FTDI sync read timeout

usbserial/src/main/java/com/felhr/usbserial/FTDISerialDevice.java

@@ -566,4 +566,50 @@ public class FTDISerialDevice extends UsbSerialDevice
         }
     }
 
+    @Override
+    public int syncRead(byte[] buffer, int timeout)
+    {
+        long beginTime = System.currentTimeMillis();
+        long stopTime = beginTime + timeout;
+
+        if (asyncMode) {
+            return -1;
+        }
+
+        if (buffer == null) {
+            return 0;
+        }
+
+        int n = buffer.length / 62;
+        if (buffer.length % 62 != 0) {
+            n++;
+        }
+
+        byte[] tempBuffer = new byte[buffer.length + n * 2];
+
+        int readen = 0;
+
+        do {
+            int timeLeft = (int) (stopTime - System.currentTimeMillis());
+            if (timeLeft <= 0) {
+                break;
+            }
+
+            int numberBytes = connection.bulkTransfer(inEndpoint, tempBuffer, tempBuffer.length, timeLeft);
+
+            if (numberBytes > 2) // Data received
+            {
+                byte[] newBuffer = this.ftdiUtilities.adaptArray(tempBuffer);
+                System.arraycopy(newBuffer, 0, buffer, 0, buffer.length);
+
+                int p = numberBytes / 64;
+                if (numberBytes % 64 != 0) {
+                    p++;
+                }
+                readen = numberBytes - p * 2;
+            }
+        } while (readen <= 0);
+
+        return readen;
+    }
 }

usbserial/src/main/java/com/felhr/usbserial/UsbSerialDevice.java

@@ -140,40 +140,14 @@ public abstract class UsbSerialDevice implements UsbSerialInterface
     @Override
     public int syncRead(byte[] buffer, int timeout)
     {
-        if(!asyncMode)
-        {
-            if(buffer == null)
-                return 0;
-            if(!isFTDIDevice())
-            {
-                return connection.bulkTransfer(inEndpoint, buffer, buffer.length, timeout);
-            }else // FTDI devices need special treatment
-            {
-                int n = buffer.length / 62;
-                if(buffer.length % 62 != 0)
-                    n++;
-
-                byte[] tempBuffer = new byte[buffer.length + n * 2];
-                int numberBytes = connection.bulkTransfer(inEndpoint, tempBuffer, tempBuffer.length, timeout);
-
-                if(numberBytes > 2) // Data received
-                {
-                    byte[] newBuffer = ((FTDISerialDevice) this).ftdiUtilities.adaptArray(tempBuffer);
-                    System.arraycopy(newBuffer, 0, buffer, 0, buffer.length);
-
-                    int p = numberBytes / 64;
-                    if(numberBytes % 64 != 0)
-                        p++;
-                    return numberBytes - p * 2;
-                }else
-                {
-                    return 0;
-                }
-            }
-        }else
-        {
+        if (asyncMode) {
             return -1;
         }
+
+        if (buffer == null)
+            return 0;
+
+        return connection.bulkTransfer(inEndpoint, buffer, buffer.length, timeout);
     }
 
     // Serial port configuration