1 /* Copyright (C) 2003 Vladimir Roubtsov. All rights reserved. 2 * 3 * This program and the accompanying materials are made available under 4 * the terms of the Common Public License v1.0 which accompanies this distribution, 5 * and is available at http://www.eclipse.org/legal/cpl-v10.html 6 * 7 * $Id: ByteArrayIStream.java,v 1.1.1.1 2004/05/09 16:57:51 vlad_r Exp $ 8 */ 9 package com.vladium.util; 10 11 import java.io.InputStream; 12 13 import com.vladium.util.asserts.$assert; 14 15 // ---------------------------------------------------------------------------- 16 /** 17 * An unsynchronized version of java.io.ByteArrayInputStream.<p> 18 * 19 * All argument validation is disabled in release mode.<p> 20 * 21 * @author (C) 2001, Vlad Roubtsov 22 */ 23 public 24 final class ByteArrayIStream extends InputStream 25 { 26 // public: ................................................................ 27 28 29 public ByteArrayIStream (final byte [] buf) 30 { 31 this (buf, buf.length); 32 } 33 34 public ByteArrayIStream (final byte [] buf, final int length) 35 { 36 if ($assert.ENABLED) $assert.ASSERT ((length >= 0) && (length <= buf.length), 37 "invalid length: " + length); 38 39 m_buf = buf; 40 m_max = length; 41 } 42 43 // InputStream: 44 45 public final int read () 46 { 47 if (m_pos >= m_max) 48 return -1; 49 else 50 return 0xFF & m_buf [m_pos ++]; 51 } 52 53 public final int read (final byte [] buf, final int offset, int length) 54 { 55 if ($assert.ENABLED) 56 $assert.ASSERT ((offset >= 0) && (offset <= buf.length) && 57 (length >= 0) && ((offset + length) <= buf.length), 58 "invalid input (" + buf.length + ", " + offset + ", " + length + ")"); 59 60 final int pos = m_pos; 61 final int max = m_max; 62 63 if (pos >= max) return -1; 64 if (pos + length > max) length = max - pos; 65 if (length <= 0) return 0; 66 67 final byte [] mbuf = m_buf; 68 69 if (length < NATIVE_COPY_THRESHOLD) 70 for (int i = 0; i < length; ++ i) buf [offset + i] = mbuf [pos + i]; 71 else 72 System.arraycopy (mbuf, pos, buf, offset, length); 73 74 m_pos += length; 75 76 return length; 77 } 78 79 public final int available () 80 { 81 return m_max - m_pos; 82 } 83 84 public final long skip (long n) 85 { 86 if (m_pos + n > m_max) n = m_max - m_pos; 87 88 if (n < 0) return 0; 89 m_pos += n; 90 91 return n; 92 } 93 94 /** 95 * Differs from the contruct for InputStream.reset() in that this method 96 * always resets the stream to the same it was immediately after creation. 97 */ 98 public final void reset () 99 { 100 m_pos = 0; 101 } 102 103 /** 104 * Equivalent to {@link #reset()}. 105 */ 106 public final void close () 107 { 108 reset (); 109 } 110 111 // protected: ............................................................. 112 113 // package: ............................................................... 114 115 // private: ............................................................... 116 117 118 private final byte [] m_buf; 119 private final int m_max; 120 private int m_pos; 121 122 private static final int NATIVE_COPY_THRESHOLD = 9; 123 124 } // end of class 125 // ----------------------------------------------------------------------------
