com.teamscale.tia.maven.GitCommit Maven / Gradle / Ivy
package com.teamscale.tia.maven;
import org.eclipse.jgit.api.Git;
import org.eclipse.jgit.lib.ObjectId;
import org.eclipse.jgit.lib.Ref;
import org.eclipse.jgit.lib.Repository;
import org.eclipse.jgit.revwalk.RevCommit;
import org.eclipse.jgit.revwalk.RevWalk;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
/**
* Represents a single commit in a Git repository.
*/
public class GitCommit {
/** The SHA1 of this commit. */
public final String sha1;
/** The timestamp of this commit (Unix epoch in milliseconds). */
public final long timestamp;
/** The branch of this commit. */
public final String branch;
private GitCommit(String sha1, long timestamp, String branch) {
this.sha1 = sha1;
this.timestamp = timestamp;
this.branch = branch;
}
/**
* Determines the current HEAD commit in the Git repository located in the or above the given search directory.
*
* @throws IOException if reading from the Git repository fails or the current directory is not a Git repository.
*/
public static GitCommit getGitHeadCommitDescriptor(Path searchDirectory) throws IOException {
Path gitDirectory = findGitBaseDirectory(searchDirectory);
Git git = Git.open(gitDirectory.toFile());
Repository repository = git.getRepository();
String branch = repository.getBranch();
RevCommit commit = getCommit(repository, branch);
long commitTimeSeconds = commit.getCommitTime();
String ref = repository.getRefDatabase().findRef("HEAD").getObjectId().getName();
return new GitCommit(ref, commitTimeSeconds * 1000L, branch);
}
/**
* Traverses the directory tree upwards until it finds a .git directory. Returns null if no .git directory is
* found.
*/
private static Path findGitBaseDirectory(Path searchDirectory) {
while (searchDirectory != null) {
if (Files.exists(searchDirectory.resolve(".git"))) {
return searchDirectory;
}
searchDirectory = searchDirectory.getParent();
}
return null;
}
private static RevCommit getCommit(Repository repository, String revisionBranchOrTag) throws IOException {
try (RevWalk revWalk = new RevWalk(repository)) {
Ref head = repository.getRefDatabase().findRef(revisionBranchOrTag);
if (head != null) {
return revWalk.parseCommit(head.getLeaf().getObjectId());
} else {
return revWalk.parseCommit(ObjectId.fromString(revisionBranchOrTag));
}
}
}
}