Add caching for the Yaesu IF command

It should speed up the WSJT-X/JTDX sequence of v,f,m,t by a fair bit removing two unnecessary IF commands that should get cached

rigs/yaesu/newcat.c

@@ -4637,8 +4637,10 @@ int newcat_get_channel(RIG *rig, channel_t *chan, int read_only)
     chan->freq = atof(retval);
 
 #warning Need to add setting rig to channel values
-    if (!read_only) {
-      // Set rig to channel values
+
+    if (!read_only)
+    {
+        // Set rig to channel values
     }
 
     return RIG_OK;
@@ -6130,6 +6132,25 @@ int newcat_get_cmd(RIG *rig)
     int retry_count = 0;
     int rc = -RIG_EPROTO;
 
+    // try to cache rapid repeats of the IF command
+    // this is for WSJT-X/JTDX sequence of v/f/m/t
+    // should reduce 3 IF requests to 1 request and 2 cache hits
+    if (strcmp(priv->cmd_str, "IF") == 0 && priv->cache_start.tv_sec != 0)
+    {
+        int cache_age_ms;
+
+        cache_age_ms = elapsed_ms(&priv->cache_start, 0);
+
+        if (cache_age_ms < 500) // 500ms cache time
+        {
+            rig_debug(RIG_DEBUG_TRACE, "%s: cache hit, age=%dms\n", __func__, cache_age_ms);
+            strcpy(priv->ret_data, priv->last_if_response);
+            return RIG_OK;
+        }
+
+        // else we drop through and do the real IF command
+    }
+
     while (rc != RIG_OK && retry_count++ <= state->rigport.retry)
     {
         if (rc != -RIG_BUSBUSY)
@@ -6223,6 +6244,10 @@ int newcat_get_cmd(RIG *rig)
         }
     }
 
+    // update the cache
+    elapsed_ms(&priv->cache_start, 1);
+    strcpy(priv->last_if_response, priv->ret_data);
+
     return rc;
 }
 

rigs/yaesu/newcat.h

@@ -88,6 +88,8 @@ struct newcat_priv_data {
     int trn_state;  /* AI state found at startup */
 		int fast_set_commands; /* do not check for ACK/NAK; needed for high throughput > 100 commands/s */
     int width_frequency; /* found at startup */
+    struct timespec cache_start;
+    char last_if_response[NEWCAT_DATA_LEN];
 };
 
 

src/misc.c

@@ -1252,6 +1252,29 @@ void HAMLIB_API rig_no_restore_ai()
 
     no_restore_ai = -1;
 }
+
+//! @cond Doxygen_Suppress
+int HAMLIB_API elapsed_ms(struct timespec *start, int flag_start)
+{
+    // If flag_start then we are starting the timing, else we get elapsed
+    struct timespec stop;
+    double elapsed_secs;
+
+    if (flag_start)
+    {
+        clock_gettime(CLOCK_REALTIME, start);
+        return 0;
+    }
+    else
+    {
+        clock_gettime(CLOCK_REALTIME, &stop);
+    }
+
+    elapsed_secs = (stop.tv_sec - start->tv_sec) * 1e6 + (stop.tv_nsec -
+                   start->tv_nsec) / 1e3;
+    return elapsed_secs / 1000;
+}
+
 //! @endcond
 
 /** @} */

src/misc.h

@@ -100,6 +100,8 @@ extern HAMLIB_EXPORT(setting_t) rig_idx2setting(int i);
 
 extern HAMLIB_EXPORT(int) hl_usleep(useconds_t usec);
 
+extern HAMLIB_EXPORT(int) elapsed_ms(struct timespec *start, int start_flag);
+
 #ifdef PRId64
 /** \brief printf(3) format to be used for long long (64bits) type */
 #  define PRIll PRId64