Take the port from the configuration file.
[cubemap] / cubemap.cpp
index 49889f2e28bec81da0e90a51ab43ad8978f3e0c7..f6824723e9f6ed8afe86eee9933a3d361ec24c67 100644 (file)
 #include <sys/types.h>
 #include <sys/ioctl.h>
 #include <sys/epoll.h>
+#include <signal.h>
 #include <errno.h>
+#include <ctype.h>
 #include <vector>
 #include <string>
 #include <map>
 
 #include "metacube.h"
 #include "server.h"
+#include "input.h"
+#include "state.pb.h"
 
 #define NUM_SERVERS 4
 #define STREAM_ID "stream"
 #define STREAM_URL "http://gruessi.zrh.sesse.net:4013/"
-#define PORT 9094
 
 using namespace std;
 
 Server *servers = NULL;
+volatile bool hupped = false;
 
-class Input {
-public:
-       Input(const string &stream_id);
-
-       // Connect to the given URL and start streaming.
-       // WARNING: Currently this blocks; it does not run in a separate thread!
-       void run(const string &url);
-
-private:
-       // Recovers the this pointer and calls curl_callback().
-       static size_t curl_callback_thunk(char *ptr, size_t size, size_t nmemb, void *userdata);
-
-       // Stores the given data, looks for Metacube blocks (skipping data if needed),
-       // and calls process_block() for each one.
-       void curl_callback(char *ptr, size_t bytes);
-       void process_block(const char *data, uint32_t size, uint32_t flags);
-
-       // Drops <num_bytes> bytes from the head of <pending_data>,
-       // and outputs a warning.
-       void drop_pending_data(size_t num_bytes);
-
-       string stream_id;
-
-       // Data we have received but not fully processed yet.
-       vector<char> pending_data;
-
-       // If <pending_data> starts with a Metacube header,
-       // this is true.
-       bool has_metacube_header;
-};
-
-Input::Input(const string &stream_id)
-       : stream_id(stream_id),
-         has_metacube_header(false)
-{
-}
-
-void Input::run(const string &url)
-{
-       CURL *curl = curl_easy_init();
-       curl_easy_setopt(curl, CURLOPT_URL, STREAM_URL);
-       curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, &Input::curl_callback_thunk);
-       curl_easy_setopt(curl, CURLOPT_WRITEDATA, this);
-       curl_easy_perform(curl);
-}
-
-size_t Input::curl_callback_thunk(char *ptr, size_t size, size_t nmemb, void *userdata)
-{
-       Input *input = static_cast<Input *>(userdata);
-       size_t bytes = size * nmemb;
-       input->curl_callback(ptr, bytes);       
-       return bytes;
-}
-       
-void Input::curl_callback(char *ptr, size_t bytes)
-{
-       pending_data.insert(pending_data.end(), ptr, ptr + bytes);
-
-       for ( ;; ) {
-               // If we don't have enough data (yet) for even the Metacube header, just return.
-               if (pending_data.size() < sizeof(metacube_block_header)) {
-                       return;
-               }
-
-               // Make sure we have the Metacube sync header at the start.
-               // We may need to skip over junk data (it _should_ not happen, though).
-               if (!has_metacube_header) {
-                       char *ptr = static_cast<char *>(
-                               memmem(pending_data.data(), pending_data.size(),
-                                      METACUBE_SYNC, strlen(METACUBE_SYNC)));
-                       if (ptr == NULL) {
-                               // OK, so we didn't find the sync marker. We know then that
-                               // we do not have the _full_ marker in the buffer, but we
-                               // could have N-1 bytes. Drop everything before that,
-                               // and then give up.
-                               drop_pending_data(pending_data.size() - (strlen(METACUBE_SYNC) - 1));
-                               return;
-                       } else {
-                               // Yay, we found the header. Drop everything (if anything) before it.
-                               drop_pending_data(ptr - pending_data.data());
-                               has_metacube_header = true;
-
-                               // Re-check that we have the entire header; we could have dropped data.
-                               if (pending_data.size() < sizeof(metacube_block_header)) {
-                                       return;
-                               }
-                       }
-               }
-
-               // Now it's safe to read the header.
-               metacube_block_header *hdr = reinterpret_cast<metacube_block_header *>(pending_data.data());    
-               assert(memcmp(hdr->sync, METACUBE_SYNC, sizeof(hdr->sync)) == 0);
-               uint32_t size = ntohl(hdr->size);
-               uint32_t flags = ntohl(hdr->flags);
-
-               // See if we have the entire block. If not, wait for more data.
-               if (pending_data.size() < sizeof(metacube_block_header) + size) {
-                       return;
-               }
-
-               process_block(pending_data.data(), size, flags);
-
-               // Consume this block. This isn't the most efficient way of dealing with things
-               // should we have many blocks, but these routines don't need to be too efficient
-               // anyway.
-               pending_data.erase(pending_data.begin(), pending_data.begin() + sizeof(metacube_block_header) + size);
-       }
-}
-               
-void Input::process_block(const char *data, uint32_t size, uint32_t flags)
-{      
-       if (flags & METACUBE_FLAGS_HEADER) {
-               string header(data, data + size);
-               for (int i = 0; i < NUM_SERVERS; ++i) {
-                       servers[i].set_header(stream_id, header);
-               }
-       } else { 
-               for (int i = 0; i < NUM_SERVERS; ++i) {
-                       servers[i].add_data(stream_id, data, size);
-               }
-       }
-}
-
-void Input::drop_pending_data(size_t num_bytes)
+void hup(int ignored)
 {
-       if (num_bytes == 0) {
-               return;
-       }
-       fprintf(stderr, "Warning: Dropping %lld junk bytes from stream, maybe it is not a Metacube stream?\n",
-               (long long)num_bytes);
-       pending_data.erase(pending_data.begin(), pending_data.begin() + num_bytes);
+       hupped = true;
 }
 
 int create_server_socket(int port)
@@ -167,6 +43,12 @@ int create_server_socket(int port)
                exit(1);
        }
 
+       int one = 1;
+       if (setsockopt(server_sock, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)) == -1) {
+               perror("setsockopt(SO_REUSEADDR)");
+               exit(1);
+       }
+
        // We want dual-stack sockets. (Sorry, OpenBSD and Windows XP...)
        int zero = 0;
        if (setsockopt(server_sock, IPPROTO_IPV6, IPV6_V6ONLY, &zero, sizeof(zero)) == -1) {
@@ -223,19 +105,261 @@ void *acceptor_thread_run(void *arg)
        }
 }
 
+// Serialize the given state to a file descriptor, and return the (still open)
+// descriptor.
+int make_tempfile(const CubemapStateProto &state)
+{
+       char tmpl[] = "/tmp/cubemapstate.XXXXXX";
+       int state_fd = mkstemp(tmpl);
+       if (state_fd == -1) {
+               perror("mkstemp");
+               exit(1);
+       }
+
+       string serialized;
+       state.SerializeToString(&serialized);
+
+       const char *ptr = serialized.data();
+       size_t to_write = serialized.size();
+       while (to_write > 0) {
+               ssize_t ret = write(state_fd, ptr, to_write);
+               if (ret == -1) {
+                       perror("write");
+                       exit(1);
+               }
+
+               ptr += ret;
+               to_write -= ret;
+       }
+
+       return state_fd;
+}
+
+// Read the state back from the file descriptor made by make_tempfile,
+// and close it.
+CubemapStateProto read_tempfile(int state_fd)
+{
+       if (lseek(state_fd, 0, SEEK_SET) == -1) {
+               perror("lseek");
+               exit(1);
+       }
+
+       string serialized;
+       char buf[4096];
+       for ( ;; ) {
+               ssize_t ret = read(state_fd, buf, sizeof(buf));
+               if (ret == -1) {
+                       perror("read");
+                       exit(1);
+               }
+               if (ret == 0) {
+                       // EOF.
+                       break;
+               }
+
+               serialized.append(string(buf, buf + ret));
+       }
+
+       close(state_fd);  // Implicitly deletes the file.
+
+       CubemapStateProto state;
+       if (!state.ParseFromString(serialized)) {
+               fprintf(stderr, "PANIC: Failed deserialization of state.\n");
+               exit(1);
+       }
+
+       return state;
+}
+
+// Split a line on whitespace, e.g. "foo  bar baz" -> {"foo", "bar", "baz"}.
+vector<string> split_tokens(const string &line)
+{
+       vector<string> ret;
+       string current_token;
+
+       for (size_t i = 0; i < line.size(); ++i) {
+               if (isspace(line[i])) {
+                       if (!current_token.empty()) {
+                               ret.push_back(current_token);
+                       }
+                       current_token.clear();
+               } else {
+                       current_token.push_back(line[i]);
+               }
+       }
+       if (!current_token.empty()) {
+               ret.push_back(current_token);
+       }
+       return ret;
+}
+
+struct ConfigLine {
+       string keyword;
+       vector<string> arguments;
+       map<string, string> parameters;
+};
+
+// Parse the configuration file.
+vector<ConfigLine> parse_config(const string &filename)
+{
+       vector<ConfigLine> ret;
+
+       FILE *fp = fopen(filename.c_str(), "r");
+       if (fp == NULL) {
+               perror(filename.c_str());
+               exit(1);
+       }
+
+       char buf[4096];
+       while (!feof(fp)) {
+               if (fgets(buf, sizeof(buf), fp) == NULL) {
+                       break;
+               }
+
+               // Chop off the string at the first #, \r or \n.
+               buf[strcspn(buf, "#\r\n")] = 0;
+
+               // Remove all whitespace from the end of the string.
+               size_t len = strlen(buf);
+               while (len > 0 && isspace(buf[len - 1])) {
+                       buf[--len] = 0;
+               }
+
+               // If the line is now all blank, ignore it.
+               if (len == 0) {
+                       continue;
+               }
+
+               vector<string> tokens = split_tokens(buf);
+               assert(!tokens.empty());
+               
+               ConfigLine line;
+               line.keyword = tokens[0];
+
+               for (size_t i = 1; i < tokens.size(); ++i) {
+                       // foo=bar is a parameter; anything else is an argument.
+                       size_t equals_pos = tokens[i].find_first_of('=');
+                       if (equals_pos == string::npos) {
+                               line.arguments.push_back(tokens[i]);
+                       } else {
+                               string key = tokens[i].substr(0, equals_pos);
+                               string value = tokens[i].substr(equals_pos + 1, string::npos);
+                               line.parameters.insert(make_pair(key, value));
+                       }
+               }
+
+               ret.push_back(line);
+       }
+
+       fclose(fp);
+       return ret;
+}
+
 int main(int argc, char **argv)
 {
+       fprintf(stderr, "\nCubemap starting.\n");
+
+       string config_filename = (argc == 1) ? "cubemap.config" : argv[1];
+       vector<ConfigLine> config = parse_config(config_filename);
+
+       // Go through each (parsed) configuration line.
+       int port = -1;
+       for (unsigned i = 0; i < config.size(); ++i) {
+               if (config[i].keyword == "port") {
+                       if (config[i].parameters.size() > 0 ||
+                           config[i].arguments.size() != 1) {
+                               fprintf(stderr, "ERROR: 'port' takes one argument and no parameters\n");
+                               exit(1);
+                       }
+                       port = atoi(config[i].arguments[0].c_str());
+               }
+       }
+       if (port <= 0 || port > 65535) {
+               fprintf(stderr, "ERROR: Missing or invalid 'port' statement in config file\n");
+               exit(1);
+       }
+
+       // Create the servers.
        servers = new Server[NUM_SERVERS];
+
+       int server_sock;
+       if (argc == 4 && strcmp(argv[2], "-state") == 0) {
+               fprintf(stderr, "Deserializing state from previous process... ");
+               int state_fd = atoi(argv[3]);
+               CubemapStateProto loaded_state = read_tempfile(state_fd);
+
+               // Deserialize the streams.
+               for (int i = 0; i < loaded_state.streams_size(); ++i) {
+                       for (int j = 0; j < NUM_SERVERS; ++j) {
+                               servers[j].add_stream_from_serialized(loaded_state.streams(i));
+                       }
+               }
+
+               // Put back the existing clients. It doesn't matter which server we
+               // allocate them to, so just do round-robin.
+               for (int i = 0; i < loaded_state.clients_size(); ++i) {
+                       servers[i % NUM_SERVERS].add_client_from_serialized(loaded_state.clients(i));
+               }
+
+               // Deserialize the server socket.
+               server_sock = loaded_state.server_sock();
+
+               fprintf(stderr, "done.\n");
+       } else {
+               server_sock = create_server_socket(port);
+
+               // TODO: This should come from the config file.
+               for (int i = 0; i < NUM_SERVERS; ++i) {
+                       servers[i].add_stream(STREAM_ID);
+               }
+       }
+
        for (int i = 0; i < NUM_SERVERS; ++i) {
-               servers[i].add_stream(STREAM_ID);
                servers[i].run();
        }
 
-       int server_sock = create_server_socket(PORT);
-
        pthread_t acceptor_thread;
        pthread_create(&acceptor_thread, NULL, acceptor_thread_run, reinterpret_cast<void *>(server_sock));
 
-       Input input(STREAM_ID);
-       input.run(STREAM_URL);
+       // TODO: This should come from the config file.
+       Input input(STREAM_ID, STREAM_URL);
+       input.run();
+
+       signal(SIGHUP, hup);
+
+       while (!hupped) {
+               usleep(100000);
+       }
+
+       input.stop();
+
+       CubemapStateProto state;
+       state.set_server_sock(server_sock);
+       for (int i = 0; i < NUM_SERVERS; ++i) {
+               servers[i].stop();
+
+               CubemapStateProto local_state = servers[i].serialize();
+
+               // The stream state should be identical between the servers, so we only store it once.
+               if (i == 0) {
+                       state.mutable_streams()->MergeFrom(local_state.streams());
+               }
+               for (int j = 0; j < local_state.clients_size(); ++j) {
+                       state.add_clients()->MergeFrom(local_state.clients(j));
+               }
+       }
+       delete[] servers;
+
+       fprintf(stderr, "Serializing state and re-execing...\n");
+       int state_fd = make_tempfile(state);
+
+       char buf[16];
+       sprintf(buf, "%d", state_fd);
+
+       for ( ;; ) {
+               execlp(argv[0], argv[0], config_filename.c_str(), "-state", buf, NULL);
+               perror("execlp");
+               fprintf(stderr, "PANIC: re-exec of %s failed. Waiting 0.2 seconds and trying again...\n", argv[0]);
+               usleep(200000);
+       }
 }