timeshift: Added on-demand buffer mode.

In this mode data will only be written to disk when paused and anything
in the buffer prior to the current play point will immediately be removed.

This implies that rewinding is never possible in this mode (though FF is)
and trying to do so will result in the buffer playback being paused.

src/timeshift.c

@@ -147,7 +147,7 @@ static void timeshift_input
       exit = 1;
 
     /* Buffer to disk */
-    if (ts->state >= TS_LIVE) {
+    if ((ts->state > TS_LIVE) || (!ts->ondemand && (ts->state == TS_LIVE))) {
       sm->sm_time = getmonoclock();
       streaming_target_deliver2(&ts->wr_queue.sq_st, sm);
     } else
@@ -170,7 +170,6 @@ void
 timeshift_destroy(streaming_target_t *pad)
 {
   timeshift_t *ts = (timeshift_t*)pad;
-  timeshift_file_t *tsf;
   streaming_message_t *sm;
 
   /* Must hold global lock */
@@ -193,8 +192,7 @@ timeshift_destroy(streaming_target_t *pad)
   close(ts->rd_pipe.wr);
 
   /* Flush files */
-  while ((tsf = TAILQ_FIRST(&ts->files)))
-    timeshift_filemgr_remove(ts, tsf, 1);
+  timeshift_filemgr_flush(ts, NULL);
 
   free(ts->path);
   free(ts);

src/timeshift/private.h

@@ -141,6 +141,7 @@ timeshift_file_t *timeshift_filemgr_next
   ( timeshift_file_t *ts, int *end, int keep );
 void timeshift_filemgr_remove
   ( timeshift_t *ts, timeshift_file_t *tsf, int force );
+void timeshift_filemgr_flush ( timeshift_t *ts, timeshift_file_t *end );
 void timeshift_filemgr_close ( timeshift_file_t *tsf );
 
 #endif /* __TVH_TIMESHIFT_PRIVATE_H__ */

src/timeshift/timeshift_filemgr.c

@@ -117,9 +117,12 @@ static void timeshift_reaper_remove ( timeshift_file_t *tsf )
 static void timeshift_filemgr_get_root ( char *buf, size_t len )
 {
   const char *path = timeshift_path;
-  if (!path || !*path)
+  if (!path || !*path) {
     path = hts_settings_get_root();
-  snprintf(buf, len, "%s/timeshift/temp", path);
+    snprintf(buf, len, "%s/timeshift/buffer", path);
+  } else {
+    snprintf(buf, len, "%s/buffer", path);
+  }
 }
 
 /*
@@ -156,6 +159,18 @@ void timeshift_filemgr_remove
   timeshift_reaper_remove(tsf);
 }
 
+/*
+ * Flush all files
+ */
+void timeshift_filemgr_flush ( timeshift_t *ts, timeshift_file_t *end )
+{
+  timeshift_file_t *tsf;
+  while ((tsf = TAILQ_FIRST(&ts->files))) {
+    if (tsf == end) break;
+    timeshift_filemgr_remove(ts, tsf, 1);
+  }
+}
+
 /*
  * Get current / new file
  */
@@ -216,6 +231,7 @@ timeshift_file_t *timeshift_filemgr_get ( timeshift_t *ts, int create )
         tsf_tmp->fd       = fd;
         tsf_tmp->path     = strdup(path);
         tsf_tmp->refcount = 0;
+        tsf_tmp->last     = getmonoclock();
         TAILQ_INIT(&tsf_tmp->iframes);
         TAILQ_INIT(&tsf_tmp->sstart);
         TAILQ_INSERT_TAIL(&ts->files, tsf_tmp, link);

src/timeshift/timeshift_reader.c

@@ -29,6 +29,8 @@
 #include <string.h>
 #include <assert.h>
 
+//#define TSHFT_TRACE
+
 /* **************************************************************************
  * File Reading
  * *************************************************************************/
@@ -223,6 +225,10 @@ void *timeshift_reader ( void *p )
           if (speed > 3200)  speed = 3200;
           if (speed < -3200) speed = -3200;
 
+          /* Ignore negative */
+          if (ts->ondemand && (speed < 0))
+            speed = 0;
+
           /* Process */
           if (cur_speed != speed) {
 
@@ -241,7 +247,7 @@ void *timeshift_reader ( void *p )
                        ts->id);
                 timeshift_writer_flush(ts);
                 pthread_mutex_lock(&ts->rdwr_mutex);
-                if ((cur_file   = timeshift_filemgr_get(ts, 0))) {
+                if ((cur_file   = timeshift_filemgr_get(ts, ts->ondemand))) {
                   cur_off    = cur_file->size;
                   pause_time = cur_file->last;
                   last_time  = pause_time;
@@ -467,6 +473,10 @@ void *timeshift_reader ( void *p )
         ctrl      = streaming_msg_create_code(SMT_SPEED, cur_speed);
         streaming_target_deliver2(ts->output, ctrl);
 
+        /* Flush ALL files */
+        if (ts->ondemand)
+          timeshift_filemgr_flush(ts, NULL);
+
       /* Pause */
       } else if (cur_speed < 0) {
         tvhlog(LOG_DEBUG, "timeshift", "ts %d sob pause stream", ts->id);
@@ -475,6 +485,10 @@ void *timeshift_reader ( void *p )
         ctrl      = streaming_msg_create_code(SMT_SPEED, cur_speed);
         streaming_target_deliver2(ts->output, ctrl);
       }
+
+    /* Flush unwanted */
+    } else if (ts->ondemand && cur_file) {
+      timeshift_filemgr_flush(ts, cur_file);
     }
 
     pthread_mutex_unlock(&ts->rdwr_mutex);