// From the parent inode, consult the vfilename and return its corresponding filename
// With any error, the string returned will be "".
// However, when the file does not exist, error WILL BE nil
func lookUp(inode string, vfilename string, io outapi.Outapi) (string, error) {
if !CheckValidFilename(vfilename) {
return "", exception.EX_INVALID_FILENAME
}
var meta, file, err = io.Get(GenFileName(inode, vfilename))
if file == nil {
return "", err
}
if meta == nil || meta[META_INODE_TYPE] != META_INODE_TYPE_FOLDER {
return "", err
}
if fileNnode, ok := file.(*filetype.Nnode); !ok {
Secretary.Warn("kernel.filesystem::lookUp", "File "+GenFileName(inode, vfilename)+" has a invalid filetype.")
return "", nil
} else {
//fmt.Println("+++++++++++++++++++++", GenFileName(inode, vfilename), "=", fileNnode.DesName)
return fileNnode.DesName, nil
}
}
// use outapi::Outapi.GenerateUniqueID() as identifier
// a nil may be returned indicating error
func GetFs(io outapi.Outapi) *Fs {
var id = io.GenerateUniqueID()
fsMapLock.RLock()
if elem, ok := globalFsMap[id]; ok {
fsMapLock.RUnlock()
return elem
}
fsMapLock.RUnlock()
fsMapLock.Lock()
defer fsMapLock.Unlock()
if elem, ok := globalFsMap[id]; ok {
return elem
}
var ret = newFs(io)
globalFsMap[id] = ret
return ret
}