From 54d3d47daf9190275bbdaf8703b84969a4593451 Mon Sep 17 00:00:00 2001 From: Corey Hulen Date: Fri, 24 Mar 2017 23:31:34 -0700 Subject: PLT-6076 Adding viper libs for config file changes (#5871) * Adding viper libs for config file changes * Removing the old fsnotify lib * updating some missing libs --- vendor/github.com/spf13/afero/cacheOnReadFs.go | 295 +++++++++++++++++++++++++ 1 file changed, 295 insertions(+) create mode 100644 vendor/github.com/spf13/afero/cacheOnReadFs.go (limited to 'vendor/github.com/spf13/afero/cacheOnReadFs.go') diff --git a/vendor/github.com/spf13/afero/cacheOnReadFs.go b/vendor/github.com/spf13/afero/cacheOnReadFs.go new file mode 100644 index 000000000..e54a4f8b4 --- /dev/null +++ b/vendor/github.com/spf13/afero/cacheOnReadFs.go @@ -0,0 +1,295 @@ +package afero + +import ( + "os" + "syscall" + "time" +) + +// If the cache duration is 0, cache time will be unlimited, i.e. once +// a file is in the layer, the base will never be read again for this file. +// +// For cache times greater than 0, the modification time of a file is +// checked. Note that a lot of file system implementations only allow a +// resolution of a second for timestamps... or as the godoc for os.Chtimes() +// states: "The underlying filesystem may truncate or round the values to a +// less precise time unit." +// +// This caching union will forward all write calls also to the base file +// system first. To prevent writing to the base Fs, wrap it in a read-only +// filter - Note: this will also make the overlay read-only, for writing files +// in the overlay, use the overlay Fs directly, not via the union Fs. +type CacheOnReadFs struct { + base Fs + layer Fs + cacheTime time.Duration +} + +func NewCacheOnReadFs(base Fs, layer Fs, cacheTime time.Duration) Fs { + return &CacheOnReadFs{base: base, layer: layer, cacheTime: cacheTime} +} + +type cacheState int + +const ( + // not present in the overlay, unknown if it exists in the base: + cacheMiss cacheState = iota + // present in the overlay and in base, base file is newer: + cacheStale + // present in the overlay - with cache time == 0 it may exist in the base, + // with cacheTime > 0 it exists in the base and is same age or newer in the + // overlay + cacheHit + // happens if someone writes directly to the overlay without + // going through this union + cacheLocal +) + +func (u *CacheOnReadFs) cacheStatus(name string) (state cacheState, fi os.FileInfo, err error) { + var lfi, bfi os.FileInfo + lfi, err = u.layer.Stat(name) + if err == nil { + if u.cacheTime == 0 { + return cacheHit, lfi, nil + } + if lfi.ModTime().Add(u.cacheTime).Before(time.Now()) { + bfi, err = u.base.Stat(name) + if err != nil { + return cacheLocal, lfi, nil + } + if bfi.ModTime().After(lfi.ModTime()) { + return cacheStale, bfi, nil + } + } + return cacheHit, lfi, nil + } + + if err == syscall.ENOENT { + return cacheMiss, nil, nil + } + var ok bool + if err, ok = err.(*os.PathError); ok { + if err == os.ErrNotExist { + return cacheMiss, nil, nil + } + } + return cacheMiss, nil, err +} + +func (u *CacheOnReadFs) copyToLayer(name string) error { + return copyToLayer(u.base, u.layer, name) +} + +func (u *CacheOnReadFs) Chtimes(name string, atime, mtime time.Time) error { + st, _, err := u.cacheStatus(name) + if err != nil { + return err + } + switch st { + case cacheLocal: + case cacheHit: + err = u.base.Chtimes(name, atime, mtime) + case cacheStale, cacheMiss: + if err := u.copyToLayer(name); err != nil { + return err + } + err = u.base.Chtimes(name, atime, mtime) + } + if err != nil { + return err + } + return u.layer.Chtimes(name, atime, mtime) +} + +func (u *CacheOnReadFs) Chmod(name string, mode os.FileMode) error { + st, _, err := u.cacheStatus(name) + if err != nil { + return err + } + switch st { + case cacheLocal: + case cacheHit: + err = u.base.Chmod(name, mode) + case cacheStale, cacheMiss: + if err := u.copyToLayer(name); err != nil { + return err + } + err = u.base.Chmod(name, mode) + } + if err != nil { + return err + } + return u.layer.Chmod(name, mode) +} + +func (u *CacheOnReadFs) Stat(name string) (os.FileInfo, error) { + st, fi, err := u.cacheStatus(name) + if err != nil { + return nil, err + } + switch st { + case cacheMiss: + return u.base.Stat(name) + default: // cacheStale has base, cacheHit and cacheLocal the layer os.FileInfo + return fi, nil + } +} + +func (u *CacheOnReadFs) Rename(oldname, newname string) error { + st, _, err := u.cacheStatus(oldname) + if err != nil { + return err + } + switch st { + case cacheLocal: + case cacheHit: + err = u.base.Rename(oldname, newname) + case cacheStale, cacheMiss: + if err := u.copyToLayer(oldname); err != nil { + return err + } + err = u.base.Rename(oldname, newname) + } + if err != nil { + return err + } + return u.layer.Rename(oldname, newname) +} + +func (u *CacheOnReadFs) Remove(name string) error { + st, _, err := u.cacheStatus(name) + if err != nil { + return err + } + switch st { + case cacheLocal: + case cacheHit, cacheStale, cacheMiss: + err = u.base.Remove(name) + } + if err != nil { + return err + } + return u.layer.Remove(name) +} + +func (u *CacheOnReadFs) RemoveAll(name string) error { + st, _, err := u.cacheStatus(name) + if err != nil { + return err + } + switch st { + case cacheLocal: + case cacheHit, cacheStale, cacheMiss: + err = u.base.RemoveAll(name) + } + if err != nil { + return err + } + return u.layer.RemoveAll(name) +} + +func (u *CacheOnReadFs) OpenFile(name string, flag int, perm os.FileMode) (File, error) { + st, _, err := u.cacheStatus(name) + if err != nil { + return nil, err + } + switch st { + case cacheLocal, cacheHit: + default: + if err := u.copyToLayer(name); err != nil { + return nil, err + } + } + if flag&(os.O_WRONLY|syscall.O_RDWR|os.O_APPEND|os.O_CREATE|os.O_TRUNC) != 0 { + bfi, err := u.base.OpenFile(name, flag, perm) + if err != nil { + return nil, err + } + lfi, err := u.layer.OpenFile(name, flag, perm) + if err != nil { + bfi.Close() // oops, what if O_TRUNC was set and file opening in the layer failed...? + return nil, err + } + return &UnionFile{base: bfi, layer: lfi}, nil + } + return u.layer.OpenFile(name, flag, perm) +} + +func (u *CacheOnReadFs) Open(name string) (File, error) { + st, fi, err := u.cacheStatus(name) + if err != nil { + return nil, err + } + + switch st { + case cacheLocal: + return u.layer.Open(name) + + case cacheMiss: + bfi, err := u.base.Stat(name) + if err != nil { + return nil, err + } + if bfi.IsDir() { + return u.base.Open(name) + } + if err := u.copyToLayer(name); err != nil { + return nil, err + } + return u.layer.Open(name) + + case cacheStale: + if !fi.IsDir() { + if err := u.copyToLayer(name); err != nil { + return nil, err + } + return u.layer.Open(name) + } + case cacheHit: + if !fi.IsDir() { + return u.layer.Open(name) + } + } + // the dirs from cacheHit, cacheStale fall down here: + bfile, _ := u.base.Open(name) + lfile, err := u.layer.Open(name) + if err != nil && bfile == nil { + return nil, err + } + return &UnionFile{base: bfile, layer: lfile}, nil +} + +func (u *CacheOnReadFs) Mkdir(name string, perm os.FileMode) error { + err := u.base.Mkdir(name, perm) + if err != nil { + return err + } + return u.layer.MkdirAll(name, perm) // yes, MkdirAll... we cannot assume it exists in the cache +} + +func (u *CacheOnReadFs) Name() string { + return "CacheOnReadFs" +} + +func (u *CacheOnReadFs) MkdirAll(name string, perm os.FileMode) error { + err := u.base.MkdirAll(name, perm) + if err != nil { + return err + } + return u.layer.MkdirAll(name, perm) +} + +func (u *CacheOnReadFs) Create(name string) (File, error) { + bfh, err := u.base.Create(name) + if err != nil { + return nil, err + } + lfh, err := u.layer.Create(name) + if err != nil { + // oops, see comment about OS_TRUNC above, should we remove? then we have to + // remember if the file did not exist before + bfh.Close() + return nil, err + } + return &UnionFile{base: bfh, layer: lfh}, nil +} -- cgit v1.2.3-1-g7c22