All Downloads are FREE. Search and download functionalities are using the official Maven repository.

com.ibm.icu.util.ByteArrayWrapper Maven / Gradle / Ivy

There is a newer version: 4.0.52
Show newest version
/**
 *******************************************************************************
 * Copyright (C) 1996-2016, International Business Machines Corporation and    *
 * others. All Rights Reserved.                                                *
 *******************************************************************************
 */

package com.ibm.icu.util;

import java.nio.ByteBuffer;

import com.ibm.icu.impl.Utility;

/**
 * A simple utility class to wrap a byte array.
 * 

* Generally passed as an argument object into a method. The method takes * responsibility of writing into the internal byte array and increasing its * size when necessary. * * @author syn wee * @stable ICU 2.8 */ public class ByteArrayWrapper implements Comparable { // public data member ------------------------------------------------ /** * Internal byte array. * @stable ICU 2.8 */ public byte[] bytes; /** * Size of the internal byte array used. * Different from bytes.length, size will be <= bytes.length. * Semantics of size is similar to java.util.Vector.size(). * @stable ICU 2.8 */ public int size; // public constructor ------------------------------------------------ /** * Construct a new ByteArrayWrapper with no data. * @stable ICU 2.8 */ public ByteArrayWrapper() { // leave bytes null, don't allocate twice } /** * Construct a new ByteArrayWrapper from a byte array and size * @param bytesToAdopt the byte array to adopt * @param size the length of valid data in the byte array * @throws IndexOutOfBoundsException if bytesToAdopt == null and size != 0, or * size < 0, or size > bytesToAdopt.length. * @stable ICU 3.2 */ public ByteArrayWrapper(byte[] bytesToAdopt, int size) { if ((bytesToAdopt == null && size != 0) || size < 0 || size > bytesToAdopt.length) { throw new IndexOutOfBoundsException("illegal size: " + size); } this.bytes = bytesToAdopt; this.size = size; } /** * Construct a new ByteArrayWrapper from the contents of a ByteBuffer. * @param source the ByteBuffer from which to get the data. * @stable ICU 3.2 */ public ByteArrayWrapper(ByteBuffer source) { size = source.limit(); bytes = new byte[size]; source.get(bytes,0,size); } /** * Create from ByteBuffer * @param byteBuffer public ByteArrayWrapper(ByteArrayWrapper source) { size = source.size; bytes = new byte[size]; copyBytes(source.bytes, 0, bytes, 0, size); } */ /** * create from byte buffer * @param src * @param start * @param limit public ByteArrayWrapper(byte[] src, int start, int limit) { size = limit - start; bytes = new byte[size]; copyBytes(src, start, bytes, 0, size); } */ // public methods ---------------------------------------------------- /** * Ensure that the internal byte array is at least of length capacity. * If the byte array is null or its length is less than capacity, a new * byte array of length capacity will be allocated. * The contents of the array (between 0 and size) remain unchanged. * @param capacity minimum length of internal byte array. * @return this ByteArrayWrapper * @stable ICU 3.2 */ public ByteArrayWrapper ensureCapacity(int capacity) { if (bytes == null || bytes.length < capacity) { byte[] newbytes = new byte[capacity]; copyBytes(bytes, 0, newbytes, 0, size); bytes = newbytes; } return this; } /** * Set the internal byte array from offset 0 to (limit - start) with the * contents of src from offset start to limit. If the byte array is null or its length is less than capacity, a new * byte array of length (limit - start) will be allocated. * This resets the size of the internal byte array to (limit - start). * @param src source byte array to copy from * @param start start offset of src to copy from * @param limit end + 1 offset of src to copy from * @return this ByteArrayWrapper * @stable ICU 3.2 */ public final ByteArrayWrapper set(byte[] src, int start, int limit) { size = 0; append(src, start, limit); return this; } /* public final ByteArrayWrapper get(byte[] target, int start, int limit) { int len = limit - start; if (len > size) throw new IllegalArgumentException("limit too long"); copyBytes(bytes, 0, target, start, len); return this; } */ /** * Appends the internal byte array from offset size with the * contents of src from offset start to limit. This increases the size of * the internal byte array to (size + limit - start). * @param src source byte array to copy from * @param start start offset of src to copy from * @param limit end + 1 offset of src to copy from * @return this ByteArrayWrapper * @stable ICU 3.2 */ public final ByteArrayWrapper append(byte[] src, int start, int limit) { int len = limit - start; ensureCapacity(size + len); copyBytes(src, start, bytes, size, len); size += len; return this; } /* public final ByteArrayWrapper append(ByteArrayWrapper other) { return append(other.bytes, 0, other.size); } */ /** * Releases the internal byte array to the caller, resets the internal * byte array to null and its size to 0. * @return internal byte array. * @stable ICU 2.8 */ public final byte[] releaseBytes() { byte result[] = bytes; bytes = null; size = 0; return result; } // Boilerplate ---------------------------------------------------- /** * Returns string value for debugging * @stable ICU 3.2 */ public String toString() { StringBuilder result = new StringBuilder(); for (int i = 0; i < size; ++i) { if (i != 0) result.append(" "); result.append(Utility.hex(bytes[i]&0xFF,2)); } return result.toString(); } /** * Return true if the bytes in each wrapper are equal. * @param other the object to compare to. * @return true if the two objects are equal. * @stable ICU 3.2 */ public boolean equals(Object other) { if (this == other) return true; if (other == null) return false; try { ByteArrayWrapper that = (ByteArrayWrapper)other; if (size != that.size) return false; for (int i = 0; i < size; ++i) { if (bytes[i] != that.bytes[i]) return false; } return true; } catch (ClassCastException e) { } return false; } /** * Return the hashcode. * @return the hashcode. * @stable ICU 3.2 */ public int hashCode() { int result = bytes.length; for (int i = 0; i < size; ++i) { result = 37*result + bytes[i]; } return result; } /** * Compare this object to another ByteArrayWrapper, which must not be null. * @param other the object to compare to. * @return a value <0, 0, or >0 as this compares less than, equal to, or * greater than other. * @throws ClassCastException if the other object is not a ByteArrayWrapper * @stable ICU 4.4 */ public int compareTo(ByteArrayWrapper other) { if (this == other) return 0; int minSize = size < other.size ? size : other.size; for (int i = 0; i < minSize; ++i) { if (bytes[i] != other.bytes[i]) { return (bytes[i] & 0xFF) - (other.bytes[i] & 0xFF); } } return size - other.size; } // private methods ----------------------------------------------------- /** * Copies the contents of src byte array from offset srcoff to the * target of tgt byte array at the offset tgtoff. * @param src source byte array to copy from * @param srcoff start offset of src to copy from * @param tgt target byte array to copy to * @param tgtoff start offset of tgt to copy to * @param length size of contents to copy */ private static final void copyBytes(byte[] src, int srcoff, byte[] tgt, int tgtoff, int length) { if (length < 64) { for (int i = srcoff, n = tgtoff; -- length >= 0; ++ i, ++ n) { tgt[n] = src[i]; } } else { System.arraycopy(src, srcoff, tgt, tgtoff, length); } } }





© 2015 - 2024 Weber Informatics LLC | Privacy Policy