Bluetooth (Linux): improve performance

1. ignore unpaired devices
2. ignore disconnected devices when `showDisconnected == false`

Author: CarterLi

src/detection/bluetooth/bluetooth_linux.c

@@ -45,16 +45,16 @@ array [                                                     //root
 ]
 */
 
-static void detectBluetoothValue(FFDBusData* dbus, DBusMessageIter* iter, FFBluetoothResult* device)
+static bool detectBluetoothValue(FFDBusData* dbus, DBusMessageIter* iter, FFBluetoothResult* device)
 {
     if(dbus->lib->ffdbus_message_iter_get_arg_type(iter) != DBUS_TYPE_DICT_ENTRY)
-        return;
+        return true;
 
     DBusMessageIter dictIter;
     dbus->lib->ffdbus_message_iter_recurse(iter, &dictIter);
 
     if(dbus->lib->ffdbus_message_iter_get_arg_type(&dictIter) != DBUS_TYPE_STRING)
-        return;
+        return true;
 
     const char* deviceProperty;
     dbus->lib->ffdbus_message_iter_get_basic(&dictIter, &deviceProperty);
@@ -75,6 +75,13 @@ static void detectBluetoothValue(FFDBusData* dbus, DBusMessageIter* iter, FFBlue
     }
     else if(ffStrEquals(deviceProperty, "Connected"))
         ffDBusGetBool(dbus, &dictIter, &device->connected);
+    else if(ffStrEquals(deviceProperty, "Paired"))
+    {
+        bool paired = true;
+        ffDBusGetBool(dbus, &dictIter, &paired);
+        if (!paired) return false;
+    }
+    return true;
 }
 
 static void detectBluetoothProperty(FFDBusData* dbus, DBusMessageIter* iter, FFBluetoothResult* device)
@@ -104,32 +111,37 @@ static void detectBluetoothProperty(FFDBusData* dbus, DBusMessageIter* iter, FFB
 
     do
     {
-        detectBluetoothValue(dbus, &arrayIter, device);
+        bool shouldContinue = detectBluetoothValue(dbus, &arrayIter, device);
+        if (!shouldContinue)
+        {
+            ffStrbufClear(&device->name);
+            break;
+        }
     } while (dbus->lib->ffdbus_message_iter_next(&arrayIter));
 }
 
-static void detectBluetoothObject(FFlist* devices, FFDBusData* dbus, DBusMessageIter* iter)
+static FFBluetoothResult* detectBluetoothObject(FFlist* devices, FFDBusData* dbus, DBusMessageIter* iter)
 {
     if(dbus->lib->ffdbus_message_iter_get_arg_type(iter) != DBUS_TYPE_DICT_ENTRY)
-        return;
+        return NULL;
 
     DBusMessageIter dictIter;
     dbus->lib->ffdbus_message_iter_recurse(iter, &dictIter);
 
     if(dbus->lib->ffdbus_message_iter_get_arg_type(&dictIter) != DBUS_TYPE_OBJECT_PATH)
-        return;
+        return NULL;
 
     const char* objectPath;
     dbus->lib->ffdbus_message_iter_get_basic(&dictIter, &objectPath);
 
     // We don't want adapter objects
     if(!ffStrContains(objectPath, "/dev_"))
-        return;
+        return NULL;
 
     dbus->lib->ffdbus_message_iter_next(&dictIter);
 
     if(dbus->lib->ffdbus_message_iter_get_arg_type(&dictIter) != DBUS_TYPE_ARRAY)
-        return;
+        return NULL;
 
     DBusMessageIter arrayIter;
     dbus->lib->ffdbus_message_iter_recurse(&dictIter, &arrayIter);
@@ -146,16 +158,10 @@ static void detectBluetoothObject(FFlist* devices, FFDBusData* dbus, DBusMessage
         detectBluetoothProperty(dbus, &arrayIter, device);
     } while (dbus->lib->ffdbus_message_iter_next(&arrayIter));
 
-    if(device->name.length == 0)
-    {
-        ffStrbufDestroy(&device->name);
-        ffStrbufDestroy(&device->address);
-        ffStrbufDestroy(&device->type);
-        --devices->length;
-    }
+    return device;
 }
 
-static void detectBluetoothRoot(FFlist* devices, FFDBusData* dbus, DBusMessageIter* iter)
+static void detectBluetoothRoot(FFlist* devices, FFDBusData* dbus, DBusMessageIter* iter, int32_t connectedCount)
 {
     if(dbus->lib->ffdbus_message_iter_get_arg_type(iter) != DBUS_TYPE_ARRAY)
         return;
@@ -165,11 +171,25 @@ static void detectBluetoothRoot(FFlist* devices, FFDBusData* dbus, DBusMessageIt
 
     do
     {
-        detectBluetoothObject(devices, dbus, &arrayIter);
+        FFBluetoothResult* device = detectBluetoothObject(devices, dbus, &arrayIter);
+
+        if (device)
+        {
+            if(device->name.length == 0 || (connectedCount > 0 && !device->connected))
+            {
+                ffStrbufDestroy(&device->name);
+                ffStrbufDestroy(&device->address);
+                ffStrbufDestroy(&device->type);
+                --devices->length;
+            }
+
+            if (device->connected && --connectedCount == 0)
+                break;
+        }
     } while (dbus->lib->ffdbus_message_iter_next(&arrayIter));
 }
 
-static const char* detectBluetooth(FFlist* devices)
+static const char* detectBluetooth(FFlist* devices, int32_t connectedCount)
 {
     FFDBusData dbus;
     const char* error = ffDBusLoadData(DBUS_BUS_SYSTEM, &dbus);
@@ -187,37 +207,43 @@ static const char* detectBluetooth(FFlist* devices)
         return "Failed to get root iterator of GetManagedObjects";
     }
 
-    detectBluetoothRoot(devices, &dbus, &rootIter);
+    detectBluetoothRoot(devices, &dbus, &rootIter, connectedCount);
 
     dbus.lib->ffdbus_message_unref(managedObjects);
     return NULL;
 }
 
-static bool hasConnectedDevices(void)
+static uint32_t connectedDevices(void)
 {
     FF_AUTO_CLOSE_DIR DIR* dirp = opendir("/sys/class/bluetooth");
     if(dirp == NULL)
-        return false;
+        return 0;
 
+    uint32_t result = 0;
     struct dirent* entry;
     while ((entry = readdir(dirp)) != NULL)
     {
-        if (strchr(entry->d_name, ':') != NULL) // ignore connected devices
-            return true;
+        if (strchr(entry->d_name, ':') != NULL)
+            ++result;
     }
 
-    return false;
+    return result;
 }
 
 #endif
 
 const char* ffDetectBluetooth(FFBluetoothOptions* options, FF_MAYBE_UNUSED FFlist* devices /* FFBluetoothResult */)
 {
     #ifdef FF_HAVE_DBUS
-        if (!options->showDisconnected && !hasConnectedDevices())
-            return NULL;
-
-        return detectBluetooth(devices);
+        int32_t connectedCount = -1;
+        if (!options->showDisconnected)
+        {
+            connectedCount = (int32_t) connectedDevices();
+            if (connectedCount == 0)
+                return NULL;
+        }
+
+        return detectBluetooth(devices, connectedCount);
     #else
         return "Fastfetch was compiled without DBus support";
     #endif