pcep/impl/src/main/java/org/opendaylight/protocol/pcep/impl/PCEPMessageHeader.java

   1 /*
   2  * Copyright (c) 2013 Cisco Systems, Inc. and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8 package org.opendaylight.protocol.pcep.impl;
   9
  10 import java.util.Arrays;
  11
  12 import org.opendaylight.protocol.util.ByteArray;
  13 import org.slf4j.Logger;
  14 import org.slf4j.LoggerFactory;
  15
  16 import com.google.common.primitives.UnsignedBytes;
  17
  18 /**
  19  * Header parser for {@link org.opendaylight.protocol.pcep.PCEPMessage PCEPMessage}
  20  */
  21 public final class PCEPMessageHeader {
  22
  23         public static final Logger logger = LoggerFactory.getLogger(PCEPMessageHeader.class);
  24
  25         /*
  26          * lengths of fields in bytes
  27          */
  28         private static final int VER_FLAGS_MF_LENGTH = 1;
  29         private static final int TYPE_F_LENGTH = 1;
  30         private static final int LENGTH_F_LENGTH = 2;
  31
  32         /*
  33          * lengths of subfields inside multi-field in bits
  34          */
  35         private static final int VERSION_SF_LENGTH = 3;
  36
  37         /*
  38          * offsets of field in bytes
  39          */
  40         private static final int VER_FLAGS_MF_OFFSET = 0;
  41         private static final int TYPE_F_OFFSET = VER_FLAGS_MF_LENGTH + VER_FLAGS_MF_OFFSET;
  42         private static final int LENGTH_F_OFFSET = TYPE_F_LENGTH + TYPE_F_OFFSET;
  43
  44         /*
  45          * offsets of subfields inside multi-filed in bits
  46          */
  47
  48         private static final int VERSION_SF_OFFSET = 0;
  49
  50         /*
  51          * COMMON HEADER LENGTH
  52          */
  53         public static final int COMMON_HEADER_LENGTH = VER_FLAGS_MF_LENGTH + TYPE_F_LENGTH + LENGTH_F_LENGTH;
  54
  55         private final int type;
  56         private final int length;
  57         private final int version;
  58
  59         public PCEPMessageHeader(final int type, final int length, final int version) {
  60                 this.type = type;
  61                 this.length = length;
  62                 this.version = version;
  63         }
  64
  65         public static PCEPMessageHeader fromBytes(final byte[] bytes) {
  66                 if (bytes == null) {
  67                         throw new IllegalArgumentException("Array of bytes is mandatory");
  68                 }
  69
  70                 logger.trace("Attempt to parse message header: {}", ByteArray.bytesToHexString(bytes));
  71
  72                 if (bytes.length < COMMON_HEADER_LENGTH) {
  73                         throw new IllegalArgumentException("Too few bytes in passed array. Passed: " + bytes.length + "; Expected: >= " + COMMON_HEADER_LENGTH + ".");
  74                 }
  75
  76                 final int type = UnsignedBytes.toInt(bytes[TYPE_F_OFFSET]);
  77
  78                 final int length = ByteArray.bytesToInt(Arrays.copyOfRange(bytes,
  79                                 LENGTH_F_OFFSET, LENGTH_F_OFFSET + LENGTH_F_LENGTH));
  80
  81                 final int version = ByteArray.copyBitsRange(bytes[VER_FLAGS_MF_OFFSET], VERSION_SF_OFFSET, VERSION_SF_LENGTH);
  82
  83                 final PCEPMessageHeader ret = new PCEPMessageHeader(type, length, version);
  84
  85                 logger.trace("Message header was parsed. {}", ret);
  86                 return ret;
  87         }
  88
  89         public byte[] toBytes() {
  90                 final byte[] retBytes = new byte[COMMON_HEADER_LENGTH];
  91
  92                 // msgVer_Flag
  93                 retBytes[VER_FLAGS_MF_OFFSET] = (byte) (this.version << (Byte.SIZE - VERSION_SF_LENGTH));
  94
  95                 // msgType
  96                 retBytes[TYPE_F_OFFSET] = (byte) this.type;
  97
  98                 // msgLength
  99                 System.arraycopy(ByteArray.intToBytes(this.length), Integer.SIZE / Byte.SIZE - LENGTH_F_LENGTH, retBytes, LENGTH_F_OFFSET, LENGTH_F_LENGTH);
 100
 101                 return retBytes;
 102         }
 103
 104         public int getLength() {
 105                 return this.length;
 106         }
 107
 108         public int getVersion() {
 109                 return this.version;
 110         }
 111
 112         public int getType() {
 113                 return this.type;
 114         }
 115
 116         @Override
 117         public String toString() {
 118                 final StringBuilder builder = new StringBuilder();
 119                 builder.append("PCEPMessageHeader [type=");
 120                 builder.append(this.type);
 121                 builder.append(", length=");
 122                 builder.append(this.length);
 123                 builder.append(", version=");
 124                 builder.append(this.version);
 125                 builder.append("]");
 126                 return builder.toString();
 127         }
 128 }