001: /*
002: * $RCSfile: StreamSegmentMapper.java,v $
003: *
004: *
005: * Copyright (c) 2005 Sun Microsystems, Inc. All Rights Reserved.
006: *
007: * Redistribution and use in source and binary forms, with or without
008: * modification, are permitted provided that the following conditions
009: * are met:
010: *
011: * - Redistribution of source code must retain the above copyright
012: * notice, this list of conditions and the following disclaimer.
013: *
014: * - Redistribution in binary form must reproduce the above copyright
015: * notice, this list of conditions and the following disclaimer in
016: * the documentation and/or other materials provided with the
017: * distribution.
018: *
019: * Neither the name of Sun Microsystems, Inc. or the names of
020: * contributors may be used to endorse or promote products derived
021: * from this software without specific prior written permission.
022: *
023: * This software is provided "AS IS," without a warranty of any
024: * kind. ALL EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND
025: * WARRANTIES, INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY,
026: * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY
027: * EXCLUDED. SUN MIDROSYSTEMS, INC. ("SUN") AND ITS LICENSORS SHALL
028: * NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF
029: * USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
030: * DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR
031: * ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL,
032: * CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND
033: * REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF THE USE OF OR
034: * INABILITY TO USE THIS SOFTWARE, EVEN IF SUN HAS BEEN ADVISED OF THE
035: * POSSIBILITY OF SUCH DAMAGES.
036: *
037: * You acknowledge that this software is not designed or intended for
038: * use in the design, construction, operation or maintenance of any
039: * nuclear facility.
040: *
041: * $Revision: 1.1 $
042: * $Date: 2005/02/11 05:01:21 $
043: * $State: Exp $
044: */
045: package com.sun.media.imageio.stream;
046:
047: /**
048: * An interface for use with the <code>SegmentedImageInputStream</code>
049: * class. An instance of the <code>StreamSegmentMapper</code>
050: * interface provides the location and length of a segment of a source
051: * <code>ImageInputStream</code> corresponding to the initial portion of
052: * a desired segment of the output stream.
053: *
054: * <p> As an example, consider a mapping between a source
055: * <code>ImageInputStream src</code> and a <code>SegmentedImageInputStream
056: * dst</code> comprising bytes 100-149 and 200-249 of the source
057: * stream. The <code>dst</code> stream has a reference to an instance
058: * <code>mapper</code> of <code>StreamSegmentMapper</code>.
059: *
060: * <p> A call to <code>dst.seek(0); dst.read(buf, 0, 10)</code> will
061: * result in a call to <code>mapper.getStreamSegment(0, 10)</code>,
062: * returning a new <code>StreamSegment</code> with a starting
063: * position of 100 and a length of 10 (or less). This indicates that
064: * in order to read bytes 0-9 of the segmented stream, bytes 100-109
065: * of the source stream should be read.
066: *
067: * <p> A call to <code>dst.seek(10); int nbytes = dst.read(buf, 0,
068: * 100)</code> is somewhat more complex, since it will require data
069: * from both segments of <code>src</code>. The method <code>
070: * mapper.getStreamSegment(10, 100)</code> will be called. This
071: * method will return a new <code>StreamSegment</code> with a starting
072: * position of 110 and a length of 40 (or less). The length is
073: * limited to 40 since a longer value would result in a read past the
074: * end of the first segment. The read will stop after the first 40
075: * bytes and an addition read or reads will be required to obtain the
076: * data contained in the second segment.
077: */
078: public interface StreamSegmentMapper {
079:
080: /**
081: * Returns a <code>StreamSegment</code> object indicating the
082: * location of the initial portion of a desired segment in the
083: * source stream. The length of the returned
084: * <code>StreamSegment</code> may be smaller than the desired
085: * length.
086: *
087: * @param pos The desired starting position in the
088: * <code>SegmentedImageInputStream</code>, as a <code>long</code>.
089: * @param length The desired segment length.
090: * @return a StreamSegment object
091: */
092: StreamSegment getStreamSegment(long pos, int length);
093:
094: /**
095: * Sets the values of a <code>StreamSegment</code> object
096: * indicating the location of the initial portion of a desired
097: * segment in the source stream. The length of the returned
098: * <code>StreamSegment</code> may be smaller than the desired
099: * length.
100: *
101: * @param pos The desired starting position in the
102: * <code>SegmentedImageInputStream</code>, as a <code>long</code>.
103: * @param length The desired segment length.
104: * @param seg A <code>StreamSegment</code> object to be overwritten.
105: */
106: void getStreamSegment(long pos, int length, StreamSegment seg);
107: }
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