1 files changed, 167 insertions, 0 deletions
diff --git a/weed/mount/inode_to_path.go b/weed/mount/inode_to_path.go
new file mode 100644
index 000000000..edea91a5d
--- /dev/null
+++ b/weed/mount/inode_to_path.go
@@ -0,0 +1,167 @@
+package mount
+
+import (
+	"github.com/chrislusf/seaweedfs/weed/glog"
+	"github.com/chrislusf/seaweedfs/weed/util"
+	"sync"
+)
+
+type InodeToPath struct {
+	sync.RWMutex
+	nextInodeId uint64
+	inode2path  map[uint64]*InodeEntry
+	path2inode  map[util.FullPath]uint64
+}
+type InodeEntry struct {
+	util.FullPath
+	nlookup          uint64
+	isDirectory      bool
+	isChildrenCached bool
+}
+
+func NewInodeToPath() *InodeToPath {
+	t := &InodeToPath{
+		inode2path:  make(map[uint64]*InodeEntry),
+		path2inode:  make(map[util.FullPath]uint64),
+		nextInodeId: 2, // the root inode id is 1
+	}
+	t.inode2path[1] = &InodeEntry{"/", 1, true, false}
+	t.path2inode["/"] = 1
+	return t
+}
+
+func (i *InodeToPath) Lookup(path util.FullPath, isDirectory bool, isLookup bool) uint64 {
+	i.Lock()
+	defer i.Unlock()
+	inode, found := i.path2inode[path]
+	if !found {
+		inode = i.nextInodeId
+		i.nextInodeId++
+		i.path2inode[path] = inode
+		if !isLookup {
+			i.inode2path[inode] = &InodeEntry{path, 0, isDirectory, false}
+		} else {
+			i.inode2path[inode] = &InodeEntry{path, 1, isDirectory, false}
+		}
+	} else {
+		if isLookup {
+			i.inode2path[inode].nlookup++
+		}
+	}
+	return inode
+}
+
+func (i *InodeToPath) GetInode(path util.FullPath) uint64 {
+	if path == "/" {
+		return 1
+	}
+	i.Lock()
+	defer i.Unlock()
+	inode, found := i.path2inode[path]
+	if !found {
+		// glog.Fatalf("GetInode unknown inode for %s", path)
+		// this could be the parent for mount point
+	}
+	return inode
+}
+
+func (i *InodeToPath) GetPath(inode uint64) util.FullPath {
+	i.RLock()
+	defer i.RUnlock()
+	path, found := i.inode2path[inode]
+	if !found {
+		glog.Fatalf("not found inode %d", inode)
+	}
+	return path.FullPath
+}
+
+func (i *InodeToPath) HasPath(path util.FullPath) bool {
+	i.RLock()
+	defer i.RUnlock()
+	_, found := i.path2inode[path]
+	return found
+}
+
+func (i *InodeToPath) MarkChildrenCached(fullpath util.FullPath) {
+	i.RLock()
+	defer i.RUnlock()
+	inode, found := i.path2inode[fullpath]
+	if !found {
+		glog.Fatalf("MarkChildrenCached not found inode %v", fullpath)
+	}
+	path, found := i.inode2path[inode]
+	path.isChildrenCached = true
+}
+
+func (i *InodeToPath) IsChildrenCached(fullpath util.FullPath) bool {
+	i.RLock()
+	defer i.RUnlock()
+	inode, found := i.path2inode[fullpath]
+	if !found {
+		return false
+	}
+	path, found := i.inode2path[inode]
+	if found {
+		return path.isChildrenCached
+	}
+	return false
+}
+
+func (i *InodeToPath) HasInode(inode uint64) bool {
+	if inode == 1 {
+		return true
+	}
+	i.RLock()
+	defer i.RUnlock()
+	_, found := i.inode2path[inode]
+	return found
+}
+
+func (i *InodeToPath) RemovePath(path util.FullPath) {
+	i.Lock()
+	defer i.Unlock()
+	inode, found := i.path2inode[path]
+	if found {
+		delete(i.path2inode, path)
+		delete(i.inode2path, inode)
+	}
+}
+
+func (i *InodeToPath) MovePath(sourcePath, targetPath util.FullPath) {
+	i.Lock()
+	defer i.Unlock()
+	sourceInode, sourceFound := i.path2inode[sourcePath]
+	targetInode, targetFound := i.path2inode[targetPath]
+	if sourceFound {
+		delete(i.path2inode, sourcePath)
+		i.path2inode[targetPath] = sourceInode
+	} else {
+		// it is possible some source folder items has not been visited before
+		// so no need to worry about their source inodes
+		return
+	}
+	i.inode2path[sourceInode].FullPath = targetPath
+	if targetFound {
+		delete(i.inode2path, targetInode)
+	} else {
+		i.inode2path[sourceInode].nlookup++
+	}
+}
+
+func (i *InodeToPath) Forget(inode, nlookup uint64, onForgetDir func(dir util.FullPath)) {
+	i.Lock()
+	path, found := i.inode2path[inode]
+	if found {
+		path.nlookup -= nlookup
+		if path.nlookup <= 0 {
+			delete(i.path2inode, path.FullPath)
+			delete(i.inode2path, inode)
+		}
+	}
+	i.Unlock()
+	if found {
+		if path.isDirectory && onForgetDir != nil {
+			onForgetDir(path.FullPath)
+		}
+	}
+}