org.eclipse.jetty.http.ByteRange Maven / Gradle / Ivy
//
// ========================================================================
// Copyright (c) 1995 Mort Bay Consulting Pty Ltd and others.
//
// This program and the accompanying materials are made available under the
// terms of the Eclipse Public License v. 2.0 which is available at
// https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
// which is available at https://www.apache.org/licenses/LICENSE-2.0.
//
// SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
// ========================================================================
//
package org.eclipse.jetty.http;
import java.util.ArrayList;
import java.util.Comparator;
import java.util.List;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* A representation of a byte range as specified by
* RFC 7233.
* This class parses the value of the {@code Range} request header value,
* for example:
* {@code
* Range: bytes=100-499
* Range: bytes=1-10,5-25,50-,-20
* }
*/
public record ByteRange(long first, long last)
{
private static final Logger LOG = LoggerFactory.getLogger(ByteRange.class);
private ByteRange coalesce(ByteRange r)
{
return new ByteRange(Math.min(first, r.first), Math.max(last, r.last));
}
private boolean overlaps(ByteRange range)
{
return
// Partial right overlap: 10-20,15-30.
(range.first >= this.first && range.first <= this.last) ||
// Partial left overlap: 20-30,15-25.
(range.last >= this.first && range.last <= this.last) ||
// Full inclusion: 20-30,10-40.
(range.first < this.first && range.last > this.last);
}
/**
* Get the length of this byte range.
* @return the length of this byte range
*/
public long getLength()
{
return last - first + 1;
}
/**
* Returns the value for the {@code Content-Range}
* response header corresponding to this byte range.
*
* @param length the content length
* @return the value for the {@code Content-Range} response header for this byte range
*/
public String toHeaderValue(long length)
{
return "bytes %d-%d/%d".formatted(first, last, length);
}
/**
* Parses the {@code Range} header values such as {@code byte=10-20}
* to obtain a list of {@code ByteRange}s.
* Returns an empty list if the parsing fails.
*
* @param headers a list of range values
* @param length the length of the resource for which ranges are requested
* @return a list of {@code ByteRange}s
*/
public static List parse(List headers, long length)
{
long end = length - 1;
List ranges = null;
String prefix = "bytes=";
for (String header : headers)
{
String value = header.trim();
if (!value.startsWith(prefix))
continue;
value = value.substring(prefix.length());
for (String range : value.split(","))
{
try
{
range = range.trim();
if (range.startsWith(prefix))
range = range.substring(prefix.length());
long first = -1;
long last = -1;
int dash = range.indexOf('-');
if (dash < 0 || range.indexOf("-", dash + 1) >= 0)
{
if (LOG.isDebugEnabled())
LOG.debug("bad range format: {}", range);
break;
}
if (dash > 0)
first = Long.parseLong(range.substring(0, dash).trim());
if (dash < (range.length() - 1))
last = Long.parseLong(range.substring(dash + 1).trim());
if (first == -1)
{
if (last == -1)
{
if (LOG.isDebugEnabled())
LOG.debug("bad range format: {}", range);
break;
}
if (last == 0)
continue;
// This is a suffix range of the form "-20".
first = Math.max(0, end - last + 1);
last = end;
}
else
{
// Range starts after end.
if (first > end)
continue;
if (last == -1 || last > end)
last = end;
}
if (last < first)
{
if (LOG.isDebugEnabled())
LOG.debug("bad range format: {}", range);
break;
}
ByteRange byteRange = new ByteRange(first, last);
if (ranges == null)
ranges = new ArrayList<>();
ranges.add(byteRange);
}
catch (Throwable x)
{
if (LOG.isDebugEnabled())
LOG.debug("could not parse range {}", header, x);
}
}
}
if (ranges == null)
return List.of();
if (ranges.size() == 1)
return ranges;
// Sort and coalesce in one pass through the list.
List result = new ArrayList<>();
ranges.sort(Comparator.comparingLong(ByteRange::first));
ByteRange range1 = ranges.get(0);
for (int i = 1; i < ranges.size(); ++i)
{
ByteRange range2 = ranges.get(i);
if (range1.overlaps(range2))
{
range1 = range1.coalesce(range2);
}
else
{
result.add(range1);
range1 = range2;
}
}
result.add(range1);
return result;
}
/**
* Returns the value for the {@code Content-Range} response header
* when the range is non satisfiable and therefore the response status
* code is {@link HttpStatus#RANGE_NOT_SATISFIABLE_416}.
*
* @param length the content length in bytes
* @return the non satisfiable value for the {@code Content-Range} response header
*/
public static String toNonSatisfiableHeaderValue(long length)
{
return "bytes */" + length;
}
}