| /* |
| * Copyright (C) 2009-2010, Google Inc. and others |
| * |
| * This program and the accompanying materials are made available under the |
| * terms of the Eclipse Distribution License v. 1.0 which is available at |
| * https://www.eclipse.org/org/documents/edl-v10.php. |
| * |
| * SPDX-License-Identifier: BSD-3-Clause |
| */ |
| |
| 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.time.Instant; |
| 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.FS; |
| |
| /** |
| * 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 Instant lastModified; |
| |
| private final long fileLen; |
| |
| private long pos; |
| |
| private long end; |
| |
| FileSender(File path) throws FileNotFoundException { |
| this.path = path; |
| this.source = new RandomAccessFile(path, "r"); |
| |
| try { |
| this.lastModified = FS.DETECTED.lastModifiedInstant(path); |
| 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. |
| } |
| } |
| |
| Instant 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) { |
| try (OutputStream out = rsp.getOutputStream()) { |
| 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(); |
| } |
| } |
| } |
| |
| 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(HttpServletRequest req) { |
| return req.getHeaders(HDR_RANGE); |
| } |
| } |