/*
* Copyright (C) 2011, 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
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* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
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package org.eclipse.jgit.blame;
import java.io.IOException;
import org.eclipse.jgit.diff.RawText;
import org.eclipse.jgit.lib.PersonIdent;
import org.eclipse.jgit.revwalk.RevCommit;
/**
* Collects line annotations for inspection by applications.
* <p>
* A result is usually updated incrementally as the BlameGenerator digs back
* further through history. Applications that want to lay annotations down text
* to the original source file in a viewer may find the BlameResult structure an
* easy way to acquire the information, at the expense of keeping tables in
* memory tracking every line of the result file.
* <p>
* This class is not thread-safe.
* <p>
* During blame processing there are two files involved:
* <ul>
* <li>result - The file whose lines are being examined. This is the revision
* the user is trying to view blame/annotation information alongside of.</li>
* <li>source - The file that was blamed with supplying one or more lines of
* data into result. The source may be a different file path (due to copy or
* rename). Source line numbers may differ from result line numbers due to lines
* being added/removed in intermediate revisions.</li>
* </ul>
*/
public class BlameResult {
/**
* Construct a new BlameResult for a generator.
*
* @param gen
* the generator the result will consume records from.
* @return the new result object. null if the generator cannot find the path
* it starts from.
* @throws IOException
* the repository cannot be read.
*/
public static BlameResult create(BlameGenerator gen) throws IOException {
String path = gen.getResultPath();
RawText contents = gen.getResultContents();
if (contents == null) {
gen.close();
return null;
}
return new BlameResult(gen, path, contents);
}
private final String resultPath;
private final RevCommit[] sourceCommits;
private final PersonIdent[] sourceAuthors;
private final PersonIdent[] sourceCommitters;
private final String[] sourcePaths;
/** Warning: these are actually 1-based. */
private final int[] sourceLines;
private RawText resultContents;
private BlameGenerator generator;
private int lastLength;
BlameResult(BlameGenerator bg, String path, RawText text) {
generator = bg;
resultPath = path;
resultContents = text;
int cnt = text.size();
sourceCommits = new RevCommit[cnt];
sourceAuthors = new PersonIdent[cnt];
sourceCommitters = new PersonIdent[cnt];
sourceLines = new int[cnt];
sourcePaths = new String[cnt];
}
/** @return path of the file this result annotates. */
public String getResultPath() {
return resultPath;
}
/** @return contents of the result file, available for display. */
public RawText getResultContents() {
return resultContents;
}
/** Throw away the {@link #getResultContents()}. */
public void discardResultContents() {
resultContents = null;
}
/**
* Check if the given result line has been annotated yet.
*
* @param idx
* line to read data of, 0 based.
* @return true if the data has been annotated, false otherwise.
*/
public boolean hasSourceData(int idx) {
return sourceLines[idx] != 0;
}
/**
* Check if the given result line has been annotated yet.
*
* @param start
* first index to examine.
* @param end
* last index to examine.
* @return true if the data has been annotated, false otherwise.
*/
public boolean hasSourceData(int start, int end) {
for (; start < end; start++)
if (sourceLines[start] == 0)
return false;
return true;
}
/**
* Get the commit that provided the specified line of the result.
* <p>
* The source commit may be null if the line was blamed to an uncommitted
* revision, such as the working tree copy, or during a reverse blame if the
* line survives to the end revision (e.g. the branch tip).
*
* @param idx
* line to read data of, 0 based.
* @return commit that provided line {@code idx}. May be null.
*/
public RevCommit getSourceCommit(int idx) {
return sourceCommits[idx];
}
/**
* Get the author that provided the specified line of the result.
*
* @param idx
* line to read data of, 0 based.
* @return author that provided line {@code idx}. May be null.
*/
public PersonIdent getSourceAuthor(int idx) {
return sourceAuthors[idx];
}
/**
* Get the committer that provided the specified line of the result.
*
* @param idx
* line to read data of, 0 based.
* @return committer that provided line {@code idx}. May be null.
*/
public PersonIdent getSourceCommitter(int idx) {
return sourceCommitters[idx];
}
/**
* Get the file path that provided the specified line of the result.
*
* @param idx
* line to read data of, 0 based.
* @return source file path that provided line {@code idx}.
*/
public String getSourcePath(int idx) {
return sourcePaths[idx];
}
/**
* Get the corresponding line number in the source file.
*
* @param idx
* line to read data of, 0 based.
* @return matching line number in the source file.
*/
public int getSourceLine(int idx) {
return sourceLines[idx] - 1;
}
/**
* Compute all pending information.
*
* @throws IOException
* the repository cannot be read.
*/
public void computeAll() throws IOException {
BlameGenerator gen = generator;
if (gen == null)
return;
try {
while (gen.next())
loadFrom(gen);
} finally {
gen.close();
generator = null;
}
}
/**
* Compute the next available segment and return the first index.
* <p>
* Computes one segment and returns to the caller the first index that is
* available. After return the caller can also inspect {@link #lastLength()}
* to determine how many lines of the result were computed.
*
* @return index that is now available. -1 if no more are available.
* @throws IOException
* the repository cannot be read.
*/
public int computeNext() throws IOException {
BlameGenerator gen = generator;
if (gen == null)
return -1;
if (gen.next()) {
loadFrom(gen);
lastLength = gen.getRegionLength();
return gen.getResultStart();
} else {
gen.close();
generator = null;
return -1;
}
}
/** @return length of the last segment found by {@link #computeNext()}. */
public int lastLength() {
return lastLength;
}
/**
* Compute until the entire range has been populated.
*
* @param start
* first index to examine (inclusive).
* @param end
* end index (exclusive).
* @throws IOException
* the repository cannot be read.
*/
public void computeRange(int start, int end) throws IOException {
BlameGenerator gen = generator;
if (gen == null)
return;
if (start == 0 && end == resultContents.size()) {
computeAll();
return;
}
while (start < end) {
if (hasSourceData(start, end))
return;
if (!gen.next()) {
gen.close();
generator = null;
return;
}
loadFrom(gen);
// If the result contains either end of our current range bounds,
// update the bounds to avoid scanning that section during the
// next loop iteration.
int resLine = gen.getResultStart();
int resEnd = gen.getResultEnd();
if (resLine <= start && start < resEnd)
start = resEnd;
if (resLine <= end && end < resEnd)
end = resLine;
}
}
@Override
public String toString() {
StringBuilder r = new StringBuilder();
r.append("BlameResult: "); //$NON-NLS-1$
r.append(getResultPath());
return r.toString();
}
private void loadFrom(BlameGenerator gen) {
RevCommit srcCommit = gen.getSourceCommit();
PersonIdent srcAuthor = gen.getSourceAuthor();
PersonIdent srcCommitter = gen.getSourceCommitter();
String srcPath = gen.getSourcePath();
int srcLine = gen.getSourceStart();
int resLine = gen.getResultStart();
int resEnd = gen.getResultEnd();
for (; resLine < resEnd; resLine++) {
// Reverse blame can generate multiple results for the same line.
// Favor the first one selected, as this is the oldest and most
// likely to be nearest to the inquiry made by the user.
if (sourceLines[resLine] != 0)
continue;
sourceCommits[resLine] = srcCommit;
sourceAuthors[resLine] = srcAuthor;
sourceCommitters[resLine] = srcCommitter;
sourcePaths[resLine] = srcPath;
// Since sourceLines is 1-based to permit hasSourceData to use 0 to
// mean the line has not been annotated yet, pre-increment instead
// of the traditional post-increment when making the assignment.
sourceLines[resLine] = ++srcLine;
}
}
}