split backends out into their own speaker-*.c

[disorder] / server / speaker-command.c

diff --git a/server/speaker-command.c b/server/speaker-command.c
new file mode 100644 (file)
index 0000000..8a8f63c
--- /dev/null
+++ b/server/speaker-command.c
@@ -0,0 +1,130 @@
+/*
+ * This file is part of DisOrder
+ * Copyright (C) 2005, 2006, 2007 Richard Kettlewell
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+ * USA
+ */
+/** @file server/speaker-command.c
+ * @brief Support for @ref BACKEND_COMMAND */
+
+#include <config.h>
+#include "types.h"
+
+#include <unistd.h>
+#include <poll.h>
+
+#include "configuration.h"
+#include "syscalls.h"
+#include "log.h"
+#include "speaker-protocol.h"
+#include "speaker.h"
+
+/** @brief Pipe to subprocess
+ *
+ * This is the file descriptor to write to for @ref BACKEND_COMMAND.
+ */
+static int cmdfd = -1;
+
+/** @brief poll array slot for @ref cmdfd
+ *
+ * Set by command_beforepoll().
+ */
+static int cmdfd_slot;
+
+/** @brief Start the subprocess for @ref BACKEND_COMMAND */
+static void fork_cmd(void) {
+  pid_t cmdpid;
+  int pfd[2];
+  if(cmdfd != -1) close(cmdfd);
+  xpipe(pfd);
+  cmdpid = xfork();
+  if(!cmdpid) {
+    signal(SIGPIPE, SIG_DFL);
+    xdup2(pfd[0], 0);
+    close(pfd[0]);
+    close(pfd[1]);
+    execl("/bin/sh", "sh", "-c", config->speaker_command, (char *)0);
+    fatal(errno, "error execing /bin/sh");
+  }
+  close(pfd[0]);
+  cmdfd = pfd[1];
+  D(("forked cmd %d, fd = %d", cmdpid, cmdfd));
+}
+
+/** @brief Command backend initialization */
+static void command_init(void) {
+  info("selected command backend");
+  fork_cmd();
+}
+
+/** @brief Play to a subprocess */
+static size_t command_play(size_t frames) {
+  size_t bytes = frames * device_bpf;
+  int written_bytes;
+
+  written_bytes = write(cmdfd, playing->buffer + playing->start, bytes);
+  D(("actually play %zu bytes, wrote %d",
+     bytes, written_bytes));
+  if(written_bytes < 0) {
+    switch(errno) {
+    case EPIPE:
+      error(0, "hmm, command died; trying another");
+      fork_cmd();
+      return 0;
+    case EAGAIN:
+      return 0;
+    default:
+      fatal(errno, "error writing to subprocess");
+    }
+  } else
+    return written_bytes / device_bpf;
+}
+
+/** @brief Update poll array for writing to subprocess */
+static void command_beforepoll(void) {
+  /* We send sample data to the subprocess as fast as it can accept it.
+   * This isn't ideal as pause latency can be very high as a result. */
+  if(cmdfd >= 0)
+    cmdfd_slot = addfd(cmdfd, POLLOUT);
+}
+
+/** @brief Process poll() results for subprocess play */
+static int command_ready(void) {
+  if(fds[cmdfd_slot].revents & (POLLOUT | POLLERR))
+    return 1;
+  else
+    return 0;
+}
+
+const struct speaker_backend command_backend = {
+  BACKEND_COMMAND,
+  FIXED_FORMAT,
+  command_init,
+  0,                                    /* activate */
+  command_play,
+  0,                                    /* deactivate */
+  command_beforepoll,
+  command_ready
+};
+
+/*
+Local Variables:
+c-basic-offset:2
+comment-column:40
+fill-column:79
+indent-tabs-mode:nil
+End:
+*/