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/**
 * Copyright 2014 JogAmp Community. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification, are
 * permitted provided that the following conditions are met:
 *
 *    1. Redistributions of source code must retain the above copyright notice, this list of
 *       conditions and the following disclaimer.
 *
 *    2. Redistributions in binary form must reproduce the above copyright notice, this list
 *       of conditions and the following disclaimer in the documentation and/or other materials
 *       provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY JogAmp Community ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL JogAmp Community OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * The views and conclusions contained in the software and documentation are those of the
 * authors and should not be interpreted as representing official policies, either expressed
 * or implied, of JogAmp Community.
 */
package com.jogamp.common.nio;

import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.nio.ByteBuffer;
import java.nio.MappedByteBuffer;
import java.nio.channels.FileChannel;
import java.nio.channels.FileChannel.MapMode;

/**
 * An {@link InputStream} implementation based on an underlying {@link ByteBuffer}
 * supporting {@link #markSupported() mark}.
 * 

* May be utilized as well with a {@link MappedByteBuffer memory-mapped} {@link FileChannel#map(MapMode, long, long) FileChannel} * using a size ≤ {@link Integer#MAX_VALUE}.
* This becomes efficient with files ≥ 10 MiB, depending on the platform * and whether the traditional method uses a {@link BufferedInputStream} supporting {@code mark} incl. it's buffer size.
* See test case {@code com.jogamp.common.nio.TestByteBufferInputStream}. *

* @since 2.3.0 */ public class ByteBufferInputStream extends InputStream { private final ByteBuffer buf; private int mark; /** * Creates a new byte-buffer input stream. * * @param buf the underlying byte buffer. */ public ByteBufferInputStream(final ByteBuffer buf) { this.buf = buf; this.mark = -1; } @Override public final int available() { return buf.remaining(); } /** * This implementation supports {@code mark}. *

* {@inheritDoc} *

*/ @Override public final boolean markSupported() { return true; } /** * This implementation supports {@code mark}. *

* {@inheritDoc} *

* @see #markSupported() */ @Override public final synchronized void mark(final int unused) { mark = buf.position(); } /** * This implementation supports {@code mark}. *

* {@inheritDoc} *

* @see #markSupported() */ @Override public final synchronized void reset() throws IOException { if ( mark == -1 ) { throw new IOException(); } buf.position(mark); } @Override public final long skip(final long n) throws IOException { if( 0 > n ) { return 0; } final int s = (int) Math.min( buf.remaining(), n ); buf.position(buf.position() + s); return s; } @Override public final int read() { if ( ! buf.hasRemaining() ) { return -1; } return buf.get() & 0xFF; } @Override public final int read(final byte[] b, final int off, final int len) { if (b == null) { throw new NullPointerException(); } else if( off < 0 || len < 0 || off > b.length || off + len > b.length || off + len < 0 ) { throw new IndexOutOfBoundsException("offset "+off+", length "+len+", b.length "+b.length); } else if ( 0 == len ) { return 0; } final int totalRem = buf.remaining(); if ( 0 == totalRem ) { return -1; } final int maxLen = Math.min(totalRem, len); if( buf.hasArray() ) { System.arraycopy(buf.array(), buf.arrayOffset() + buf.position(), b, off, maxLen); buf.position( buf.position() + maxLen ); } else { buf.get(b, off, maxLen); } return maxLen; } // @Override public final int read(final ByteBuffer b, final int len) { if (b == null) { throw new NullPointerException(); } else if (len < 0 || len > b.remaining()) { throw new IndexOutOfBoundsException("length "+len+", b "+b); } else if ( 0 == len ) { return 0; } final int remaining = buf.remaining(); if ( 0 == remaining ) { return -1; } final int maxLen = Math.min(remaining, len); if( buf.hasArray() && b.hasArray() ) { System.arraycopy(buf.array(), buf.arrayOffset() + buf.position(), b.array(), b.arrayOffset() + b.position(), maxLen); buf.position( buf.position() + maxLen ); b.position( b.position() + maxLen ); } else if( maxLen == remaining ) { b.put(buf); } else { final int _limit = buf.limit(); buf.limit(maxLen); try { b.put(buf); } finally { buf.limit(_limit); } } return maxLen; } public final ByteBuffer getBuffer() { return buf; } }




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