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The Adobe Experience Manager SDK
/*
*
* ADOBE CONFIDENTIAL
* __________________
*
* Copyright 2017 Adobe Systems Incorporated
* All Rights Reserved.
*
* NOTICE: All information contained herein is, and remains
* the property of Adobe Systems Incorporated and its suppliers,
* if any. The intellectual and technical concepts contained
* herein are proprietary to Adobe Systems Incorporated and its
* suppliers and are protected by trade secret or copyright law.
* Dissemination of this information or reproduction of this material
* is strictly forbidden unless prior written permission is obtained
* from Adobe Systems Incorporated.
*/
package com.day.util.diff;
import java.io.IOException;
/**
* A hunk records a block of diff between the left and the right document.
* it represents either a insertion, deletion, change or identity. several
* hunks are chained in a linked list.
*/
public class Hunk {
/**
* type indicates an unmodified block
*/
public static final int UNMODIFIED = 0;
/**
* type indicates an inserted block
*/
public static final int INSERTED = 1;
/**
* type indicates a deleted block
*/
public static final int DELETED = 2;
/**
* type indicates a changed block
*/
public static final int CHANGED = INSERTED | DELETED;
/**
* the range in the left document
*/
public final Range left;
/**
* the rnage in the right document
*/
public final Range right;
/**
* the hunk type
*/
public final int type;
/**
* the previous hunk
*/
private Hunk prev;
/**
* the next hunk
*/
private Hunk next;
/**
* Creates a new hunk and adds it to the previous hunk
* @param left the left range
* @param right the right range
* @param type the hunk type
* @param prev the previous hunk
*/
public Hunk(Range left, Range right, int type, Hunk prev) {
this.left = left;
this.right = right;
this.prev = prev;
this.type = type;
if (prev != null) {
prev.next = this;
}
}
/**
* Returns the previous hunk of this chain
* @return the previous hunk.
*/
public Hunk prev() {
return prev;
}
/**
* Returns the next hunk of this chain
* @return the next hunk.
*/
public Hunk next() {
return next;
}
/**
* Writes a unified diff to the given writer and returns the next hunk to
* continue the output.
*
* @param out the writer
* @param numContextLines the number of context lines to include in the
* diff blocks. do not change during iteration!
* @return the next hunk or null.
* @throws IOException if an I/O error occurs.
*/
public Hunk write(DiffWriter out, int numContextLines) throws IOException {
if (type == UNMODIFIED) {
//writeData(out, left, " ");
return next;
} else {
Hunk last = next;
Hunk prevLast = this;
// search hunk that is big enough to hold 2 x numContextLines or is
// the last hunk.
while (last != null) {
if (last.type == UNMODIFIED
&&
(last.left.len() > 2*numContextLines || last.next == null)) {
break;
}
prevLast = last;
last = last.next;
}
// get new ranges for diff line
Range prevRange;
if (prev == null) {
// this is the very first hunk, so no previous context lines
prevRange = new Range(left.doc, left.low, left.low);
} else {
// the search above ensures that the previous one never overlaps
// this hunk. we just need to guard the very first hunk
prevRange = new Range(left.doc, Math.max(left.low - numContextLines, 0), left.low);
}
Range lastRange;
if (last == null) {
// if we did not find a last hunk, create an empty range
// with the bounds of the hunk previous to the last
lastRange = new Range(left.doc, prevLast.left.high, prevLast.left.high);
} else {
// we are not allowed to enlarge the range
lastRange = new Range(left.doc, last.left.low, Math.min(last.left.high, last.left.low + numContextLines));
}
// handle special case where our diff differs from the GNU diff
// i reckon this is a bug in {@link Diff} where the line number
// of a deletion or insertion is 1 too big.
int prevLen0 = prevRange.len();
int lastLen0 = lastRange.len();
int prevLen1 = prevRange.len();
int lastLen1 = lastRange.len();
if (left.len() == 0 && numContextLines == 0) {
prevLen0 = 1;
lastLen0--;
}
if (right.len() == 0 && numContextLines == 0) {
prevLen1 = 1;
lastLen1--;
}
Range newLeft = new Range(left.doc,
left.low - prevLen0,
prevLast.left.high + lastLen0);
Range newRight = new Range(right.doc,
right.low - prevLen1,
prevLast.right.high + lastLen1);
out.write("@@ -");
out.write(newLeft.toRangeString());
out.write(" +");
out.write(newRight.toRangeString());
out.write(" @@");
out.writeNewLine();
// output previous context line
writeData(out, prevRange, " ");
Hunk h = this;
while (h != last) {
h.writeBody(out);
h = h.next;
}
writeData(out, lastRange, " ");
return last;
}
}
/**
* Writes the body of this hunk
* @param out the writer
* @throws IOException if an I/O error occurs.
*/
private void writeBody(DiffWriter out) throws IOException {
if (type == UNMODIFIED) {
writeData(out, left, " ");
}
if ((type & DELETED) != 0) {
writeData(out, left, "-");
}
if ((type & INSERTED) != 0) {
writeData(out, right, "+");
}
}
/**
* Write the actual lines
* @param out the writer
* @param range the range
* @param prefix the prefix
* @throws IOException if an I/O error occurs
*/
private static void writeData(DiffWriter out, Range range, String prefix)
throws IOException {
for (int i=range.low; i© 2015 - 2024 Weber Informatics LLC | Privacy Policy