print_volume(linux): Open a new mixer every time.

This fix the following bug:
    If you switch your sound card on-the-fly, print_volume continued to
    use the old sound card.

diff --git a/src/print_volume.c b/src/print_volume.c
index d3a97084554d55c47d391e35f66b44fd591e7828..d84b3ecd44549284a19a6bc0a1247f82395159fe 100644 (file)
--- a/src/print_volume.c
+++ b/src/print_volume.c
@@ -26,29 +26,6 @@
 #include "i3status.h"
 #include "queue.h"
 
-#ifdef LINUX
-struct mixer_hdl {
-       char *device;
-       char *mixer;
-       int mixer_idx;
-       snd_mixer_selem_id_t *sid;
-       snd_mixer_t *m;
-       snd_mixer_elem_t *elem;
-       long min;
-       long max;
-
-       TAILQ_ENTRY(mixer_hdl) handles;
-};
-
-TAILQ_HEAD(handles_head, mixer_hdl) cached = TAILQ_HEAD_INITIALIZER(cached);
-
-static void free_hdl(struct mixer_hdl *hdl) {
-       free(hdl->device);
-       free(hdl->mixer);
-       free(hdl);
-}
-#endif
-
 void print_volume(yajl_gen json_gen, char *buffer, const char *fmt, const char *device, const char *mixer, int mixer_idx) {
         char *outwalk = buffer;
        int pbval = 1;
@@ -61,100 +38,69 @@ void print_volume(yajl_gen json_gen, char *buffer, const char *fmt, const char *
                 free(instance);
         }
 #ifdef LINUX
-       /* Check if we already opened the mixer and get the handle
-        * from cache if so */
-       bool found = false;
        int err;
-       struct mixer_hdl *hdl;
-       TAILQ_FOREACH(hdl, &cached, handles) {
-               if (strcmp(hdl->device, device) != 0 ||
-                   strcmp(hdl->mixer, mixer) != 0 ||
-                   hdl->mixer_idx != mixer_idx)
-                       continue;
-               found = true;
-               break;
-       }
-
-       if (!found) {
-               if ((hdl = calloc(sizeof(struct mixer_hdl), 1)) == NULL)
-                       goto out;
-
-               if ((hdl->device = strdup(device)) == NULL) {
-                       free(hdl);
-                       goto out;
-               }
-
-               if ((hdl->mixer = strdup(mixer)) == NULL) {
-                       free(hdl->device);
-                       free(hdl);
-                       goto out;
-               }
-
-               hdl->mixer_idx = mixer_idx;
-               snd_mixer_selem_id_malloc(&(hdl->sid));
-               if (hdl->sid == NULL) {
-                       free_hdl(hdl);
-                       goto out;
-               }
+       snd_mixer_t *m;
+       snd_mixer_selem_id_t *sid;
+       snd_mixer_elem_t *elem;
+       long min, max, val;
+       int avg;
 
-               if ((err = snd_mixer_open(&(hdl->m), 0)) < 0) {
-                       fprintf(stderr, "i3status: ALSA: Cannot open mixer: %s\n", snd_strerror(err));
-                       free_hdl(hdl);
-                       goto out;
-               }
+       if ((err = snd_mixer_open(&m, 0)) < 0) {
+               fprintf(stderr, "i3status: ALSA: Cannot open mixer: %s\n", snd_strerror(err));
+               goto out;
+       }
 
-               /* Attach this mixer handle to the given device */
-               if ((err = snd_mixer_attach(hdl->m, device)) < 0) {
-                       fprintf(stderr, "i3status: ALSA: Cannot attach mixer to device: %s\n", snd_strerror(err));
-                       snd_mixer_close(hdl->m);
-                       free_hdl(hdl);
-                       goto out;
-               }
+       /* Attach this mixer handle to the given device */
+       if ((err = snd_mixer_attach(m, device)) < 0) {
+               fprintf(stderr, "i3status: ALSA: Cannot attach mixer to device: %s\n", snd_strerror(err));
+               snd_mixer_close(m);
+               goto out;
+       }
 
-               /* Register this mixer */
-               if ((err = snd_mixer_selem_register(hdl->m, NULL, NULL)) < 0) {
-                       fprintf(stderr, "i3status: ALSA: snd_mixer_selem_register: %s\n", snd_strerror(err));
-                       snd_mixer_close(hdl->m);
-                       free_hdl(hdl);
-                       goto out;
-               }
+       /* Register this mixer */
+       if ((err = snd_mixer_selem_register(m, NULL, NULL)) < 0) {
+               fprintf(stderr, "i3status: ALSA: snd_mixer_selem_register: %s\n", snd_strerror(err));
+               snd_mixer_close(m);
+               goto out;
+       }
 
-               if ((err = snd_mixer_load(hdl->m)) < 0) {
-                       fprintf(stderr, "i3status: ALSA: snd_mixer_load: %s\n", snd_strerror(err));
-                       snd_mixer_close(hdl->m);
-                       free_hdl(hdl);
-                       goto out;
-               }
+       if ((err = snd_mixer_load(m)) < 0) {
+               fprintf(stderr, "i3status: ALSA: snd_mixer_load: %s\n", snd_strerror(err));
+               snd_mixer_close(m);
+               goto out;
+       }
 
-               /* Find the given mixer */
-               snd_mixer_selem_id_set_index(hdl->sid, mixer_idx);
-               snd_mixer_selem_id_set_name(hdl->sid, mixer);
-               if (!(hdl->elem = snd_mixer_find_selem(hdl->m, hdl->sid))) {
-                       fprintf(stderr, "i3status: ALSA: Cannot find mixer %s (index %i)\n",
-                               snd_mixer_selem_id_get_name(hdl->sid), snd_mixer_selem_id_get_index(hdl->sid));
-                       snd_mixer_close(hdl->m);
-                       free_hdl(hdl);
-                       goto out;
-               }
+       snd_mixer_selem_id_malloc(&sid);
+       if (sid == NULL) {
+               snd_mixer_close(m);
+               goto out;
+       }
 
-               /* Get the volume range to convert the volume later */
-               snd_mixer_selem_get_playback_volume_range(hdl->elem, &(hdl->min), &(hdl->max));
-               TAILQ_INSERT_TAIL(&cached, hdl, handles);
+       /* Find the given mixer */
+       snd_mixer_selem_id_set_index(sid, mixer_idx);
+       snd_mixer_selem_id_set_name(sid, mixer);
+       if (!(elem = snd_mixer_find_selem(m, sid))) {
+               fprintf(stderr, "i3status: ALSA: Cannot find mixer %s (index %i)\n",
+                       snd_mixer_selem_id_get_name(sid), snd_mixer_selem_id_get_index(sid));
+               snd_mixer_close(m);
+               snd_mixer_selem_id_free(sid);
+               goto out;
        }
 
-       long val;
-       snd_mixer_handle_events (hdl->m);
-       snd_mixer_selem_get_playback_volume (hdl->elem, 0, &val);
-       int avg;
-       if (hdl->max != 100) {
-               float avgf = ((float)val / hdl->max) * 100;
+       /* Get the volume range to convert the volume later */
+       snd_mixer_selem_get_playback_volume_range(elem, &min, &max);
+
+       snd_mixer_handle_events (m);
+       snd_mixer_selem_get_playback_volume (elem, 0, &val);
+       if (max != 100) {
+               float avgf = ((float)val / max) * 100;
                avg = (int)avgf;
                avg = (avgf - avg < 0.5 ? avg : (avg+1));
        } else avg = (int)val;
 
        /* Check for mute */
-       if (snd_mixer_selem_has_playback_switch(hdl->elem)) {
-               if ((err = snd_mixer_selem_get_playback_switch(hdl->elem, 0, &pbval)) < 0)
+       if (snd_mixer_selem_has_playback_switch(elem)) {
+               if ((err = snd_mixer_selem_get_playback_switch(elem, 0, &pbval)) < 0)
                        fprintf (stderr, "i3status: ALSA: playback_switch: %s\n", snd_strerror(err));
                if (!pbval)  {
                        START_COLOR("color_degraded");
@@ -162,6 +108,9 @@ void print_volume(yajl_gen json_gen, char *buffer, const char *fmt, const char *
                }
        }
 
+       snd_mixer_close(m);
+       snd_mixer_selem_id_free(sid);
+
        const char *walk = fmt;
        for (; *walk != '\0'; walk++) {
                if (*walk != '%') {