plugins/org.eclipse.wst.server.core/servercore/org/eclipse/wst/server/core/internal/tar/TarInputStream.java - servertools/webtools.servertools - Git at Google

 /*******************************************************************************
  * Copyright (c) 2004, 2007 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.wst.server.core.internal.tar;

 import java.io.FilterInputStream;
 import java.io.IOException;
 import java.io.InputStream;
 /**
  * Input stream for reading files in ustar format (tar) compatible
  * with the specification in IEEE Std 1003.1-2001.  Also supports
  * long filenames encoded using the GNU @LongLink extension.
  * <p>
  * Copied from org.eclipse.ui.internal.wizards.datatransfer.
  * </p>
  */
 public class TarInputStream extends FilterInputStream {
 	private int nextEntry = 0;
 	private int nextEOF = 0;
 	private int filepos = 0;
 	private int bytesread = 0;
 	private TarEntry firstEntry = null;
 	private String longLinkName = null;

 	/**
 	 * Creates a new tar input stream on the given input stream.
 	 *
 	 * @param in input stream
 	 * @throws TarException
 	 * @throws IOException
 	 */
 	public TarInputStream(InputStream in) throws TarException, IOException {
 		super(in);

 		// Read in the first TarEntry to make sure
 		// the input is a valid tar file stream.
 		firstEntry = getNextEntry();
 	}

 	/**
 	 * Create a new tar input stream, skipping ahead to the given entry
 	 * in the file.
 	 *
 	 * @param in input stream
 	 * @param entry skips to this entry in the file
 	 * @throws TarException
 	 * @throws IOException
 	 */
 	TarInputStream(InputStream in, TarEntry entry) throws TarException, IOException {
 		super(in);
 		skipToEntry(entry);
 	}

 	/**
 	 *  The checksum of a tar file header is simply the sum of the bytes in
 	 *  the header.
 	 *
 	 * @param header
 	 * @return checksum
 	 */
 	private long headerChecksum(byte[] header) {
 		long sum = 0;
 		for(int i = 0; i < 512; i++) {
 			sum += header[i] & 0xff;
 		}
 		return sum;
 	}

 	/**
 	 * Skips ahead to the position of the given entry in the file.
 	 *
 	 * @param entry
 	 * @returns false if the entry has already been passed
 	 * @throws TarException
 	 * @throws IOException
 	 */
 	boolean skipToEntry(TarEntry entry) throws TarException, IOException {
 		int bytestoskip = entry.filepos - bytesread;
 		if(bytestoskip < 0) {
 			return false;
 		}
 		while(bytestoskip > 0) {
 			long ret = in.skip(bytestoskip);
 			if(ret < 0) {
 				throw new IOException("early end of stream"); //$NON-NLS-1$
 			}
 			bytestoskip -= ret;
 			bytesread += ret;
 		}
 		filepos = entry.filepos;
 		nextEntry = 0;
 		nextEOF = 0;
 		// Read next header to seek to file data.
 		getNextEntry();
 		return true;
 	}

 	/**
 	 * Returns true if the header checksum is correct.
 	 *
 	 * @param header
 	 * @return true if this header has a valid checksum
 	 */
 	private boolean isValidTarHeader(byte[] header) {
 		long fileChecksum, calculatedChecksum;
 		int pos, i;

 		pos = 148;
 		StringBuffer checksumString = new StringBuffer();
 		for(i = 0; i < 8; i++) {
 			if(header[pos + i] == ' ') {
 				continue;
 			}
 			if(header[pos + i] == 0 || !Character.isDigit((char) header[pos + i])) {
 				break;
 			}
 			checksumString.append((char) header[pos + i]);
 		}
 		if(checksumString.length() == 0) {
 			return false;
 		}
 		if(checksumString.charAt(0) != '0') {
 			checksumString.insert(0, '0');
 		}
 		try {
 			fileChecksum = Long.decode(checksumString.toString()).longValue();
 		} catch(NumberFormatException exception) {
 			//This is not valid if it cannot be parsed
 			return false;
 		}

 		// Blank out the checksum.
 		for(i = 0; i < 8; i++) {
 			header[pos + i] = ' ';
 		}
 		calculatedChecksum = headerChecksum(header);

 		return (fileChecksum == calculatedChecksum);
 	}

 	/**
 	 * Returns the next entry in the tar file.  Does not handle
 	 * GNU @LongLink extensions.
 	 *
 	 * @return the next entry in the tar file
 	 * @throws TarException
 	 * @throws IOException
 	 */
 	TarEntry getNextEntryInternal() throws TarException, IOException {
 		byte[] header = new byte[512];
 		int pos = 0;
 		int i;

 		if(firstEntry != null) {
 			TarEntry entryReturn = firstEntry;
 			firstEntry = null;
 			return entryReturn;
 		}

 		while(nextEntry > 0) {
 			long ret = in.skip(nextEntry);
 			if(ret < 0) {
 				throw new IOException("early end of stream"); //$NON-NLS-1$
 			}
 			nextEntry -= ret;
 			bytesread += ret;
 		}

 		int bytestoread = 512;
 		while(bytestoread > 0) {
 			int ret = super.read(header, 512 - bytestoread, bytestoread);
 			if( ret < 0 ) {
 				throw new IOException("early end of stream"); //$NON-NLS-1$
 			}
 			bytestoread -= ret;
 			bytesread += ret;
 		}

 		// If we have a header of all zeros, this marks the end of the file.
 		if(headerChecksum(header) == 0) {
 			// We are at the end of the file.
 			if(filepos > 0) {
 				return null;
 			}

 			// Invalid stream.
 			throw new TarException("not in tar format"); //$NON-NLS-1$
 		}

 		// Validate checksum.
 		if(!isValidTarHeader(header)) {
 			throw new TarException("not in tar format"); //$NON-NLS-1$
 		}

 		while (pos < 100 && header[pos] != 0) {
 			pos++;
 		}
 		String name = new String(header, 0, pos, "UTF8"); //$NON-NLS-1$
 		// Prepend the prefix here.
 		pos = 345;
 		if(header[pos] != 0) {
 			while (pos < 500 && header[pos] != 0) {
 				pos++;
 			}
 			String prefix = new String(header, 345, pos - 345, "UTF8"); //$NON-NLS-1$
 			name = prefix + "/" + name; //$NON-NLS-1$
 		}

 		TarEntry entry;
 		if(longLinkName != null) {
 			entry = new TarEntry(longLinkName, filepos);
 			longLinkName = null;
 		} else {
 			entry = new TarEntry(name, filepos);
 		}
 		if(header[156] != 0) {
 			entry.setFileType(header[156]);
 		}

 		pos = 100;
 		StringBuffer mode = new StringBuffer();
 		for(i = 0; i < 8; i++) {
 			if(header[pos + i] == 0) {
 				break;
 			}
 			if(header[pos + i] == ' ') {
 				continue;
 			}
 			mode.append((char) header[pos + i]);
 		}
 		if(mode.length() > 0 && mode.charAt(0) != '0') {
 			mode.insert(0, '0');
 		}
 		try {
 			long fileMode = Long.decode(mode.toString()).longValue();
 			entry.setMode(fileMode);
 		} catch(NumberFormatException nfe) { // TODO
 			throw new TarException("TarImport_invalid_tar_format" + nfe);
 		}

 		pos = 100 + 24;
 		StringBuffer size = new StringBuffer();
 		for(i = 0; i < 12; i++) {
 			if(header[pos + i] == 0) {
 				break;
 			}
 			if(header[pos + i] == ' ') {
 				continue;
 			}
 			size.append((char) header[pos + i]);
 		}
 		if(size.charAt(0) != '0') {
 			size.insert(0, '0');
 		}
 		int fileSize;
 		try {
 			fileSize = Integer.decode(size.toString()).intValue();
 		} catch(NumberFormatException nfe) { // TODO
 			throw new TarException("DataTransferMessages.TarImport_invalid_tar_format" + nfe);
 		}

 		entry.setSize(fileSize);
 		nextEOF = fileSize;
 		if(fileSize % 512 > 0) {
 			nextEntry = fileSize + (512 - (fileSize % 512));
 		} else {
 			nextEntry = fileSize;
 		}
 		filepos += (nextEntry + 512);
 		return entry;
 	}

 	/**
 	 * Moves ahead to the next file in the tar archive and returns
 	 * a TarEntry object describing it.
 	 *
 	 * @return the next entry in the tar file
 	 * @throws TarException
 	 * @throws IOException
 	 */
 	public TarEntry getNextEntry() throws TarException, IOException {
 		TarEntry entry = getNextEntryInternal();

 		if(entry != null && entry.getName().equals("././@LongLink")) { //$NON-NLS-1$
 			// This is a GNU extension for doing long filenames.
 			// We get a file called ././@LongLink which just contains
 			// the real pathname.
 			byte[] longNameData = new byte[(int) entry.getSize()];
 			int bytesread2 = 0;
 			while (bytesread2 < longNameData.length) {
 				int cur = read(longNameData, bytesread2, longNameData.length - bytesread2);
 				if (cur < 0) {
 					throw new IOException("early end of stream"); //$NON-NLS-1$
 				}
 				bytesread2 += cur;
 			}

 			int pos = 0;
 			while (pos < longNameData.length && longNameData[pos] != 0) {
 				pos++;
 			}
 			longLinkName = new String(longNameData, 0, pos, "UTF8"); //$NON-NLS-1$
 			return getNextEntryInternal();
 		}
 		return entry;
 	}

 	/* (non-Javadoc)
 	 * @see java.io.FilterInputStream#read(byte[], int, int)
 	 */
 	public int read(byte[] b, int off, int len) throws IOException {
 		if(nextEOF == 0) {
 			return -1;
 		}
 		if(len > nextEOF) {
 			len = nextEOF;
 		}
 		int size = super.read(b, off, len);
 		nextEntry -= size;
 		nextEOF -= size;
 		bytesread += size;
 		return size;
 	}

 	/* (non-Javadoc)
 	 * @see java.io.FilterInputStream#read()
 	 */
 	public int read() throws IOException {
 		byte[] data = new byte[1];
 		int size = read(data, 0, 1);
 		if (size < 0) {
 			return size;
 		}
 		return data[0];
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2004, 2007 IBM Corporation and others.
	* All rights reserved. This program and the accompanying materials
	* are made available under the terms of the Eclipse Public License v1.0
	* which accompanies this distribution, and is available at
	* http://www.eclipse.org/legal/epl-v10.html
	*
	* Contributors:
	* IBM Corporation - initial API and implementation
	*******************************************************************************/
	package org.eclipse.wst.server.core.internal.tar;

	import java.io.FilterInputStream;
	import java.io.IOException;
	import java.io.InputStream;
	/**
	* Input stream for reading files in ustar format (tar) compatible
	* with the specification in IEEE Std 1003.1-2001. Also supports
	* long filenames encoded using the GNU @LongLink extension.
	* <p>
	* Copied from org.eclipse.ui.internal.wizards.datatransfer.
	* </p>
	*/
	public class TarInputStream extends FilterInputStream {
	private int nextEntry = 0;
	private int nextEOF = 0;
	private int filepos = 0;
	private int bytesread = 0;
	private TarEntry firstEntry = null;
	private String longLinkName = null;

	/**
	* Creates a new tar input stream on the given input stream.
	*
	* @param in input stream
	* @throws TarException
	* @throws IOException
	*/
	public TarInputStream(InputStream in) throws TarException, IOException {
	super(in);

	// Read in the first TarEntry to make sure
	// the input is a valid tar file stream.
	firstEntry = getNextEntry();
	}

	/**
	* Create a new tar input stream, skipping ahead to the given entry
	* in the file.
	*
	* @param in input stream
	* @param entry skips to this entry in the file
	* @throws TarException
	* @throws IOException
	*/
	TarInputStream(InputStream in, TarEntry entry) throws TarException, IOException {
	super(in);
	skipToEntry(entry);
	}

	/**
	* The checksum of a tar file header is simply the sum of the bytes in
	* the header.
	*
	* @param header
	* @return checksum
	*/
	private long headerChecksum(byte[] header) {
	long sum = 0;
	for(int i = 0; i < 512; i++) {
	sum += header[i] & 0xff;
	}
	return sum;
	}

	/**
	* Skips ahead to the position of the given entry in the file.
	*
	* @param entry
	* @returns false if the entry has already been passed
	* @throws TarException
	* @throws IOException
	*/
	boolean skipToEntry(TarEntry entry) throws TarException, IOException {
	int bytestoskip = entry.filepos - bytesread;
	if(bytestoskip < 0) {
	return false;
	}
	while(bytestoskip > 0) {
	long ret = in.skip(bytestoskip);
	if(ret < 0) {
	throw new IOException("early end of stream"); //$NON-NLS-1$
	}
	bytestoskip -= ret;
	bytesread += ret;
	}
	filepos = entry.filepos;
	nextEntry = 0;
	nextEOF = 0;
	// Read next header to seek to file data.
	getNextEntry();
	return true;
	}

	/**
	* Returns true if the header checksum is correct.
	*
	* @param header
	* @return true if this header has a valid checksum
	*/
	private boolean isValidTarHeader(byte[] header) {
	long fileChecksum, calculatedChecksum;
	int pos, i;

	pos = 148;
	StringBuffer checksumString = new StringBuffer();
	for(i = 0; i < 8; i++) {
	if(header[pos + i] == ' ') {
	continue;
	}
	if(header[pos + i] == 0 \|\| !Character.isDigit((char) header[pos + i])) {
	break;
	}
	checksumString.append((char) header[pos + i]);
	}
	if(checksumString.length() == 0) {
	return false;
	}
	if(checksumString.charAt(0) != '0') {
	checksumString.insert(0, '0');
	}
	try {
	fileChecksum = Long.decode(checksumString.toString()).longValue();
	} catch(NumberFormatException exception) {
	//This is not valid if it cannot be parsed
	return false;
	}

	// Blank out the checksum.
	for(i = 0; i < 8; i++) {
	header[pos + i] = ' ';
	}
	calculatedChecksum = headerChecksum(header);

	return (fileChecksum == calculatedChecksum);
	}

	/**
	* Returns the next entry in the tar file. Does not handle
	* GNU @LongLink extensions.
	*
	* @return the next entry in the tar file
	* @throws TarException
	* @throws IOException
	*/
	TarEntry getNextEntryInternal() throws TarException, IOException {
	byte[] header = new byte[512];
	int pos = 0;
	int i;

	if(firstEntry != null) {
	TarEntry entryReturn = firstEntry;
	firstEntry = null;
	return entryReturn;
	}

	while(nextEntry > 0) {
	long ret = in.skip(nextEntry);
	if(ret < 0) {
	throw new IOException("early end of stream"); //$NON-NLS-1$
	}
	nextEntry -= ret;
	bytesread += ret;
	}

	int bytestoread = 512;
	while(bytestoread > 0) {
	int ret = super.read(header, 512 - bytestoread, bytestoread);
	if( ret < 0 ) {
	throw new IOException("early end of stream"); //$NON-NLS-1$
	}
	bytestoread -= ret;
	bytesread += ret;
	}

	// If we have a header of all zeros, this marks the end of the file.
	if(headerChecksum(header) == 0) {
	// We are at the end of the file.
	if(filepos > 0) {
	return null;
	}

	// Invalid stream.
	throw new TarException("not in tar format"); //$NON-NLS-1$
	}

	// Validate checksum.
	if(!isValidTarHeader(header)) {
	throw new TarException("not in tar format"); //$NON-NLS-1$
	}

	while (pos < 100 && header[pos] != 0) {
	pos++;
	}
	String name = new String(header, 0, pos, "UTF8"); //$NON-NLS-1$
	// Prepend the prefix here.
	pos = 345;
	if(header[pos] != 0) {
	while (pos < 500 && header[pos] != 0) {
	pos++;
	}
	String prefix = new String(header, 345, pos - 345, "UTF8"); //$NON-NLS-1$
	name = prefix + "/" + name; //$NON-NLS-1$
	}

	TarEntry entry;
	if(longLinkName != null) {
	entry = new TarEntry(longLinkName, filepos);
	longLinkName = null;
	} else {
	entry = new TarEntry(name, filepos);
	}
	if(header[156] != 0) {
	entry.setFileType(header[156]);
	}

	pos = 100;
	StringBuffer mode = new StringBuffer();
	for(i = 0; i < 8; i++) {
	if(header[pos + i] == 0) {
	break;
	}
	if(header[pos + i] == ' ') {
	continue;
	}
	mode.append((char) header[pos + i]);
	}
	if(mode.length() > 0 && mode.charAt(0) != '0') {
	mode.insert(0, '0');
	}
	try {
	long fileMode = Long.decode(mode.toString()).longValue();
	entry.setMode(fileMode);
	} catch(NumberFormatException nfe) { // TODO
	throw new TarException("TarImport_invalid_tar_format" + nfe);
	}

	pos = 100 + 24;
	StringBuffer size = new StringBuffer();
	for(i = 0; i < 12; i++) {
	if(header[pos + i] == 0) {
	break;
	}
	if(header[pos + i] == ' ') {
	continue;
	}
	size.append((char) header[pos + i]);
	}
	if(size.charAt(0) != '0') {
	size.insert(0, '0');
	}
	int fileSize;
	try {
	fileSize = Integer.decode(size.toString()).intValue();
	} catch(NumberFormatException nfe) { // TODO
	throw new TarException("DataTransferMessages.TarImport_invalid_tar_format" + nfe);
	}

	entry.setSize(fileSize);
	nextEOF = fileSize;
	if(fileSize % 512 > 0) {
	nextEntry = fileSize + (512 - (fileSize % 512));
	} else {
	nextEntry = fileSize;
	}
	filepos += (nextEntry + 512);
	return entry;
	}

	/**
	* Moves ahead to the next file in the tar archive and returns
	* a TarEntry object describing it.
	*
	* @return the next entry in the tar file
	* @throws TarException
	* @throws IOException
	*/
	public TarEntry getNextEntry() throws TarException, IOException {
	TarEntry entry = getNextEntryInternal();

	if(entry != null && entry.getName().equals("././@LongLink")) { //$NON-NLS-1$
	// This is a GNU extension for doing long filenames.
	// We get a file called ././@LongLink which just contains
	// the real pathname.
	byte[] longNameData = new byte[(int) entry.getSize()];
	int bytesread2 = 0;
	while (bytesread2 < longNameData.length) {
	int cur = read(longNameData, bytesread2, longNameData.length - bytesread2);
	if (cur < 0) {
	throw new IOException("early end of stream"); //$NON-NLS-1$
	}
	bytesread2 += cur;
	}

	int pos = 0;
	while (pos < longNameData.length && longNameData[pos] != 0) {
	pos++;
	}
	longLinkName = new String(longNameData, 0, pos, "UTF8"); //$NON-NLS-1$
	return getNextEntryInternal();
	}
	return entry;
	}

	/* (non-Javadoc)
	* @see java.io.FilterInputStream#read(byte[], int, int)
	*/
	public int read(byte[] b, int off, int len) throws IOException {
	if(nextEOF == 0) {
	return -1;
	}
	if(len > nextEOF) {
	len = nextEOF;
	}
	int size = super.read(b, off, len);
	nextEntry -= size;
	nextEOF -= size;
	bytesread += size;
	return size;
	}

	/* (non-Javadoc)
	* @see java.io.FilterInputStream#read()
	*/
	public int read() throws IOException {
	byte[] data = new byte[1];
	int size = read(data, 0, 1);
	if (size < 0) {
	return size;
	}
	return data[0];
	}
	}