/*
 * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * 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.
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package jdk.jshell.execution;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

Author:Jan Lahoda
/** * * @author Jan Lahoda */
class PipeInputStream extends InputStream { private static final int INITIAL_SIZE = 128; private int[] buffer = new int[INITIAL_SIZE]; private int start; private int end; private boolean closed; @Override public synchronized int read() throws IOException { if (start == end && !closed) { inputNeeded(); } while (start == end) { if (closed) { return -1; } try { wait(); } catch (InterruptedException ex) { //ignore } } try { return buffer[start]; } finally { start = (start + 1) % buffer.length; } } @Override public synchronized int read(byte[] b, int off, int len) throws IOException { if (b == null) { throw new NullPointerException(); } else if (off < 0 || len < 0 || len > b.length - off) { throw new IndexOutOfBoundsException(); } else if (len == 0) { return 0; } int c = read(); if (c == -1) { return -1; } b[off] = (byte)c; int totalRead = 1; while (totalRead < len && start != end) { int r = read(); if (r == (-1)) break; b[off + totalRead++] = (byte) r; } return totalRead; } protected void inputNeeded() throws IOException {} private synchronized void write(int b) { if (closed) { throw new IllegalStateException("Already closed."); } int newEnd = (end + 1) % buffer.length; if (newEnd == start) { //overflow: int[] newBuffer = new int[buffer.length * 2]; int rightPart = (end > start ? end : buffer.length) - start; int leftPart = end > start ? 0 : start - 1; System.arraycopy(buffer, start, newBuffer, 0, rightPart); System.arraycopy(buffer, 0, newBuffer, rightPart, leftPart); buffer = newBuffer; start = 0; end = rightPart + leftPart; newEnd = end + 1; } buffer[end] = b; end = newEnd; notifyAll(); } @Override public synchronized void close() { closed = true; notifyAll(); } public OutputStream createOutput() { return new OutputStream() { @Override public void write(int b) throws IOException { PipeInputStream.this.write(b); } @Override public void write(byte[] b, int off, int len) throws IOException { for (int i = 0 ; i < len ; i++) { write(Byte.toUnsignedInt(b[off + i])); } } @Override public void close() throws IOException { PipeInputStream.this.close(); } }; } }