mmq-player.c

   1 #include "mmq.h"
   2 #include "fixeddec/fixeddec.h"
   3
   4 #ifndef MMQ_MQUEUE
   5 #  define MMQ_MQUEUE "/mmq"
   6 #endif
   7
   8 #ifndef MMQ_MSGSIZE
   9 #  define MMQ_MSGSIZE 256
  10 #endif
  11
  12 #ifndef MMQ_MAXMSG
  13 #  define MMQ_MAXMSG 10 /* Linux 2.6 default */
  14 #endif
  15
  16 enum player_state g_state;
  17 long g_seek_msec;
  18 static struct mq_attr attr;
  19 static mqd_t mq;
  20
  21 /*
  22  * we only have two opcodes for messages in the queue, signals handle
  23  * everything else
  24  */
  25 enum opcode {
  26         OP_PLAY_PATH = '=', /* path to an audio file */
  27         OP_SEEK_PRE = ':' /* seek point for next song before playback */
  28 };
  29
  30 static void next_handler(UNUSED int signum)
  31 {
  32         g_state = STATE_NEXT;
  33         emit("^\n");
  34 }
  35
  36 static void sig_init(void)
  37 {
  38         struct sigaction sa;
  39
  40         memset(&sa, 0, sizeof(struct sigaction));
  41         sigemptyset(&sa.sa_mask);
  42         sa.sa_flags = SA_RESTART;
  43         sa.sa_handler = next_handler;
  44         sigaction(SIGUSR1, &sa, NULL);
  45 }
  46
  47 static void set_mq_nonblock(int nb)
  48 {
  49         attr.mq_flags = nb ? O_NONBLOCK : 0;
  50
  51         if (mq_setattr(mq, &attr, NULL) < 0)
  52                 die("mq_setattr: %s\n", strerror(errno));
  53 }
  54
  55 static void read_seek_point(char *buf, ssize_t len)
  56 {
  57         buf[len] = '\0';
  58         g_seek_msec = strtol(buf, NULL, 10);
  59
  60         emit(":%ld\n", g_seek_msec);
  61 }
  62
  63 static void play_path(char *buf, ssize_t len)
  64 {
  65         g_state = STATE_PLAY;
  66         buf[len] = '\n';
  67         write(STDOUT_FILENO, buf - 1, len + 2);
  68         buf[len] = '\0';
  69         fixeddec_play(buf, len);
  70         emit(".\n");
  71         if (g_state == STATE_NEXT)
  72                 audio_close(0);
  73 }
  74
  75 static void unknown(const char *buf, ssize_t len)
  76 {
  77         warn("unknown message received:\n");
  78         write(2, buf, len);
  79         warn("\n-------------------------\n");
  80 }
  81
  82 /* lets try to get away without accepting command-line arguments... */
  83 int main(void)
  84 {
  85         char tmp[MMQ_MSGSIZE + 1];
  86         ssize_t r;
  87
  88         attr.mq_msgsize = MMQ_MSGSIZE;
  89         attr.mq_maxmsg = MMQ_MAXMSG;
  90
  91         mq = mq_open(MMQ_MQUEUE, O_CREAT|O_RDONLY, 0666, &attr);
  92         if (mq == (mqd_t)-1)
  93                 die("mq_open(%s): %s\n", MMQ_MQUEUE, strerror(errno));
  94
  95         sig_init();
  96         for (;;) {
  97                 r = mq_receive(mq, tmp, attr.mq_msgsize, NULL);
  98                 if (r == 0 || (r < 0 && errno == EINTR)) {
  99                         /* ignore */
 100                 } else if (r < 0) {
 101                         int err = errno;
 102
 103                         if (err == EAGAIN) {
 104                                 audio_close(1);
 105                                 set_mq_nonblock(0);
 106                         } else {
 107                                 die("mq_receive: %s\n", strerror(err));
 108                         }
 109                 } else {
 110                         assert(r > 0 && "r is not positive");
 111                         switch (*tmp) {
 112                         case OP_SEEK_PRE:
 113                                 read_seek_point(tmp + 1, r - 1);
 114                                 break;
 115                         case OP_PLAY_PATH:
 116                                 play_path(tmp + 1, r - 1);
 117                                 set_mq_nonblock(1);
 118                                 break;
 119                         default: unknown(tmp, r);
 120                         }
 121                 }
 122         }
 123
 124         return 0;
 125 }