From bd56172b829d447d320cd6933b6d72363dae7dac Mon Sep 17 00:00:00 2001
From: Chris Lu <chris.lu@gmail.com>
Date: Wed, 8 Apr 2020 12:50:20 -0700
Subject: [PATCH] simplify file handle management

---
 weed/filesys/wfs.go | 36 +++++++++++-------------------------
 1 file changed, 11 insertions(+), 25 deletions(-)

diff --git a/weed/filesys/wfs.go b/weed/filesys/wfs.go
index 590c39790..191b79845 100644
--- a/weed/filesys/wfs.go
+++ b/weed/filesys/wfs.go
@@ -54,9 +54,8 @@ type WFS struct {
 	listDirectoryEntriesCache *ccache.Cache
 
 	// contains all open handles, protected by handlesLock
-	handlesLock       sync.Mutex
-	handles           []*FileHandle
-	pathToHandleIndex map[util.FullPath]int
+	handlesLock sync.Mutex
+	handles     map[uint64]*FileHandle
 
 	bufPool sync.Pool
 
@@ -76,7 +75,7 @@ func NewSeaweedFileSystem(option *Option) *WFS {
 	wfs := &WFS{
 		option:                    option,
 		listDirectoryEntriesCache: ccache.New(ccache.Configure().MaxSize(option.DirListCacheLimit * 3).ItemsToPrune(100)),
-		pathToHandleIndex:         make(map[util.FullPath]int),
+		handles:                   make(map[uint64]*FileHandle),
 		bufPool: sync.Pool{
 			New: func() interface{} {
 				return make([]byte, option.ChunkSizeLimit)
@@ -117,26 +116,15 @@ func (wfs *WFS) AcquireHandle(file *File, uid, gid uint32) (fileHandle *FileHand
 	wfs.handlesLock.Lock()
 	defer wfs.handlesLock.Unlock()
 
-	index, found := wfs.pathToHandleIndex[fullpath]
-	if found && wfs.handles[index] != nil {
-		glog.V(2).Infoln(fullpath, "found fileHandle id", index)
-		return wfs.handles[index]
+	inodeId := file.fullpath().AsInode()
+	existingHandle, found := wfs.handles[inodeId]
+	if found && existingHandle != nil {
+		return existingHandle
 	}
 
 	fileHandle = newFileHandle(file, uid, gid)
-	for i, h := range wfs.handles {
-		if h == nil {
-			wfs.handles[i] = fileHandle
-			fileHandle.handle = uint64(i)
-			wfs.pathToHandleIndex[fullpath] = i
-			glog.V(4).Infof("%s reuse fh %d", fullpath, fileHandle.handle)
-			return
-		}
-	}
-
-	wfs.handles = append(wfs.handles, fileHandle)
-	fileHandle.handle = uint64(len(wfs.handles) - 1)
-	wfs.pathToHandleIndex[fullpath] = int(fileHandle.handle)
+	wfs.handles[inodeId] = fileHandle
+	fileHandle.handle = inodeId
 	glog.V(4).Infof("%s new fh %d", fullpath, fileHandle.handle)
 
 	return
@@ -147,10 +135,8 @@ func (wfs *WFS) ReleaseHandle(fullpath util.FullPath, handleId fuse.HandleID) {
 	defer wfs.handlesLock.Unlock()
 
 	glog.V(4).Infof("%s ReleaseHandle id %d current handles length %d", fullpath, handleId, len(wfs.handles))
-	delete(wfs.pathToHandleIndex, fullpath)
-	if int(handleId) < len(wfs.handles) {
-		wfs.handles[int(handleId)] = nil
-	}
+
+	delete(wfs.handles, fullpath.AsInode())
 
 	return
 }