From 11605b56ad6bcec05b835aca910d19be69e2fa7d Mon Sep 17 00:00:00 2001
From: Kamalakannan G <56466387+kamal-lab@users.noreply.github.com>
Date: Wed, 5 May 2021 20:36:47 +0530
Subject: [PATCH] Updated bulk transfer method

Currently I'm unable to transfer data like 10000bytes through syncWrite method. So, I split the data into small pockets.
---
 .../com/felhr/usbserial/UsbSerialDevice.java  | 27 +++++++++++++++++--
 1 file changed, 25 insertions(+), 2 deletions(-)

diff --git a/usbserial/src/main/java/com/felhr/usbserial/UsbSerialDevice.java b/usbserial/src/main/java/com/felhr/usbserial/UsbSerialDevice.java
index fe24aa4..0a95e56 100644
--- a/usbserial/src/main/java/com/felhr/usbserial/UsbSerialDevice.java
+++ b/usbserial/src/main/java/com/felhr/usbserial/UsbSerialDevice.java
@@ -30,6 +30,7 @@ public abstract class UsbSerialDevice implements UsbSerialInterface
     protected final UsbDeviceConnection connection;
 
     protected static final int USB_TIMEOUT = 0;
+    private static final int USB_MAX_BUFFER = 4096;
 
     protected SerialBuffer serialBuffer;
 
@@ -196,7 +197,18 @@ public abstract class UsbSerialDevice implements UsbSerialInterface
             if(buffer == null)
                 return 0;
 
-            return connection.bulkTransfer(outEndpoint, buffer, buffer.length, timeout);
+            int totalLength = buffer.length;
+            byte[] bArr2 = new byte[USB_MAX_BUFFER];
+            int i3 = 0;
+            int i4 = 0;
+            while (totalLength > 0 && i3 < totalLength && i4 != -1) {
+                int min = Math.min(USB_MAX_BUFFER, totalLength - i3);
+                System.arraycopy(buffer, i3, bArr2, 0, min);
+                i4 = connection.bulkTransfer(outEndpoint, bArr2, min, timeout);
+                i3 += i4;
+            }
+
+            return i3;
         }else
         {
             return -1;
@@ -225,7 +237,18 @@ public abstract class UsbSerialDevice implements UsbSerialInterface
             if(buffer == null)
                 return 0;
 
-            return connection.bulkTransfer(outEndpoint, buffer, offset, length, timeout);
+            int totalLength = buffer.length;
+            byte[] bArr2 = new byte[USB_MAX_BUFFER];
+            int i3 = 0;
+            int i4 = 0;
+            while (totalLength > 0 && i3 < totalLength && i4 != -1) {
+                int min = Math.min(USB_MAX_BUFFER, totalLength - i3);
+                System.arraycopy(buffer, i3, bArr2, 0, min);
+                i4 = connection.bulkTransfer(outEndpoint, bArr2, min, timeout);
+                i3 += i4;
+            }
+
+            return i3;
         }else
         {
             return -1;