org.eclipse.jgit.http.server/src/org/eclipse/jgit/http/server/FileSender.java - sop/jgit - Git at Google

 /*
  * Copyright (C) 2009-2010, Google Inc.
  * and other copyright owners as documented in the project's IP log.
  *
  * This program and the accompanying materials are made available
  * under the terms of the Eclipse Distribution License v1.0 which
  * accompanies this distribution, is reproduced below, and is
  * available at http://www.eclipse.org/org/documents/edl-v10.php
  *
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or
  * without modification, are permitted provided that the following
  * conditions are met:
  *
  * - Redistributions of source code must retain the above copyright
  *   notice, this list of conditions and the following disclaimer.
  *
  * - 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.
  *
  * - Neither the name of the Eclipse Foundation, Inc. nor the
  *   names of its contributors may be used to endorse or promote
  *   products derived from this software without specific prior
  *   written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
  * CONTRIBUTORS "AS IS" AND ANY EXPRESS 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 COPYRIGHT OWNER OR
  * 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.
  */

 package org.eclipse.jgit.http.server;

 import static javax.servlet.http.HttpServletResponse.SC_PARTIAL_CONTENT;
 import static javax.servlet.http.HttpServletResponse.SC_REQUESTED_RANGE_NOT_SATISFIABLE;
 import static org.eclipse.jgit.util.HttpSupport.HDR_ACCEPT_RANGES;
 import static org.eclipse.jgit.util.HttpSupport.HDR_CONTENT_LENGTH;
 import static org.eclipse.jgit.util.HttpSupport.HDR_CONTENT_RANGE;
 import static org.eclipse.jgit.util.HttpSupport.HDR_IF_RANGE;
 import static org.eclipse.jgit.util.HttpSupport.HDR_RANGE;

 import java.io.EOFException;
 import java.io.File;
 import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.io.OutputStream;
 import java.io.RandomAccessFile;
 import java.text.MessageFormat;
 import java.util.Enumeration;

 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;

 import org.eclipse.jgit.lib.ObjectId;

 /**
  * Dumps a file over HTTP GET (or its information via HEAD).
  * <p>
  * Supports a single byte range requested via {@code Range} HTTP header. This
  * feature supports a dumb client to resume download of a larger object file.
  */
 final class FileSender {
 	private final File path;

 	private final RandomAccessFile source;

 	private final long lastModified;

 	private final long fileLen;

 	private long pos;

 	private long end;

 	FileSender(final File path) throws FileNotFoundException {
 		this.path = path;
 		this.source = new RandomAccessFile(path, "r");

 		try {
 			this.lastModified = path.lastModified();
 			this.fileLen = source.getChannel().size();
 			this.end = fileLen;
 		} catch (IOException e) {
 			try {
 				source.close();
 			} catch (IOException closeError) {
 				// Ignore any error closing the stream.
 			}

 			final FileNotFoundException r;
 			r = new FileNotFoundException(MessageFormat.format(HttpServerText.get().cannotGetLengthOf, path));
 			r.initCause(e);
 			throw r;
 		}
 	}

 	void close() {
 		try {
 			source.close();
 		} catch (IOException e) {
 			// Ignore close errors on a read-only stream.
 		}
 	}

 	long getLastModified() {
 		return lastModified;
 	}

 	String getTailChecksum() throws IOException {
 		final int n = 20;
 		final byte[] buf = new byte[n];
 		source.seek(fileLen - n);
 		source.readFully(buf, 0, n);
 		return ObjectId.fromRaw(buf).getName();
 	}

 	void serve(final HttpServletRequest req, final HttpServletResponse rsp,
 			final boolean sendBody) throws IOException {
 		if (!initRangeRequest(req, rsp)) {
 			rsp.sendError(SC_REQUESTED_RANGE_NOT_SATISFIABLE);
 			return;
 		}

 		rsp.setHeader(HDR_ACCEPT_RANGES, "bytes");
 		rsp.setHeader(HDR_CONTENT_LENGTH, Long.toString(end - pos));

 		if (sendBody) {
 			final OutputStream out = rsp.getOutputStream();
 			try {
 				final byte[] buf = new byte[4096];
 				source.seek(pos);
 				while (pos < end) {
 					final int r = (int) Math.min(buf.length, end - pos);
 					final int n = source.read(buf, 0, r);
 					if (n < 0) {
 						throw new EOFException(MessageFormat.format(HttpServerText.get().unexpectedeOFOn, path));
 					}
 					out.write(buf, 0, n);
 					pos += n;
 				}
 				out.flush();
 			} finally {
 				out.close();
 			}
 		}
 	}

 	private boolean initRangeRequest(final HttpServletRequest req,
 			final HttpServletResponse rsp) throws IOException {
 		final Enumeration<String> rangeHeaders = getRange(req);
 		if (!rangeHeaders.hasMoreElements()) {
 			// No range headers, the request is fine.
 			return true;
 		}

 		final String range = rangeHeaders.nextElement();
 		if (rangeHeaders.hasMoreElements()) {
 			// To simplify the code we support only one range.
 			return false;
 		}

 		final int eq = range.indexOf('=');
 		final int dash = range.indexOf('-');
 		if (eq < 0 || dash < 0 || !range.startsWith("bytes=")) {
 			return false;
 		}

 		final String ifRange = req.getHeader(HDR_IF_RANGE);
 		if (ifRange != null && !getTailChecksum().equals(ifRange)) {
 			// If the client asked us to verify the ETag and its not
 			// what they expected we need to send the entire content.
 			return true;
 		}

 		try {
 			if (eq + 1 == dash) {
 				// "bytes=-500" means last 500 bytes
 				pos = Long.parseLong(range.substring(dash + 1));
 				pos = fileLen - pos;
 			} else {
 				// "bytes=500-" (position 500 to end)
 				// "bytes=500-1000" (position 500 to 1000)
 				pos = Long.parseLong(range.substring(eq + 1, dash));
 				if (dash < range.length() - 1) {
 					end = Long.parseLong(range.substring(dash + 1));
 					end++; // range was inclusive, want exclusive
 				}
 			}
 		} catch (NumberFormatException e) {
 			// We probably hit here because of a non-digit such as
 			// "," appearing at the end of the first range telling
 			// us there is a second range following. To simplify
 			// the code we support only one range.
 			return false;
 		}

 		if (end > fileLen) {
 			end = fileLen;
 		}
 		if (pos >= end) {
 			return false;
 		}

 		rsp.setStatus(SC_PARTIAL_CONTENT);
 		rsp.setHeader(HDR_CONTENT_RANGE, "bytes " + pos + "-" + (end - 1) + "/"
 				+ fileLen);
 		source.seek(pos);
 		return true;
 	}

 	private static Enumeration<String> getRange(final HttpServletRequest req) {
 		return req.getHeaders(HDR_RANGE);
 	}
 }
	/*
	* Copyright (C) 2009-2010, Google Inc.
	* and other copyright owners as documented in the project's IP log.
	*
	* This program and the accompanying materials are made available
	* under the terms of the Eclipse Distribution License v1.0 which
	* accompanies this distribution, is reproduced below, and is
	* available at http://www.eclipse.org/org/documents/edl-v10.php
	*
	* All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or
	* without modification, are permitted provided that the following
	* conditions are met:
	*
	* - Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	*
	* - 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.
	*
	* - Neither the name of the Eclipse Foundation, Inc. nor the
	* names of its contributors may be used to endorse or promote
	* products derived from this software without specific prior
	* written permission.
	*
	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
	* CONTRIBUTORS "AS IS" AND ANY EXPRESS 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 COPYRIGHT OWNER OR
	* 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.
	*/

	package org.eclipse.jgit.http.server;

	import static javax.servlet.http.HttpServletResponse.SC_PARTIAL_CONTENT;
	import static javax.servlet.http.HttpServletResponse.SC_REQUESTED_RANGE_NOT_SATISFIABLE;
	import static org.eclipse.jgit.util.HttpSupport.HDR_ACCEPT_RANGES;
	import static org.eclipse.jgit.util.HttpSupport.HDR_CONTENT_LENGTH;
	import static org.eclipse.jgit.util.HttpSupport.HDR_CONTENT_RANGE;
	import static org.eclipse.jgit.util.HttpSupport.HDR_IF_RANGE;
	import static org.eclipse.jgit.util.HttpSupport.HDR_RANGE;

	import java.io.EOFException;
	import java.io.File;
	import java.io.FileNotFoundException;
	import java.io.IOException;
	import java.io.OutputStream;
	import java.io.RandomAccessFile;
	import java.text.MessageFormat;
	import java.util.Enumeration;

	import javax.servlet.http.HttpServletRequest;
	import javax.servlet.http.HttpServletResponse;

	import org.eclipse.jgit.lib.ObjectId;

	/**
	* Dumps a file over HTTP GET (or its information via HEAD).
	* <p>
	* Supports a single byte range requested via {@code Range} HTTP header. This
	* feature supports a dumb client to resume download of a larger object file.
	*/
	final class FileSender {
	private final File path;

	private final RandomAccessFile source;

	private final long lastModified;

	private final long fileLen;

	private long pos;

	private long end;

	FileSender(final File path) throws FileNotFoundException {
	this.path = path;
	this.source = new RandomAccessFile(path, "r");

	try {
	this.lastModified = path.lastModified();
	this.fileLen = source.getChannel().size();
	this.end = fileLen;
	} catch (IOException e) {
	try {
	source.close();
	} catch (IOException closeError) {
	// Ignore any error closing the stream.
	}

	final FileNotFoundException r;
	r = new FileNotFoundException(MessageFormat.format(HttpServerText.get().cannotGetLengthOf, path));
	r.initCause(e);
	throw r;
	}
	}

	void close() {
	try {
	source.close();
	} catch (IOException e) {
	// Ignore close errors on a read-only stream.
	}
	}

	long getLastModified() {
	return lastModified;
	}

	String getTailChecksum() throws IOException {
	final int n = 20;
	final byte[] buf = new byte[n];
	source.seek(fileLen - n);
	source.readFully(buf, 0, n);
	return ObjectId.fromRaw(buf).getName();
	}

	void serve(final HttpServletRequest req, final HttpServletResponse rsp,
	final boolean sendBody) throws IOException {
	if (!initRangeRequest(req, rsp)) {
	rsp.sendError(SC_REQUESTED_RANGE_NOT_SATISFIABLE);
	return;
	}

	rsp.setHeader(HDR_ACCEPT_RANGES, "bytes");
	rsp.setHeader(HDR_CONTENT_LENGTH, Long.toString(end - pos));

	if (sendBody) {
	final OutputStream out = rsp.getOutputStream();
	try {
	final byte[] buf = new byte[4096];
	source.seek(pos);
	while (pos < end) {
	final int r = (int) Math.min(buf.length, end - pos);
	final int n = source.read(buf, 0, r);
	if (n < 0) {
	throw new EOFException(MessageFormat.format(HttpServerText.get().unexpectedeOFOn, path));
	}
	out.write(buf, 0, n);
	pos += n;
	}
	out.flush();
	} finally {
	out.close();
	}
	}
	}

	private boolean initRangeRequest(final HttpServletRequest req,
	final HttpServletResponse rsp) throws IOException {
	final Enumeration<String> rangeHeaders = getRange(req);
	if (!rangeHeaders.hasMoreElements()) {
	// No range headers, the request is fine.
	return true;
	}

	final String range = rangeHeaders.nextElement();
	if (rangeHeaders.hasMoreElements()) {
	// To simplify the code we support only one range.
	return false;
	}

	final int eq = range.indexOf('=');
	final int dash = range.indexOf('-');
	if (eq < 0 \|\| dash < 0 \|\| !range.startsWith("bytes=")) {
	return false;
	}

	final String ifRange = req.getHeader(HDR_IF_RANGE);
	if (ifRange != null && !getTailChecksum().equals(ifRange)) {
	// If the client asked us to verify the ETag and its not
	// what they expected we need to send the entire content.
	return true;
	}

	try {
	if (eq + 1 == dash) {
	// "bytes=-500" means last 500 bytes
	pos = Long.parseLong(range.substring(dash + 1));
	pos = fileLen - pos;
	} else {
	// "bytes=500-" (position 500 to end)
	// "bytes=500-1000" (position 500 to 1000)
	pos = Long.parseLong(range.substring(eq + 1, dash));
	if (dash < range.length() - 1) {
	end = Long.parseLong(range.substring(dash + 1));
	end++; // range was inclusive, want exclusive
	}
	}
	} catch (NumberFormatException e) {
	// We probably hit here because of a non-digit such as
	// "," appearing at the end of the first range telling
	// us there is a second range following. To simplify
	// the code we support only one range.
	return false;
	}

	if (end > fileLen) {
	end = fileLen;
	}
	if (pos >= end) {
	return false;
	}

	rsp.setStatus(SC_PARTIAL_CONTENT);
	rsp.setHeader(HDR_CONTENT_RANGE, "bytes " + pos + "-" + (end - 1) + "/"
	+ fileLen);
	source.seek(pos);
	return true;
	}

	private static Enumeration<String> getRange(final HttpServletRequest req) {
	return req.getHeaders(HDR_RANGE);
	}
	}