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/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package io.milton.zsync;
import java.text.ParseException;
import io.milton.http.Range;
/**
*An object consisting of a Range and a long offset.
*
*A RelocateRange is an instruction sent as part of a ZSync PUT upload,
*which informs the server of the new offset of a single range of blocks from the original file. The String
*format for this object as it appears in the upload is currently "A-B/C", where A-B
*indicates the block range starting at A and ending at B-1, and C represents the location
*of this sequence of blocks in the updated (client-side) file.
*
* @author Nick
*
*/
public final class RelocateRange {
/**
* The String separating the Range from the offset in the String representation
* of this object.
*/
public static final String DIV = "/";
private final Range blockRange;
private final long newOffset;
/**
* Constructs a RelocateRange from a Range and offset. The object is immutable; the fields
* cannot be changed after construction.
*
* @param range A range of block indices in the remote file
* @param offset The new byte position of range
*/
public RelocateRange(Range range, long offset){
this.blockRange = range;
this.newOffset = offset;
}
/**
* Returns a String description of this object, not meant to be inserted into a ZSync PUT.
* For the proper PUT formatting, use {@link #getRelocation()}
*
* @return A brief description of this object
*
*/
@Override
public String toString(){
return "Relocate blocks " + blockRange.getRange() + " to " + newOffset;
}
/**
* Returns a String representing this object, e.g. "10-20/1234",
* ready to be inserted into a ZSync PUT upload request.
*
* @return A String representing this object
*/
public String getRelocation(){
return blockRange.getRange() + DIV + newOffset;
}
/**
* Constructs and returns a RelocateRange object from the input String. The String
* should be in the format A-B/C.
*
* Note: Leading and trailing whitespaces in the argument are ignored, but there should be no
* spaces between the non-ws chars.
*
* @param relocString The String to be parsed
* @return The RelocateRange object corresponding to relocString
* @throws ParseException If the format of the input String is incorrect or the numbers cannot
* be properly parsed
*
*/
public static RelocateRange parse(String relocString) throws ParseException{
String[] parts = relocString.split(DIV);
if (parts.length != 2){
throw new ParseException("Couldn't parse: \"" + relocString
+ "\" as RelocateRange. String contains " + (parts.length - 1)
+ " occurences of " + DIV, -1 );
}
try{
Range range = Range.parse(parts[0].trim());
long loc = Long.parseLong(parts[1].trim());
return new RelocateRange(range, loc);
}
catch(Exception ex){
ParseException parseEx =
new ParseException("Couldn't parse \"" + relocString + "\" " +
"into a RelocateRange. Format should be A-B/C, with no whitespaces", -1);
parseEx.initCause(ex);
throw parseEx;
}
}
/**
* Returns the range of blocks to be relocated.
*
* The numbers in the Range are indices of the blocks in the server's copy
* of the file. The Range consists of the pair (firstBlock, lastBlock + 1).
*
* @return A Range object containing the block range
*/
public Range getBlockRange() {
return blockRange;
}
/**
* Returns the byte position to which the Range should be relocated.
*
* @return The new offset of the Range
*/
public long getOffset() {
return newOffset;
}
}