Function OpenChainIndex

plumbing/format/commitgraph/v2/chain.go:69–100

OpenChainIndex expects a billy.Filesystem representing a .git directory. It will read a commit-graph chain file and return a coalesced index. If the chain file or a graph in that chain is not present, an error is returned. See: https://git-scm.com/docs/commit-graph

(fs billy.Filesystem)

//
// See: https://git-scm.com/docs/commit-graph
func OpenChainIndex(fs billy.Filesystem) (Index, error) {
	chainFile, err := fs.Open(path.Join("objects", "info", "commit-graphs", "commit-graph-chain"))
	if err != nil {
		return nil, err
	}

	chain, err := OpenChainFile(chainFile)
	_ = chainFile.Close()
	if err != nil {
		return nil, err
	}

	var index Index
	for _, hash := range chain {

		file, err := fs.Open(path.Join("objects", "info", "commit-graphs", "graph-"+hash+".graph"))
		if err != nil {
			// Ignore all other file closing errors and return the error from opening the last file in the graph
			_ = index.Close()
			return nil, err
		}

		index, err = OpenFileIndexWithParent(file, index)
		if err != nil {
			// Ignore file closing errors and return the error from OpenFileIndex instead
			_ = index.Close()
			return nil, err
		}
	}

	return index, nil
}