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- /*
- * 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.util.Enumeration;
-
- import javax.servlet.http.HttpServletRequest;
- import javax.servlet.http.HttpServletResponse;
-
- import org.eclipse.jgit.lib.ObjectId;
- import org.eclipse.jgit.util.IO;
-
- /**
- * 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("Cannot get length of " + 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];
- IO.readFully(source.getChannel(), fileLen - n, 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];
- 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("Unexpected EOF on " + 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;
- }
-
- @SuppressWarnings("unchecked")
- private static Enumeration<String> getRange(final HttpServletRequest req) {
- return req.getHeaders(HDR_RANGE);
- }
- }
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