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[bug-65184] Improve performance of POFSMiniStore getBlockAt. Thanks to sits
git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1887604 13f79535-47bb-0310-9956-ffa450edef68
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PJ Fanning
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5758145ce8
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c70b649e73
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@ -1,4 +1,3 @@
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/* ====================================================================
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Licensed to the Apache Software Foundation (ASF) under one or more
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contributor license agreements. See the NOTICE file distributed with
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@ -33,141 +32,140 @@ import org.apache.poi.poifs.storage.HeaderBlock;
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/**
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* This class handles the MiniStream (small block store)
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* in the NIO case for {@link POIFSFileSystem}
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* in the NIO case for {@link POIFSFileSystem}
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*/
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public class POIFSMiniStore extends BlockStore
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{
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public class POIFSMiniStore extends BlockStore {
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private final POIFSFileSystem _filesystem;
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private POIFSStream _mini_stream;
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private final List<BATBlock> _sbat_blocks;
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private final HeaderBlock _header;
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private final RootProperty _root;
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private final List<BATBlock> _sbat_blocks;
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private final HeaderBlock _header;
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private final RootProperty _root;
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POIFSMiniStore(POIFSFileSystem filesystem, RootProperty root,
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List<BATBlock> sbats, HeaderBlock header)
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{
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this._filesystem = filesystem;
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this._sbat_blocks = sbats;
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this._header = header;
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this._root = root;
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List<BATBlock> sbats, HeaderBlock header) {
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this._filesystem = filesystem;
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this._sbat_blocks = sbats;
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this._header = header;
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this._root = root;
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this._mini_stream = new POIFSStream(filesystem, root.getStartBlock());
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this._mini_stream = new POIFSStream(filesystem, root.getStartBlock());
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}
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/**
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* Load the block at the given offset.
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*/
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protected ByteBuffer getBlockAt(final int offset) {
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// Which big block is this?
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int byteOffset = offset * POIFSConstants.SMALL_BLOCK_SIZE;
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int bigBlockNumber = byteOffset / _filesystem.getBigBlockSize();
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int bigBlockOffset = byteOffset % _filesystem.getBigBlockSize();
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// Which big block is this?
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int byteOffset = offset * POIFSConstants.SMALL_BLOCK_SIZE;
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int bigBlockNumber = byteOffset / _filesystem.getBigBlockSize();
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int bigBlockOffset = byteOffset % _filesystem.getBigBlockSize();
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// Now locate the data block for it
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Iterator<ByteBuffer> it = _mini_stream.getBlockIterator();
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for(int i=0; i<bigBlockNumber; i++) {
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it.next();
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}
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ByteBuffer dataBlock = it.next();
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assert(dataBlock != null);
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// Now locate the data block for it
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Iterator<ByteBuffer> it = _mini_stream.getBlockIterator();
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for (int i = 0; i < bigBlockNumber; i++) {
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it.next();
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}
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ByteBuffer dataBlock = it.next();
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assert (dataBlock != null);
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// Position ourselves, and take a slice
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dataBlock.position(
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dataBlock.position() + bigBlockOffset
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);
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ByteBuffer miniBuffer = dataBlock.slice();
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miniBuffer.limit(POIFSConstants.SMALL_BLOCK_SIZE);
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return miniBuffer;
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// Position ourselves, and take a slice
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dataBlock.position(
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dataBlock.position() + bigBlockOffset
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);
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ByteBuffer miniBuffer = dataBlock.slice();
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miniBuffer.limit(POIFSConstants.SMALL_BLOCK_SIZE);
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return miniBuffer;
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}
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/**
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* Load the block, extending the underlying stream if needed
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*/
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protected ByteBuffer createBlockIfNeeded(final int offset) throws IOException {
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boolean firstInStore = false;
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if (_mini_stream.getStartBlock() == POIFSConstants.END_OF_CHAIN) {
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firstInStore = true;
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}
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boolean firstInStore = false;
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if (_mini_stream.getStartBlock() == POIFSConstants.END_OF_CHAIN) {
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firstInStore = true;
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}
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// Try to get it without extending the stream
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if (! firstInStore) {
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try {
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return getBlockAt(offset);
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} catch(NoSuchElementException ignored) {}
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}
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// Try to get it without extending the stream
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if (!firstInStore) {
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try {
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return getBlockAt(offset);
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} catch (NoSuchElementException ignored) {
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}
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}
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// Need to extend the stream
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// TODO Replace this with proper append support
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// For now, do the extending by hand...
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// Need to extend the stream
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// TODO Replace this with proper append support
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// For now, do the extending by hand...
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// Ask for another block
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int newBigBlock = _filesystem.getFreeBlock();
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_filesystem.createBlockIfNeeded(newBigBlock);
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// Ask for another block
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int newBigBlock = _filesystem.getFreeBlock();
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_filesystem.createBlockIfNeeded(newBigBlock);
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// If we are the first block to be allocated, initialise the stream
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if (firstInStore) {
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_filesystem._get_property_table().getRoot().setStartBlock(newBigBlock);
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_mini_stream = new POIFSStream(_filesystem, newBigBlock);
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} else {
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// Tack it onto the end of our chain
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ChainLoopDetector loopDetector = _filesystem.getChainLoopDetector();
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int block = _mini_stream.getStartBlock();
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while(true) {
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loopDetector.claim(block);
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int next = _filesystem.getNextBlock(block);
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if(next == POIFSConstants.END_OF_CHAIN) {
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break;
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}
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block = next;
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}
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_filesystem.setNextBlock(block, newBigBlock);
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}
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// If we are the first block to be allocated, initialise the stream
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if (firstInStore) {
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_filesystem._get_property_table().getRoot().setStartBlock(newBigBlock);
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_mini_stream = new POIFSStream(_filesystem, newBigBlock);
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} else {
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// Tack it onto the end of our chain
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ChainLoopDetector loopDetector = _filesystem.getChainLoopDetector();
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int block = _mini_stream.getStartBlock();
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while (true) {
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loopDetector.claim(block);
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int next = _filesystem.getNextBlock(block);
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if (next == POIFSConstants.END_OF_CHAIN) {
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break;
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}
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block = next;
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}
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_filesystem.setNextBlock(block, newBigBlock);
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}
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// This is now the new end
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_filesystem.setNextBlock(newBigBlock, POIFSConstants.END_OF_CHAIN);
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// This is now the new end
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_filesystem.setNextBlock(newBigBlock, POIFSConstants.END_OF_CHAIN);
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// Now try again, to get the real small block
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return createBlockIfNeeded(offset);
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// Now try again, to get the real small block
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return createBlockIfNeeded(offset);
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}
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/**
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* Returns the BATBlock that handles the specified offset,
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* and the relative index within it
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* and the relative index within it
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*/
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protected BATBlockAndIndex getBATBlockAndIndex(final int offset) {
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return BATBlock.getSBATBlockAndIndex(
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offset, _header, _sbat_blocks
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);
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return BATBlock.getSBATBlockAndIndex(
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offset, _header, _sbat_blocks
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);
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}
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/**
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* Works out what block follows the specified one.
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*/
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protected int getNextBlock(final int offset) {
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BATBlockAndIndex bai = getBATBlockAndIndex(offset);
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return bai.getBlock().getValueAt( bai.getIndex() );
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BATBlockAndIndex bai = getBATBlockAndIndex(offset);
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return bai.getBlock().getValueAt(bai.getIndex());
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}
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/**
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* Changes the record of what block follows the specified one.
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*/
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protected void setNextBlock(final int offset, final int nextBlock) {
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BATBlockAndIndex bai = getBATBlockAndIndex(offset);
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bai.getBlock().setValueAt(
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bai.getIndex(), nextBlock
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);
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BATBlockAndIndex bai = getBATBlockAndIndex(offset);
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bai.getBlock().setValueAt(
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bai.getIndex(), nextBlock
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);
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}
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/**
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* Finds a free block, and returns its offset.
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* This method will extend the file if needed, and if doing
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* so, allocate new FAT blocks to address the extra space.
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* so, allocate new FAT blocks to address the extra space.
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*/
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protected int getFreeBlock() throws IOException {
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int sectorsPerSBAT = _filesystem.getBigBlockSizeDetails().getBATEntriesPerBlock();
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int sectorsPerSBAT = _filesystem.getBigBlockSizeDetails().getBATEntriesPerBlock();
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// First up, do we have any spare ones?
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int offset = 0;
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// First up, do we have any spare ones?
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int offset = 0;
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for (BATBlock sbat : _sbat_blocks) {
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// Check this one
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if (sbat.hasFreeSectors()) {
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@ -185,79 +183,79 @@ public class POIFSMiniStore extends BlockStore
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offset += sectorsPerSBAT;
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}
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// If we get here, then there aren't any
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// free sectors in any of the SBATs
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// So, we need to extend the chain and add another
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// If we get here, then there aren't any
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// free sectors in any of the SBATs
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// So, we need to extend the chain and add another
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// Create a new BATBlock
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BATBlock newSBAT = BATBlock.createEmptyBATBlock(_filesystem.getBigBlockSizeDetails(), false);
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int batForSBAT = _filesystem.getFreeBlock();
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newSBAT.setOurBlockIndex(batForSBAT);
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// Create a new BATBlock
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BATBlock newSBAT = BATBlock.createEmptyBATBlock(_filesystem.getBigBlockSizeDetails(), false);
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int batForSBAT = _filesystem.getFreeBlock();
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newSBAT.setOurBlockIndex(batForSBAT);
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// Are we the first SBAT?
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if(_header.getSBATCount() == 0) {
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// Tell the header that we've got our first SBAT there
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_header.setSBATStart(batForSBAT);
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_header.setSBATBlockCount(1);
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} else {
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// Find the end of the SBAT stream, and add the sbat in there
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ChainLoopDetector loopDetector = _filesystem.getChainLoopDetector();
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int batOffset = _header.getSBATStart();
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while(true) {
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loopDetector.claim(batOffset);
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int nextBat = _filesystem.getNextBlock(batOffset);
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if(nextBat == POIFSConstants.END_OF_CHAIN) {
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break;
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}
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batOffset = nextBat;
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}
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// Are we the first SBAT?
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if (_header.getSBATCount() == 0) {
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// Tell the header that we've got our first SBAT there
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_header.setSBATStart(batForSBAT);
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_header.setSBATBlockCount(1);
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} else {
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// Find the end of the SBAT stream, and add the sbat in there
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ChainLoopDetector loopDetector = _filesystem.getChainLoopDetector();
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int batOffset = _header.getSBATStart();
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while (true) {
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loopDetector.claim(batOffset);
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int nextBat = _filesystem.getNextBlock(batOffset);
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if (nextBat == POIFSConstants.END_OF_CHAIN) {
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break;
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}
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batOffset = nextBat;
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}
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// Add it in at the end
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_filesystem.setNextBlock(batOffset, batForSBAT);
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// Add it in at the end
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_filesystem.setNextBlock(batOffset, batForSBAT);
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// And update the count
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_header.setSBATBlockCount(
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_header.getSBATCount() + 1
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);
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}
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// And update the count
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_header.setSBATBlockCount(
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_header.getSBATCount() + 1
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);
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}
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// Finish allocating
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_filesystem.setNextBlock(batForSBAT, POIFSConstants.END_OF_CHAIN);
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_sbat_blocks.add(newSBAT);
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// Finish allocating
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_filesystem.setNextBlock(batForSBAT, POIFSConstants.END_OF_CHAIN);
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_sbat_blocks.add(newSBAT);
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// Return our first spot
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return offset;
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// Return our first spot
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return offset;
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}
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@Override
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protected ChainLoopDetector getChainLoopDetector() {
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return new ChainLoopDetector( _root.getSize() );
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return new ChainLoopDetector(_root.getSize());
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}
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protected int getBlockStoreBlockSize() {
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return POIFSConstants.SMALL_BLOCK_SIZE;
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return POIFSConstants.SMALL_BLOCK_SIZE;
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}
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/**
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* Writes the SBATs to their backing blocks, and updates
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* the mini-stream size in the properties. Stream size is
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* based on full blocks used, not the data within the streams
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* the mini-stream size in the properties. Stream size is
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* based on full blocks used, not the data within the streams
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*/
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void syncWithDataSource() throws IOException {
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int blocksUsed = 0;
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for (BATBlock sbat : _sbat_blocks) {
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ByteBuffer block = _filesystem.getBlockAt(sbat.getOurBlockIndex());
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sbat.writeData(block);
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int blocksUsed = 0;
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for (BATBlock sbat : _sbat_blocks) {
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ByteBuffer block = _filesystem.getBlockAt(sbat.getOurBlockIndex());
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sbat.writeData(block);
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if (!sbat.hasFreeSectors()) {
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blocksUsed += _filesystem.getBigBlockSizeDetails().getBATEntriesPerBlock();
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} else {
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blocksUsed += sbat.getOccupiedSize();
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}
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}
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// Set the size on the root in terms of the number of SBAT blocks
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// RootProperty.setSize does the sbat -> bytes conversion for us
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_filesystem._get_property_table().getRoot().setSize(blocksUsed);
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if (!sbat.hasFreeSectors()) {
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blocksUsed += _filesystem.getBigBlockSizeDetails().getBATEntriesPerBlock();
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} else {
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blocksUsed += sbat.getOccupiedSize();
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}
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}
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// Set the size on the root in terms of the number of SBAT blocks
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// RootProperty.setSize does the sbat -> bytes conversion for us
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_filesystem._get_property_table().getRoot().setSize(blocksUsed);
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}
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@Override
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