use persistent connection for polling

mpdclient.ino

@@ -22,7 +22,7 @@ Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);
 const char* ssid = "hiddennetworkforchromecast";
 const char* password = "raisingelephantsissoutterlyboring";
 
-WiFiClient espClient;
+WiFiClient songinfoClient;
 
 struct song_info {
     String title;
@@ -266,17 +266,23 @@ int get_player_info(player_info* player_info) {
 } 
 
 int get_song_info(song_info* song_info) {
-    WiFiClient client;
+    if (!songinfoClient.connected()) {
+        Serial.println("reconnect");
+        if (!songinfoClient.connect(MPDHOST, MPDPORT)) {
+            display_error("mpd connect failed");
+            Serial.println("mpd connect failed");
+            songinfoClient.stop();
+            return 1;
+        }
+    }
 
-    if (client.connect(MPDHOST, MPDPORT)) {
-        Serial.println("connected");
-        client.print("currentsong\n");
+    songinfoClient.print("currentsong\n");
 
-        while (client.connected() || client.available())
+    while (songinfoClient.connected() || songinfoClient.available())
         {
-              if (client.available())
+          if (songinfoClient.available())
           {
-                String line = client.readStringUntil('\n');
+            String line = songinfoClient.readStringUntil('\n');
             if (line.startsWith("Title: ")) {
                 song_info->title = line.substring(7);
             }
@@ -284,20 +290,11 @@ int get_song_info(song_info* song_info) {
                 song_info->artist = line.substring(8);
             }
             else if (line.equals("OK")) {
-                    client.stop();
+                break;
             }
           }
         }
 
-        client.stop();
-        Serial.println("connection done");
-    }
-    else {
-        display_error("mpd connect failed");
-        client.stop();
-        return 1;
-    }
-
     return 0;
 }