more solid weed mount (#4089)

* compare chunks by timestamp

* fix slab clearing error

* fix test compilation

* move oldest chunk to sealed, instead of by fullness

* lock on fh.entryViewCache

* remove verbose logs

* revert slat clearing

* less logs

* less logs

* track write and read by timestamp

* remove useless logic

* add entry lock on file handle release

* use mem chunk only, swap file chunk has problems

* comment out code that maybe used later

* add debug mode to compare data read and write

* more efficient readResolvedChunks with linked list

* small optimization

* fix test compilation

* minor fix on writer

* add SeparateGarbageChunks

* group chunks into sections

* turn off debug mode

* fix tests

* fix tests

* tmp enable swap file chunk

* Revert "tmp enable swap file chunk"

This reverts commit 985137ec472924e4815f258189f6ca9f2168a0a7.

* simple refactoring

* simple refactoring

* do not re-use swap file chunk. Sealed chunks should not be re-used.

* comment out debugging facilities

* either mem chunk or swap file chunk is fine now

* remove orderedMutex  as *semaphore.Weighted

not found impactful

* optimize size calculation for changing large files

* optimize performance to avoid going through the long list of chunks

* still problems with swap file chunk

* rename

* tiny optimization

* swap file chunk save only successfully read data

* fix

* enable both mem and swap file chunk

* resolve chunks with range

* rename

* fix chunk interval list

* also change file handle chunk group when adding chunks

* pick in-active chunk with time-decayed counter

* fix compilation

* avoid nil with empty fh.entry

* refactoring

* rename

* rename

* refactor visible intervals to *list.List

* refactor chunkViews to *list.List

* add IntervalList for generic interval list

* change visible interval to use IntervalList in generics

* cahnge chunkViews to *IntervalList[*ChunkView]

* use NewFileChunkSection to create

* rename variables

* refactor

* fix renaming leftover

* renaming

* renaming

* add insert interval

* interval list adds lock

* incrementally add chunks to readers

Fixes:
1. set start and stop offset for the value object
2. clone the value object
3. use pointer instead of copy-by-value when passing to interval.Value
4. use insert interval since adding chunk could be out of order

* fix tests compilation

* fix tests compilation

weed/server/webdav_server.go

@@ -102,14 +102,14 @@ func (fi *FileInfo) IsDir() bool        { return fi.isDirectory }
 func (fi *FileInfo) Sys() interface{}   { return nil }
 
 type WebDavFile struct {
-	fs             *WebDavFileSystem
-	name           string
-	isDirectory    bool
-	off            int64
-	entry          *filer_pb.Entry
-	entryViewCache []filer.VisibleInterval
-	reader         io.ReaderAt
-	bufWriter      *buffered_writer.BufferedWriteCloser
+	fs               *WebDavFileSystem
+	name             string
+	isDirectory      bool
+	off              int64
+	entry            *filer_pb.Entry
+	visibleIntervals *filer.IntervalList[*filer.VisibleInterval]
+	reader           io.ReaderAt
+	bufWriter        *buffered_writer.BufferedWriteCloser
 }
 
 func NewWebDavFileSystem(option *WebDavOption) (webdav.FileSystem, error) {
@@ -381,7 +381,7 @@ func (fs *WebDavFileSystem) Stat(ctx context.Context, name string) (os.FileInfo,
 	return fs.stat(ctx, name)
 }
 
-func (f *WebDavFile) saveDataAsChunk(reader io.Reader, name string, offset int64) (chunk *filer_pb.FileChunk, err error) {
+func (f *WebDavFile) saveDataAsChunk(reader io.Reader, name string, offset int64, tsNs int64) (chunk *filer_pb.FileChunk, err error) {
 
 	fileId, uploadResult, flushErr, _ := operation.UploadWithRetry(
 		f.fs,
@@ -413,7 +413,7 @@ func (f *WebDavFile) saveDataAsChunk(reader io.Reader, name string, offset int64
 		glog.V(0).Infof("upload failure %v: %v", f.name, flushErr)
 		return nil, fmt.Errorf("upload result: %v", uploadResult.Error)
 	}
-	return uploadResult.ToPbFileChunk(fileId, offset), nil
+	return uploadResult.ToPbFileChunk(fileId, offset, tsNs), nil
 }
 
 func (f *WebDavFile) Write(buf []byte) (int, error) {
@@ -439,7 +439,7 @@ func (f *WebDavFile) Write(buf []byte) (int, error) {
 		f.bufWriter.FlushFunc = func(data []byte, offset int64) (flushErr error) {
 
 			var chunk *filer_pb.FileChunk
-			chunk, flushErr = f.saveDataAsChunk(util.NewBytesReader(data), f.name, offset)
+			chunk, flushErr = f.saveDataAsChunk(util.NewBytesReader(data), f.name, offset, time.Now().UnixNano())
 
 			if flushErr != nil {
 				return fmt.Errorf("%s upload result: %v", f.name, flushErr)
@@ -498,7 +498,7 @@ func (f *WebDavFile) Close() error {
 
 	if f.entry != nil {
 		f.entry = nil
-		f.entryViewCache = nil
+		f.visibleIntervals = nil
 	}
 
 	return err
@@ -521,12 +521,12 @@ func (f *WebDavFile) Read(p []byte) (readSize int, err error) {
 	if fileSize == 0 {
 		return 0, io.EOF
 	}
-	if f.entryViewCache == nil {
-		f.entryViewCache, _ = filer.NonOverlappingVisibleIntervals(filer.LookupFn(f.fs), f.entry.GetChunks(), 0, fileSize)
+	if f.visibleIntervals == nil {
+		f.visibleIntervals, _ = filer.NonOverlappingVisibleIntervals(filer.LookupFn(f.fs), f.entry.GetChunks(), 0, fileSize)
 		f.reader = nil
 	}
 	if f.reader == nil {
-		chunkViews := filer.ViewFromVisibleIntervals(f.entryViewCache, 0, fileSize)
+		chunkViews := filer.ViewFromVisibleIntervals(f.visibleIntervals, 0, fileSize)
 		f.reader = filer.NewChunkReaderAtFromClient(filer.LookupFn(f.fs), chunkViews, f.fs.chunkCache, fileSize)
 	}