| /* |
| * Copyright (c) 1997, 1999, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code 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 |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package sun.rmi.log; |
| |
| import java.io.*; |
| |
| public |
| class LogInputStream extends InputStream { |
| private InputStream in; |
| private int length; |
| |
| /** |
| * Creates a log input file with the specified system dependent |
| * file descriptor. |
| * @param fd the system dependent file descriptor |
| * @param length the total number of bytes allowed to be read |
| * @exception IOException If an I/O error has occurred. |
| */ |
| public LogInputStream(InputStream in, int length) throws IOException { |
| this.in = in; |
| this.length = length; |
| } |
| |
| /** |
| * Reads a byte of data. This method will block if no input is |
| * available. |
| * @return the byte read, or -1 if the end of the log or end of the |
| * stream is reached. |
| * @exception IOException If an I/O error has occurred. |
| */ |
| public int read() throws IOException { |
| if (length == 0) |
| return -1; |
| int c = in.read(); |
| length = (c != -1) ? length - 1 : 0; |
| return c; |
| } |
| |
| /** |
| * Reads data into an array of bytes. |
| * This method blocks until some input is available. |
| * @param b the buffer into which the data is read |
| * @return the actual number of bytes read, or -1 if the end of the log |
| * or end of the stream is reached. |
| * @exception IOException If an I/O error has occurred. |
| */ |
| public int read(byte b[]) throws IOException { |
| return read(b, 0, b.length); |
| } |
| |
| /** |
| * Reads data into an array of bytes. |
| * This method blocks until some input is available. |
| * @param b the buffer into which the data is read |
| * @param off the start offset of the data |
| * @param len the maximum number of bytes read |
| * @return the actual number of bytes read, or -1 if the end of the log or |
| * end of the stream is reached. |
| * @exception IOException If an I/O error has occurred. |
| */ |
| public int read(byte b[], int off, int len) throws IOException { |
| if (length == 0) |
| return -1; |
| len = (length < len) ? length : len; |
| int n = in.read(b, off, len); |
| length = (n != -1) ? length - n : 0; |
| return n; |
| } |
| |
| /** |
| * Skips n bytes of input. |
| * @param n the number of bytes to be skipped |
| * @return the actual number of bytes skipped. |
| * @exception IOException If an I/O error has occurred. |
| */ |
| public long skip(long n) throws IOException { |
| if (n > Integer.MAX_VALUE) |
| throw new IOException("Too many bytes to skip - " + n); |
| if (length == 0) |
| return 0; |
| n = (length < n) ? length : n; |
| n = in.skip(n); |
| length -= n; |
| return n; |
| } |
| |
| /** |
| * Returns the number of bytes that can be read without blocking. |
| * @return the number of available bytes, which is initially |
| * equal to the file size. |
| */ |
| public int available() throws IOException { |
| int avail = in.available(); |
| return (length < avail) ? length : avail; |
| } |
| |
| /** |
| * Closes the input stream. No further input can be read. |
| * the stream. |
| */ |
| public void close() { |
| length = 0; |
| } |
| |
| /** |
| * Closes the stream when garbage is collected. |
| */ |
| protected void finalize() throws IOException { |
| close(); |
| } |
| } |