// Copyright (C) 2009 The Android Open Source Project
//
// Licensed 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 com.google.gerrit.server.patch;
import com.google.gerrit.common.errors.CorruptEntityException;
import com.google.gerrit.common.errors.NoSuchEntityException;
import com.google.gerrit.reviewdb.client.Patch;
import org.eclipse.jgit.errors.CorruptObjectException;
import org.eclipse.jgit.errors.IncorrectObjectTypeException;
import org.eclipse.jgit.errors.MissingObjectException;
import org.eclipse.jgit.lib.Constants;
import org.eclipse.jgit.lib.ObjectId;
import org.eclipse.jgit.lib.ObjectReader;
import org.eclipse.jgit.lib.Repository;
import org.eclipse.jgit.revwalk.RevCommit;
import org.eclipse.jgit.revwalk.RevTree;
import org.eclipse.jgit.revwalk.RevWalk;
import org.eclipse.jgit.treewalk.TreeWalk;
import java.io.IOException;
import java.nio.charset.CharacterCodingException;
/** State supporting processing of a single {@link Patch} instance. */
public class PatchFile {
private final Repository repo;
private final PatchListEntry entry;
private final RevTree aTree;
private final RevTree bTree;
private Text a;
private Text b;
public PatchFile(final Repository repo, final PatchList patchList,
final String fileName) throws MissingObjectException,
IncorrectObjectTypeException, IOException {
this.repo = repo;
this.entry = patchList.get(fileName);
final ObjectReader reader = repo.newObjectReader();
try {
final RevWalk rw = new RevWalk(reader);
final RevCommit bCommit = rw.parseCommit(patchList.getNewId());
if (Patch.COMMIT_MSG.equals(fileName)) {
if (patchList.isAgainstParent()) {
a = Text.EMPTY;
} else {
a = Text.forCommit(repo, reader, patchList.getOldId());
}
b = Text.forCommit(repo, reader, bCommit);
aTree = null;
bTree = null;
} else {
if (patchList.getOldId() != null) {
aTree = rw.parseTree(patchList.getOldId());
} else {
final RevCommit p = bCommit.getParent(0);
rw.parseHeaders(p);
aTree = p.getTree();
}
bTree = bCommit.getTree();
}
} finally {
reader.release();
}
}
/**
* Extract a line from the file, as a string.
*
* @param file the file index to extract.
* @param line the line number to extract (1 based; 1 is the first line).
* @return the string version of the file line.
* @throws CorruptEntityException the patch cannot be read.
* @throws IOException the patch or complete file content cannot be read.
* @throws NoSuchEntityException
* @throws CharacterCodingException the file is not a known character set.
*/
public String getLine(final int file, final int line)
throws CorruptEntityException, IOException, NoSuchEntityException {
switch (file) {
case 0:
if (a == null) {
a = load(aTree, entry.getOldName());
}
return a.getString(line - 1);
case 1:
if (b == null) {
b = load(bTree, entry.getNewName());
}
return b.getString(line - 1);
default:
throw new NoSuchEntityException();
}
}
/**
* Return number of lines in file.
*
* @param file the file index to extract.
* @return number of lines in file.
* @throws CorruptEntityException the patch cannot be read.
* @throws IOException the patch or complete file content cannot be read.
* @throws NoSuchEntityException the file is not exist.
*/
public int getLineCount(final int file)
throws CorruptEntityException, IOException, NoSuchEntityException {
switch (file) {
case 0:
if (a == null) {
a = load(aTree, entry.getOldName());
}
return a.size();
case 1:
if (b == null) {
b = load(bTree, entry.getNewName());
}
return b.size();
default:
throw new NoSuchEntityException();
}
}
private Text load(final ObjectId tree, final String path)
throws MissingObjectException, IncorrectObjectTypeException,
CorruptObjectException, IOException {
if (path == null) {
return Text.EMPTY;
}
final TreeWalk tw = TreeWalk.forPath(repo, path, tree);
if (tw == null) {
return Text.EMPTY;
}
if (tw.getFileMode(0).getObjectType() != Constants.OBJ_BLOB) {
return Text.EMPTY;
}
return new Text(repo.open(tw.getObjectId(0), Constants.OBJ_BLOB));
}
}