From: Tom Tromey Date: Fri, 31 Aug 2001 05:58:46 +0000 (+0000) Subject: * java/io/ByteArrayInputStream.java: Merged with Classpath. X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=35ddff9f08028b857cd335bb176c150f3613d846;p=gcc.git * java/io/ByteArrayInputStream.java: Merged with Classpath. From-SVN: r45309 --- diff --git a/libjava/ChangeLog b/libjava/ChangeLog index 8ee275a8a9f..edfb3418d39 100644 --- a/libjava/ChangeLog +++ b/libjava/ChangeLog @@ -1,3 +1,7 @@ +2001-08-31 Tom Tromey + + * java/io/ByteArrayInputStream.java: Merged with Classpath. + 2001-08-30 Tom Tromey * java/io/BufferedReader.java: Re-merged with Classpath. diff --git a/libjava/java/io/ByteArrayInputStream.java b/libjava/java/io/ByteArrayInputStream.java index 0d9339363c1..f95e6533a6b 100644 --- a/libjava/java/io/ByteArrayInputStream.java +++ b/libjava/java/io/ByteArrayInputStream.java @@ -1,43 +1,103 @@ -/* Copyright (C) 1998, 1999 Free Software Foundation +/* ByteArrayInputStream.java -- Read an array as a stream + Copyright (C) 1998, 1999, 2001 Free Software Foundation, Inc. - This file is part of libgcj. +This file is part of GNU Classpath. -This software is copyrighted work licensed under the terms of the -Libgcj License. Please consult the file "LIBGCJ_LICENSE" for -details. */ +GNU Classpath is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2, or (at your option) +any later version. +GNU Classpath is distributed in the hope that it will be useful, but +WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +General Public License for more details. + +You should have received a copy of the GNU General Public License +along with GNU Classpath; see the file COPYING. If not, write to the +Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA +02111-1307 USA. + +As a special exception, if you link this library with other files to +produce an executable, this library does not by itself cause the +resulting executable to be covered by the GNU General Public License. +This exception does not however invalidate any other reasons why the +executable file might be covered by the GNU General Public License. */ + + package java.io; /** - * @author Warren Levy - * @date October 7, 1998. - */ - -/* Written using "Java Class Libraries", 2nd edition, ISBN 0-201-31002-3 - * "The Java Language Specification", ISBN 0-201-63451-1 - * plus online API docs for JDK 1.2 beta from http://www.javasoft.com. - * Status: Believed complete and correct - */ - + * This class permits an array of bytes to be read as an input stream. + * + * @author Warren Levy + * @author Aaron M. Renn (arenn@urbanophile.com) + */ public class ByteArrayInputStream extends InputStream { - /* An array of bytes provided by the creator of the stream. */ + /** + * The array that contains the data supplied during read operations + */ protected byte[] buf; - /* Position of the next byte in buf to be read. */ + /** + * The array index of the next byte to be read from the buffer + * buf + */ protected int pos; - /* The currently marked position in the stream. */ + /** + * The currently marked position in the stream. This defaults to 0, so a + * reset operation on the stream resets it to read from array index 0 in + * the buffer - even if the stream was initially created with an offset + * greater than 0 + */ protected int mark; - /* The index in buf one greater than the last valid character. */ + /** + * This indicates the maximum number of bytes that can be read from this + * stream. It is the array index of the position after the last valid + * byte in the buffer buf + */ protected int count; + /** + * Create a new ByteArrayInputStream that will read bytes from the passed + * in byte array. This stream will read from the beginning to the end + * of the array. It is identical to calling an overloaded constructor + * as ByteArrayInputStream(buf, 0, buf.length). + *

+ * Note that this array is not copied. If its contents are changed + * while this stream is being read, those changes will be reflected in the + * bytes supplied to the reader. Please use caution in changing the + * contents of the buffer while this stream is open. + * + * @param buf The byte array buffer this stream will read from. + */ public ByteArrayInputStream(byte[] buffer) { this(buffer, 0, buffer.length); } + /** + * Create a new ByteArrayInputStream that will read bytes from the + * passed in byte array. This stream will read from position + * offset in the array for a length of + * length bytes past offset. If the + * stream is reset to a position before offset then + * more than length bytes can be read from the stream. + * The length value should be viewed as the array index + * one greater than the last position in the buffer to read. + *

+ * Note that this array is not copied. If its contents are changed + * while this stream is being read, those changes will be reflected in the + * bytes supplied to the reader. Please use caution in changing the + * contents of the buffer while this stream is open. + * + * @param buf The byte array buffer this stream will read from. + * @param offset The index into the buffer to start reading bytes from + * @param length The number of bytes to read from the buffer + */ public ByteArrayInputStream(byte[] buffer, int offset, int length) { if (offset < 0 || length < 0 || offset > buffer.length) @@ -53,22 +113,60 @@ public class ByteArrayInputStream extends InputStream mark = pos; } + /** + * This method returns the number of bytes available to be read from this + * stream. The value returned will be equal to count - pos. + * + * @return The number of bytes that can be read from this stream + * before blocking, which is all of them + */ public synchronized int available() { return count - pos; } + /** + * This method sets the mark position in this stream to the current + * position. Note that the readlimit parameter in this + * method does nothing as this stream is always capable of + * remembering all the bytes int it. + *

+ * Note that in this class the mark position is set by default to + * position 0 in the stream. This is in constrast to some other + * stream types where there is no default mark position. + * + * @param readlimit The number of bytes this stream must remember. + * This parameter is ignored. + */ public synchronized void mark(int readAheadLimit) { // readAheadLimit is ignored per Java Class Lib. book, p.220. mark = pos; } + /** + * This method overrides the markSupported method in + * InputStream in order to return true - + * indicating that this stream class supports mark/reset + * functionality. + * + * @return true to indicate that this class supports + * mark/reset. + */ public boolean markSupported() { return true; } + /** + * This method reads one byte from the stream. The pos + * counter is advanced to the next byte to be read. The byte read is + * returned as an int in the range of 0-255. If the stream position + * is already at the end of the buffer, no byte is read and a -1 is + * returned in order to indicate the end of the stream. + * + * @return The byte read, or -1 if end of stream + */ public synchronized int read() { if (pos < count) @@ -76,6 +174,24 @@ public class ByteArrayInputStream extends InputStream return -1; } + /** + * This method reads bytes from the stream and stores them into a + * caller supplied buffer. It starts storing the data at index + * offset into the buffer and attempts to read + * len bytes. This method can return before reading + * the number of bytes requested if the end of the stream is + * encountered first. The actual number of bytes read is returned. + * If no bytes can be read because the stream is already at the end + * of stream position, a -1 is returned. + *

+ * This method does not block. + * + * @param buf The array into which the bytes read should be stored. + * @param offset The offset into the array to start storing bytes + * @param len The requested number of bytes to read + * + * @return The actual number of bytes read, or -1 if end of stream. + */ public synchronized int read(byte[] b, int off, int len) { if (pos >= count) @@ -87,11 +203,30 @@ public class ByteArrayInputStream extends InputStream return numBytes; } + /** + * This method sets the read position in the stream to the mark + * point by setting the pos variable equal to the + * mark variable. Since a mark can be set anywhere in + * the array, the mark/reset methods int this class can be used to + * provide random search capabilities for this type of stream. + */ public synchronized void reset() { pos = mark; } + /** + * This method attempts to skip the requested number of bytes in the + * input stream. It does this by advancing the pos + * value by the specified number of bytes. It this would exceed the + * length of the buffer, then only enough bytes are skipped to + * position the stream at the end of the buffer. The actual number + * of bytes skipped is returned. + * + * @param num_bytes The requested number of bytes to skip + * + * @return The actual number of bytes skipped. + */ public synchronized long skip(long n) { // Even though the var numBytes is a long, in reality it can never