go-mtree/fseval.go

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package mtree
import "os"
// FsEval is a mock-friendly method of specifying to go-mtree how to carry out
// filesystem operations such as opening files and the like. The semantics of
// all of these wrappers MUST be identical to the semantics described here.
type FsEval interface {
// Open must have the same semantics as os.Open.
Open(path string) (*os.File, error)
// Lstat must have the same semantics as os.Lstat.
Lstat(path string) (os.FileInfo, error)
// Readdir must have the same semantics as calling os.Open on the given
// path and then returning the result of (*os.File).Readdir(-1).
Readdir(path string) ([]os.FileInfo, error)
// KeywordFunc must return a wrapper around the provided function (in other
// words, the returned function must refer to the same keyword).
KeywordFunc(fn KeywordFunc) KeywordFunc
}
// DefaultFsEval is the default implementation of FsEval (and is the default
// used if a nil interface is passed to any mtree function). It does not modify
// or wrap any of the methods (they all just call out to os.*).
type DefaultFsEval struct{}
// Open must have the same semantics as os.Open.
func (fs DefaultFsEval) Open(path string) (*os.File, error) {
return os.Open(path)
}
// Lstat must have the same semantics as os.Lstat.
func (fs DefaultFsEval) Lstat(path string) (os.FileInfo, error) {
return os.Lstat(path)
}
// Readdir must have the same semantics as calling os.Open on the given
// path and then returning the result of (*os.File).Readdir(-1).
func (fs DefaultFsEval) Readdir(path string) ([]os.FileInfo, error) {
fh, err := os.Open(path)
if err != nil {
return nil, err
}
defer fh.Close()
return fh.Readdir(-1)
}
// KeywordFunc must return a wrapper around the provided function (in other
// words, the returned function must refer to the same keyword).
func (fs DefaultFsEval) KeywordFunc(fn KeywordFunc) KeywordFunc {
return fn
}