Use slices instead of new buffers

88 files changed, 158 insertions, 158 deletions

diff --git a/src/org/traccar/protocol/AdmProtocolDecoder.java b/src/org/traccar/protocol/AdmProtocolDecoder.java
index 04a607749..4c41d29cd 100644
--- a/src/org/traccar/protocol/AdmProtocolDecoder.java
+++ b/src/org/traccar/protocol/AdmProtocolDecoder.java
@@ -132,7 +132,7 @@ public class AdmProtocolDecoder extends BaseProtocolDecoder {
         if (responseTextLength < 0) {
             responseTextLength = CMD_RESPONSE_SIZE - 3;
         }
-        position.set(Position.KEY_RESULT, buf.readBytes(responseTextLength).toString(StandardCharsets.UTF_8));
+        position.set(Position.KEY_RESULT, buf.readSlice(responseTextLength).toString(StandardCharsets.UTF_8));
 
         return position;
     }
@@ -147,7 +147,7 @@ public class AdmProtocolDecoder extends BaseProtocolDecoder {
         if (size != CMD_RESPONSE_SIZE) {
             int type = buf.readUnsignedByte();
             if (type == MSG_IMEI) {
-                getDeviceSession(channel, remoteAddress, buf.readBytes(15).toString(StandardCharsets.UTF_8));
+                getDeviceSession(channel, remoteAddress, buf.readSlice(15).toString(StandardCharsets.UTF_8));
             } else {
                 return decodeData(channel, remoteAddress, buf, type);
             }
diff --git a/src/org/traccar/protocol/AlematicsFrameDecoder.java b/src/org/traccar/protocol/AlematicsFrameDecoder.java
index daac868c0..be7666657 100644
--- a/src/org/traccar/protocol/AlematicsFrameDecoder.java
+++ b/src/org/traccar/protocol/AlematicsFrameDecoder.java
@@ -38,7 +38,7 @@ public class AlematicsFrameDecoder extends LineBasedFrameDecoder {
         }
 
         if (buf.getUnsignedShort(buf.readerIndex()) == 0xFAF8) {
-            ByteBuf heartbeat = buf.readBytes(12);
+            ByteBuf heartbeat = buf.readRetainedSlice(12);
             if (ctx != null && ctx.channel() != null) {
                 ctx.channel().writeAndFlush(new NetworkMessage(heartbeat, ctx.channel().remoteAddress()));
             }
diff --git a/src/org/traccar/protocol/ApelProtocolDecoder.java b/src/org/traccar/protocol/ApelProtocolDecoder.java
index bb99783f0..affbdedaf 100644
--- a/src/org/traccar/protocol/ApelProtocolDecoder.java
+++ b/src/org/traccar/protocol/ApelProtocolDecoder.java
@@ -111,7 +111,7 @@ public class ApelProtocolDecoder extends BaseProtocolDecoder {
             int length = buf.readUnsignedShortLE();
             buf.skipBytes(length);
             length = buf.readUnsignedShortLE();
-            getDeviceSession(channel, remoteAddress, buf.readBytes(length).toString(StandardCharsets.US_ASCII));
+            getDeviceSession(channel, remoteAddress, buf.readSlice(length).toString(StandardCharsets.US_ASCII));
 
         } else if (type == MSG_LAST_LOG_INDEX) {
 
diff --git a/src/org/traccar/protocol/AplicomFrameDecoder.java b/src/org/traccar/protocol/AplicomFrameDecoder.java
index 813bd49c6..6e81e8202 100644
--- a/src/org/traccar/protocol/AplicomFrameDecoder.java
+++ b/src/org/traccar/protocol/AplicomFrameDecoder.java
@@ -53,7 +53,7 @@ public class AplicomFrameDecoder extends BaseFrameDecoder {
 

         // Return buffer

         if (buf.readableBytes() >= length) {

-            return buf.readBytes(length);

+            return buf.readRetainedSlice(length);

         }

 

         return null;

diff --git a/src/org/traccar/protocol/AplicomProtocolDecoder.java b/src/org/traccar/protocol/AplicomProtocolDecoder.java
index b9da609ed..54b15700a 100644
--- a/src/org/traccar/protocol/AplicomProtocolDecoder.java
+++ b/src/org/traccar/protocol/AplicomProtocolDecoder.java
@@ -131,7 +131,7 @@ public class AplicomProtocolDecoder extends BaseProtocolDecoder {
         ArrayList<ByteBuf> values = new ArrayList<>(count);
 
         for (int i = 0; i < count; i++) {
-            values.add(buf.readBytes(8));
+            values.add(buf.readSlice(8));
         }
 
         for (int i = 0; i < count; i++) {
@@ -349,13 +349,13 @@ public class AplicomProtocolDecoder extends BaseProtocolDecoder {
         }
 
         if ((selector & 0x0800) != 0) {
-            position.set(Position.KEY_VIN, buf.readBytes(18).toString(StandardCharsets.US_ASCII).trim());
+            position.set(Position.KEY_VIN, buf.readSlice(18).toString(StandardCharsets.US_ASCII).trim());
         }
 
         if ((selector & 0x2000) != 0) {
             buf.readUnsignedByte(); // card 1 type
             buf.readUnsignedByte(); // card 1 country code
-            String card = buf.readBytes(20).toString(StandardCharsets.US_ASCII).trim();
+            String card = buf.readSlice(20).toString(StandardCharsets.US_ASCII).trim();
             if (!card.isEmpty()) {
                 position.set("card1", card);
             }
@@ -364,7 +364,7 @@ public class AplicomProtocolDecoder extends BaseProtocolDecoder {
         if ((selector & 0x4000) != 0) {
             buf.readUnsignedByte(); // card 2 type
             buf.readUnsignedByte(); // card 2 country code
-            String card = buf.readBytes(20).toString(StandardCharsets.US_ASCII).trim();
+            String card = buf.readSlice(20).toString(StandardCharsets.US_ASCII).trim();
             if (!card.isEmpty()) {
                 position.set("card2", card);
             }
@@ -373,7 +373,7 @@ public class AplicomProtocolDecoder extends BaseProtocolDecoder {
         if ((selector & 0x10000) != 0) {
             int count = buf.readUnsignedByte();
             for (int i = 1; i <= count; i++) {
-                position.set("driver" + i, buf.readBytes(22).toString(StandardCharsets.US_ASCII).trim());
+                position.set("driver" + i, buf.readSlice(22).toString(StandardCharsets.US_ASCII).trim());
                 position.set("driverTime" + i, buf.readUnsignedInt());
             }
         }
@@ -477,7 +477,7 @@ public class AplicomProtocolDecoder extends BaseProtocolDecoder {
 
             switch (type) {
                 case 0x01:
-                    position.set("brakeFlags", ByteBufUtil.hexDump(buf.readBytes(length)));
+                    position.set("brakeFlags", ByteBufUtil.hexDump(buf.readSlice(length)));
                     break;
                 case 0x02:
                     position.set("wheelSpeed", buf.readUnsignedShort() / 256.0);
@@ -507,10 +507,10 @@ public class AplicomProtocolDecoder extends BaseProtocolDecoder {
                     position.set("vdcActiveCounter", buf.readUnsignedShort());
                     break;
                 case 0x0B:
-                    position.set("brakeMinMaxData", ByteBufUtil.hexDump(buf.readBytes(length)));
+                    position.set("brakeMinMaxData", ByteBufUtil.hexDump(buf.readSlice(length)));
                     break;
                 case 0x0C:
-                    position.set("missingPgn", ByteBufUtil.hexDump(buf.readBytes(length)));
+                    position.set("missingPgn", ByteBufUtil.hexDump(buf.readSlice(length)));
                     break;
                 case 0x0D:
                     buf.readUnsignedByte();
diff --git a/src/org/traccar/protocol/AstraProtocolDecoder.java b/src/org/traccar/protocol/AstraProtocolDecoder.java
index 7a4e1ee85..c386c7757 100644
--- a/src/org/traccar/protocol/AstraProtocolDecoder.java
+++ b/src/org/traccar/protocol/AstraProtocolDecoder.java
@@ -105,7 +105,7 @@ public class AstraProtocolDecoder extends BaseProtocolDecoder {
             buf.readUnsignedByte(); // geofence events
 
             if (BitUtil.check(status, 8)) {
-                position.set(Position.KEY_DRIVER_UNIQUE_ID, buf.readBytes(7).toString(StandardCharsets.US_ASCII));
+                position.set(Position.KEY_DRIVER_UNIQUE_ID, buf.readSlice(7).toString(StandardCharsets.US_ASCII));
                 position.set(Position.KEY_ODOMETER, buf.readUnsignedMedium() * 1000);
                 position.set(Position.KEY_HOURS, UnitsConverter.msFromHours(buf.readUnsignedShort()));
             }
diff --git a/src/org/traccar/protocol/At2000FrameDecoder.java b/src/org/traccar/protocol/At2000FrameDecoder.java
index c02e38b65..5fa82a5f7 100644
--- a/src/org/traccar/protocol/At2000FrameDecoder.java
+++ b/src/org/traccar/protocol/At2000FrameDecoder.java
@@ -72,7 +72,7 @@ public class At2000FrameDecoder extends BaseFrameDecoder {
         }
 
         if (buf.readableBytes() >= length) {
-            return buf.readBytes(length);
+            return buf.readRetainedSlice(length);
         }
 
         return null;
diff --git a/src/org/traccar/protocol/At2000ProtocolDecoder.java b/src/org/traccar/protocol/At2000ProtocolDecoder.java
index cba7c92c6..4c2967158 100644
--- a/src/org/traccar/protocol/At2000ProtocolDecoder.java
+++ b/src/org/traccar/protocol/At2000ProtocolDecoder.java
@@ -76,7 +76,7 @@ public class At2000ProtocolDecoder extends BaseProtocolDecoder {
 
         if (type == MSG_DEVICE_ID) {
 
-            String imei = buf.readBytes(15).toString(StandardCharsets.US_ASCII);
+            String imei = buf.readSlice(15).toString(StandardCharsets.US_ASCII);
             if (getDeviceSession(channel, remoteAddress, imei) != null) {
 
                 byte[] iv = new byte[BLOCK_LENGTH];
diff --git a/src/org/traccar/protocol/AtrackFrameDecoder.java b/src/org/traccar/protocol/AtrackFrameDecoder.java
index 4e1758f2d..3d33d9862 100644
--- a/src/org/traccar/protocol/AtrackFrameDecoder.java
+++ b/src/org/traccar/protocol/AtrackFrameDecoder.java
@@ -34,7 +34,7 @@ public class AtrackFrameDecoder extends BaseFrameDecoder {
             if (buf.getUnsignedShort(buf.readerIndex()) == 0xfe02) {
 
                 if (buf.readableBytes() >= KEEPALIVE_LENGTH) {
-                    return buf.readBytes(KEEPALIVE_LENGTH);
+                    return buf.readRetainedSlice(KEEPALIVE_LENGTH);
                 }
 
             } else if (buf.getUnsignedShort(buf.readerIndex()) == 0x4050 && buf.getByte(buf.readerIndex() + 2) != ',') {
@@ -42,7 +42,7 @@ public class AtrackFrameDecoder extends BaseFrameDecoder {
                 if (buf.readableBytes() > 6) {
                     int length = buf.getUnsignedShort(buf.readerIndex() + 4) + 4 + 2;
                     if (buf.readableBytes() >= length) {
-                        return buf.readBytes(length);
+                        return buf.readRetainedSlice(length);
                     }
                 }
 
@@ -50,7 +50,7 @@ public class AtrackFrameDecoder extends BaseFrameDecoder {
 
                 int endIndex = BufferUtil.indexOf("\r\n", buf);
                 if (endIndex > 0) {
-                    return buf.readBytes(endIndex - buf.readerIndex() + 2);
+                    return buf.readRetainedSlice(endIndex - buf.readerIndex() + 2);
                 }
 
             }
diff --git a/src/org/traccar/protocol/AtrackProtocolDecoder.java b/src/org/traccar/protocol/AtrackProtocolDecoder.java
index 19746f31e..ebccfec94 100644
--- a/src/org/traccar/protocol/AtrackProtocolDecoder.java
+++ b/src/org/traccar/protocol/AtrackProtocolDecoder.java
@@ -93,7 +93,7 @@ public class AtrackProtocolDecoder extends BaseProtocolDecoder {
         String result = null;
         int index = buf.indexOf(buf.readerIndex(), buf.writerIndex(), (byte) 0);
         if (index > buf.readerIndex()) {
-            result = buf.readBytes(index - buf.readerIndex()).toString(StandardCharsets.US_ASCII);
+            result = buf.readSlice(index - buf.readerIndex()).toString(StandardCharsets.US_ASCII);
         }
         buf.readByte();
         return result;
diff --git a/src/org/traccar/protocol/AutoFonFrameDecoder.java b/src/org/traccar/protocol/AutoFonFrameDecoder.java
index 517f4b124..69f28133f 100644
--- a/src/org/traccar/protocol/AutoFonFrameDecoder.java
+++ b/src/org/traccar/protocol/AutoFonFrameDecoder.java
@@ -56,7 +56,7 @@ public class AutoFonFrameDecoder extends BaseFrameDecoder {
 
         // Check length and return buffer
         if (length != 0 && buf.readableBytes() >= length) {
-            return buf.readBytes(length);
+            return buf.readRetainedSlice(length);
         }
 
         return null;
diff --git a/src/org/traccar/protocol/AutoFonProtocolDecoder.java b/src/org/traccar/protocol/AutoFonProtocolDecoder.java
index c0c57720e..c5a3692f2 100644
--- a/src/org/traccar/protocol/AutoFonProtocolDecoder.java
+++ b/src/org/traccar/protocol/AutoFonProtocolDecoder.java
@@ -131,7 +131,7 @@ public class AutoFonProtocolDecoder extends BaseProtocolDecoder {
                 buf.readUnsignedByte(); // software version
             }
 
-            String imei = ByteBufUtil.hexDump(buf.readBytes(8)).substring(1);
+            String imei = ByteBufUtil.hexDump(buf.readSlice(8)).substring(1);
             DeviceSession deviceSession = getDeviceSession(channel, remoteAddress, imei);
 
             if (deviceSession != null && channel != null) {
diff --git a/src/org/traccar/protocol/BceFrameDecoder.java b/src/org/traccar/protocol/BceFrameDecoder.java
index 15ae40148..381a97696 100644
--- a/src/org/traccar/protocol/BceFrameDecoder.java
+++ b/src/org/traccar/protocol/BceFrameDecoder.java
@@ -49,7 +49,7 @@ public class BceFrameDecoder extends BaseFrameDecoder {
             end += buf.getUnsignedShortLE(buf.readerIndex() + end) + 2;
 
             if (buf.readableBytes() > end && checksum(buf, end) == buf.getByte(buf.readerIndex() + end)) {
-                return buf.readBytes(end + 1);
+                return buf.readRetainedSlice(end + 1);
             }
         }
 
diff --git a/src/org/traccar/protocol/BlackKiteProtocolDecoder.java b/src/org/traccar/protocol/BlackKiteProtocolDecoder.java
index 9701a8059..54761b87c 100644
--- a/src/org/traccar/protocol/BlackKiteProtocolDecoder.java
+++ b/src/org/traccar/protocol/BlackKiteProtocolDecoder.java
@@ -95,7 +95,7 @@ public class BlackKiteProtocolDecoder extends BaseProtocolDecoder {
             switch (tag) {
 
                 case TAG_IMEI:
-                    getDeviceSession(channel, remoteAddress, buf.readBytes(15).toString(StandardCharsets.US_ASCII));
+                    getDeviceSession(channel, remoteAddress, buf.readSlice(15).toString(StandardCharsets.US_ASCII));
                     break;
 
                 case TAG_DATE:
diff --git a/src/org/traccar/protocol/CalAmpProtocolDecoder.java b/src/org/traccar/protocol/CalAmpProtocolDecoder.java
index 9e9bd1336..d495e7400 100644
--- a/src/org/traccar/protocol/CalAmpProtocolDecoder.java
+++ b/src/org/traccar/protocol/CalAmpProtocolDecoder.java
@@ -152,7 +152,7 @@ public class CalAmpProtocolDecoder extends BaseProtocolDecoder {
             int content = buf.readUnsignedByte();
 
             if (BitUtil.check(content, 0)) {
-                String id = ByteBufUtil.hexDump(buf.readBytes(buf.readUnsignedByte()));
+                String id = ByteBufUtil.hexDump(buf.readSlice(buf.readUnsignedByte()));
                 getDeviceSession(channel, remoteAddress, id);
             }
 
diff --git a/src/org/traccar/protocol/CastelProtocolDecoder.java b/src/org/traccar/protocol/CastelProtocolDecoder.java
index 3c3ad6117..af0bb9d41 100644
--- a/src/org/traccar/protocol/CastelProtocolDecoder.java
+++ b/src/org/traccar/protocol/CastelProtocolDecoder.java
@@ -383,7 +383,7 @@ public class CastelProtocolDecoder extends BaseProtocolDecoder {
             decodeStat(position, buf);
 
             buf.readUnsignedByte(); // flag
-            position.add(ObdDecoder.decodeCodes(ByteBufUtil.hexDump(buf.readBytes(buf.readUnsignedByte()))));
+            position.add(ObdDecoder.decodeCodes(ByteBufUtil.hexDump(buf.readSlice(buf.readUnsignedByte()))));
 
             return position;
 
@@ -426,7 +426,7 @@ public class CastelProtocolDecoder extends BaseProtocolDecoder {
             for (int i = 0; i < successCount; i++) {
                 buf.readUnsignedShortLE(); // tag
                 position.set(Position.KEY_RESULT,
-                        buf.readBytes(buf.readUnsignedShortLE()).toString(StandardCharsets.US_ASCII));
+                        buf.readSlice(buf.readUnsignedShortLE()).toString(StandardCharsets.US_ASCII));
             }
 
             return position;
@@ -548,7 +548,7 @@ public class CastelProtocolDecoder extends BaseProtocolDecoder {
             version = buf.readUnsignedByte();
         }
 
-        ByteBuf id = buf.readBytes(20);
+        ByteBuf id = buf.readSlice(20);
         short type = buf.readShort();
 
         DeviceSession deviceSession = getDeviceSession(
diff --git a/src/org/traccar/protocol/CellocatorFrameDecoder.java b/src/org/traccar/protocol/CellocatorFrameDecoder.java
index 8cdba18e0..986dc75ec 100644
--- a/src/org/traccar/protocol/CellocatorFrameDecoder.java
+++ b/src/org/traccar/protocol/CellocatorFrameDecoder.java
@@ -59,7 +59,7 @@ public class CellocatorFrameDecoder extends BaseFrameDecoder {
         }
 
         if (length > 0 && buf.readableBytes() >= length) {
-            return buf.readBytes(length);
+            return buf.readRetainedSlice(length);
         }
 
         return null;
diff --git a/src/org/traccar/protocol/CityeasyProtocolDecoder.java b/src/org/traccar/protocol/CityeasyProtocolDecoder.java
index 5e5568402..a66b9adb3 100644
--- a/src/org/traccar/protocol/CityeasyProtocolDecoder.java
+++ b/src/org/traccar/protocol/CityeasyProtocolDecoder.java
@@ -74,7 +74,7 @@ public class CityeasyProtocolDecoder extends BaseProtocolDecoder {
         buf.skipBytes(2); // header
         buf.readUnsignedShort(); // length
 
-        String imei = ByteBufUtil.hexDump(buf.readBytes(7));
+        String imei = ByteBufUtil.hexDump(buf.readSlice(7));
         DeviceSession deviceSession = getDeviceSession(
                 channel, remoteAddress, imei, imei + Checksum.luhn(Long.parseLong(imei)));
         if (deviceSession == null) {
diff --git a/src/org/traccar/protocol/DmtProtocolDecoder.java b/src/org/traccar/protocol/DmtProtocolDecoder.java
index 9b414531a..25055d892 100644
--- a/src/org/traccar/protocol/DmtProtocolDecoder.java
+++ b/src/org/traccar/protocol/DmtProtocolDecoder.java
@@ -242,7 +242,7 @@ public class DmtProtocolDecoder extends BaseProtocolDecoder {
             buf.readUnsignedIntLE(); // device serial number
 
             DeviceSession deviceSession = getDeviceSession(
-                    channel, remoteAddress, buf.readBytes(15).toString(StandardCharsets.US_ASCII));
+                    channel, remoteAddress, buf.readSlice(15).toString(StandardCharsets.US_ASCII));
 
             ByteBuf response = Unpooled.buffer(0);
             if (length == 51) {
diff --git a/src/org/traccar/protocol/EelinkProtocolDecoder.java b/src/org/traccar/protocol/EelinkProtocolDecoder.java
index 1ed21893d..67e7f5127 100644
--- a/src/org/traccar/protocol/EelinkProtocolDecoder.java
+++ b/src/org/traccar/protocol/EelinkProtocolDecoder.java
@@ -339,7 +339,7 @@ public class EelinkProtocolDecoder extends BaseProtocolDecoder {
 
         if (buf.getByte(0) == 'E' && buf.getByte(1) == 'L') {
             buf.skipBytes(2 + 2 + 2); // udp header
-            uniqueId = ByteBufUtil.hexDump(buf.readBytes(8)).substring(1);
+            uniqueId = ByteBufUtil.hexDump(buf.readSlice(8)).substring(1);
             deviceSession = getDeviceSession(channel, remoteAddress, uniqueId);
         } else {
             deviceSession = getDeviceSession(channel, remoteAddress);
@@ -357,7 +357,7 @@ public class EelinkProtocolDecoder extends BaseProtocolDecoder {
         if (type == MSG_LOGIN) {
 
             if (deviceSession == null) {
-                getDeviceSession(channel, remoteAddress, ByteBufUtil.hexDump(buf.readBytes(8)).substring(1));
+                getDeviceSession(channel, remoteAddress, ByteBufUtil.hexDump(buf.readSlice(8)).substring(1));
             }
 
         } else {
diff --git a/src/org/traccar/protocol/EgtsFrameDecoder.java b/src/org/traccar/protocol/EgtsFrameDecoder.java
index c85eeff00..84f1f11a7 100644
--- a/src/org/traccar/protocol/EgtsFrameDecoder.java
+++ b/src/org/traccar/protocol/EgtsFrameDecoder.java
@@ -36,7 +36,7 @@ public class EgtsFrameDecoder extends BaseFrameDecoder {
         int length = headerLength + frameLength + (frameLength > 0 ? 2 : 0);
 
         if (buf.readableBytes() >= length) {
-            return buf.readBytes(length);
+            return buf.readRetainedSlice(length);
         }
 
         return null;
diff --git a/src/org/traccar/protocol/EgtsProtocolDecoder.java b/src/org/traccar/protocol/EgtsProtocolDecoder.java
index bb78f89a2..df02b8f7f 100644
--- a/src/org/traccar/protocol/EgtsProtocolDecoder.java
+++ b/src/org/traccar/protocol/EgtsProtocolDecoder.java
@@ -169,11 +169,11 @@ public class EgtsProtocolDecoder extends BaseProtocolDecoder {
                     }
                     if (BitUtil.check(flags, 1)) {
                         getDeviceSession(
-                                channel, remoteAddress, buf.readBytes(15).toString(StandardCharsets.US_ASCII).trim());
+                                channel, remoteAddress, buf.readSlice(15).toString(StandardCharsets.US_ASCII).trim());
                     }
                     if (BitUtil.check(flags, 2)) {
                         getDeviceSession(
-                                channel, remoteAddress, buf.readBytes(16).toString(StandardCharsets.US_ASCII).trim());
+                                channel, remoteAddress, buf.readSlice(16).toString(StandardCharsets.US_ASCII).trim());
                     }
                     if (BitUtil.check(flags, 3)) {
                         buf.skipBytes(3); // language identifier
@@ -186,7 +186,7 @@ public class EgtsProtocolDecoder extends BaseProtocolDecoder {
                     }
                     if (BitUtil.check(flags, 7)) {
                         getDeviceSession(
-                                channel, remoteAddress, buf.readBytes(15).toString(StandardCharsets.US_ASCII).trim());
+                                channel, remoteAddress, buf.readSlice(15).toString(StandardCharsets.US_ASCII).trim());
                     }
 
                     response = Unpooled.buffer(0);
diff --git a/src/org/traccar/protocol/EskyFrameDecoder.java b/src/org/traccar/protocol/EskyFrameDecoder.java
index a1470e12b..da24c1273 100644
--- a/src/org/traccar/protocol/EskyFrameDecoder.java
+++ b/src/org/traccar/protocol/EskyFrameDecoder.java
@@ -30,9 +30,9 @@ public class EskyFrameDecoder extends BaseFrameDecoder {
 
         int endIndex = buf.indexOf(buf.readerIndex() + 1, buf.writerIndex(), (byte) 'E');
         if (endIndex > 0) {
-            return buf.readBytes(endIndex - buf.readerIndex());
+            return buf.readRetainedSlice(endIndex - buf.readerIndex());
         } else {
-            return buf.readBytes(buf.readableBytes()); // assume full frame
+            return buf.readRetainedSlice(buf.readableBytes()); // assume full frame
         }
     }
 
diff --git a/src/org/traccar/protocol/GalileoFrameDecoder.java b/src/org/traccar/protocol/GalileoFrameDecoder.java
index 5a57c3a95..c23d26c83 100644
--- a/src/org/traccar/protocol/GalileoFrameDecoder.java
+++ b/src/org/traccar/protocol/GalileoFrameDecoder.java
@@ -34,7 +34,7 @@ public class GalileoFrameDecoder extends BaseFrameDecoder {
 
         int length = buf.getUnsignedShortLE(buf.readerIndex() + 1) & 0x7fff;
         if (buf.readableBytes() >= (length + MESSAGE_MINIMUM_LENGTH)) {
-            return buf.readBytes(length + MESSAGE_MINIMUM_LENGTH);
+            return buf.readRetainedSlice(length + MESSAGE_MINIMUM_LENGTH);
         }
 
         return null;
diff --git a/src/org/traccar/protocol/GalileoProtocolDecoder.java b/src/org/traccar/protocol/GalileoProtocolDecoder.java
index dae92fa8a..746e05f5d 100644
--- a/src/org/traccar/protocol/GalileoProtocolDecoder.java
+++ b/src/org/traccar/protocol/GalileoProtocolDecoder.java
@@ -215,7 +215,7 @@ public class GalileoProtocolDecoder extends BaseProtocolDecoder {
                 break;
             case 0xe1:
                 position.set(Position.KEY_RESULT,
-                        buf.readBytes(buf.readUnsignedByte()).toString(StandardCharsets.US_ASCII));
+                        buf.readSlice(buf.readUnsignedByte()).toString(StandardCharsets.US_ASCII));
                 break;
             case 0xe2:
             case 0xe3:
@@ -228,8 +228,8 @@ public class GalileoProtocolDecoder extends BaseProtocolDecoder {
                 position.set("userData" + (tag - 0xe2), buf.readUnsignedIntLE());
                 break;
             case 0xea:
-                position.set("userDataArray", ByteBufUtil.hexDump(buf.readBytes(buf.readUnsignedByte())));
-                position.set("userDataArray", ByteBufUtil.hexDump(buf.readBytes(buf.readUnsignedByte())));
+                position.set("userDataArray", ByteBufUtil.hexDump(buf.readSlice(buf.readUnsignedByte())));
+                position.set("userDataArray", ByteBufUtil.hexDump(buf.readSlice(buf.readUnsignedByte())));
                 break;
             default:
                 buf.skipBytes(getTagLength(tag));
@@ -268,7 +268,7 @@ public class GalileoProtocolDecoder extends BaseProtocolDecoder {
 
             if (tag == 0x03) {
                 deviceSession = getDeviceSession(
-                        channel, remoteAddress, buf.readBytes(15).toString(StandardCharsets.US_ASCII));
+                        channel, remoteAddress, buf.readSlice(15).toString(StandardCharsets.US_ASCII));
             } else if (tag == 0x30) {
                 hasLocation = true;
                 position.setValid((buf.readUnsignedByte() & 0xf0) == 0x00);
diff --git a/src/org/traccar/protocol/Gl200BinaryProtocolDecoder.java b/src/org/traccar/protocol/Gl200BinaryProtocolDecoder.java
index e249cd936..62caaf13d 100644
--- a/src/org/traccar/protocol/Gl200BinaryProtocolDecoder.java
+++ b/src/org/traccar/protocol/Gl200BinaryProtocolDecoder.java
@@ -113,7 +113,7 @@ public class Gl200BinaryProtocolDecoder extends BaseProtocolDecoder {
 
                 switch (BitUtil.from(buf.getUnsignedByte(buf.readerIndex()), 8 - 2)) {
                     case 1:
-                        bits = new BitBuffer(buf.readBytes(3));
+                        bits = new BitBuffer(buf.readSlice(3));
                         bits.readUnsigned(2); // point attribute
                         bits.readUnsigned(1); // fix type
                         speed = bits.readUnsigned(12);
@@ -125,7 +125,7 @@ public class Gl200BinaryProtocolDecoder extends BaseProtocolDecoder {
                         }
                         break;
                     case 2:
-                        bits = new BitBuffer(buf.readBytes(5));
+                        bits = new BitBuffer(buf.readSlice(5));
                         bits.readUnsigned(2); // point attribute
                         bits.readUnsigned(1); // fix type
                         speed += bits.readSigned(7);
@@ -387,7 +387,7 @@ public class Gl200BinaryProtocolDecoder extends BaseProtocolDecoder {
 
         ByteBuf buf = (ByteBuf) msg;
 
-        switch (buf.readBytes(4).toString(StandardCharsets.US_ASCII)) {
+        switch (buf.readSlice(4).toString(StandardCharsets.US_ASCII)) {
             case "+RSP":
                 return decodeLocation(channel, remoteAddress, buf);
             case "+INF":
diff --git a/src/org/traccar/protocol/Gl200FrameDecoder.java b/src/org/traccar/protocol/Gl200FrameDecoder.java
index bcddb1aff..c192cc28d 100644
--- a/src/org/traccar/protocol/Gl200FrameDecoder.java
+++ b/src/org/traccar/protocol/Gl200FrameDecoder.java
@@ -74,7 +74,7 @@ public class Gl200FrameDecoder extends BaseFrameDecoder {
             }
 
             if (buf.readableBytes() >= length) {
-                return buf.readBytes(length);
+                return buf.readRetainedSlice(length);
             }
 
         } else {
@@ -84,7 +84,7 @@ public class Gl200FrameDecoder extends BaseFrameDecoder {
                 endIndex = buf.indexOf(buf.readerIndex(), buf.writerIndex(), (byte) 0);
             }
             if (endIndex > 0) {
-                ByteBuf frame = buf.readBytes(endIndex - buf.readerIndex());
+                ByteBuf frame = buf.readRetainedSlice(endIndex - buf.readerIndex());
                 buf.readByte(); // delimiter
                 return frame;
             }
diff --git a/src/org/traccar/protocol/Gps056FrameDecoder.java b/src/org/traccar/protocol/Gps056FrameDecoder.java
index 7cfd54c4e..0d84bf231 100644
--- a/src/org/traccar/protocol/Gps056FrameDecoder.java
+++ b/src/org/traccar/protocol/Gps056FrameDecoder.java
@@ -33,7 +33,7 @@ public class Gps056FrameDecoder extends BaseFrameDecoder {
         if (buf.readableBytes() >= MESSAGE_HEADER) {
             int length = Integer.parseInt(buf.toString(2, 2, StandardCharsets.US_ASCII)) + 5;
             if (buf.readableBytes() >= length) {
-                ByteBuf frame = buf.readBytes(length);
+                ByteBuf frame = buf.readRetainedSlice(length);
                 while (buf.isReadable() && buf.getUnsignedByte(buf.readerIndex()) != '$') {
                     buf.readByte();
                 }
diff --git a/src/org/traccar/protocol/Gps056ProtocolDecoder.java b/src/org/traccar/protocol/Gps056ProtocolDecoder.java
index c2a8372b0..bfe9fc68e 100644
--- a/src/org/traccar/protocol/Gps056ProtocolDecoder.java
+++ b/src/org/traccar/protocol/Gps056ProtocolDecoder.java
@@ -79,8 +79,8 @@ public class Gps056ProtocolDecoder extends BaseProtocolDecoder {
         buf.skipBytes(2); // header
         buf.skipBytes(2); // length
 
-        String type = buf.readBytes(7).toString(StandardCharsets.US_ASCII);
-        String imei = buf.readBytes(15).toString(StandardCharsets.US_ASCII);
+        String type = buf.readSlice(7).toString(StandardCharsets.US_ASCII);
+        String imei = buf.readSlice(15).toString(StandardCharsets.US_ASCII);
 
         DeviceSession deviceSession = getDeviceSession(channel, remoteAddress, imei);
         if (deviceSession == null) {
@@ -110,7 +110,7 @@ public class Gps056ProtocolDecoder extends BaseProtocolDecoder {
 
             decodeStatus(buf, position);
 
-            sendResponse(channel, "GPSA" + type.substring(4), imei, buf.readBytes(2));
+            sendResponse(channel, "GPSA" + type.substring(4), imei, buf.readSlice(2));
 
             return position;
 
diff --git a/src/org/traccar/protocol/GranitFrameDecoder.java b/src/org/traccar/protocol/GranitFrameDecoder.java
index 5e555fb15..bb7f4be44 100644
--- a/src/org/traccar/protocol/GranitFrameDecoder.java
+++ b/src/org/traccar/protocol/GranitFrameDecoder.java
@@ -37,7 +37,7 @@ public class GranitFrameDecoder extends BaseFrameDecoder {
                     return null;
                 }
             }
-            ByteBuf frame = buf.readBytes(indexEnd - buf.readerIndex());
+            ByteBuf frame = buf.readRetainedSlice(indexEnd - buf.readerIndex());
             buf.skipBytes(2);
             return frame;
         }
diff --git a/src/org/traccar/protocol/GranitProtocolDecoder.java b/src/org/traccar/protocol/GranitProtocolDecoder.java
index c3eff7d34..495faef30 100644
--- a/src/org/traccar/protocol/GranitProtocolDecoder.java
+++ b/src/org/traccar/protocol/GranitProtocolDecoder.java
@@ -170,7 +170,7 @@ public class GranitProtocolDecoder extends BaseProtocolDecoder {
         if (buf.readableBytes() < HEADER_LENGTH) {
             return null;
         }
-        String header = buf.readBytes(HEADER_LENGTH).toString(StandardCharsets.US_ASCII);
+        String header = buf.readSlice(HEADER_LENGTH).toString(StandardCharsets.US_ASCII);
 
         if (header.equals("+RRCB~")) {
 
diff --git a/src/org/traccar/protocol/Gt02ProtocolDecoder.java b/src/org/traccar/protocol/Gt02ProtocolDecoder.java
index 83be9d996..ab4c7022e 100644
--- a/src/org/traccar/protocol/Gt02ProtocolDecoder.java
+++ b/src/org/traccar/protocol/Gt02ProtocolDecoder.java
@@ -55,7 +55,7 @@ public class Gt02ProtocolDecoder extends BaseProtocolDecoder {
         int power = buf.readUnsignedByte();
         int gsm = buf.readUnsignedByte();
 
-        String imei = ByteBufUtil.hexDump(buf.readBytes(8)).substring(1);
+        String imei = ByteBufUtil.hexDump(buf.readSlice(8)).substring(1);
         DeviceSession deviceSession = getDeviceSession(channel, remoteAddress, imei);
         if (deviceSession == null) {
             return null;
@@ -110,7 +110,7 @@ public class Gt02ProtocolDecoder extends BaseProtocolDecoder {
             getLastLocation(position, null);
 
             position.set(Position.KEY_RESULT,
-                    buf.readBytes(buf.readUnsignedByte()).toString(StandardCharsets.US_ASCII));
+                    buf.readSlice(buf.readUnsignedByte()).toString(StandardCharsets.US_ASCII));
 
         } else {
 
diff --git a/src/org/traccar/protocol/Gt06FrameDecoder.java b/src/org/traccar/protocol/Gt06FrameDecoder.java
index 41e56415a..cc934be42 100644
--- a/src/org/traccar/protocol/Gt06FrameDecoder.java
+++ b/src/org/traccar/protocol/Gt06FrameDecoder.java
@@ -39,14 +39,14 @@ public class Gt06FrameDecoder extends BaseFrameDecoder {
         }
 
         if (buf.readableBytes() >= length && buf.getUnsignedShort(buf.readerIndex() + length - 2) == 0x0d0a) {
-            return buf.readBytes(length);
+            return buf.readRetainedSlice(length);
         }
 
         int endIndex = buf.readerIndex() - 1;
         do {
             endIndex = buf.indexOf(endIndex + 1, buf.writerIndex(), (byte) 0x0d);
             if (endIndex > 0 && buf.writerIndex() > endIndex + 1 && buf.getByte(endIndex + 1) == 0x0a) {
-                return buf.readBytes(endIndex + 2 - buf.readerIndex());
+                return buf.readRetainedSlice(endIndex + 2 - buf.readerIndex());
             }
         } while (endIndex > 0);
 
diff --git a/src/org/traccar/protocol/Gt06ProtocolDecoder.java b/src/org/traccar/protocol/Gt06ProtocolDecoder.java
index 490c366ea..cc37d5602 100644
--- a/src/org/traccar/protocol/Gt06ProtocolDecoder.java
+++ b/src/org/traccar/protocol/Gt06ProtocolDecoder.java
@@ -388,7 +388,7 @@ public class Gt06ProtocolDecoder extends BaseProtocolDecoder {
 
         if (type == MSG_LOGIN) {
 
-            String imei = ByteBufUtil.hexDump(buf.readBytes(8)).substring(1);
+            String imei = ByteBufUtil.hexDump(buf.readSlice(8)).substring(1);
             buf.readUnsignedShort(); // type
 
             deviceSession = getDeviceSession(channel, remoteAddress, imei);
@@ -573,7 +573,7 @@ public class Gt06ProtocolDecoder extends BaseProtocolDecoder {
             if (type != MSG_LBS_MULTIPLE && type != MSG_LBS_2) {
                 int wifiCount = buf.readUnsignedByte();
                 for (int i = 0; i < wifiCount; i++) {
-                    String mac = ByteBufUtil.hexDump(buf.readBytes(6)).replaceAll("(..)", "$1:");
+                    String mac = ByteBufUtil.hexDump(buf.readSlice(6)).replaceAll("(..)", "$1:");
                     network.addWifiAccessPoint(WifiAccessPoint.from(
                             mac.substring(0, mac.length() - 1), buf.readUnsignedByte()));
                 }
@@ -590,7 +590,7 @@ public class Gt06ProtocolDecoder extends BaseProtocolDecoder {
             if (commandLength > 0) {
                 buf.readUnsignedByte(); // server flag (reserved)
                 position.set(Position.KEY_RESULT,
-                        buf.readBytes(commandLength - 1).toString(StandardCharsets.US_ASCII));
+                        buf.readSlice(commandLength - 1).toString(StandardCharsets.US_ASCII));
             }
 
         } else if (isSupported(type)) {
@@ -666,9 +666,9 @@ public class Gt06ProtocolDecoder extends BaseProtocolDecoder {
             buf.readUnsignedInt(); // server flag
             String data;
             if (buf.readUnsignedByte() == 1) {
-                data = buf.readBytes(buf.readableBytes() - 6).toString(StandardCharsets.US_ASCII);
+                data = buf.readSlice(buf.readableBytes() - 6).toString(StandardCharsets.US_ASCII);
             } else {
-                data = buf.readBytes(buf.readableBytes() - 6).toString(StandardCharsets.UTF_16BE);
+                data = buf.readSlice(buf.readableBytes() - 6).toString(StandardCharsets.UTF_16BE);
             }
 
             if (decodeLocationString(position, data) == null) {
diff --git a/src/org/traccar/protocol/H02FrameDecoder.java b/src/org/traccar/protocol/H02FrameDecoder.java
index 4f7d78cea..583ad599f 100644
--- a/src/org/traccar/protocol/H02FrameDecoder.java
+++ b/src/org/traccar/protocol/H02FrameDecoder.java
@@ -50,7 +50,7 @@ public class H02FrameDecoder extends BaseFrameDecoder {
                 // Return text message
                 int index = buf.indexOf(buf.readerIndex(), buf.writerIndex(), (byte) '#');
                 if (index != -1) {
-                    ByteBuf result = buf.readBytes(index + 1 - buf.readerIndex());
+                    ByteBuf result = buf.readRetainedSlice(index + 1 - buf.readerIndex());
                     while (buf.isReadable()
                             && (buf.getByte(buf.readerIndex()) == '\r' || buf.getByte(buf.readerIndex()) == '\n')) {
                         buf.readByte(); // skip new line
@@ -71,7 +71,7 @@ public class H02FrameDecoder extends BaseFrameDecoder {
                 }
 
                 if (buf.readableBytes() >= messageLength) {
-                    return buf.readBytes(messageLength);
+                    return buf.readRetainedSlice(messageLength);
                 }
 
                 break;
@@ -79,7 +79,7 @@ public class H02FrameDecoder extends BaseFrameDecoder {
             case 'X':
 
                 if (buf.readableBytes() >= MESSAGE_SHORT) {
-                    return buf.readBytes(MESSAGE_SHORT);
+                    return buf.readRetainedSlice(MESSAGE_SHORT);
                 }
 
                 break;
diff --git a/src/org/traccar/protocol/H02ProtocolDecoder.java b/src/org/traccar/protocol/H02ProtocolDecoder.java
index e6fd86897..2abde7d6f 100644
--- a/src/org/traccar/protocol/H02ProtocolDecoder.java
+++ b/src/org/traccar/protocol/H02ProtocolDecoder.java
@@ -106,7 +106,7 @@ public class H02ProtocolDecoder extends BaseProtocolDecoder {
         buf.readByte(); // marker
 
         DeviceSession deviceSession = getDeviceSession(
-                channel, remoteAddress, ByteBufUtil.hexDump(buf.readBytes(5)));
+                channel, remoteAddress, ByteBufUtil.hexDump(buf.readSlice(5)));
         if (deviceSession == null) {
             return null;
         }
diff --git a/src/org/traccar/protocol/HuaShengProtocolDecoder.java b/src/org/traccar/protocol/HuaShengProtocolDecoder.java
index 6349a6792..79ba660ee 100644
--- a/src/org/traccar/protocol/HuaShengProtocolDecoder.java
+++ b/src/org/traccar/protocol/HuaShengProtocolDecoder.java
@@ -81,7 +81,7 @@ public class HuaShengProtocolDecoder extends BaseProtocolDecoder {
                 int subtype = buf.readUnsignedShort();
                 int length = buf.readUnsignedShort() - 4;
                 if (subtype == 0x0003) {
-                    String imei = buf.readBytes(length).toString(StandardCharsets.US_ASCII);
+                    String imei = buf.readSlice(length).toString(StandardCharsets.US_ASCII);
                     DeviceSession deviceSession = getDeviceSession(channel, remoteAddress, imei);
                     if (deviceSession != null && channel != null) {
                         ByteBuf content = Unpooled.buffer();
@@ -115,7 +115,7 @@ public class HuaShengProtocolDecoder extends BaseProtocolDecoder {
             position.set(Position.KEY_IGNITION, BitUtil.check(status, 14));
             position.set(Position.KEY_EVENT, buf.readUnsignedShort());
 
-            String time = buf.readBytes(12).toString(StandardCharsets.US_ASCII);
+            String time = buf.readSlice(12).toString(StandardCharsets.US_ASCII);
 
             DateBuilder dateBuilder = new DateBuilder()
                     .setYear(Integer.parseInt(time.substring(0, 2)))
diff --git a/src/org/traccar/protocol/HuabaoProtocolDecoder.java b/src/org/traccar/protocol/HuabaoProtocolDecoder.java
index 7735092fc..c9868b21e 100644
--- a/src/org/traccar/protocol/HuabaoProtocolDecoder.java
+++ b/src/org/traccar/protocol/HuabaoProtocolDecoder.java
@@ -107,7 +107,7 @@ public class HuabaoProtocolDecoder extends BaseProtocolDecoder {
         buf.readUnsignedByte(); // start marker
         int type = buf.readUnsignedShort();
         buf.readUnsignedShort(); // body length
-        ByteBuf id = buf.readBytes(6); // phone number
+        ByteBuf id = buf.readSlice(6); // phone number
         int index = buf.readUnsignedShort();
 
         DeviceSession deviceSession = getDeviceSession(channel, remoteAddress, ByteBufUtil.hexDump(id));
diff --git a/src/org/traccar/protocol/IntellitracFrameDecoder.java b/src/org/traccar/protocol/IntellitracFrameDecoder.java
index 2cf91bf59..8322e65ba 100644
--- a/src/org/traccar/protocol/IntellitracFrameDecoder.java
+++ b/src/org/traccar/protocol/IntellitracFrameDecoder.java
@@ -40,7 +40,7 @@ public class IntellitracFrameDecoder extends LineBasedFrameDecoder {
 
         // Check for sync packet
         if (buf.getUnsignedShort(buf.readerIndex()) == 0xFAF8) {
-            ByteBuf syncMessage = buf.readBytes(8);
+            ByteBuf syncMessage = buf.readRetainedSlice(8);
             if (ctx != null && ctx.channel() != null) {
                 ctx.channel().writeAndFlush(new NetworkMessage(syncMessage, ctx.channel().remoteAddress()));
             }
diff --git a/src/org/traccar/protocol/JpKorjarFrameDecoder.java b/src/org/traccar/protocol/JpKorjarFrameDecoder.java
index 9a0158230..0eb65c8ef 100644
--- a/src/org/traccar/protocol/JpKorjarFrameDecoder.java
+++ b/src/org/traccar/protocol/JpKorjarFrameDecoder.java
@@ -41,7 +41,7 @@ public class JpKorjarFrameDecoder extends BaseFrameDecoder {
             return null;
         }
 
-        return buf.readBytes(endIndex + 1);
+        return buf.readRetainedSlice(endIndex + 1);
     }
 
 }
diff --git a/src/org/traccar/protocol/Jt600FrameDecoder.java b/src/org/traccar/protocol/Jt600FrameDecoder.java
index 5b712a7b4..b5d060ecc 100644
--- a/src/org/traccar/protocol/Jt600FrameDecoder.java
+++ b/src/org/traccar/protocol/Jt600FrameDecoder.java
@@ -38,12 +38,12 @@ public class Jt600FrameDecoder extends BaseFrameDecoder {
             boolean longFormat = buf.getUnsignedByte(buf.readerIndex() + 1) == 0x75;
             int length = buf.getUnsignedShort(buf.readerIndex() + (longFormat ? 8 : 7)) + 10;
             if (length <= buf.readableBytes()) {
-                return buf.readBytes(length);
+                return buf.readRetainedSlice(length);
             }
         } else if (type == '(') {
             int endIndex = buf.indexOf(buf.readerIndex(), buf.writerIndex(), (byte) ')');
             if (endIndex != -1) {
-                return buf.readBytes(endIndex + 1);
+                return buf.readRetainedSlice(endIndex + 1);
             }
         } else {
             throw new ParseException(null, 0); // unknown message
diff --git a/src/org/traccar/protocol/Jt600ProtocolDecoder.java b/src/org/traccar/protocol/Jt600ProtocolDecoder.java
index 58ec8c613..87996a0c3 100644
--- a/src/org/traccar/protocol/Jt600ProtocolDecoder.java
+++ b/src/org/traccar/protocol/Jt600ProtocolDecoder.java
@@ -93,7 +93,7 @@ public class Jt600ProtocolDecoder extends BaseProtocolDecoder {
 
         boolean longFormat = buf.getUnsignedByte(buf.readerIndex()) == 0x75;
 
-        String id = String.valueOf(Long.parseLong(ByteBufUtil.hexDump(buf.readBytes(5))));
+        String id = String.valueOf(Long.parseLong(ByteBufUtil.hexDump(buf.readSlice(5))));
         DeviceSession deviceSession = getDeviceSession(channel, remoteAddress, id);
         if (deviceSession == null) {
             return null;
diff --git a/src/org/traccar/protocol/L100FrameDecoder.java b/src/org/traccar/protocol/L100FrameDecoder.java
index 29839eb3a..d407ac0b5 100644
--- a/src/org/traccar/protocol/L100FrameDecoder.java
+++ b/src/org/traccar/protocol/L100FrameDecoder.java
@@ -42,7 +42,7 @@ public class L100FrameDecoder extends BaseFrameDecoder {
 
         if (buf.readableBytes() >= index - buf.readerIndex()) {
             buf.skipBytes(2); // header
-            ByteBuf frame = buf.readBytes(index - buf.readerIndex() - 2);
+            ByteBuf frame = buf.readRetainedSlice(index - buf.readerIndex() - 2);
             buf.skipBytes(2); // footer
             return frame;
         }
diff --git a/src/org/traccar/protocol/MegastekFrameDecoder.java b/src/org/traccar/protocol/MegastekFrameDecoder.java
index 0bdd06a79..347fa24b1 100644
--- a/src/org/traccar/protocol/MegastekFrameDecoder.java
+++ b/src/org/traccar/protocol/MegastekFrameDecoder.java
@@ -36,7 +36,7 @@ public class MegastekFrameDecoder extends BaseFrameDecoder {
         if (Character.isDigit(buf.getByte(buf.readerIndex()))) {
             int length = 4 + Integer.parseInt(buf.toString(buf.readerIndex(), 4, StandardCharsets.US_ASCII));
             if (buf.readableBytes() >= length) {
-                return buf.readBytes(length);
+                return buf.readRetainedSlice(length);
             }
         } else {
             while (buf.getByte(buf.readerIndex()) == '\r' || buf.getByte(buf.readerIndex()) == '\n') {
@@ -47,7 +47,7 @@ public class MegastekFrameDecoder extends BaseFrameDecoder {
                 delimiter = buf.indexOf(buf.readerIndex(), buf.writerIndex(), (byte) '!');
             }
             if (delimiter != -1) {
-                ByteBuf result = buf.readBytes(delimiter - buf.readerIndex());
+                ByteBuf result = buf.readRetainedSlice(delimiter - buf.readerIndex());
                 buf.skipBytes(1);
                 return result;
             }
diff --git a/src/org/traccar/protocol/MeiligaoFrameDecoder.java b/src/org/traccar/protocol/MeiligaoFrameDecoder.java
index e14d8ed58..52f9ae26d 100644
--- a/src/org/traccar/protocol/MeiligaoFrameDecoder.java
+++ b/src/org/traccar/protocol/MeiligaoFrameDecoder.java
@@ -37,7 +37,7 @@ public class MeiligaoFrameDecoder extends BaseFrameDecoder {
         if (buf.readableBytes() >= MESSAGE_HEADER) {
             int length = buf.getUnsignedShort(buf.readerIndex() + 2);
             if (buf.readableBytes() >= length) {
-                return buf.readBytes(length);
+                return buf.readRetainedSlice(length);
             }
         }
 
diff --git a/src/org/traccar/protocol/MeiligaoProtocolDecoder.java b/src/org/traccar/protocol/MeiligaoProtocolDecoder.java
index 35512945a..6813ffcfe 100644
--- a/src/org/traccar/protocol/MeiligaoProtocolDecoder.java
+++ b/src/org/traccar/protocol/MeiligaoProtocolDecoder.java
@@ -371,7 +371,7 @@ public class MeiligaoProtocolDecoder extends BaseProtocolDecoder {
                 endIndex = buf.writerIndex() - 4;
             }
 
-            String sentence = buf.readBytes(endIndex - buf.readerIndex()).toString(StandardCharsets.US_ASCII);
+            String sentence = buf.readSlice(endIndex - buf.readerIndex()).toString(StandardCharsets.US_ASCII);
 
             Position position = new Position(getProtocolName());
             position.setDeviceId(deviceSession.getDeviceId());
@@ -398,7 +398,7 @@ public class MeiligaoProtocolDecoder extends BaseProtocolDecoder {
         ByteBuf buf = (ByteBuf) msg;
         buf.skipBytes(2); // header
         buf.readShort(); // length
-        ByteBuf id = buf.readBytes(7);
+        ByteBuf id = buf.readSlice(7);
         int command = buf.readUnsignedShort();
         ByteBuf response;
 
diff --git a/src/org/traccar/protocol/MeitrackFrameDecoder.java b/src/org/traccar/protocol/MeitrackFrameDecoder.java
index 5133dd2dc..d122bca0c 100644
--- a/src/org/traccar/protocol/MeitrackFrameDecoder.java
+++ b/src/org/traccar/protocol/MeitrackFrameDecoder.java
@@ -37,7 +37,7 @@ public class MeitrackFrameDecoder extends BaseFrameDecoder {
             int length = index - buf.readerIndex() + Integer.parseInt(
                     buf.toString(buf.readerIndex() + 3, index - buf.readerIndex() - 3, StandardCharsets.US_ASCII));
             if (buf.readableBytes() >= length) {
-                return buf.readBytes(length);
+                return buf.readRetainedSlice(length);
             }
         }
 
diff --git a/src/org/traccar/protocol/MeitrackProtocolDecoder.java b/src/org/traccar/protocol/MeitrackProtocolDecoder.java
index a38f52b77..3f027559a 100644
--- a/src/org/traccar/protocol/MeitrackProtocolDecoder.java
+++ b/src/org/traccar/protocol/MeitrackProtocolDecoder.java
@@ -348,7 +348,7 @@ public class MeitrackProtocolDecoder extends BaseProtocolDecoder {
         List<Position> positions = new LinkedList<>();
 
         buf.readerIndex(buf.indexOf(buf.readerIndex(), buf.writerIndex(), (byte) ',') + 1);
-        String imei = buf.readBytes(15).toString(StandardCharsets.US_ASCII);
+        String imei = buf.readSlice(15).toString(StandardCharsets.US_ASCII);
         buf.skipBytes(1 + 3 + 1);
 
         DeviceSession deviceSession = getDeviceSession(channel, remoteAddress, imei);
@@ -485,7 +485,7 @@ public class MeitrackProtocolDecoder extends BaseProtocolDecoder {
                 int current = Integer.parseInt(buf.toString(index, endIndex - index, StandardCharsets.US_ASCII));
 
                 buf.readerIndex(endIndex + 1);
-                photo.writeBytes(buf.readBytes(buf.readableBytes() - 1 - 2 - 2));
+                photo.writeBytes(buf.readSlice(buf.readableBytes() - 1 - 2 - 2));
 
                 if (current == total - 1) {
                     Position position = new Position(getProtocolName());
diff --git a/src/org/traccar/protocol/NavigilFrameDecoder.java b/src/org/traccar/protocol/NavigilFrameDecoder.java
index 90912fb45..e8b6bea52 100644
--- a/src/org/traccar/protocol/NavigilFrameDecoder.java
+++ b/src/org/traccar/protocol/NavigilFrameDecoder.java
@@ -47,7 +47,7 @@ public class NavigilFrameDecoder extends BaseFrameDecoder {
                 buf.readUnsignedIntLE();
                 length -= 4;
             }
-            return buf.readBytes(length);
+            return buf.readRetainedSlice(length);
         }
 
         return null;
diff --git a/src/org/traccar/protocol/NoranProtocolDecoder.java b/src/org/traccar/protocol/NoranProtocolDecoder.java
index 5e41cd6bc..2c5da4a78 100644
--- a/src/org/traccar/protocol/NoranProtocolDecoder.java
+++ b/src/org/traccar/protocol/NoranProtocolDecoder.java
@@ -129,9 +129,9 @@ public class NoranProtocolDecoder extends BaseProtocolDecoder {
 
             ByteBuf rawId;
             if (newFormat) {
-                rawId = buf.readBytes(12);
+                rawId = buf.readSlice(12);
             } else {
-                rawId = buf.readBytes(11);
+                rawId = buf.readSlice(11);
             }
             String id = rawId.toString(StandardCharsets.US_ASCII).replaceAll("[^\\p{Print}]", "");
             DeviceSession deviceSession = getDeviceSession(channel, remoteAddress, id);
@@ -142,7 +142,7 @@ public class NoranProtocolDecoder extends BaseProtocolDecoder {
 
             if (newFormat) {
                 DateFormat dateFormat = new SimpleDateFormat("yy-MM-dd HH:mm:ss");
-                position.setTime(dateFormat.parse(buf.readBytes(17).toString(StandardCharsets.US_ASCII)));
+                position.setTime(dateFormat.parse(buf.readSlice(17).toString(StandardCharsets.US_ASCII)));
                 buf.readByte();
             }
 
diff --git a/src/org/traccar/protocol/NvsFrameDecoder.java b/src/org/traccar/protocol/NvsFrameDecoder.java
index 4fa1cab1c..e93a58cf6 100644
--- a/src/org/traccar/protocol/NvsFrameDecoder.java
+++ b/src/org/traccar/protocol/NvsFrameDecoder.java
@@ -38,7 +38,7 @@ public class NvsFrameDecoder extends BaseFrameDecoder {
         }
 
         if (buf.readableBytes() >= length) {
-            return buf.readBytes(length);
+            return buf.readRetainedSlice(length);
         }
 
         return null;
diff --git a/src/org/traccar/protocol/ObdDongleProtocolDecoder.java b/src/org/traccar/protocol/ObdDongleProtocolDecoder.java
index bb925ca3e..dcfba242d 100644
--- a/src/org/traccar/protocol/ObdDongleProtocolDecoder.java
+++ b/src/org/traccar/protocol/ObdDongleProtocolDecoder.java
@@ -67,7 +67,7 @@ public class ObdDongleProtocolDecoder extends BaseProtocolDecoder {
         buf.skipBytes(2); // header
         int index = buf.readUnsignedShort();
 
-        String imei = buf.readBytes(15).toString(StandardCharsets.US_ASCII);
+        String imei = buf.readSlice(15).toString(StandardCharsets.US_ASCII);
         DeviceSession deviceSession = getDeviceSession(channel, remoteAddress, imei);
         if (deviceSession == null) {
             return null;
diff --git a/src/org/traccar/protocol/OigoProtocolDecoder.java b/src/org/traccar/protocol/OigoProtocolDecoder.java
index 9067bac21..fe356f7cf 100644
--- a/src/org/traccar/protocol/OigoProtocolDecoder.java
+++ b/src/org/traccar/protocol/OigoProtocolDecoder.java
@@ -53,12 +53,12 @@ public class OigoProtocolDecoder extends BaseProtocolDecoder {
         DeviceSession deviceSession;
         switch (BitUtil.to(tag, 3)) {
             case 0:
-                String imei = ByteBufUtil.hexDump(buf.readBytes(8)).substring(1);
+                String imei = ByteBufUtil.hexDump(buf.readSlice(8)).substring(1);
                 deviceSession = getDeviceSession(channel, remoteAddress, imei);
                 break;
             case 1:
                 buf.skipBytes(1);
-                String meid = buf.readBytes(14).toString(StandardCharsets.US_ASCII);
+                String meid = buf.readSlice(14).toString(StandardCharsets.US_ASCII);
                 deviceSession = getDeviceSession(channel, remoteAddress, meid);
                 break;
             default:
@@ -171,7 +171,7 @@ public class OigoProtocolDecoder extends BaseProtocolDecoder {
             buf.readUnsignedByte(); // flags
             deviceSession = getDeviceSession(channel, remoteAddress);
         } else {
-            String imei = ByteBufUtil.hexDump(buf.readBytes(8)).substring(1);
+            String imei = ByteBufUtil.hexDump(buf.readSlice(8)).substring(1);
             deviceSession = getDeviceSession(channel, remoteAddress, imei);
         }
 
diff --git a/src/org/traccar/protocol/OrionFrameDecoder.java b/src/org/traccar/protocol/OrionFrameDecoder.java
index ce5a06478..948806609 100644
--- a/src/org/traccar/protocol/OrionFrameDecoder.java
+++ b/src/org/traccar/protocol/OrionFrameDecoder.java
@@ -49,14 +49,14 @@ public class OrionFrameDecoder extends BaseFrameDecoder {
                 }
 
                 if (buf.readableBytes() >= length) {
-                    return buf.readBytes(length);
+                    return buf.readRetainedSlice(length);
                 }
 
             } else if (type == OrionProtocolDecoder.MSG_SYSLOG && buf.readableBytes() >= length + 12) {
 
                 length += buf.getUnsignedShortLE(buf.readerIndex() + 8);
                 if (buf.readableBytes() >= length) {
-                    return buf.readBytes(length);
+                    return buf.readRetainedSlice(length);
                 }
 
             }
diff --git a/src/org/traccar/protocol/PricolProtocolDecoder.java b/src/org/traccar/protocol/PricolProtocolDecoder.java
index e0ab300be..b76e5f27f 100644
--- a/src/org/traccar/protocol/PricolProtocolDecoder.java
+++ b/src/org/traccar/protocol/PricolProtocolDecoder.java
@@ -43,7 +43,7 @@ public class PricolProtocolDecoder extends BaseProtocolDecoder {
         buf.readUnsignedByte(); // header
 
         DeviceSession deviceSession = getDeviceSession(
-                channel, remoteAddress, buf.readBytes(7).toString(StandardCharsets.US_ASCII));
+                channel, remoteAddress, buf.readSlice(7).toString(StandardCharsets.US_ASCII));
         if (deviceSession == null) {
             return null;
         }
diff --git a/src/org/traccar/protocol/ProgressProtocolDecoder.java b/src/org/traccar/protocol/ProgressProtocolDecoder.java
index c57d6e5ce..dca0e649e 100644
--- a/src/org/traccar/protocol/ProgressProtocolDecoder.java
+++ b/src/org/traccar/protocol/ProgressProtocolDecoder.java
@@ -79,7 +79,7 @@ public class ProgressProtocolDecoder extends BaseProtocolDecoder {
             length = buf.readUnsignedShortLE();
             buf.skipBytes(length);
             length = buf.readUnsignedShortLE();
-            String imei = buf.readBytes(length).toString(StandardCharsets.US_ASCII);
+            String imei = buf.readSlice(length).toString(StandardCharsets.US_ASCII);
             getDeviceSession(channel, remoteAddress, imei);
 
         } else if (type == MSG_POINT || type == MSG_ALARM || type == MSG_LOGMSG) {
@@ -146,7 +146,7 @@ public class ProgressProtocolDecoder extends BaseProtocolDecoder {
                 }
 
                 if (BitUtil.check(extraFlags, 2)) {
-                    position.set("passenger", ByteBufUtil.hexDump(buf.readBytes(buf.readUnsignedShortLE())));
+                    position.set("passenger", ByteBufUtil.hexDump(buf.readSlice(buf.readUnsignedShortLE())));
                 }
 
                 if (type == MSG_ALARM) {
diff --git a/src/org/traccar/protocol/Pt502FrameDecoder.java b/src/org/traccar/protocol/Pt502FrameDecoder.java
index 9c7989446..316cd987f 100644
--- a/src/org/traccar/protocol/Pt502FrameDecoder.java
+++ b/src/org/traccar/protocol/Pt502FrameDecoder.java
@@ -40,7 +40,7 @@ public class Pt502FrameDecoder extends BaseFrameDecoder {
             int length = buf.getUnsignedShortLE(buf.readerIndex() + 3);
             if (buf.readableBytes() >= length) {
                 buf.skipBytes(BINARY_HEADER);
-                ByteBuf result = buf.readBytes(length - BINARY_HEADER - 2);
+                ByteBuf result = buf.readRetainedSlice(length - BINARY_HEADER - 2);
                 buf.skipBytes(2); // line break
                 return result;
             }
@@ -57,7 +57,7 @@ public class Pt502FrameDecoder extends BaseFrameDecoder {
             }
 
             if (index > 0) {
-                ByteBuf result = buf.readBytes(index - buf.readerIndex());
+                ByteBuf result = buf.readRetainedSlice(index - buf.readerIndex());
                 while (buf.isReadable()
                         && (buf.getByte(buf.readerIndex()) == '\r' || buf.getByte(buf.readerIndex()) == '\n')) {
                     buf.skipBytes(1);
diff --git a/src/org/traccar/protocol/Pt502ProtocolDecoder.java b/src/org/traccar/protocol/Pt502ProtocolDecoder.java
index 05d498cb4..4d218653b 100644
--- a/src/org/traccar/protocol/Pt502ProtocolDecoder.java
+++ b/src/org/traccar/protocol/Pt502ProtocolDecoder.java
@@ -165,7 +165,7 @@ public class Pt502ProtocolDecoder extends BaseProtocolDecoder {
 

             if (photo != null) {

 

-                photo.writeBytes(buf.readBytes(buf.readableBytes()));

+                photo.writeBytes(buf.readSlice(buf.readableBytes()));

 

                 if (photo.writableBytes() > 0) {

 

diff --git a/src/org/traccar/protocol/RecodaProtocolDecoder.java b/src/org/traccar/protocol/RecodaProtocolDecoder.java
index c948ff1b7..eef1cb5af 100644
--- a/src/org/traccar/protocol/RecodaProtocolDecoder.java
+++ b/src/org/traccar/protocol/RecodaProtocolDecoder.java
@@ -55,7 +55,7 @@ public class RecodaProtocolDecoder extends BaseProtocolDecoder {
 
         if (type == MSG_SIGNAL_LINK_REGISTRATION) {
 
-            getDeviceSession(channel, remoteAddress, buf.readBytes(12).toString(StandardCharsets.US_ASCII));
+            getDeviceSession(channel, remoteAddress, buf.readSlice(12).toString(StandardCharsets.US_ASCII));
 
         } else if (type == MSG_GPS_DATA) {
 
diff --git a/src/org/traccar/protocol/RoboTrackFrameDecoder.java b/src/org/traccar/protocol/RoboTrackFrameDecoder.java
index 297e221d6..aecbaaa3b 100644
--- a/src/org/traccar/protocol/RoboTrackFrameDecoder.java
+++ b/src/org/traccar/protocol/RoboTrackFrameDecoder.java
@@ -48,7 +48,7 @@ public class RoboTrackFrameDecoder extends BaseFrameDecoder {
         int length = messageLength(buf);
 
         if (buf.readableBytes() >= length) {
-            return buf.readBytes(length);
+            return buf.readRetainedSlice(length);
         }
 
         return null;
diff --git a/src/org/traccar/protocol/RoboTrackProtocolDecoder.java b/src/org/traccar/protocol/RoboTrackProtocolDecoder.java
index caf3d28d5..26d6bc4ff 100644
--- a/src/org/traccar/protocol/RoboTrackProtocolDecoder.java
+++ b/src/org/traccar/protocol/RoboTrackProtocolDecoder.java
@@ -57,7 +57,7 @@ public class RoboTrackProtocolDecoder extends BaseProtocolDecoder {
 
             buf.skipBytes(16); // name
 
-            String imei = buf.readBytes(15).toString(StandardCharsets.US_ASCII);
+            String imei = buf.readSlice(15).toString(StandardCharsets.US_ASCII);
 
             if (getDeviceSession(channel, remoteAddress, imei) != null && channel != null) {
                 ByteBuf response = Unpooled.buffer(0);
diff --git a/src/org/traccar/protocol/RuptelaProtocolDecoder.java b/src/org/traccar/protocol/RuptelaProtocolDecoder.java
index 2df0b6e25..e5d196fed 100644
--- a/src/org/traccar/protocol/RuptelaProtocolDecoder.java
+++ b/src/org/traccar/protocol/RuptelaProtocolDecoder.java
@@ -225,7 +225,7 @@ public class RuptelaProtocolDecoder extends BaseProtocolDecoder {
                     position.set(Position.KEY_ARCHIVE, true);
                 }
 
-                position.set(Position.KEY_DTCS, buf.readBytes(5).toString(StandardCharsets.US_ASCII));
+                position.set(Position.KEY_DTCS, buf.readSlice(5).toString(StandardCharsets.US_ASCII));
 
                 positions.add(position);
             }
diff --git a/src/org/traccar/protocol/SabertekFrameDecoder.java b/src/org/traccar/protocol/SabertekFrameDecoder.java
index 35dcd8928..771ef9cfb 100644
--- a/src/org/traccar/protocol/SabertekFrameDecoder.java
+++ b/src/org/traccar/protocol/SabertekFrameDecoder.java
@@ -31,7 +31,7 @@ public class SabertekFrameDecoder extends BaseFrameDecoder {
             int endIndex = buf.indexOf(buf.readerIndex(), buf.writerIndex(), (byte) 0x03);
             if (beginIndex >= 0) {
                 buf.readerIndex(beginIndex + 1);
-                ByteBuf frame = buf.readBytes(endIndex - beginIndex - 1);
+                ByteBuf frame = buf.readRetainedSlice(endIndex - beginIndex - 1);
                 buf.readerIndex(endIndex + 1);
                 buf.skipBytes(2); // end line
                 return frame;
diff --git a/src/org/traccar/protocol/SmokeyProtocolDecoder.java b/src/org/traccar/protocol/SmokeyProtocolDecoder.java
index 2fd90a4ff..825108ed2 100644
--- a/src/org/traccar/protocol/SmokeyProtocolDecoder.java
+++ b/src/org/traccar/protocol/SmokeyProtocolDecoder.java
@@ -78,7 +78,7 @@ public class SmokeyProtocolDecoder extends BaseProtocolDecoder {
 
         int type = buf.readUnsignedByte();
 
-        ByteBuf id = buf.readBytes(8);
+        ByteBuf id = buf.readSlice(8);
         DeviceSession deviceSession = getDeviceSession(channel, remoteAddress, ByteBufUtil.hexDump(id));
         if (deviceSession == null) {
             return null;
diff --git a/src/org/traccar/protocol/Stl060FrameDecoder.java b/src/org/traccar/protocol/Stl060FrameDecoder.java
index 831360ec2..f72474e2b 100644
--- a/src/org/traccar/protocol/Stl060FrameDecoder.java
+++ b/src/org/traccar/protocol/Stl060FrameDecoder.java
@@ -37,7 +37,7 @@ public class Stl060FrameDecoder extends CharacterDelimiterFrameDecoder {
                 return result;
             } else {
                 result.skipBytes(index);
-                return result.readBytes(result.readableBytes());
+                return result.readRetainedSlice(result.readableBytes());
             }
 
         }
diff --git a/src/org/traccar/protocol/T57FrameDecoder.java b/src/org/traccar/protocol/T57FrameDecoder.java
index 844043088..14ba31453 100644
--- a/src/org/traccar/protocol/T57FrameDecoder.java
+++ b/src/org/traccar/protocol/T57FrameDecoder.java
@@ -43,7 +43,7 @@ public class T57FrameDecoder extends BaseFrameDecoder {
             }
         }
 
-        return index > 0 ? buf.readBytes(index + 1 - buf.readerIndex()) : null;
+        return index > 0 ? buf.readRetainedSlice(index + 1 - buf.readerIndex()) : null;
     }
 
 }
diff --git a/src/org/traccar/protocol/T800xProtocolDecoder.java b/src/org/traccar/protocol/T800xProtocolDecoder.java
index d91fe9d42..d5504c190 100644
--- a/src/org/traccar/protocol/T800xProtocolDecoder.java
+++ b/src/org/traccar/protocol/T800xProtocolDecoder.java
@@ -85,7 +85,7 @@ public class T800xProtocolDecoder extends BaseProtocolDecoder {
         int type = buf.readUnsignedByte();
         buf.readUnsignedShort(); // length
         int index = buf.readUnsignedShort();
-        ByteBuf imei = buf.readBytes(8);
+        ByteBuf imei = buf.readSlice(8);
 
         DeviceSession deviceSession = getDeviceSession(
                 channel, remoteAddress, ByteBufUtil.hexDump(imei).substring(1));
diff --git a/src/org/traccar/protocol/TelicFrameDecoder.java b/src/org/traccar/protocol/TelicFrameDecoder.java
index b99ef98bf..d1fef1b5b 100644
--- a/src/org/traccar/protocol/TelicFrameDecoder.java
+++ b/src/org/traccar/protocol/TelicFrameDecoder.java
@@ -36,12 +36,12 @@ public class TelicFrameDecoder extends BaseFrameDecoder {
         if (length < 1024) {
             if (buf.readableBytes() >= length + 4) {
                 buf.readUnsignedIntLE();
-                return buf.readBytes((int) length);
+                return buf.readRetainedSlice((int) length);
             }
         } else {
             int endIndex = buf.indexOf(buf.readerIndex(), buf.writerIndex(), (byte) 0);
             if (endIndex >= 0) {
-                ByteBuf frame = buf.readBytes(endIndex - buf.readerIndex());
+                ByteBuf frame = buf.readRetainedSlice(endIndex - buf.readerIndex());
                 buf.readByte();
                 if (frame.readableBytes() > 0) {
                     return frame;
diff --git a/src/org/traccar/protocol/TeltonikaFrameDecoder.java b/src/org/traccar/protocol/TeltonikaFrameDecoder.java
index 17c6264e0..4d4d79d8d 100644
--- a/src/org/traccar/protocol/TeltonikaFrameDecoder.java
+++ b/src/org/traccar/protocol/TeltonikaFrameDecoder.java
@@ -38,12 +38,12 @@ public class TeltonikaFrameDecoder extends BaseFrameDecoder {
         int length = buf.getUnsignedShort(buf.readerIndex());
         if (length > 0) {
             if (buf.readableBytes() >= (length + 2)) {
-                return buf.readBytes(length + 2);
+                return buf.readRetainedSlice(length + 2);
             }
         } else {
             int dataLength = buf.getInt(buf.readerIndex() + 4);
             if (buf.readableBytes() >= (dataLength + 12)) {
-                return buf.readBytes(dataLength + 12);
+                return buf.readRetainedSlice(dataLength + 12);
             }
         }
 
diff --git a/src/org/traccar/protocol/TeltonikaProtocolDecoder.java b/src/org/traccar/protocol/TeltonikaProtocolDecoder.java
index 34afe28ad..5e9b6640e 100644
--- a/src/org/traccar/protocol/TeltonikaProtocolDecoder.java
+++ b/src/org/traccar/protocol/TeltonikaProtocolDecoder.java
@@ -79,7 +79,7 @@ public class TeltonikaProtocolDecoder extends BaseProtocolDecoder {
 
         position.set(Position.KEY_TYPE, buf.readUnsignedByte());
 
-        position.set(Position.KEY_RESULT, buf.readBytes(buf.readInt()).toString(StandardCharsets.US_ASCII));
+        position.set(Position.KEY_RESULT, buf.readSlice(buf.readInt()).toString(StandardCharsets.US_ASCII));
 
     }
 
@@ -151,7 +151,7 @@ public class TeltonikaProtocolDecoder extends BaseProtocolDecoder {
             case 134:
                 String driver = id == 129 || id == 132 ? "" : position.getString("driver1");
                 position.set("driver" + (id >= 132 ? 2 : 1),
-                        driver + buf.readBytes(length).toString(StandardCharsets.US_ASCII).trim());
+                        driver + buf.readSlice(length).toString(StandardCharsets.US_ASCII).trim());
                 break;
             case 179:
                 position.set(Position.PREFIX_OUT + 1, readValue(buf, length, false) == 1);
@@ -394,7 +394,7 @@ public class TeltonikaProtocolDecoder extends BaseProtocolDecoder {
         if (extended) {
             int cnt = buf.readUnsignedByte();
             for (int j = 0; j < cnt; j++) {
-                position.set(Position.PREFIX_IO + buf.readUnsignedByte(), ByteBufUtil.hexDump(buf.readBytes(16)));
+                position.set(Position.PREFIX_IO + buf.readUnsignedByte(), ByteBufUtil.hexDump(buf.readSlice(16)));
             }
         }
 
@@ -482,7 +482,7 @@ public class TeltonikaProtocolDecoder extends BaseProtocolDecoder {
         buf.readUnsignedShort(); // packet id
         buf.readUnsignedByte(); // packet type
         int locationPacketId = buf.readUnsignedByte();
-        String imei = buf.readBytes(buf.readUnsignedShort()).toString(StandardCharsets.US_ASCII);
+        String imei = buf.readSlice(buf.readUnsignedShort()).toString(StandardCharsets.US_ASCII);
 
         return parseData(channel, remoteAddress, buf, locationPacketId, imei);
 
diff --git a/src/org/traccar/protocol/ThinkRaceProtocolDecoder.java b/src/org/traccar/protocol/ThinkRaceProtocolDecoder.java
index dd1f34254..451f1c448 100644
--- a/src/org/traccar/protocol/ThinkRaceProtocolDecoder.java
+++ b/src/org/traccar/protocol/ThinkRaceProtocolDecoder.java
@@ -56,7 +56,7 @@ public class ThinkRaceProtocolDecoder extends BaseProtocolDecoder {
         ByteBuf buf = (ByteBuf) msg;
 
         buf.skipBytes(2); // header
-        ByteBuf id = buf.readBytes(12);
+        ByteBuf id = buf.readSlice(12);
         buf.readUnsignedByte(); // separator
         int type = buf.readUnsignedByte();
         buf.readUnsignedShort(); // length
diff --git a/src/org/traccar/protocol/Tk102ProtocolDecoder.java b/src/org/traccar/protocol/Tk102ProtocolDecoder.java
index 1419000be..5bbbddbef 100644
--- a/src/org/traccar/protocol/Tk102ProtocolDecoder.java
+++ b/src/org/traccar/protocol/Tk102ProtocolDecoder.java
@@ -81,12 +81,12 @@ public class Tk102ProtocolDecoder extends BaseProtocolDecoder {
 
         buf.skipBytes(1); // header
         int type = buf.readUnsignedByte();
-        ByteBuf dataSequence = buf.readBytes(10);
+        ByteBuf dataSequence = buf.readSlice(10);
         int length = buf.readUnsignedByte();
 
         if (type == MSG_LOGIN_REQUEST || type == MSG_LOGIN_REQUEST_2) {
 
-            ByteBuf data = buf.readBytes(length);
+            ByteBuf data = buf.readSlice(length);
 
             String id;
             if (type == MSG_LOGIN_REQUEST) {
@@ -104,7 +104,7 @@ public class Tk102ProtocolDecoder extends BaseProtocolDecoder {
 
         } else if (type == MSG_HEARTBEAT_REQUEST) {
 
-            sendResponse(channel, MSG_HEARTBEAT_RESPONSE, dataSequence, buf.readBytes(length));
+            sendResponse(channel, MSG_HEARTBEAT_RESPONSE, dataSequence, buf.readSlice(length));
 
         } else {
 
@@ -113,7 +113,7 @@ public class Tk102ProtocolDecoder extends BaseProtocolDecoder {
                 return null;
             }
 
-            Parser parser = new Parser(PATTERN, buf.readBytes(length).toString(StandardCharsets.US_ASCII));
+            Parser parser = new Parser(PATTERN, buf.readSlice(length).toString(StandardCharsets.US_ASCII));
             if (!parser.matches()) {
                 return null;
             }
diff --git a/src/org/traccar/protocol/Tk103FrameDecoder.java b/src/org/traccar/protocol/Tk103FrameDecoder.java
index 3ad1cd2c9..b61a42563 100644
--- a/src/org/traccar/protocol/Tk103FrameDecoder.java
+++ b/src/org/traccar/protocol/Tk103FrameDecoder.java
@@ -69,7 +69,7 @@ public class Tk103FrameDecoder extends BaseFrameDecoder {
 
         buf.readerIndex(frameStartIndex);
 
-        return buf.readBytes(frameEndIndex + 1 - frameStartIndex);
+        return buf.readRetainedSlice(frameEndIndex + 1 - frameStartIndex);
     }
 
 }
diff --git a/src/org/traccar/protocol/TlvProtocolDecoder.java b/src/org/traccar/protocol/TlvProtocolDecoder.java
index ae1a3346a..b682345db 100644
--- a/src/org/traccar/protocol/TlvProtocolDecoder.java
+++ b/src/org/traccar/protocol/TlvProtocolDecoder.java
@@ -48,7 +48,7 @@ public class TlvProtocolDecoder extends BaseProtocolDecoder {
     }
 
     private String readArgument(ByteBuf buf) {
-        return buf.readBytes(buf.readUnsignedByte()).toString(StandardCharsets.US_ASCII);
+        return buf.readSlice(buf.readUnsignedByte()).toString(StandardCharsets.US_ASCII);
     }
 
     @Override
@@ -57,7 +57,7 @@ public class TlvProtocolDecoder extends BaseProtocolDecoder {
 
         ByteBuf buf = (ByteBuf) msg;
 
-        String type = buf.readBytes(2).toString(StandardCharsets.US_ASCII);
+        String type = buf.readSlice(2).toString(StandardCharsets.US_ASCII);
 
         if (channel != null) {
             switch (type) {
diff --git a/src/org/traccar/protocol/TmgFrameDecoder.java b/src/org/traccar/protocol/TmgFrameDecoder.java
index a2039ff52..205adaa51 100644
--- a/src/org/traccar/protocol/TmgFrameDecoder.java
+++ b/src/org/traccar/protocol/TmgFrameDecoder.java
@@ -54,7 +54,7 @@ public class TmgFrameDecoder extends BaseFrameDecoder {
             int endIndex = buf.indexOf(beginIndex, buf.writerIndex(), (byte) '\n');
 
             if (endIndex >= 0) {
-                ByteBuf frame = buf.readBytes(endIndex - beginIndex);
+                ByteBuf frame = buf.readRetainedSlice(endIndex - beginIndex);
                 buf.readByte(); // delimiter
                 return frame;
             }
diff --git a/src/org/traccar/protocol/TotemFrameDecoder.java b/src/org/traccar/protocol/TotemFrameDecoder.java
index a7e134c09..3fa5abc7a 100644
--- a/src/org/traccar/protocol/TotemFrameDecoder.java
+++ b/src/org/traccar/protocol/TotemFrameDecoder.java
@@ -50,7 +50,7 @@ public class TotemFrameDecoder extends BaseFrameDecoder {
         }
 
         if (length <= buf.readableBytes()) {
-            return buf.readBytes(length);
+            return buf.readRetainedSlice(length);
         }
 
         return null;
diff --git a/src/org/traccar/protocol/TramigoFrameDecoder.java b/src/org/traccar/protocol/TramigoFrameDecoder.java
index 6c7e639ac..fae9efecf 100644
--- a/src/org/traccar/protocol/TramigoFrameDecoder.java
+++ b/src/org/traccar/protocol/TramigoFrameDecoder.java
@@ -37,7 +37,7 @@ public class TramigoFrameDecoder extends BaseFrameDecoder {
         }
 
         if (length >= buf.readableBytes()) {
-            return buf.readBytes(length);
+            return buf.readRetainedSlice(length);
         }
 
         return null;
diff --git a/src/org/traccar/protocol/TytanProtocolDecoder.java b/src/org/traccar/protocol/TytanProtocolDecoder.java
index 221df6081..ac94e5ca7 100644
--- a/src/org/traccar/protocol/TytanProtocolDecoder.java
+++ b/src/org/traccar/protocol/TytanProtocolDecoder.java
@@ -75,10 +75,10 @@ public class TytanProtocolDecoder extends BaseProtocolDecoder {
                     position.set("antihijack", buf.readUnsignedByte());
                     break;
                 case 9:
-                    position.set("unauthorized", ByteBufUtil.hexDump(buf.readBytes(8)));
+                    position.set("unauthorized", ByteBufUtil.hexDump(buf.readSlice(8)));
                     break;
                 case 10:
-                    position.set("authorized", ByteBufUtil.hexDump(buf.readBytes(8)));
+                    position.set("authorized", ByteBufUtil.hexDump(buf.readSlice(8)));
                     break;
                 case 24:
                     for (int i = 0; i < length / 2; i++) {
diff --git a/src/org/traccar/protocol/TzoneProtocolDecoder.java b/src/org/traccar/protocol/TzoneProtocolDecoder.java
index 4983410a5..6f6ff3878 100644
--- a/src/org/traccar/protocol/TzoneProtocolDecoder.java
+++ b/src/org/traccar/protocol/TzoneProtocolDecoder.java
@@ -77,7 +77,7 @@ public class TzoneProtocolDecoder extends BaseProtocolDecoder {
                         length += 1;
                     }
 
-                    String num = ByteBufUtil.hexDump(buf.readBytes(length / 2));
+                    String num = ByteBufUtil.hexDump(buf.readSlice(length / 2));
 
                     if (odd) {
                         num = num.substring(1);
@@ -122,7 +122,7 @@ public class TzoneProtocolDecoder extends BaseProtocolDecoder {
         int hardware = buf.readUnsignedShort();
         long firmware = buf.readUnsignedInt();
 
-        String imei = ByteBufUtil.hexDump(buf.readBytes(8)).substring(1);
+        String imei = ByteBufUtil.hexDump(buf.readSlice(8)).substring(1);
         DeviceSession deviceSession = getDeviceSession(channel, remoteAddress, imei);
         if (deviceSession == null) {
             return null;
diff --git a/src/org/traccar/protocol/UlbotechFrameDecoder.java b/src/org/traccar/protocol/UlbotechFrameDecoder.java
index 963b0e2ab..f141dc9b7 100644
--- a/src/org/traccar/protocol/UlbotechFrameDecoder.java
+++ b/src/org/traccar/protocol/UlbotechFrameDecoder.java
@@ -59,7 +59,7 @@ public class UlbotechFrameDecoder extends BaseFrameDecoder {
 
             int index = buf.indexOf(buf.readerIndex(), buf.writerIndex(), (byte) '#');
             if (index != -1) {
-                return buf.readBytes(index + 1 - buf.readerIndex());
+                return buf.readRetainedSlice(index + 1 - buf.readerIndex());
             }
 
         }
diff --git a/src/org/traccar/protocol/UlbotechProtocolDecoder.java b/src/org/traccar/protocol/UlbotechProtocolDecoder.java
index 0c3ea6391..ed4695a44 100644
--- a/src/org/traccar/protocol/UlbotechProtocolDecoder.java
+++ b/src/org/traccar/protocol/UlbotechProtocolDecoder.java
@@ -67,7 +67,7 @@ public class UlbotechProtocolDecoder extends BaseProtocolDecoder {
         while (buf.readerIndex() < end) {
             int parameterLength = buf.getUnsignedByte(buf.readerIndex()) >> 4;
             int mode = buf.readUnsignedByte() & 0x0F;
-            position.add(ObdDecoder.decode(mode, ByteBufUtil.hexDump(buf.readBytes(parameterLength - 1))));
+            position.add(ObdDecoder.decode(mode, ByteBufUtil.hexDump(buf.readSlice(parameterLength - 1))));
         }
     }
 
@@ -83,7 +83,7 @@ public class UlbotechProtocolDecoder extends BaseProtocolDecoder {
             if (type == 3) {
                 id += 256;
             }
-            String value = ByteBufUtil.hexDump(buf.readBytes(len - 1));
+            String value = ByteBufUtil.hexDump(buf.readSlice(len - 1));
             if (type == 2 || type == 3) {
                 position.set("pid" + id, value);
             }
@@ -206,7 +206,7 @@ public class UlbotechProtocolDecoder extends BaseProtocolDecoder {
         buf.readUnsignedByte(); // version
         buf.readUnsignedByte(); // type
 
-        String imei = ByteBufUtil.hexDump(buf.readBytes(8)).substring(1);
+        String imei = ByteBufUtil.hexDump(buf.readSlice(8)).substring(1);
 
         DeviceSession deviceSession = getDeviceSession(channel, remoteAddress, imei);
         if (deviceSession == null) {
@@ -296,7 +296,7 @@ public class UlbotechProtocolDecoder extends BaseProtocolDecoder {
                     break;
 
                 case DATA_CANBUS:
-                    position.set("can", ByteBufUtil.hexDump(buf.readBytes(length)));
+                    position.set("can", ByteBufUtil.hexDump(buf.readSlice(length)));
                     break;
 
                 case DATA_J1708:
@@ -304,12 +304,12 @@ public class UlbotechProtocolDecoder extends BaseProtocolDecoder {
                     break;
 
                 case DATA_VIN:
-                    position.set(Position.KEY_VIN, buf.readBytes(length).toString(StandardCharsets.US_ASCII));
+                    position.set(Position.KEY_VIN, buf.readSlice(length).toString(StandardCharsets.US_ASCII));
                     break;
 
                 case DATA_RFID:
                     position.set(Position.KEY_DRIVER_UNIQUE_ID,
-                            buf.readBytes(length - 1).toString(StandardCharsets.US_ASCII));
+                            buf.readSlice(length - 1).toString(StandardCharsets.US_ASCII));
                     position.set("authorized", buf.readUnsignedByte() != 0);
                     break;
 
diff --git a/src/org/traccar/protocol/UproProtocolDecoder.java b/src/org/traccar/protocol/UproProtocolDecoder.java
index 4e09d544a..1c2944a6c 100644
--- a/src/org/traccar/protocol/UproProtocolDecoder.java
+++ b/src/org/traccar/protocol/UproProtocolDecoder.java
@@ -103,7 +103,7 @@ public class UproProtocolDecoder extends BaseProtocolDecoder {
         if (headerIndex < 0) {
             headerIndex = buf.writerIndex();
         }
-        String header = buf.readBytes(headerIndex - buf.readerIndex()).toString(StandardCharsets.US_ASCII);
+        String header = buf.readSlice(headerIndex - buf.readerIndex()).toString(StandardCharsets.US_ASCII);
 
         Parser parser = new Parser(PATTERN_HEADER, header);
         if (!parser.matches()) {
@@ -138,7 +138,7 @@ public class UproProtocolDecoder extends BaseProtocolDecoder {
                 delimiterIndex = buf.writerIndex();
             }
 
-            ByteBuf data = buf.readBytes(delimiterIndex - buf.readerIndex());
+            ByteBuf data = buf.readSlice(delimiterIndex - buf.readerIndex());
 
             switch (dataType) {
                 case 'A':
@@ -157,10 +157,10 @@ public class UproProtocolDecoder extends BaseProtocolDecoder {
                     break;
                 case 'P':
                     position.setNetwork(new Network(CellTower.from(
-                            Integer.parseInt(data.readBytes(4).toString(StandardCharsets.US_ASCII)),
-                            Integer.parseInt(data.readBytes(4).toString(StandardCharsets.US_ASCII)),
-                            Integer.parseInt(data.readBytes(4).toString(StandardCharsets.US_ASCII), 16),
-                            Integer.parseInt(data.readBytes(4).toString(StandardCharsets.US_ASCII), 16))));
+                            Integer.parseInt(data.readSlice(4).toString(StandardCharsets.US_ASCII)),
+                            Integer.parseInt(data.readSlice(4).toString(StandardCharsets.US_ASCII)),
+                            Integer.parseInt(data.readSlice(4).toString(StandardCharsets.US_ASCII), 16),
+                            Integer.parseInt(data.readSlice(4).toString(StandardCharsets.US_ASCII), 16))));
                     break;
                 case 'Q':
                     position.set("obd-pid", ByteBufUtil.hexDump(data));
diff --git a/src/org/traccar/protocol/Vt200ProtocolDecoder.java b/src/org/traccar/protocol/Vt200ProtocolDecoder.java
index d0ee32c5d..d5035bd5c 100644
--- a/src/org/traccar/protocol/Vt200ProtocolDecoder.java
+++ b/src/org/traccar/protocol/Vt200ProtocolDecoder.java
@@ -57,7 +57,7 @@ public class Vt200ProtocolDecoder extends BaseProtocolDecoder {
 
         buf.skipBytes(1); // header
 
-        String id = ByteBufUtil.hexDump(buf.readBytes(6));
+        String id = ByteBufUtil.hexDump(buf.readSlice(6));
         DeviceSession deviceSession = getDeviceSession(channel, remoteAddress, id);
         if (deviceSession == null) {
             return null;
diff --git a/src/org/traccar/protocol/VtfmsFrameDecoder.java b/src/org/traccar/protocol/VtfmsFrameDecoder.java
index 98072711f..62a189960 100644
--- a/src/org/traccar/protocol/VtfmsFrameDecoder.java
+++ b/src/org/traccar/protocol/VtfmsFrameDecoder.java
@@ -31,7 +31,7 @@ public class VtfmsFrameDecoder extends BaseFrameDecoder {
         if (endIndex > 0) {
             endIndex += 1 + 3;
             if (buf.writerIndex() >= endIndex) {
-                return buf.readBytes(endIndex - buf.readerIndex());
+                return buf.readRetainedSlice(endIndex - buf.readerIndex());
             }
         }
 
diff --git a/src/org/traccar/protocol/WatchProtocolDecoder.java b/src/org/traccar/protocol/WatchProtocolDecoder.java
index 04da066c5..4e5d8c377 100644
--- a/src/org/traccar/protocol/WatchProtocolDecoder.java
+++ b/src/org/traccar/protocol/WatchProtocolDecoder.java
@@ -180,11 +180,11 @@ public class WatchProtocolDecoder extends BaseProtocolDecoder {
         ByteBuf buf = (ByteBuf) msg;
 
         buf.skipBytes(1); // header
-        manufacturer = buf.readBytes(2).toString(StandardCharsets.US_ASCII);
+        manufacturer = buf.readSlice(2).toString(StandardCharsets.US_ASCII);
         buf.skipBytes(1); // delimiter
 
         int idIndex = buf.indexOf(buf.readerIndex(), buf.writerIndex(), (byte) '*');
-        String id = buf.readBytes(idIndex - buf.readerIndex()).toString(StandardCharsets.US_ASCII);
+        String id = buf.readSlice(idIndex - buf.readerIndex()).toString(StandardCharsets.US_ASCII);
         DeviceSession deviceSession = getDeviceSession(channel, remoteAddress, id);
         if (deviceSession == null) {
             return null;
@@ -198,7 +198,7 @@ public class WatchProtocolDecoder extends BaseProtocolDecoder {
                 && buf.toString(contentIndex + 1, 4, StandardCharsets.US_ASCII).matches("\\p{XDigit}+")) {
             int indexLength = buf.indexOf(buf.readerIndex(), buf.writerIndex(), (byte) '*') - buf.readerIndex();
             hasIndex = true;
-            index = buf.readBytes(indexLength).toString(StandardCharsets.US_ASCII);
+            index = buf.readSlice(indexLength).toString(StandardCharsets.US_ASCII);
             buf.skipBytes(1); // delimiter
         }
 
@@ -212,7 +212,7 @@ public class WatchProtocolDecoder extends BaseProtocolDecoder {
             contentIndex = buf.writerIndex();
         }
 
-        String type = buf.readBytes(contentIndex - buf.readerIndex()).toString(StandardCharsets.US_ASCII);
+        String type = buf.readSlice(contentIndex - buf.readerIndex()).toString(StandardCharsets.US_ASCII);
 
         if (contentIndex < buf.writerIndex()) {
             buf.readerIndex(contentIndex + 1);
diff --git a/src/org/traccar/protocol/WondexFrameDecoder.java b/src/org/traccar/protocol/WondexFrameDecoder.java
index b09306b57..c223c87ff 100644
--- a/src/org/traccar/protocol/WondexFrameDecoder.java
+++ b/src/org/traccar/protocol/WondexFrameDecoder.java
@@ -38,7 +38,7 @@ public class WondexFrameDecoder extends BaseFrameDecoder {
         if (buf.getUnsignedByte(buf.readerIndex()) == 0xD0) {
 
             // Send response
-            ByteBuf frame = buf.readBytes(KEEP_ALIVE_LENGTH);
+            ByteBuf frame = buf.readRetainedSlice(KEEP_ALIVE_LENGTH);
             if (channel != null) {
                 channel.writeAndFlush(new NetworkMessage(frame, channel.remoteAddress()));
             }
@@ -48,7 +48,7 @@ public class WondexFrameDecoder extends BaseFrameDecoder {
 
             int index = BufferUtil.indexOf("\r\n", buf);
             if (index != -1) {
-                ByteBuf frame = buf.readBytes(index - buf.readerIndex());
+                ByteBuf frame = buf.readRetainedSlice(index - buf.readerIndex());
                 buf.skipBytes(2);
                 return frame;
             }
diff --git a/src/org/traccar/protocol/XexunFrameDecoder.java b/src/org/traccar/protocol/XexunFrameDecoder.java
index 15011ac7a..114e94061 100644
--- a/src/org/traccar/protocol/XexunFrameDecoder.java
+++ b/src/org/traccar/protocol/XexunFrameDecoder.java
@@ -52,7 +52,7 @@ public class XexunFrameDecoder extends BaseFrameDecoder {
 
         buf.skipBytes(beginIndex - buf.readerIndex());
 
-        return buf.readBytes(endIndex - beginIndex + 1);
+        return buf.readRetainedSlice(endIndex - beginIndex + 1);
     }
 
 }
diff --git a/src/org/traccar/protocol/Xt2400ProtocolDecoder.java b/src/org/traccar/protocol/Xt2400ProtocolDecoder.java
index 25395238c..a01a64b5b 100644
--- a/src/org/traccar/protocol/Xt2400ProtocolDecoder.java
+++ b/src/org/traccar/protocol/Xt2400ProtocolDecoder.java
@@ -174,10 +174,10 @@ public class Xt2400ProtocolDecoder extends BaseProtocolDecoder {
                     position.set(Position.KEY_OBD_SPEED, UnitsConverter.knotsFromKph(buf.readUnsignedShort()));
                     break;
                 case 0x65:
-                    position.set(Position.KEY_VIN, buf.readBytes(17).toString(StandardCharsets.US_ASCII));
+                    position.set(Position.KEY_VIN, buf.readSlice(17).toString(StandardCharsets.US_ASCII));
                     break;
                 case 0x73:
-                    position.set(Position.KEY_VERSION_FW, buf.readBytes(16).toString(StandardCharsets.US_ASCII).trim());
+                    position.set(Position.KEY_VERSION_FW, buf.readSlice(16).toString(StandardCharsets.US_ASCII).trim());
                     break;
                 default:
                     buf.skipBytes(getTagLength(tag));