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Diffstat (limited to 'plumbing/format/commitgraph/v2/memory.go')
-rw-r--r-- | plumbing/format/commitgraph/v2/memory.go | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/plumbing/format/commitgraph/v2/memory.go b/plumbing/format/commitgraph/v2/memory.go new file mode 100644 index 0000000..ab7ddfa --- /dev/null +++ b/plumbing/format/commitgraph/v2/memory.go @@ -0,0 +1,91 @@ +package v2 + +import ( + "github.com/go-git/go-git/v5/plumbing" +) + +// MemoryIndex provides a way to build the commit-graph in memory +// for later encoding to file. +type MemoryIndex struct { + commitData []commitData + indexMap map[plumbing.Hash]uint32 +} + +type commitData struct { + Hash plumbing.Hash + *CommitData +} + +// NewMemoryIndex creates in-memory commit graph representation +func NewMemoryIndex() *MemoryIndex { + return &MemoryIndex{ + indexMap: make(map[plumbing.Hash]uint32), + } +} + +// GetIndexByHash gets the index in the commit graph from commit hash, if available +func (mi *MemoryIndex) GetIndexByHash(h plumbing.Hash) (uint32, error) { + i, ok := mi.indexMap[h] + if ok { + return i, nil + } + + return 0, plumbing.ErrObjectNotFound +} + +// GetHashByIndex gets the hash given an index in the commit graph +func (mi *MemoryIndex) GetHashByIndex(i uint32) (plumbing.Hash, error) { + if i >= uint32(len(mi.commitData)) { + return plumbing.ZeroHash, plumbing.ErrObjectNotFound + } + + return mi.commitData[i].Hash, nil +} + +// GetCommitDataByIndex gets the commit node from the commit graph using index +// obtained from child node, if available +func (mi *MemoryIndex) GetCommitDataByIndex(i uint32) (*CommitData, error) { + if i >= uint32(len(mi.commitData)) { + return nil, plumbing.ErrObjectNotFound + } + + commitData := mi.commitData[i] + + // Map parent hashes to parent indexes + if commitData.ParentIndexes == nil { + parentIndexes := make([]uint32, len(commitData.ParentHashes)) + for i, parentHash := range commitData.ParentHashes { + var err error + if parentIndexes[i], err = mi.GetIndexByHash(parentHash); err != nil { + return nil, err + } + } + commitData.ParentIndexes = parentIndexes + } + + return commitData.CommitData, nil +} + +// Hashes returns all the hashes that are available in the index +func (mi *MemoryIndex) Hashes() []plumbing.Hash { + hashes := make([]plumbing.Hash, 0, len(mi.indexMap)) + for k := range mi.indexMap { + hashes = append(hashes, k) + } + return hashes +} + +// Add adds new node to the memory index +func (mi *MemoryIndex) Add(hash plumbing.Hash, data *CommitData) { + // The parent indexes are calculated lazily in GetNodeByIndex + // which allows adding nodes out of order as long as all parents + // are eventually resolved + data.ParentIndexes = nil + mi.indexMap[hash] = uint32(len(mi.commitData)) + mi.commitData = append(mi.commitData, commitData{Hash: hash, CommitData: data}) +} + +// Close closes the index +func (mi *MemoryIndex) Close() error { + return nil +} |