001 /** 002 * 003 * Copyright 2004 Protique Ltd 004 * 005 * Licensed under the Apache License, Version 2.0 (the "License"); 006 * you may not use this file except in compliance with the License. 007 * You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 * 017 **/ 018 019 package org.activemq.io.util; 020 /** 021 * Compression stream 022 * 023 * @version $Revision: 1.1.1.1 $ 024 */ 025 public class ByteArrayFragmentation { 026 /** 027 * Data size above which fragmentation will be used 028 */ 029 public static final int DEFAULT_FRAGMENTATION_LIMIT = 64 * 1024; 030 private int fragmentationLimit = DEFAULT_FRAGMENTATION_LIMIT; 031 032 /** 033 * @return Returns the fragmentationLimit. 034 */ 035 public int getFragmentationLimit() { 036 return fragmentationLimit; 037 } 038 039 /** 040 * @param fragmentationLimit The fragmentationLimit to set. 041 */ 042 public void setFragmentationLimit(int fragmentationLimit) { 043 this.fragmentationLimit = fragmentationLimit; 044 } 045 046 /** 047 * @param ba 048 * @return true if fragmentation will be applied 049 */ 050 public boolean doFragmentation(ByteArray ba) { 051 return ba != null && ba.getLength() > fragmentationLimit; 052 } 053 054 /** 055 * Fragment a ByteArray into a number of parts 056 * 057 * @param ba 058 * @return 059 */ 060 public ByteArray[] fragment(ByteArray ba) { 061 ByteArray[] answer = null; 062 if (ba != null) { 063 if (doFragmentation(ba)) { 064 //find out how many parts 065 int bytesRemaining = ba.getLength(); 066 int numberOfParts = bytesRemaining / fragmentationLimit; 067 answer = new ByteArray[numberOfParts]; 068 int partLength = ba.getLength() / numberOfParts + 1; 069 byte[] buffer = ba.getBuf(); 070 int offset = ba.getOffset(); 071 int count = 0; 072 while (bytesRemaining > 0) { 073 answer[count] = new ByteArray(buffer, offset, partLength); 074 bytesRemaining -= partLength; 075 offset += partLength; 076 partLength = partLength < bytesRemaining ? partLength : bytesRemaining; 077 count++; 078 } 079 } 080 else { 081 answer = new ByteArray[]{ba}; 082 } 083 } 084 return answer; 085 } 086 087 /** 088 * Assemble a ByteArray from an array of fragements 089 * 090 * @param array 091 * @return 092 */ 093 public ByteArray assemble(ByteArray[] array) { 094 ByteArray answer = new ByteArray(); 095 if (array != null) { 096 //get the length to assemble; 097 int length = 0; 098 for (int i = 0;i < array.length;i++) { 099 length += array[i].getLength(); 100 } 101 byte[] data = new byte[length]; 102 int offset = 0; 103 for (int i = 0;i < array.length;i++) { 104 System.arraycopy(array[i].getBuf(), array[i].getOffset(), data, offset, array[i].getLength()); 105 offset += array[i].getLength(); 106 answer.reset(data); 107 } 108 } 109 return answer; 110 } 111 }