com.itextpdf.text.io.GetBufferedRandomAccessSource Maven / Gradle / Ivy
/*
* $Id: 65ea25d483f2cb5eb03b4f890ce5b2d0aa456733 $
*
* This file is part of the iText (R) project.
* Copyright (c) 1998-2016 iText Group NV
* Authors: Kevin Day, Bruno Lowagie, et al.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License version 3
* as published by the Free Software Foundation with the addition of the
* following permission added to Section 15 as permitted in Section 7(a):
* FOR ANY PART OF THE COVERED WORK IN WHICH THE COPYRIGHT IS OWNED BY
* ITEXT GROUP. ITEXT GROUP DISCLAIMS THE WARRANTY OF NON INFRINGEMENT
* OF THIRD PARTY RIGHTS.
*
* This program 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 Affero General License for more
* details. You should have received a copy of the GNU Affero General License
* along with this program; if not, see http://www.gnu.org/licenses or write to
* the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
* MA, 02110-1301 USA, or download the license from the following URL:
* http://itextpdf.com/terms-of-use/
*
* The interactive user interfaces in modified source and object code versions
* of this program must display Appropriate Legal Notices, as required under
* Section 5 of the GNU Affero General License.
*
* In accordance with Section 7(b) of the GNU Affero General License, a covered
* work must retain the producer line in every PDF that is created or
* manipulated using iText.
*
* You can be released from the requirements of the license by purchasing a
* commercial license. Buying such a license is mandatory as soon as you develop
* commercial activities involving the iText software without disclosing the
* source code of your own applications. These activities include: offering paid
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*
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*/
package com.itextpdf.text.io;
import java.io.IOException;
/**
* @since 5.3.5
*/
public class GetBufferedRandomAccessSource implements RandomAccessSource {
/**
* The source
*/
private final RandomAccessSource source;
private final byte[] getBuffer;
private long getBufferStart = -1;
private long getBufferEnd = -1;
/**
* Constructs a new OffsetRandomAccessSource
* @param source the source
*/
public GetBufferedRandomAccessSource(RandomAccessSource source) {
this.source = source;
this.getBuffer = new byte[(int)Math.min(Math.max(source.length()/4, 1), (long)4096)];
this.getBufferStart = -1;
this.getBufferEnd = -1;
}
/**
* {@inheritDoc}
*/
public int get(long position) throws IOException {
if (position < getBufferStart || position > getBufferEnd){
int count = source.get(position, getBuffer, 0, getBuffer.length);
if (count == -1)
return -1;
getBufferStart = position;
getBufferEnd = position + count - 1;
}
int bufPos = (int)(position-getBufferStart);
return 0xff & getBuffer[bufPos];
}
/**
* {@inheritDoc}
*/
public int get(long position, byte[] bytes, int off, int len) throws IOException {
return source.get(position, bytes, off, len);
}
/**
* {@inheritDoc}
*/
public long length() {
return source.length();
}
/**
* Does nothing - the underlying source is not closed
*/
public void close() throws IOException {
source.close();
getBufferStart = -1;
getBufferEnd = -1;
}
}