1 files changed, 321 insertions, 0 deletions
diff --git a/src/java/org/apache/poi/poifs/filesystem/ODocumentInputStream.java b/src/java/org/apache/poi/poifs/filesystem/ODocumentInputStream.java
new file mode 100644
index 0000000000..a1bc5da95f
--- /dev/null
+++ b/src/java/org/apache/poi/poifs/filesystem/ODocumentInputStream.java
@@ -0,0 +1,321 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.poifs.filesystem;
+
+import java.io.IOException;
+
+import org.apache.poi.poifs.storage.DataInputBlock;
+
+/**
+ * This class provides methods to read a DocumentEntry managed by a
+ * {@link POIFSFileSystem} instance.
+ *
+ * @author Marc Johnson (mjohnson at apache dot org)
+ */
+public final class ODocumentInputStream extends DocumentInputStream {
+	/** current offset into the Document */
+	private int _current_offset;
+
+	/** current marked offset into the Document (used by mark and reset) */
+	private int _marked_offset;
+
+	/** the Document's size */
+	private int _document_size;
+
+	/** have we been closed? */
+	private boolean _closed;
+
+	/** the actual Document */
+	private POIFSDocument _document;
+
+	/** the data block containing the current stream pointer */
+	private DataInputBlock _currentBlock;
+
+	/**
+	 * Create an InputStream from the specified DocumentEntry
+	 * 
+	 * @param document the DocumentEntry to be read
+	 * 
+	 * @exception IOException if the DocumentEntry cannot be opened (like, maybe it has
+	 *                been deleted?)
+	 */
+	public ODocumentInputStream(DocumentEntry document) throws IOException {
+		if (!(document instanceof DocumentNode)) {
+			throw new IOException("Cannot open internal document storage");
+		}
+		DocumentNode documentNode = (DocumentNode)document;
+		if(documentNode.getDocument() == null) {
+         throw new IOException("Cannot open internal document storage");
+		}
+		      
+		_current_offset = 0;
+		_marked_offset = 0;
+		_document_size = document.getSize();
+		_closed = false;
+		_document = documentNode.getDocument();
+		_currentBlock = getDataInputBlock(0);
+	}
+
+	/**
+	 * Create an InputStream from the specified Document
+	 * 
+	 * @param document the Document to be read
+	 */
+	public ODocumentInputStream(POIFSDocument document) {
+		_current_offset = 0;
+		_marked_offset = 0;
+		_document_size = document.getSize();
+		_closed = false;
+		_document = document;
+		_currentBlock = getDataInputBlock(0);
+	}
+
+	@Override
+	public int available() {
+		if (_closed) {
+			throw new IllegalStateException("cannot perform requested operation on a closed stream");
+		}
+		return _document_size - _current_offset;
+	}
+
+   @Override
+	public void close() {
+		_closed = true;
+	}
+
+   @Override
+	public void mark(int ignoredReadlimit) {
+		_marked_offset = _current_offset;
+	}
+
+	private DataInputBlock getDataInputBlock(int offset) {
+		return _document.getDataInputBlock(offset);
+	}
+
+   @Override
+	public int read() throws IOException {
+		dieIfClosed();
+		if (atEOD()) {
+			return EOF;
+		}
+		int result = _currentBlock.readUByte();
+		_current_offset++;
+		if (_currentBlock.available() < 1) {
+			_currentBlock = getDataInputBlock(_current_offset);
+		}
+		return result;
+	}
+
+   @Override
+	public int read(byte[] b, int off, int len) throws IOException {
+		dieIfClosed();
+		if (b == null) {
+			throw new IllegalArgumentException("buffer must not be null");
+		}
+		if (off < 0 || len < 0 || b.length < off + len) {
+			throw new IndexOutOfBoundsException("can't read past buffer boundaries");
+		}
+		if (len == 0) {
+			return 0;
+		}
+		if (atEOD()) {
+			return EOF;
+		}
+		int limit = Math.min(available(), len);
+		readFully(b, off, limit);
+		return limit;
+	}
+
+	/**
+	 * Repositions this stream to the position at the time the mark() method was
+	 * last called on this input stream. If mark() has not been called this
+	 * method repositions the stream to its beginning.
+	 */
+   @Override
+	public void reset() {
+		_current_offset = _marked_offset;
+		_currentBlock = getDataInputBlock(_current_offset);
+	}
+
+   @Override
+	public long skip(long n) throws IOException {
+		dieIfClosed();
+		if (n < 0) {
+			return 0;
+		}
+		int new_offset = _current_offset + (int) n;
+
+		if (new_offset < _current_offset) {
+
+			// wrap around in converting a VERY large long to an int
+			new_offset = _document_size;
+		} else if (new_offset > _document_size) {
+			new_offset = _document_size;
+		}
+		long rval = new_offset - _current_offset;
+
+		_current_offset = new_offset;
+		_currentBlock = getDataInputBlock(_current_offset);
+		return rval;
+	}
+
+	private void dieIfClosed() throws IOException {
+		if (_closed) {
+			throw new IOException("cannot perform requested operation on a closed stream");
+		}
+	}
+
+	private boolean atEOD() {
+		return _current_offset == _document_size;
+	}
+
+	private void checkAvaliable(int requestedSize) {
+		if (_closed) {
+			throw new IllegalStateException("cannot perform requested operation on a closed stream");
+		}
+		if (requestedSize > _document_size - _current_offset) {
+			throw new RuntimeException("Buffer underrun - requested " + requestedSize
+					+ " bytes but " + (_document_size - _current_offset) + " was available");
+		}
+	}
+
+   @Override
+	public byte readByte() {
+		return (byte) readUByte();
+	}
+
+   @Override
+	public double readDouble() {
+		return Double.longBitsToDouble(readLong());
+	}
+
+   @Override
+	public short readShort() {
+		return (short) readUShort();
+	}
+
+   @Override
+	public void readFully(byte[] buf, int off, int len) {
+		checkAvaliable(len);
+		int blockAvailable = _currentBlock.available();
+		if (blockAvailable > len) {
+			_currentBlock.readFully(buf, off, len);
+			_current_offset += len;
+			return;
+		}
+		// else read big amount in chunks
+		int remaining = len;
+		int writePos = off;
+		while (remaining > 0) {
+			boolean blockIsExpiring = remaining >= blockAvailable;
+			int reqSize;
+			if (blockIsExpiring) {
+				reqSize = blockAvailable;
+			} else {
+				reqSize = remaining;
+			}
+			_currentBlock.readFully(buf, writePos, reqSize);
+			remaining -= reqSize;
+			writePos += reqSize;
+			_current_offset += reqSize;
+			if (blockIsExpiring) {
+				if (_current_offset == _document_size) {
+					if (remaining > 0) {
+						throw new IllegalStateException(
+								"reached end of document stream unexpectedly");
+					}
+					_currentBlock = null;
+					break;
+				}
+				_currentBlock = getDataInputBlock(_current_offset);
+				blockAvailable = _currentBlock.available();
+			}
+		}
+	}
+
+   @Override
+	public long readLong() {
+		checkAvaliable(SIZE_LONG);
+		int blockAvailable = _currentBlock.available();
+		long result;
+		if (blockAvailable > SIZE_LONG) {
+			result = _currentBlock.readLongLE();
+		} else {
+			DataInputBlock nextBlock = getDataInputBlock(_current_offset + blockAvailable);
+			if (blockAvailable == SIZE_LONG) {
+				result = _currentBlock.readLongLE();
+			} else {
+				result = nextBlock.readLongLE(_currentBlock, blockAvailable);
+			}
+			_currentBlock = nextBlock;
+		}
+		_current_offset += SIZE_LONG;
+		return result;
+	}
+
+   @Override
+	public int readInt() {
+		checkAvaliable(SIZE_INT);
+		int blockAvailable = _currentBlock.available();
+		int result;
+		if (blockAvailable > SIZE_INT) {
+			result = _currentBlock.readIntLE();
+		} else {
+			DataInputBlock nextBlock = getDataInputBlock(_current_offset + blockAvailable);
+			if (blockAvailable == SIZE_INT) {
+				result = _currentBlock.readIntLE();
+			} else {
+				result = nextBlock.readIntLE(_currentBlock, blockAvailable);
+			}
+			_currentBlock = nextBlock;
+		}
+		_current_offset += SIZE_INT;
+		return result;
+	}
+
+   @Override
+	public int readUShort() {
+		checkAvaliable(SIZE_SHORT);
+		int blockAvailable = _currentBlock.available();
+		int result;
+		if (blockAvailable > SIZE_SHORT) {
+			result = _currentBlock.readUShortLE();
+		} else {
+			DataInputBlock nextBlock = getDataInputBlock(_current_offset + blockAvailable);
+			if (blockAvailable == SIZE_SHORT) {
+				result = _currentBlock.readUShortLE();
+			} else {
+				result = nextBlock.readUShortLE(_currentBlock);
+			}
+			_currentBlock = nextBlock;
+		}
+		_current_offset += SIZE_SHORT;
+		return result;
+	}
+
+   @Override
+	public int readUByte() {
+		checkAvaliable(1);
+		int result = _currentBlock.readUByte();
+		_current_offset++;
+		if (_currentBlock.available() < 1) {
+			_currentBlock = getDataInputBlock(_current_offset);
+		}
+		return result;
+	}
+}