diff options
| -rw-r--r-- | src/java/org/apache/poi/poifs/filesystem/POIFSMiniStore.java | 304 |
1 files changed, 151 insertions, 153 deletions
diff --git a/src/java/org/apache/poi/poifs/filesystem/POIFSMiniStore.java b/src/java/org/apache/poi/poifs/filesystem/POIFSMiniStore.java index c381c517ab..701dad68a4 100644 --- a/src/java/org/apache/poi/poifs/filesystem/POIFSMiniStore.java +++ b/src/java/org/apache/poi/poifs/filesystem/POIFSMiniStore.java @@ -1,4 +1,3 @@ - /* ==================================================================== Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements. See the NOTICE file distributed with @@ -33,141 +32,140 @@ import org.apache.poi.poifs.storage.HeaderBlock; /** * This class handles the MiniStream (small block store) - * in the NIO case for {@link POIFSFileSystem} + * in the NIO case for {@link POIFSFileSystem} */ -public class POIFSMiniStore extends BlockStore -{ +public class POIFSMiniStore extends BlockStore { private final POIFSFileSystem _filesystem; private POIFSStream _mini_stream; - private final List<BATBlock> _sbat_blocks; - private final HeaderBlock _header; - private final RootProperty _root; + private final List<BATBlock> _sbat_blocks; + private final HeaderBlock _header; + private final RootProperty _root; POIFSMiniStore(POIFSFileSystem filesystem, RootProperty root, - List<BATBlock> sbats, HeaderBlock header) - { - this._filesystem = filesystem; - this._sbat_blocks = sbats; - this._header = header; - this._root = root; - - this._mini_stream = new POIFSStream(filesystem, root.getStartBlock()); + List<BATBlock> sbats, HeaderBlock header) { + this._filesystem = filesystem; + this._sbat_blocks = sbats; + this._header = header; + this._root = root; + + this._mini_stream = new POIFSStream(filesystem, root.getStartBlock()); } /** * Load the block at the given offset. */ protected ByteBuffer getBlockAt(final int offset) { - // Which big block is this? - int byteOffset = offset * POIFSConstants.SMALL_BLOCK_SIZE; - int bigBlockNumber = byteOffset / _filesystem.getBigBlockSize(); - int bigBlockOffset = byteOffset % _filesystem.getBigBlockSize(); - - // Now locate the data block for it - Iterator<ByteBuffer> it = _mini_stream.getBlockIterator(); - for(int i=0; i<bigBlockNumber; i++) { - it.next(); - } - ByteBuffer dataBlock = it.next(); - assert(dataBlock != null); - - // Position ourselves, and take a slice - dataBlock.position( - dataBlock.position() + bigBlockOffset - ); - ByteBuffer miniBuffer = dataBlock.slice(); - miniBuffer.limit(POIFSConstants.SMALL_BLOCK_SIZE); - return miniBuffer; + // Which big block is this? + int byteOffset = offset * POIFSConstants.SMALL_BLOCK_SIZE; + int bigBlockNumber = byteOffset / _filesystem.getBigBlockSize(); + int bigBlockOffset = byteOffset % _filesystem.getBigBlockSize(); + + // Now locate the data block for it + Iterator<ByteBuffer> it = _mini_stream.getBlockIterator(); + for (int i = 0; i < bigBlockNumber; i++) { + it.next(); + } + ByteBuffer dataBlock = it.next(); + assert (dataBlock != null); + + // Position ourselves, and take a slice + dataBlock.position( + dataBlock.position() + bigBlockOffset + ); + ByteBuffer miniBuffer = dataBlock.slice(); + miniBuffer.limit(POIFSConstants.SMALL_BLOCK_SIZE); + return miniBuffer; } /** * Load the block, extending the underlying stream if needed */ protected ByteBuffer createBlockIfNeeded(final int offset) throws IOException { - boolean firstInStore = false; - if (_mini_stream.getStartBlock() == POIFSConstants.END_OF_CHAIN) { - firstInStore = true; - } - - // Try to get it without extending the stream - if (! firstInStore) { - try { - return getBlockAt(offset); - } catch(NoSuchElementException ignored) {} - } - - // Need to extend the stream - // TODO Replace this with proper append support - // For now, do the extending by hand... - - // Ask for another block - int newBigBlock = _filesystem.getFreeBlock(); - _filesystem.createBlockIfNeeded(newBigBlock); - - // If we are the first block to be allocated, initialise the stream - if (firstInStore) { - _filesystem._get_property_table().getRoot().setStartBlock(newBigBlock); - _mini_stream = new POIFSStream(_filesystem, newBigBlock); - } else { - // Tack it onto the end of our chain - ChainLoopDetector loopDetector = _filesystem.getChainLoopDetector(); - int block = _mini_stream.getStartBlock(); - while(true) { - loopDetector.claim(block); - int next = _filesystem.getNextBlock(block); - if(next == POIFSConstants.END_OF_CHAIN) { - break; - } - block = next; - } - _filesystem.setNextBlock(block, newBigBlock); - } - - // This is now the new end - _filesystem.setNextBlock(newBigBlock, POIFSConstants.END_OF_CHAIN); - - // Now try again, to get the real small block - return createBlockIfNeeded(offset); + boolean firstInStore = false; + if (_mini_stream.getStartBlock() == POIFSConstants.END_OF_CHAIN) { + firstInStore = true; + } + + // Try to get it without extending the stream + if (!firstInStore) { + try { + return getBlockAt(offset); + } catch (NoSuchElementException ignored) { + } + } + + // Need to extend the stream + // TODO Replace this with proper append support + // For now, do the extending by hand... + + // Ask for another block + int newBigBlock = _filesystem.getFreeBlock(); + _filesystem.createBlockIfNeeded(newBigBlock); + + // If we are the first block to be allocated, initialise the stream + if (firstInStore) { + _filesystem._get_property_table().getRoot().setStartBlock(newBigBlock); + _mini_stream = new POIFSStream(_filesystem, newBigBlock); + } else { + // Tack it onto the end of our chain + ChainLoopDetector loopDetector = _filesystem.getChainLoopDetector(); + int block = _mini_stream.getStartBlock(); + while (true) { + loopDetector.claim(block); + int next = _filesystem.getNextBlock(block); + if (next == POIFSConstants.END_OF_CHAIN) { + break; + } + block = next; + } + _filesystem.setNextBlock(block, newBigBlock); + } + + // This is now the new end + _filesystem.setNextBlock(newBigBlock, POIFSConstants.END_OF_CHAIN); + + // Now try again, to get the real small block + return createBlockIfNeeded(offset); } /** * Returns the BATBlock that handles the specified offset, - * and the relative index within it + * and the relative index within it */ protected BATBlockAndIndex getBATBlockAndIndex(final int offset) { - return BATBlock.getSBATBlockAndIndex( - offset, _header, _sbat_blocks - ); + return BATBlock.getSBATBlockAndIndex( + offset, _header, _sbat_blocks + ); } /** * Works out what block follows the specified one. */ protected int getNextBlock(final int offset) { - BATBlockAndIndex bai = getBATBlockAndIndex(offset); - return bai.getBlock().getValueAt( bai.getIndex() ); + BATBlockAndIndex bai = getBATBlockAndIndex(offset); + return bai.getBlock().getValueAt(bai.getIndex()); } /** * Changes the record of what block follows the specified one. */ protected void setNextBlock(final int offset, final int nextBlock) { - BATBlockAndIndex bai = getBATBlockAndIndex(offset); - bai.getBlock().setValueAt( - bai.getIndex(), nextBlock - ); + BATBlockAndIndex bai = getBATBlockAndIndex(offset); + bai.getBlock().setValueAt( + bai.getIndex(), nextBlock + ); } /** * Finds a free block, and returns its offset. * This method will extend the file if needed, and if doing - * so, allocate new FAT blocks to address the extra space. + * so, allocate new FAT blocks to address the extra space. */ protected int getFreeBlock() throws IOException { - int sectorsPerSBAT = _filesystem.getBigBlockSizeDetails().getBATEntriesPerBlock(); + int sectorsPerSBAT = _filesystem.getBigBlockSizeDetails().getBATEntriesPerBlock(); - // First up, do we have any spare ones? - int offset = 0; + // First up, do we have any spare ones? + int offset = 0; for (BATBlock sbat : _sbat_blocks) { // Check this one if (sbat.hasFreeSectors()) { @@ -185,79 +183,79 @@ public class POIFSMiniStore extends BlockStore offset += sectorsPerSBAT; } - // If we get here, then there aren't any - // free sectors in any of the SBATs - // So, we need to extend the chain and add another - - // Create a new BATBlock - BATBlock newSBAT = BATBlock.createEmptyBATBlock(_filesystem.getBigBlockSizeDetails(), false); - int batForSBAT = _filesystem.getFreeBlock(); - newSBAT.setOurBlockIndex(batForSBAT); - - // Are we the first SBAT? - if(_header.getSBATCount() == 0) { - // Tell the header that we've got our first SBAT there - _header.setSBATStart(batForSBAT); - _header.setSBATBlockCount(1); - } else { - // Find the end of the SBAT stream, and add the sbat in there - ChainLoopDetector loopDetector = _filesystem.getChainLoopDetector(); - int batOffset = _header.getSBATStart(); - while(true) { - loopDetector.claim(batOffset); - int nextBat = _filesystem.getNextBlock(batOffset); - if(nextBat == POIFSConstants.END_OF_CHAIN) { - break; - } - batOffset = nextBat; - } - - // Add it in at the end - _filesystem.setNextBlock(batOffset, batForSBAT); - - // And update the count - _header.setSBATBlockCount( - _header.getSBATCount() + 1 - ); - } - - // Finish allocating - _filesystem.setNextBlock(batForSBAT, POIFSConstants.END_OF_CHAIN); - _sbat_blocks.add(newSBAT); - - // Return our first spot - return offset; + // If we get here, then there aren't any + // free sectors in any of the SBATs + // So, we need to extend the chain and add another + + // Create a new BATBlock + BATBlock newSBAT = BATBlock.createEmptyBATBlock(_filesystem.getBigBlockSizeDetails(), false); + int batForSBAT = _filesystem.getFreeBlock(); + newSBAT.setOurBlockIndex(batForSBAT); + + // Are we the first SBAT? + if (_header.getSBATCount() == 0) { + // Tell the header that we've got our first SBAT there + _header.setSBATStart(batForSBAT); + _header.setSBATBlockCount(1); + } else { + // Find the end of the SBAT stream, and add the sbat in there + ChainLoopDetector loopDetector = _filesystem.getChainLoopDetector(); + int batOffset = _header.getSBATStart(); + while (true) { + loopDetector.claim(batOffset); + int nextBat = _filesystem.getNextBlock(batOffset); + if (nextBat == POIFSConstants.END_OF_CHAIN) { + break; + } + batOffset = nextBat; + } + + // Add it in at the end + _filesystem.setNextBlock(batOffset, batForSBAT); + + // And update the count + _header.setSBATBlockCount( + _header.getSBATCount() + 1 + ); + } + + // Finish allocating + _filesystem.setNextBlock(batForSBAT, POIFSConstants.END_OF_CHAIN); + _sbat_blocks.add(newSBAT); + + // Return our first spot + return offset; } @Override protected ChainLoopDetector getChainLoopDetector() { - return new ChainLoopDetector( _root.getSize() ); + return new ChainLoopDetector(_root.getSize()); } protected int getBlockStoreBlockSize() { - return POIFSConstants.SMALL_BLOCK_SIZE; + return POIFSConstants.SMALL_BLOCK_SIZE; } /** * Writes the SBATs to their backing blocks, and updates - * the mini-stream size in the properties. Stream size is - * based on full blocks used, not the data within the streams + * the mini-stream size in the properties. Stream size is + * based on full blocks used, not the data within the streams */ void syncWithDataSource() throws IOException { - int blocksUsed = 0; - for (BATBlock sbat : _sbat_blocks) { - ByteBuffer block = _filesystem.getBlockAt(sbat.getOurBlockIndex()); - sbat.writeData(block); - - if (!sbat.hasFreeSectors()) { - blocksUsed += _filesystem.getBigBlockSizeDetails().getBATEntriesPerBlock(); - } else { - blocksUsed += sbat.getOccupiedSize(); - } - } - // Set the size on the root in terms of the number of SBAT blocks - // RootProperty.setSize does the sbat -> bytes conversion for us - _filesystem._get_property_table().getRoot().setSize(blocksUsed); + int blocksUsed = 0; + for (BATBlock sbat : _sbat_blocks) { + ByteBuffer block = _filesystem.getBlockAt(sbat.getOurBlockIndex()); + sbat.writeData(block); + + if (!sbat.hasFreeSectors()) { + blocksUsed += _filesystem.getBigBlockSizeDetails().getBATEntriesPerBlock(); + } else { + blocksUsed += sbat.getOccupiedSize(); + } + } + // Set the size on the root in terms of the number of SBAT blocks + // RootProperty.setSize does the sbat -> bytes conversion for us + _filesystem._get_property_table().getRoot().setSize(blocksUsed); } @Override |