Golang Directory.FileLength方法代码示例

/*
Initialize the deleter: find all previous commits in the Directory,
incref the files they reference, call the policy to let it delete
commits. This will remove any files not referenced by any of the
commits.
*/
func newIndexFileDeleter(directory store.Directory, policy IndexDeletionPolicy,
	segmentInfos *SegmentInfos, infoStream util.InfoStream, writer *IndexWriter,
	initialIndexExists bool) (*IndexFileDeleter, error) {

	currentSegmentsFile := segmentInfos.SegmentsFileName()
	if infoStream.IsEnabled("IFD") {
		infoStream.Message("IFD", "init: current segments file is '%v'; deletePolicy=%v",
			currentSegmentsFile, policy)
	}

	fd := &IndexFileDeleter{
		infoStream: infoStream,
		writer:     writer,
		policy:     policy,
		directory:  directory,
		refCounts:  make(map[string]*RefCount),
	}

	// First pass: walk the files and initialize our ref counts:
	currentGen := segmentInfos.generation

	var currentCommitPoint *CommitPoint
	var files []string
	files, err := directory.ListAll()
	if _, ok := err.(*store.NoSuchDirectoryError); ok {
		// it means the directory is empty, so ignore it
		files = make([]string, 0)
	} else if err != nil {
		return nil, err
	}

	if currentSegmentsFile != "" {
		m := model.CODEC_FILE_PATTERN
		for _, filename := range files {
			if !strings.HasSuffix(filename, "write.lock") &&
				filename != INDEX_FILENAME_SEGMENTS_GEN &&
				(m.MatchString(filename) || strings.HasPrefix(filename, util.SEGMENTS)) {

				// Add this file to refCounts with initial count 0:
				fd.refCount(filename)

				if strings.HasPrefix(filename, util.SEGMENTS) {
					// This is a commit (segments or segments_N), and it's
					// valid (<= the max gen). Load it, then incref all files
					// it refers to:
					if infoStream.IsEnabled("IFD") {
						infoStream.Message("IFD", "init: load commit '%v'", filename)
					}
					sis := &SegmentInfos{}
					err := sis.Read(directory, filename)
					if os.IsNotExist(err) {
						// LUCENE-948: on NFS (and maybe others), if
						// you have writers switching back and forth
						// between machines, it's very likely that the
						// dir listing will be stale and will claim a
						// file segments_X exists when in fact it
						// doesn't.  So, we catch this and handle it
						// as if the file does not exist
						if infoStream.IsEnabled("IFD") {
							infoStream.Message("IFD",
								"init: hit FileNotFoundException when loading commit '%v'; skipping this commit point",
								filename)
						}
						sis = nil
					} else if err != nil {
						if GenerationFromSegmentsFileName(filename) <= currentGen {
							length, _ := directory.FileLength(filename)
							if length > 0 {
								return nil, err
							}
						}
						// Most likely we are opening an index that has an
						// aborted "future" commit, so suppress exc in this case
						sis = nil
					} else { // sis != nil
						commitPoint := newCommitPoint(fd.commitsToDelete, directory, sis)
						if sis.generation == segmentInfos.generation {
							currentCommitPoint = commitPoint
						}
						fd.commits = append(fd.commits, commitPoint)
						fd.incRef(sis, true)

						if fd.lastSegmentInfos == nil || sis.generation > fd.lastSegmentInfos.generation {
							fd.lastSegmentInfos = sis
						}
					}
				}
			}
		}
	}

	if currentCommitPoint == nil && currentSegmentsFile != "" && initialIndexExists {
		// We did not in fact see the segments_N file corresponding to
		// the segmentInfos that was passed in. Yet, it must exist,
//.........这里部分代码省略.........