package remotecontext // import "github.com/docker/docker/builder/remotecontext" import ( "os" "sync" "github.com/docker/docker/pkg/containerfs" iradix "github.com/hashicorp/go-immutable-radix" "github.com/opencontainers/go-digest" "github.com/pkg/errors" "github.com/tonistiigi/fsutil" ) type hashed interface { Digest() digest.Digest } // CachableSource is a source that contains cache records for its contents type CachableSource struct { mu sync.Mutex root containerfs.ContainerFS tree *iradix.Tree txn *iradix.Txn } // NewCachableSource creates new CachableSource func NewCachableSource(root string) *CachableSource { ts := &CachableSource{ tree: iradix.New(), root: containerfs.NewLocalContainerFS(root), } return ts } // MarshalBinary marshals current cache information to a byte array func (cs *CachableSource) MarshalBinary() ([]byte, error) { b := TarsumBackup{Hashes: make(map[string]string)} root := cs.getRoot() root.Walk(func(k []byte, v interface{}) bool { b.Hashes[string(k)] = v.(*fileInfo).sum return false }) return b.Marshal() } // UnmarshalBinary decodes cache information for presented byte array func (cs *CachableSource) UnmarshalBinary(data []byte) error { var b TarsumBackup if err := b.Unmarshal(data); err != nil { return err } txn := iradix.New().Txn() for p, v := range b.Hashes { txn.Insert([]byte(p), &fileInfo{sum: v}) } cs.mu.Lock() defer cs.mu.Unlock() cs.tree = txn.Commit() return nil } // Scan rescans the cache information from the file system func (cs *CachableSource) Scan() error { lc, err := NewLazySource(cs.root) if err != nil { return err } txn := iradix.New().Txn() err = cs.root.Walk(cs.root.Path(), func(path string, info os.FileInfo, err error) error { if err != nil { return errors.Wrapf(err, "failed to walk %s", path) } rel, err := Rel(cs.root, path) if err != nil { return err } h, err := lc.Hash(rel) if err != nil { return err } txn.Insert([]byte(rel), &fileInfo{sum: h}) return nil }) if err != nil { return err } cs.mu.Lock() defer cs.mu.Unlock() cs.tree = txn.Commit() return nil } // HandleChange notifies the source about a modification operation func (cs *CachableSource) HandleChange(kind fsutil.ChangeKind, p string, fi os.FileInfo, err error) (retErr error) { cs.mu.Lock() if cs.txn == nil { cs.txn = cs.tree.Txn() } if kind == fsutil.ChangeKindDelete { cs.txn.Delete([]byte(p)) cs.mu.Unlock() return } h, ok := fi.(hashed) if !ok { cs.mu.Unlock() return errors.Errorf("invalid fileinfo: %s", p) } hfi := &fileInfo{ sum: h.Digest().Hex(), } cs.txn.Insert([]byte(p), hfi) cs.mu.Unlock() return nil } func (cs *CachableSource) getRoot() *iradix.Node { cs.mu.Lock() if cs.txn != nil { cs.tree = cs.txn.Commit() cs.txn = nil } t := cs.tree cs.mu.Unlock() return t.Root() } // Close closes the source func (cs *CachableSource) Close() error { return nil } // Hash returns a hash for a single file in the source func (cs *CachableSource) Hash(path string) (string, error) { n := cs.getRoot() // TODO: check this for symlinks v, ok := n.Get([]byte(path)) if !ok { return path, nil } return v.(*fileInfo).sum, nil } // Root returns a root directory for the source func (cs *CachableSource) Root() containerfs.ContainerFS { return cs.root } type fileInfo struct { sum string } func (fi *fileInfo) Hash() string { return fi.sum }