients.begin();
+            client_it != clients.end();
+            ++client_it) {
+               skip_lost_data(&client_it->second);
+       }
+
        CubemapStateProto serialized;
        for (map<int, Client>::const_iterator client_it = clients.begin();
             client_it != clients.end();
             ++client_it) {
                serialized.add_clients()->MergeFrom(client_it->second.serialize());
        }
-       for (map<string, Stream *>::const_iterator stream_it = streams.begin();
-            stream_it != streams.end();
-            ++stream_it) {
-               serialized.add_streams()->MergeFrom(stream_it->second->serialize());
+       for (size_t i = 0; i < streams.size(); ++i) {   
+               serialized.add_streams()->MergeFrom(streams[i]->serialize());
        }
        return serialized;
 }
 
 void Server::add_client_deferred(int sock)
 {
-       MutexLock lock(&queued_data_mutex);
+       MutexLock lock(&queued_clients_mutex);
        queued_add_clients.push_back(sock);
 }
 
@@ -152,6 +217,17 @@ void Server::add_client(int sock)
        assert(ret.second == true);  // Should not already exist.
        Client *client_ptr = &ret.first->second;
 
+       // Connection timestamps must be nondecreasing. I can't find any guarantee
+       // that even the monotonic clock can't go backwards by a small amount
+       // (think switching between CPUs with non-synchronized TSCs), so if
+       // this actually should happen, we hack around it by fudging
+       // connect_time.
+       if (!clients_ordered_by_connect_time.empty() &&
+           is_earlier(client_ptr->connect_time, clients_ordered_by_connect_time.back().first)) {
+               client_ptr->connect_time = clients_ordered_by_connect_time.back().first;
+       }
+       clients_ordered_by_connect_time.push(make_pair(client_ptr->connect_time, sock));
+
        // Start listening on data from this socket.
        epoll_event ev;
        ev.events = EPOLLIN | EPOLLET | EPOLLRDHUP;
@@ -168,17 +244,23 @@ void Server::add_client_from_serialized(const ClientProto &client)
 {
        MutexLock lock(&mutex);
        Stream *stream;
-       map<string, Stream *>::iterator stream_it = streams.find(client.stream_id());
-       if (stream_it == streams.end()) {
+       int stream_index = lookup_stream_by_url(client.url());
+       if (stream_index == -1) {
+               assert(client.state() != Client::SENDING_DATA);
                stream = NULL;
        } else {
-               stream = stream_it->second;
+               stream = streams[stream_index];
        }
        pair<map<int, Client>::iterator, bool> ret =
                clients.insert(make_pair(client.sock(), Client(client, stream)));
        assert(ret.second == true);  // Should not already exist.
        Client *client_ptr = &ret.first->second;
 
+       // Connection timestamps must be nondecreasing.
+       assert(clients_ordered_by_connect_time.empty() ||
+              !is_earlier(client_ptr->connect_time, clients_ordered_by_connect_time.back().first));
+       clients_ordered_by_connect_time.push(make_pair(client_ptr->connect_time, client.sock()));
+
        // Start listening on data from this socket.
        epoll_event ev;
        if (client.state() == Client::READING_REQUEST) {
@@ -188,77 +270,99 @@ void Server::add_client_from_serialized(const ClientProto &client)
                // the sleeping array again soon.
                ev.events = EPOLLOUT | EPOLLET | EPOLLRDHUP;
        }
-       ev.data.u64 = 0;  // Keep Valgrind happy.
        ev.data.u64 = reinterpret_cast<uint64_t>(client_ptr);
        if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, client.sock(), &ev) == -1) {
                log_perror("epoll_ctl(EPOLL_CTL_ADD)");
                exit(1);
        }
 
-       if (client_ptr->state == Client::SENDING_DATA && 
-           client_ptr->stream_pos == client_ptr->stream->bytes_received) {
+       if (client_ptr->state == Client::WAITING_FOR_KEYFRAME ||
+           client_ptr->state == Client::PREBUFFERING ||
+           (client_ptr->state == Client::SENDING_DATA &&
+            client_ptr->stream_pos == client_ptr->stream->bytes_received)) {
                client_ptr->stream->put_client_to_sleep(client_ptr);
        } else {
                process_client(client_ptr);
        }
 }
 
-void Server::add_stream(const string &stream_id, size_t backlog_size, Stream::Encoding encoding)
+int Server::lookup_stream_by_url(const string &url) const
+{
+       map<string, int>::const_iterator url_it = url_map.find(url);
+       if (url_it == url_map.end()) {
+               return -1;
+       }
+       return url_it->second;
+}
+
+int Server::add_stream(const string &url, size_t backlog_size, size_t prebuffering_bytes, Stream::Encoding encoding)
 {
        MutexLock lock(&mutex);
-       streams.insert(make_pair(stream_id, new Stream(stream_id, backlog_size, encoding)));
+       url_map.insert(make_pair(url, streams.size()));
+       streams.push_back(new Stream(url, backlog_size, prebuffering_bytes, encoding));
+       return streams.size() - 1;
 }
 
-void Server::add_stream_from_serialized(const StreamProto &stream, int data_fd)
+int Server::add_stream_from_serialized(const StreamProto &stream, int data_fd)
 {
        MutexLock lock(&mutex);
-       streams.insert(make_pair(stream.stream_id(), new Stream(stream, data_fd)));
+       url_map.insert(make_pair(stream.url(), streams.size()));
+       streams.push_back(new Stream(stream, data_fd));
+       return streams.size() - 1;
 }
        
-void Server::set_backlog_size(const string &stream_id, size_t new_size)
+void Server::set_backlog_size(int stream_index, size_t new_size)
+{
+       MutexLock lock(&mutex);
+       assert(stream_index >= 0 && stream_index < ssize_t(streams.size()));
+       streams[stream_index]->set_backlog_size(new_size);
+}
+
+void Server::set_prebuffering_bytes(int stream_index, size_t new_amount)
 {
        MutexLock lock(&mutex);
-       assert(streams.count(stream_id) != 0);
-       streams[stream_id]->set_backlog_size(new_size);
+       assert(stream_index >= 0 && stream_index < ssize_t(streams.size()));
+       streams[stream_index]->prebuffering_bytes = new_amount;
 }
        
-void Server::set_encoding(const string &stream_id, Stream::Encoding encoding)
+void Server::set_encoding(int stream_index, Stream::Encoding encoding)
 {
        MutexLock lock(&mutex);
-       assert(streams.count(stream_id) != 0);
-       streams[stream_id]->encoding = encoding;
+       assert(stream_index >= 0 && stream_index < ssize_t(streams.size()));
+       streams[stream_index]->encoding = encoding;
 }
        
-void Server::set_header(const string &stream_id, const string &http_header, const string &stream_header)
+void Server::set_header(int stream_index, const string &http_header, const string &stream_header)
 {
        MutexLock lock(&mutex);
-       find_stream(stream_id)->http_header = http_header;
-       find_stream(stream_id)->stream_header = stream_header;
-
-       // If there are clients we haven't sent anything to yet, we should give
-       // them the header, so push back into the SENDING_HEADER state.
-       for (map<int, Client>::iterator client_it = clients.begin();
-            client_it != clients.end();
-            ++client_it) {
-               Client *client = &client_it->second;
-               if (client->state == Client::SENDING_DATA &&
-                   client->stream_pos == 0) {
-                       construct_header(client);
-               }
+       assert(stream_index >= 0 && stream_index < ssize_t(streams.size()));
+       streams[stream_index]->http_header = http_header;
+
+       if (stream_header != streams[stream_index]->stream_header) {
+               // We cannot start at any of the older starting points anymore,
+               // since they'd get the wrong header for the stream (not to mention
+               // that a changed header probably means the stream restarted,
+               // which means any client starting on the old one would probably
+               // stop playing properly at the change point). Next block
+               // should be a suitable starting point (if not, something is
+               // pretty strange), so it will fill up again soon enough.
+               streams[stream_index]->suitable_starting_points.clear();
        }
+       streams[stream_index]->stream_header = stream_header;
 }
        
-void Server::set_mark_pool(const string &stream_id, MarkPool *mark_pool)
+void Server::set_pacing_rate(int stream_index, uint32_t pacing_rate)
 {
        MutexLock lock(&mutex);
        assert(clients.empty());
-       find_stream(stream_id)->mark_pool = mark_pool;
+       assert(stream_index >= 0 && stream_index < ssize_t(streams.size()));
+       streams[stream_index]->pacing_rate = pacing_rate;
 }
 
-void Server::add_data_deferred(const string &stream_id, const char *data, size_t bytes)
+void Server::add_data_deferred(int stream_index, const char *data, size_t bytes, StreamStartSuitability suitable_for_stream_start)
 {
-       MutexLock lock(&queued_data_mutex);
-       queued_data[stream_id].append(string(data, data + bytes));
+       assert(stream_index >= 0 && stream_index < ssize_t(streams.size()));
+       streams[stream_index]->add_data_deferred(data, bytes, suitable_for_stream_start);
 }
 
 // See the .h file for postconditions after this function.     
@@ -319,17 +423,17 @@ read_request_again:
                }
 
                // We've changed states, so fall through.
-               assert(client->state == Client::SENDING_ERROR ||
+               assert(client->state == Client::SENDING_SHORT_RESPONSE ||
                       client->state == Client::SENDING_HEADER);
        }
-       case Client::SENDING_ERROR:
+       case Client::SENDING_SHORT_RESPONSE:
        case Client::SENDING_HEADER: {
-sending_header_or_error_again:
+sending_header_or_short_response_again:
                int ret;
                do {
                        ret = write(client->sock,
-                                   client->header_or_error.data() + client->header_or_error_bytes_sent,
-                                   client->header_or_error.size() - client->header_or_error_bytes_sent);
+                                   client->header_or_short_response.data() + client->header_or_short_response_bytes_sent,
+                                   client->header_or_short_response.size() - client->header_or_short_response_bytes_sent);
                } while (ret == -1 && errno == EINTR);
 
                if (ret == -1 && errno == EAGAIN) {
@@ -347,54 +451,103 @@ sending_header_or_error_again:
                        return;
                }
                
-               client->header_or_error_bytes_sent += ret;
-               assert(client->header_or_error_bytes_sent <= client->header_or_error.size());
+               client->header_or_short_response_bytes_sent += ret;
+               assert(client->header_or_short_response_bytes_sent <= client->header_or_short_response.size());
 
-               if (client->header_or_error_bytes_sent < client->header_or_error.size()) {
+               if (client->header_or_short_response_bytes_sent < client->header_or_short_response.size()) {
                        // We haven't sent all yet. Fine; go another round.
-                       goto sending_header_or_error_again;
+                       goto sending_header_or_short_response_again;
                }
 
                // We're done sending the header or error! Clear it to release some memory.
-               client->header_or_error.clear();
+               client->header_or_short_response.clear();
 
-               if (client->state == Client::SENDING_ERROR) {
+               if (client->state == Client::SENDING_SHORT_RESPONSE) {
                        // We're done sending the error, so now close.  
                        // This is postcondition #1.
                        close_client(client);
                        return;
                }
 
-               // Start sending from the end. In other words, we won't send any of the backlog,
-               // but we'll start sending immediately as we get data.
-               // This is postcondition #3.
+               Stream *stream = client->stream;
+               if (client->stream_pos == size_t(-2)) {
+                       // Start sending from the beginning of the backlog.
+                       client->stream_pos = min<size_t>(
+                           stream->bytes_received - stream->backlog_size,
+                           0);
+                       client->state = Client::SENDING_DATA;
+                       goto sending_data;
+               } else if (stream->prebuffering_bytes == 0) {
+                       // Start sending from the first keyframe we get. In other
+                       // words, we won't send any of the backlog, but we'll start
+                       // sending immediately as we get the next keyframe block.
+                       // Note that this is functionally identical to the next if branch,
+                       // except that we save a binary search.
+                       client->stream_pos = stream->bytes_received;
+                       client->state = Client::WAITING_FOR_KEYFRAME;
+               } else {
+                       // We're not going to send anything to the client before we have
+                       // N bytes. However, this wait might be boring; we can just as well
+                       // use it to send older data if we have it. We use lower_bound()
+                       // so that we are conservative and never add extra latency over just
+                       // waiting (assuming CBR or nearly so); otherwise, we could want e.g.
+                       // 100 kB prebuffer but end up sending a 10 MB GOP.
+                       deque<size_t>::const_iterator starting_point_it =
+                               lower_bound(stream->suitable_starting_points.begin(),
+                                           stream->suitable_starting_points.end(),
+                                           stream->bytes_received - stream->prebuffering_bytes);
+                       if (starting_point_it == stream->suitable_starting_points.end()) {
+                               // None found. Just put us at the end, and then wait for the
+                               // first keyframe to appear.
+                               client->stream_pos = stream->bytes_received;
+                               client->state = Client::WAITING_FOR_KEYFRAME;
+                       } else {
+                               client->stream_pos = *starting_point_it;
+                               client->state = Client::PREBUFFERING;
+                               goto prebuffering;
+                       }
+               }
+               // Fall through.
+       }
+       case Client::WAITING_FOR_KEYFRAME: {
+               Stream *stream = client->stream;
+               if (stream->suitable_starting_points.empty() ||
+                   client->stream_pos > stream->suitable_starting_points.back()) {
+                       // We haven't received a keyframe since this stream started waiting,
+                       // so keep on waiting for one.
+                       // This is postcondition #3.
+                       stream->put_client_to_sleep(client);
+                       return;
+               }
+               client->stream_pos = stream->suitable_starting_points.back();
+               client->state = Client::PREBUFFERING;
+               // Fall through.
+       }
+       case Client::PREBUFFERING: {
+prebuffering:
+               Stream *stream = client->stream;
+               size_t bytes_to_send = stream->bytes_received - client->stream_pos;
+               assert(bytes_to_send <= stream->backlog_size);
+               if (bytes_to_send < stream->prebuffering_bytes) {
+                       // We don't have enough bytes buffered to start this client yet.
+                       // This is postcondition #3.
+                       stream->put_client_to_sleep(client);
+                       return;
+               }
                client->state = Client::SENDING_DATA;
-               client->stream_pos = client->stream->bytes_received;
-               client->stream->put_client_to_sleep(client);
-               return;
+               // Fall through.
        }
        case Client::SENDING_DATA: {
-sending_data_again:
-               // See if there's some data we've lost. Ideally, we should drop to a block boundary,
-               // but resync will be the mux's problem.
+sending_data:
+               skip_lost_data(client);
                Stream *stream = client->stream;
+
+sending_data_again:
                size_t bytes_to_send = stream->bytes_received - client->stream_pos;
+               assert(bytes_to_send <= stream->backlog_size);
                if (bytes_to_send == 0) {
                        return;
                }
-               if (bytes_to_send > stream->backlog_size) {
-                       size_t bytes_lost = bytes_to_send - stream->backlog_size;
-                       client->stream_pos = stream->bytes_received - stream->backlog_size;
-                       client->bytes_lost += bytes_lost;
-                       ++client->num_loss_events;
-                       bytes_to_send = stream->backlog_size;
-
-                       double loss_fraction = double(client->bytes_lost) / double(client->bytes_lost + client->bytes_sent);
-                       log(WARNING, "[%s] Client lost %lld bytes (total loss: %.2f%%), maybe too slow connection",
-                               client->remote_addr.c_str(),
-                               (long long int)(bytes_lost),
-                               100.0 * loss_fraction);
-               }
 
                // See if we need to split across the circular buffer.
                bool more_data = false;
@@ -405,7 +558,7 @@ sending_data_again:
 
                ssize_t ret;
                do {
-                       loff_t offset = client->stream_pos % stream->backlog_size;
+                       off_t offset = client->stream_pos % stream->backlog_size;
                        ret = sendfile(client->sock, stream->data_fd, &offset, bytes_to_send);
                } while (ret == -1 && errno == EINTR);
 
@@ -438,6 +591,23 @@ sending_data_again:
        }
 }
 
+// See if there's some data we've lost. Ideally, we should drop to a block boundary,
+// but resync will be the mux's problem.
+void Server::skip_lost_data(Client *client)
+{
+       Stream *stream = client->stream;
+       if (stream == NULL) {
+               return;
+       }
+       size_t bytes_to_send = stream->bytes_received - client->stream_pos;
+       if (bytes_to_send > stream->backlog_size) {
+               size_t bytes_lost = bytes_to_send - stream->backlog_size;
+               client->stream_pos = stream->bytes_received - stream->backlog_size;
+               client->bytes_lost += bytes_lost;
+               ++client->num_loss_events;
+       }
+}
+
 int Server::parse_request(Client *client)
 {
        vector<string> lines = split_lines(client->request);
@@ -445,6 +615,18 @@ int Server::parse_request(Client *client)
                return 400;  // Bad request (empty).
        }
 
+       // Parse the headers, for logging purposes.
+       // TODO: Case-insensitivity.
+       multimap<string, string> headers = extract_headers(lines, client->remote_addr);
+       multimap<string, string>::const_iterator referer_it = headers.find("Referer");
+       if (referer_it != headers.end()) {
+               client->referer = referer_it->second;
+       }
+       multimap<string, string>::const_iterator user_agent_it = headers.find("User-Agent");
+       if (user_agent_it != headers.end()) {
+               client->user_agent = user_agent_it->second;
+       }
+
        vector<string> request_tokens = split_tokens(lines[0]);
        if (request_tokens.size() < 2) {
                return 400;  // Bad request (empty).
@@ -452,20 +634,31 @@ int Server::parse_request(Client *client)
        if (request_tokens[0] != "GET") {
                return 400;  // Should maybe be 405 instead?
        }
-       if (streams.count(request_tokens[1]) == 0) {
+
+       string url = request_tokens[1];
+       if (url.find("?backlog") == url.size() - 8) {
+               client->stream_pos = -2;
+               url = url.substr(0, url.size() - 8);
+       } else {
+               client->stream_pos = -1;
+       }
+
+       map<string, int>::const_iterator url_map_it = url_map.find(url);
+       if (url_map_it == url_map.end()) {
                return 404;  // Not found.
        }
 
-       client->stream_id = request_tokens[1];
-       client->stream = find_stream(client->stream_id);
-       if (client->stream->mark_pool != NULL) {
-               client->fwmark = client->stream->mark_pool->get_mark();
-       } else {
-               client->fwmark = 0;  // No mark.
+       Stream *stream = streams[url_map_it->second];
+       if (stream->http_header.empty()) {
+               return 503;  // Service unavailable.
        }
-       if (setsockopt(client->sock, SOL_SOCKET, SO_MARK, &client->fwmark, sizeof(client->fwmark)) == -1) {                          
-               if (client->fwmark != 0) {
-                       log_perror("setsockopt(SO_MARK)");
+
+       client->url = request_tokens[1];
+
+       client->stream = stream;
+       if (setsockopt(client->sock, SOL_SOCKET, SO_MAX_PACING_RATE, &client->stream->pacing_rate, sizeof(client->stream->pacing_rate)) == -1) {
+               if (client->stream->pacing_rate != ~0U) {
+                       log_perror("setsockopt(SO_MAX_PACING_RATE)");
                }
        }
        client->request.clear();
@@ -475,24 +668,25 @@ int Server::parse_request(Client *client)
 
 void Server::construct_header(Client *client)
 {
-       Stream *stream = find_stream(client->stream_id);
+       Stream *stream = client->stream;
        if (stream->encoding == Stream::STREAM_ENCODING_RAW) {
-               client->header_or_error = stream->http_header +
+               client->header_or_short_response = stream->http_header +
                        "\r\n" +
                        stream->stream_header;
        } else if (stream->encoding == Stream::STREAM_ENCODING_METACUBE) {
-               client->header_or_error = stream->http_header +
+               client->header_or_short_response = stream->http_header +
                        "Content-encoding: metacube\r\n" +
                        "\r\n";
                if (!stream->stream_header.empty()) {
-                       metacube_block_header hdr;
-                       memcpy(hdr.sync, METACUBE_SYNC, sizeof(hdr.sync));
+                       metacube2_block_header hdr;
+                       memcpy(hdr.sync, METACUBE2_SYNC, sizeof(hdr.sync));
                        hdr.size = htonl(stream->stream_header.size());
-                       hdr.flags = htonl(METACUBE_FLAGS_HEADER);
-                       client->header_or_error.append(
+                       hdr.flags = htons(METACUBE_FLAGS_HEADER);
+                       hdr.csum = htons(metacube2_compute_crc(&hdr));
+                       client->header_or_short_response.append(
                                string(reinterpret_cast<char *>(&hdr), sizeof(hdr)));
                }
-               client->header_or_error.append(stream->stream_header);
+               client->header_or_short_response.append(stream->stream_header);
        } else {
                assert(false);
        }
@@ -515,10 +709,10 @@ void Server::construct_error(Client *client, int error_code)
        char error[256];
        snprintf(error, 256, "HTTP/1.0 %d Error\r\nContent-type: text/plain\r\n\r\nSomething went wrong. Sorry.\r\n",
                error_code);
-       client->header_or_error = error;
+       client->header_or_short_response = error;
 
        // Switch states.
-       client->state = Client::SENDING_ERROR;
+       client->state = Client::SENDING_SHORT_RESPONSE;
 
        epoll_event ev;
        ev.events = EPOLLOUT | EPOLLET | EPOLLRDHUP;
@@ -548,50 +742,29 @@ void Server::close_client(Client *client)
        if (client->stream != NULL) {
                delete_from(&client->stream->sleeping_clients, client);
                delete_from(&client->stream->to_process, client);
-               if (client->stream->mark_pool != NULL) {
-                       int fwmark = client->fwmark;
-                       client->stream->mark_pool->release_mark(fwmark);
-               }
        }
 
        // Log to access_log.
        access_log->write(client->get_stats());
 
        // Bye-bye!
-       int ret;
-       do {
-               ret = close(client->sock);
-       } while (ret == -1 && errno == EINTR);
-
-       if (ret == -1) {
-               log_perror("close");
-       }
+       safe_close(client->sock);
 
        clients.erase(client->sock);
 }
        
-Stream *Server::find_stream(const string &stream_id)
-{
-       map<string, Stream *>::iterator it = streams.find(stream_id);
-       assert(it != streams.end());
-       return it->second;
-}
-
 void Server::process_queued_data()
 {
-       MutexLock lock(&queued_data_mutex);
+       {
+               MutexLock lock(&queued_clients_mutex);
+
+               for (size_t i = 0; i < queued_add_clients.size(); ++i) {
+                       add_client(queued_add_clients[i]);
+               }
+               queued_add_clients.clear();
+       }
 
-       for (size_t i = 0; i < queued_add_clients.size(); ++i) {
-               add_client(queued_add_clients[i]);
+       for (size_t i = 0; i < streams.size(); ++i) {   
+               streams[i]->process_queued_data();
        }
-       queued_add_clients.clear();     
-       
-       for (map<string, string>::iterator queued_it = queued_data.begin();
-            queued_it != queued_data.end();
-            ++queued_it) {
-               Stream *stream = find_stream(queued_it->first);
-               stream->add_data(queued_it->second.data(), queued_it->second.size());
-               stream->wake_up_all_clients();
-       }
-       queued_data.clear();
 }