Mercurial > hg > blitz_stable
diff src/com/go/trove/io/SpilloverByteBuffer.java @ 0:3dc0c5604566
Initial checkin of blitz 2.0 fcs - no installer yet.
author | Dan Creswell <dan.creswell@gmail.com> |
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date | Sat, 21 Mar 2009 11:00:06 +0000 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/com/go/trove/io/SpilloverByteBuffer.java Sat Mar 21 11:00:06 2009 +0000 @@ -0,0 +1,266 @@ +/* ==================================================================== + * Trove - Copyright (c) 1999-2000 Walt Disney Internet Group + * ==================================================================== + * The Tea Software License, Version 1.1 + * + * Copyright (c) 2000 Walt Disney Internet Group. 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. + * + * 3. The end-user documentation included with the redistribution, + * if any, must include the following acknowledgment: + * "This product includes software developed by the + * Walt Disney Internet Group (http://opensource.go.com/)." + * Alternately, this acknowledgment may appear in the software itself, + * if and wherever such third-party acknowledgments normally appear. + * + * 4. The names "Tea", "TeaServlet", "Kettle", "Trove" and "BeanDoc" must + * not be used to endorse or promote products derived from this + * software without prior written permission. For written + * permission, please contact opensource@dig.com. + * + * 5. Products derived from this software may not be called "Tea", + * "TeaServlet", "Kettle" or "Trove", nor may "Tea", "TeaServlet", + * "Kettle", "Trove" or "BeanDoc" appear in their name, without prior + * written permission of the Walt Disney Internet Group. + * + * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED 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 THE WALT DISNEY INTERNET GROUP OR ITS + * 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. + * ==================================================================== + * + * For more information about Tea, please see http://opensource.go.com/. + */ + +package com.go.trove.io; + +import java.io.OutputStream; +import java.io.IOException; +import java.util.List; +import java.util.ArrayList; + +/****************************************************************************** + * A ByteBuffer implementation that initially stores its data in a + * DefaultByteBuffer, but after a certain threshold is reached, spills over + * into a FileByteBuffer. + * + * @author Brian S O'Neill + * @version + * <!--$$Revision: 1.1 $-->, <!--$$JustDate:--> 00/12/05 <!-- $--> + */ +public class SpilloverByteBuffer implements ByteBuffer { + private Group mGroup; + + private ByteBuffer mLocalBuffer; + private ByteBuffer mSpillover; + + private List mCaptureBuffers; + + /** + * Create a SpilloverByteBuffer against a Group that sets the threshold + * and can create a spillover FileByteBuffer. The Group can be shared + * among many SpilloverByteBuffers. + * + * @param group a group that can be shared among many SpilloverByteBuffers + */ + public SpilloverByteBuffer(Group group) { + mGroup = group; + mLocalBuffer = new DefaultByteBuffer(); + } + + public long getBaseByteCount() throws IOException { + if (mSpillover == null) { + return mLocalBuffer.getBaseByteCount(); + } + else { + return mSpillover.getBaseByteCount(); + } + } + + public long getByteCount() throws IOException { + if (mSpillover == null) { + return mLocalBuffer.getByteCount(); + } + else { + return mSpillover.getByteCount(); + } + } + + public void writeTo(OutputStream out) throws IOException { + if (mSpillover == null) { + mLocalBuffer.writeTo(out); + } + else { + mSpillover.writeTo(out); + } + } + + public void append(byte b) throws IOException { + List captureBuffers; + if ((captureBuffers = mCaptureBuffers) != null) { + int size = captureBuffers.size(); + for (int i=0; i<size; i++) { + ((ByteBuffer)captureBuffers.get(i)).append(b); + } + } + + if (mSpillover == null) { + if (mGroup.adjustLevel(1)) { + mLocalBuffer.append(b); + return; + } + spillover(); + } + + mSpillover.append(b); + } + + public void append(byte[] bytes) throws IOException { + append(bytes, 0, bytes.length); + } + + public void append(byte[] bytes, int offset, int length) + throws IOException + { + List captureBuffers; + if ((captureBuffers = mCaptureBuffers) != null) { + int size = captureBuffers.size(); + for (int i=0; i<size; i++) { + ((ByteBuffer)captureBuffers.get(i)).append + (bytes, offset, length); + } + } + + if (mSpillover == null) { + if (mGroup.adjustLevel(length)) { + mLocalBuffer.append(bytes, offset, length); + return; + } + spillover(); + } + + mSpillover.append(bytes, offset, length); + } + + public void appendSurrogate(ByteData s) throws IOException { + if (s == null) { + return; + } + + List captureBuffers; + if ((captureBuffers = mCaptureBuffers) != null) { + int size = captureBuffers.size(); + for (int i=0; i<size; i++) { + ((ByteBuffer)captureBuffers.get(i)).appendSurrogate(s); + } + } + + if (mSpillover == null) { + mLocalBuffer.appendSurrogate(s); + } + else { + mSpillover.appendSurrogate(s); + } + } + + public void addCaptureBuffer(ByteBuffer buffer) { + List captureBuffers; + if ((captureBuffers = mCaptureBuffers) == null) { + captureBuffers = mCaptureBuffers = new ArrayList(); + } + captureBuffers.add(buffer); + } + + public void removeCaptureBuffer(ByteBuffer buffer) { + List captureBuffers; + if ((captureBuffers = mCaptureBuffers) != null) { + captureBuffers.remove(buffer); + } + } + + public void reset() throws IOException { + mLocalBuffer.reset(); + if (mSpillover != null) { + mSpillover.reset(); + } + + List captureBuffers; + if ((captureBuffers = mCaptureBuffers) != null) { + int size = captureBuffers.size(); + for (int i=0; i<size; i++) { + ((ByteData)captureBuffers.get(i)).reset(); + } + } + } + + protected void finalize() throws IOException { + if (mLocalBuffer != null) { + long count = mLocalBuffer.getBaseByteCount(); + mLocalBuffer = null; + mGroup.adjustLevel(-count); + } + } + + private void spillover() throws IOException { + mSpillover = mGroup.createFileByteBuffer(); + // TODO: This is bad! By writing out the contents of the existing + // buffer early, surrogates are evaluated too soon! + mLocalBuffer.writeTo(new ByteBufferOutputStream(mSpillover)); + + long count = mLocalBuffer.getBaseByteCount(); + mLocalBuffer = null; + mGroup.adjustLevel(-count); + } + + public static abstract class Group { + private final long mThreshold; + private long mLevel; + + public Group(long threshold) { + mThreshold = threshold; + } + + public final long getThreshold() { + return mThreshold; + } + + public final synchronized long getCurrentLevel() { + return mLevel; + } + + public abstract FileByteBuffer createFileByteBuffer() + throws IOException; + + synchronized boolean adjustLevel(long delta) { + long newLevel; + if ((newLevel = mLevel + delta) > mThreshold) { + return false; + } + else { + if (newLevel < 0) { + newLevel = 0; + } + mLevel = newLevel; + return true; + } + } + } +}