| /* |
| * Copyright (c) 1999, 2008, 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. |
| * |
| * 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 bench.serial; |
| |
| import java.io.InputStream; |
| import java.io.OutputStream; |
| import java.io.IOException; |
| |
| /** |
| * The StreamBuffer class provides a space that can be written to with an |
| * OutputStream and read from with an InputStream. It is similar to |
| * PipedInput/OutputStream except that it is unsynchronized and more |
| * lightweight. StreamBuffers are used inside of the serialization benchmarks |
| * in order to minimize the overhead incurred by reading and writing to/from the |
| * underlying stream (using ByteArrayInput/OutputStreams results in allocation |
| * of a new byte array with each cycle, while using PipedInput/OutputStreams |
| * involves threading and synchronization). |
| * <p> |
| * Writes/reads to and from a StreamBuffer must occur in distinct phases; reads |
| * from a StreamBuffer effectively close the StreamBuffer output stream. These |
| * semantics are necessary to avoid using wait/notify in |
| * StreamBufferInputStream.read(). |
| */ |
| public class StreamBuffer { |
| |
| /** |
| * Output stream for writing to stream buffer. |
| */ |
| private class StreamBufferOutputStream extends OutputStream { |
| |
| private int pos; |
| |
| public void write(int b) throws IOException { |
| if (mode != WRITE_MODE) |
| throw new IOException(); |
| while (pos >= buf.length) |
| grow(); |
| buf[pos++] = (byte) b; |
| } |
| |
| public void write(byte[] b, int off, int len) throws IOException { |
| if (mode != WRITE_MODE) |
| throw new IOException(); |
| while (pos + len > buf.length) |
| grow(); |
| System.arraycopy(b, off, buf, pos, len); |
| pos += len; |
| } |
| |
| public void close() throws IOException { |
| if (mode != WRITE_MODE) |
| throw new IOException(); |
| mode = READ_MODE; |
| } |
| } |
| |
| /** |
| * Input stream for reading from stream buffer. |
| */ |
| private class StreamBufferInputStream extends InputStream { |
| |
| private int pos; |
| |
| public int read() throws IOException { |
| if (mode == CLOSED_MODE) |
| throw new IOException(); |
| mode = READ_MODE; |
| return (pos < out.pos) ? (buf[pos++] & 0xFF) : -1; |
| } |
| |
| public int read(byte[] b, int off, int len) throws IOException { |
| if (mode == CLOSED_MODE) |
| throw new IOException(); |
| mode = READ_MODE; |
| int avail = out.pos - pos; |
| int rlen = (avail < len) ? avail : len; |
| System.arraycopy(buf, pos, b, off, rlen); |
| pos += rlen; |
| return rlen; |
| } |
| |
| public long skip(long len) throws IOException { |
| if (mode == CLOSED_MODE) |
| throw new IOException(); |
| mode = READ_MODE; |
| int avail = out.pos - pos; |
| long slen = (avail < len) ? avail : len; |
| pos += slen; |
| return slen; |
| } |
| |
| public int available() throws IOException { |
| if (mode == CLOSED_MODE) |
| throw new IOException(); |
| mode = READ_MODE; |
| return out.pos - pos; |
| } |
| |
| public void close() throws IOException { |
| if (mode == CLOSED_MODE) |
| throw new IOException(); |
| mode = CLOSED_MODE; |
| } |
| } |
| |
| private static final int START_BUFSIZE = 256; |
| private static final int GROW_FACTOR = 2; |
| private static final int CLOSED_MODE = 0; |
| private static final int WRITE_MODE = 1; |
| private static final int READ_MODE = 2; |
| |
| private byte[] buf; |
| private StreamBufferOutputStream out = new StreamBufferOutputStream(); |
| private StreamBufferInputStream in = new StreamBufferInputStream(); |
| private int mode = WRITE_MODE; |
| |
| public StreamBuffer() { |
| this(START_BUFSIZE); |
| } |
| |
| public StreamBuffer(int size) { |
| buf = new byte[size]; |
| } |
| |
| public OutputStream getOutputStream() { |
| return out; |
| } |
| |
| public InputStream getInputStream() { |
| return in; |
| } |
| |
| public void reset() { |
| in.pos = out.pos = 0; |
| mode = WRITE_MODE; |
| } |
| |
| private void grow() { |
| byte[] newbuf = new byte[buf.length * GROW_FACTOR]; |
| System.arraycopy(buf, 0, newbuf, 0, buf.length); |
| buf = newbuf; |
| } |
| } |