Git blame view doesn't work

[bruntib]

When opening git blame view on the GUI, the CPU seems to be working but there is no result.

[mcserep]

If I remember correctly this issue was only faced with projects/files with a long history.

Based on the code I think the source of the issue will be, that GitServiceHandler::getBlameInfo creates the blame object through the libgit2 API, but then loads the metadata for all hunks (see line 266):

CodeCompass/plugins/git/service/src/gitservice.cpp

Lines 244 to 314 in ff4b4cf

	void GitServiceHandler::getBlameInfo(
	std::vector<GitBlameHunk>& return_,
	const std::string& repoId_,
	const std::string& hexOid_,
	const std::string& path_,
	const std::string& localModificationsFileId_)
	{
	RepositoryPtr repo = createRepository(repoId_);
	if (!repo)
	return;
	BlameOptsPtr opt = createBlameOpts(gitOidFromStr(hexOid_));
	BlamePtr blame = createBlame(repo.get(), path_.c_str(), opt.get());
	if (!localModificationsFileId_.empty())
	{
	std::string fileContent;
	_projectHandler.getFileContent(fileContent, localModificationsFileId_);
	blame = getBlameData(blame, fileContent);
	}
	for (std::uint32_t i = 0; i < git_blame_get_hunk_count(blame.get()); ++i)
	{
	const git_blame_hunk* hunk = git_blame_get_hunk_byindex(blame.get(), i);
	GitBlameHunk blameHunk;
	blameHunk.linesInHunk = hunk->lines_in_hunk;
	blameHunk.boundary = hunk->boundary;
	blameHunk.finalCommitId = gitOidToString(&hunk->final_commit_id);
	blameHunk.finalStartLineNumber = hunk->final_start_line_number;
	// If files are locally changed, final_signature will be null pointer.
	// I think it will be a `libgit2` bug.
	if (hunk->final_signature)
	{
	blameHunk.finalSignature.name = hunk->final_signature->name;
	blameHunk.finalSignature.email = hunk->final_signature->email;
	blameHunk.finalSignature.time = hunk->final_signature->when.time;
	}
	else if (!git_oid_iszero(&hunk->final_commit_id))
	{
	CommitPtr commit = createCommit(repo.get(), hunk->final_commit_id);
	const git_signature* author = git_commit_author(commit.get());
	blameHunk.finalSignature.name = author->name;
	blameHunk.finalSignature.email = author->email;
	blameHunk.finalSignature.time = author->when.time;
	}
	//--- If the changes are not committed yet ---//
	if (blameHunk.finalSignature.time)
	{
	CommitPtr commit = createCommit(repo.get(), hunk->final_commit_id);
	blameHunk.finalCommitMessage = git_commit_message(commit.get());
	}
	blameHunk.origCommitId = gitOidToString(&hunk->orig_commit_id);
	blameHunk.origPath = hunk->orig_path;
	blameHunk.origStartLineNumber = hunk->orig_start_line_number;
	if (hunk->orig_signature)
	{
	blameHunk.origSignature.name = hunk->orig_signature->name;
	blameHunk.origSignature.email = hunk->orig_signature->email;
	blameHunk.origSignature.time = hunk->orig_signature->when.time;
	}
	return_.push_back(std::move(blameHunk));
	}
	}

Then the full history of the file is sent to the webclient. In the browser it seems like the blame history is loaded dynamically upon scrolling, but this is just a JavaScript effect on the client side, once the blame view is loaded for a file, there is no further communication with the webserver. (I have tested it.)

That's why it is so slow for files/projects with a large history, like LLVM.

[intjftw]

@bruntib @mcserep Does anyone remember in which particular file we had this issue? I remember it was in LLVM, but not the exact file. However, I could reproduce the problem for <llvm_root>/llvm/tools/gold/gold-plugin.cpp, to add an example. The GitService returned a (failed) net::ERR_EMPTY_RESPONSE error for this file's git blame.

[mcserep]

@bruntib @mcserep Does anyone remember in which particular file we had this issue? I remember it was in LLVM, but not the exact file. However, I could reproduce the problem for <llvm_root>/llvm/tools/gold/gold-plugin.cpp, to add an example. The GitService returned a (failed) net::ERR_EMPTY_RESPONSE error for this file's git blame.

@intjftw Does executing blame with the Git CLI succeeds for this file? (To verify that the issue is not with git/libgit itself.)

[intjftw]

@mcserep Yes, it executes in less than 1 minute.

[zporky]

An example page where the git/blame takes timeout
http://poirot.codechecker.gic.ericsson.se:8301/#wsid=ml66_proj&fid=17940882928923629289&select=40|9|53|14&center=text

[whisperity]

Something is terribly wrong on the site linked by @zporky, potentially not really related to the Git plugin. The database behind that server is corrupted. I am clicking around, and constantly getting errors in JS like this:

11:32:29.318 Uncaught 
Object { message: "TException - service has thrown: InvalidId(msg=Invalid CppAstNode ID, fid=<null>, nodeid=0)", code: 0, stack: "" }
codemirror.js:3924:29

[mcserep]

What is the status of this bug report @intjftw ? Is it still present or has it been resolved?

[mcserep]

I reevaluated this with the current Gershwin version, and fetching the blame info for files with a long history (e.g. CREDITS.TXT for the LLVM project) still takes a very long time.