Method makeRenameMap

fs/sync/sync.go:842–879

makeRenameMap builds a map of the destination files by hash that match sizes in the slice of objects in s.renameCheck

()

// makeRenameMap builds a map of the destination files by hash that
// match sizes in the slice of objects in s.renameCheck
func (s *syncCopyMove) makeRenameMap() {
	fs.Infof(s.fdst, "Making map for --track-renames")

	// first make a map of possible sizes we need to check
	possibleSizes := map[int64]struct{}{}
	for _, obj := range s.renameCheck {
		possibleSizes[obj.Size()] = struct{}{}
	}

	// pump all the dstFiles into in
	in := make(chan fs.Object, s.ci.Checkers)
	go s.pumpMapToChan(s.dstFiles, in)

	// now make a map of size,hash for all dstFiles
	s.renameMap = make(map[string][]fs.Object)
	var wg sync.WaitGroup
	wg.Add(s.ci.Checkers)
	for range s.ci.Checkers {
		go func() {
			defer wg.Done()
			for obj := range in {
				// only create hash for dst fs.Object if its size could match
				if _, found := possibleSizes[obj.Size()]; found {
					tr := accounting.Stats(s.ctx).NewCheckingTransfer(obj, "renaming")
					hash := s.renameID(obj, s.trackRenamesStrategy, s.modifyWindow)

					if hash != "" {
						s.pushRenameMap(hash, obj)
					}

					tr.Done(s.ctx, nil)
				}
			}
		}()
	}
	wg.Wait()
	fs.Infof(s.fdst, "Finished making map for --track-renames")
}

// tryRename renames an src object when doing track renames if
// possible, it returns true if the object was renamed.