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 985137ec47.

* 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/filer/reader_cache.go

@@ -43,7 +43,7 @@ func newReaderCache(limit int, chunkCache chunk_cache.ChunkCache, lookupFileIdFn
 	}
 }
 
-func (rc *ReaderCache) MaybeCache(chunkViews []*ChunkView) {
+func (rc *ReaderCache) MaybeCache(chunkViews *Interval[*ChunkView]) {
 	if rc.lookupFileIdFn == nil {
 		return
 	}
@@ -55,7 +55,8 @@ func (rc *ReaderCache) MaybeCache(chunkViews []*ChunkView) {
 		return
 	}
 
-	for _, chunkView := range chunkViews {
+	for x := chunkViews; x != nil; x = x.Next {
+		chunkView := x.Value
 		if _, found := rc.downloaders[chunkView.FileId]; found {
 			continue
 		}
@@ -65,7 +66,7 @@ func (rc *ReaderCache) MaybeCache(chunkViews []*ChunkView) {
 			return
 		}
 
-		// glog.V(4).Infof("prefetch %s offset %d", chunkView.FileId, chunkView.LogicOffset)
+		// glog.V(4).Infof("prefetch %s offset %d", chunkView.FileId, chunkView.ViewOffset)
 		// cache this chunk if not yet
 		cacher := newSingleChunkCacher(rc, chunkView.FileId, chunkView.CipherKey, chunkView.IsGzipped, int(chunkView.ChunkSize), false)
 		go cacher.startCaching()