Rename client_request to request, and clear it when we are done with it.
[cubemap] / server.cpp
index 31e5c0a31da327bc80499c543bbb4dee932b74bb..08f2afdfc907c38d8858de1715b46ce0ac2c179a 100644 (file)
@@ -13,6 +13,7 @@
 #include <vector>
 #include <string>
 #include <map>
+#include <algorithm>
 
 #include "metacube.h"
 #include "server.h"
@@ -47,9 +48,26 @@ void *Server::do_work_thunk(void *arg)
 void Server::do_work()
 {
        for ( ;; ) {
-               MutexLock lock(&mutex);
-               printf("server thread running\n");
-               sleep(1);
+               int nfds = epoll_wait(epoll_fd, events, EPOLL_MAX_EVENTS, EPOLL_TIMEOUT_MS);
+
+               MutexLock lock(&mutex);  // We release the mutex between iterations.
+               if (nfds == -1) {
+                       perror("epoll_wait");
+                       exit(1);
+               }
+               
+               for (int i = 0; i < nfds; ++i) {
+                       int fd = events[i].data.fd;
+                       assert(clients.count(fd) != 0);
+                       Client *client = &clients[fd];
+
+                       if (events[i].events & (EPOLLERR | EPOLLRDHUP | EPOLLHUP)) {
+                               close_client(client);
+                               continue;
+                       }
+
+                       process_client(client);
+               }
        }
 }
        
@@ -57,6 +75,8 @@ void Server::add_client(int sock)
 {
        MutexLock lock(&mutex);
        Client new_client;
+       new_client.sock = sock;
+       new_client.request.reserve(1024);
        new_client.state = Client::READING_REQUEST;
        new_client.header_bytes_sent = 0;
        new_client.bytes_sent = 0;
@@ -65,7 +85,7 @@ void Server::add_client(int sock)
 
        // Start listening on data from this socket.
        epoll_event ev;
-       ev.events = EPOLLIN;
+       ev.events = EPOLLIN | EPOLLRDHUP;
        ev.data.fd = sock;
        if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, sock, &ev) == -1) {
                perror("epoll_ctl(EPOLL_CTL_ADD)");
@@ -75,16 +95,231 @@ void Server::add_client(int sock)
        
 void Server::add_stream(const string &stream_id)
 {
-       // TODO
+       MutexLock lock(&mutex);
+       streams.insert(make_pair(stream_id, Stream()));
 }
        
 void Server::set_header(const string &stream_id, const string &header)
 {
-       // TODO
-       printf("got header! %lu bytes\n", header.size());
+       MutexLock lock(&mutex);
+       assert(streams.count(stream_id) != 0);
+       streams[stream_id].header = header;
 }
        
 void Server::add_data(const string &stream_id, const char *data, size_t bytes)
 {
-       // TODO
+       if (bytes == 0) {
+               return;
+       }
+
+       MutexLock lock(&mutex);
+       assert(streams.count(stream_id) != 0);
+       Stream *stream = &streams[stream_id];
+       size_t pos = stream->data_size % BACKLOG_SIZE;
+       stream->data_size += bytes;
+
+       if (pos + bytes > BACKLOG_SIZE) {
+               size_t to_copy = BACKLOG_SIZE - pos;
+               memcpy(stream->data + pos, data, to_copy);
+               data += to_copy;
+               bytes -= to_copy;
+               pos = 0;
+       }
+
+       memcpy(stream->data + pos, data, bytes);
+       wake_up_all_clients();
+}
+       
+void Server::process_client(Client *client)
+{
+       switch (client->state) {
+       case Client::READING_REQUEST: {
+               // Try to read more of the request.
+               char buf[1024];
+               int ret = read(client->sock, buf, sizeof(buf));
+               if (ret == -1) {
+                       perror("read");
+                       close_client(client);
+                       return;
+               }
+               if (ret == 0) {
+                       // No data? This really means that we were triggered for something else than
+                       // POLLIN (which suggests a logic error in epoll).
+                       fprintf(stderr, "WARNING: fd %d returned unexpectedly 0 bytes!\n", client->sock);
+                       close_client(client);
+                       return;
+               }
+
+               // Guard against overlong requests gobbling up all of our space.
+               if (client->request.size() + ret > MAX_CLIENT_REQUEST) {
+                       fprintf(stderr, "WARNING: fd %d sent overlong request!\n", client->sock);
+                       close_client(client);
+                       return;
+               }       
+
+               // See if we have \r\n\r\n anywhere in the request. We start three bytes
+               // before what we just appended, in case we just got the final character.
+               size_t existing_req_bytes = client->request.size();
+               client->request.append(string(buf, buf + ret));
+       
+               size_t start_at = (existing_req_bytes >= 3 ? existing_req_bytes - 3 : 0);
+               const char *ptr = reinterpret_cast<char *>(
+                       memmem(client->request.data() + start_at, client->request.size() - start_at,
+                              "\r\n\r\n", 4));
+               if (ptr == NULL) {
+                       // OK, we don't have the entire header yet. Fine; we'll get it later.
+                       return;
+               }
+
+               if (ptr != client->request.data() + client->request.size() - 4) {
+                       fprintf(stderr, "WARNING: fd %d had junk data after request!\n", client->sock);
+                       close_client(client);
+                       return;
+               }
+
+               parse_request(client);
+               break;
+       }
+       case Client::SENDING_HEADER: {
+               int ret = write(client->sock,
+                               client->header.data() + client->header_bytes_sent,
+                               client->header.size() - client->header_bytes_sent);
+               if (ret == -1) {
+                       perror("write");
+                       close_client(client);
+                       return;
+               }
+               
+               client->header_bytes_sent += ret;
+               assert(client->header_bytes_sent <= client->header.size());
+
+               if (client->header_bytes_sent < client->header.size()) {
+                       // We haven't sent all yet. Fine; we'll do that later.
+                       return;
+               }
+
+               // We're done sending the header! Clear the entire header to release some memory.
+               client->header.clear();
+
+               // 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.
+               client->state = Client::SENDING_DATA;
+               client->bytes_sent = streams[client->stream_id].data_size;
+               break;
+       }
+       case Client::SENDING_DATA: {
+               // 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.
+               const Stream &stream = streams[client->stream_id];
+               size_t bytes_to_send = stream.data_size - client->bytes_sent;
+               if (bytes_to_send > BACKLOG_SIZE) {
+                       fprintf(stderr, "WARNING: fd %d lost %lld bytes, maybe too slow connection\n",
+                               client->sock,
+                               (long long int)(bytes_to_send - BACKLOG_SIZE));
+                       client->bytes_sent = streams[client->stream_id].data_size - BACKLOG_SIZE;
+                       bytes_to_send = BACKLOG_SIZE;
+               }
+
+               // See if we need to split across the circular buffer.
+               ssize_t ret;
+               if ((client->bytes_sent % BACKLOG_SIZE) + bytes_to_send > BACKLOG_SIZE) {
+                       size_t bytes_first_part = BACKLOG_SIZE - (client->bytes_sent % BACKLOG_SIZE);
+
+                       iovec iov[2];
+                       iov[0].iov_base = const_cast<char *>(stream.data + (client->bytes_sent % BACKLOG_SIZE));
+                       iov[0].iov_len = bytes_first_part;
+
+                       iov[1].iov_base = const_cast<char *>(stream.data);
+                       iov[1].iov_len = bytes_to_send - bytes_first_part;
+
+                       ret = writev(client->sock, iov, 2);
+               } else {
+                       ret = write(client->sock,
+                                   stream.data + (client->bytes_sent % BACKLOG_SIZE),
+                                   bytes_to_send);
+               }
+               if (ret == -1) {
+                       perror("write/writev");
+                       close_client(client);
+                       return;
+               }
+               client->bytes_sent += ret;
+
+               if (client->bytes_sent == stream.data_size) {
+                       // We don't have any more data for this client, so put it to sleep.
+                       put_client_to_sleep(client);
+               }
+               break;
+       }
+       default:
+               assert(false);
+       }
+}
+
+void Server::parse_request(Client *client)
+{
+       // TODO: Actually parse the request. :-)
+       client->stream_id = "stream";
+       client->request.clear();
+
+       // Construct the header.
+       client->header = "HTTP/1.0 200 OK\r\n  Content-type: video/x-flv\r\nCache-Control: no-cache\r\nContent-type: todo/fixme\r\n\r\n" +
+               streams[client->stream_id].header;
+
+       // Switch states.
+       client->state = Client::SENDING_HEADER;
+
+       epoll_event ev;
+       ev.events = EPOLLOUT | EPOLLRDHUP;
+       ev.data.fd = client->sock;
+
+       if (epoll_ctl(epoll_fd, EPOLL_CTL_MOD, client->sock, &ev) == -1) {
+               perror("epoll_ctl(EPOLL_CTL_MOD)");
+               exit(1);
+       }
+}
+       
+void Server::close_client(Client *client)
+{
+       if (epoll_ctl(epoll_fd, EPOLL_CTL_DEL, client->sock, NULL) == -1) {
+               perror("epoll_ctl(EPOLL_CTL_DEL)");
+               exit(1);
+       }
+
+       // This client could be sleeping, so we'll need to fix that. (Argh, O(n).)
+       vector<int>::iterator new_end =
+               remove(sleeping_clients.begin(), sleeping_clients.end(), client->sock);
+       sleeping_clients.erase(new_end, sleeping_clients.end());
+       
+       // Bye-bye!
+       close(client->sock);
+       clients.erase(client->sock);
+}
+       
+void Server::put_client_to_sleep(Client *client)
+{
+       epoll_event ev;
+       ev.events = EPOLLRDHUP;
+       ev.data.fd = client->sock;
+
+       if (epoll_ctl(epoll_fd, EPOLL_CTL_MOD, client->sock, &ev) == -1) {
+               perror("epoll_ctl(EPOLL_CTL_MOD)");
+               exit(1);
+       }
+
+       sleeping_clients.push_back(client->sock);
+}
+
+void Server::wake_up_all_clients()
+{
+       for (unsigned i = 0; i < sleeping_clients.size(); ++i) {
+               epoll_event ev;
+               ev.events = EPOLLOUT | EPOLLRDHUP;
+               ev.data.fd = sleeping_clients[i];
+               if (epoll_ctl(epoll_fd, EPOLL_CTL_MOD, sleeping_clients[i], &ev) == -1) {
+                       perror("epoll_ctl(EPOLL_CTL_MOD)");
+                       exit(1);
+               }
+       }
+       sleeping_clients.clear();
 }