tree

type Copier interface {
	Write([]byte) (n int, err error)
	Finish() (info FileInfo, parentInfo FileInfo, err error)
	Cancel() error // must not do anything when finished
}

type Entry interface {
	// Name returns the name of this file.
	Name() string
	// RelativePath returns the path relative to the root of this tree.
	RelativePath() []string
	// Type returns the file type (see the Type constants above)
	Type() Type
	// Mode returns the mode (permission) bits of this file.
	Mode() Mode
	// HasMode returns the permission bits the filesystem supports.
	HasMode() Mode
	// ModTime returns the last modification time.
	ModTime() time.Time
	// Size returns the filesize for regular files. For others, it's
	// implementation-dependent.
	Size() int64
	// Id returns the inode and the filesystem for this file. If the inode isn't
	// available, return 0 for it. If the id is nonzero, the filesystem must be
	// non-nil as well.
	Id() (inode uint64, fs *LocalFilesystem)
	// Hash calculates the blake2b hash of the file and returns it.
	Hash() (Hash, error)
	// Info returns a FileInfo without a hash from this Entry.
	// It must be fast (it shouldn't do any I/O).
	Info() FileInfo
	// FullInfo returns a FileInfo with hash from this Entry.
	// The FileInfo comes from Info(), but it has the hash set for regular
	// files.
	FullInfo() (FileInfo, error)
	// Tree returns the tree this entry belongs to.
	Tree() Tree
	// Return a list of children, in alphabetic order.
	// Returns an error when this is not a directory.
	List(ListOptions) ([]Entry, error)
}

type EntrySlice []Entry

type ErrNotImplemented string

type FileInfo interface {
	// Name returns the name of this file.
	Name() string
	// RelativePath returns the path relative to the root of this tree. The last
	// element is always the same as the name.
	RelativePath() []string
	// Type returns the file type (see the Type constants above)
	Type() Type
	// Mode returns the mode bits (mainly permissions), see os.FileMode.
	Mode() Mode
	// HasMode returns the supported mode bits, 0 for the simplest filesystems
	// (e.g. FAT32).
	HasMode() Mode
	// ModTime returns the last modification time.
	ModTime() time.Time
	// Size returns the filesize for regular files. For others, it's
	// implementation-dependent.
	Size() int64
	// Inode returns the inode number, if available (otherwise 0).
	Inode() uint64
	// Hash returns the blake2b hash of the file, or nil if no hash is known
	// (e.g. for directories).
	Hash() Hash
}

type FileInfoStruct struct {
	// contains filtered or unexported fields
}

type FileTree interface {
	Tree

	// Open a file for writing with the specified name in the parent, with the
	// metadata as specified in 'source'. Calling Finish() should create the
	// file atomically at the target location. For example, by writing to it at
	// a temporary location and moving it to the destination.
	// Implementations should check that the target doesn't yet exist.
	CreateFile(name string, parent, source FileInfo) (Copier, error)

	// Update this file. May do about the same as CreateFile.
	UpdateFile(file, source FileInfo) (Copier, error)

	// Create a symbolic link.
	CreateSymlink(name string, parent, source FileInfo, contents string) (FileInfo, FileInfo, error)

	// Update a symbolic link.
	UpdateSymlink(file, source FileInfo, contents string) (FileInfo, FileInfo, error)

	// Read the contents (target path) of a symbolic link.
	ReadSymlink(file FileInfo) (string, error)

	// CopySource returns a io.ReadCloser, but checks first whether the FileInfo
	// matches.
	CopySource(info FileInfo) (io.ReadCloser, error)
}

type Filesystem int64

type Hash struct {
	Type HashType
	Data []byte
}

type HashType int

type ListOptions struct {
	Follow func([]string) bool
}

type LocalFileTree interface {
	LocalTree
	FileTree

	// UpdateRsync returns a source file and a file to write, for use by the
	// rsync algorithm.
	UpdateRsync(info, source FileInfo) (RsyncBasis, Copier, error)

	// Get this file. This only exists to read the status file, not to implement
	// copying in the syncer!
	GetFile(name string) (io.ReadCloser, error)

	// PutFile is analogous to GetFile.
	PutFile(name string) (Copier, error)
}

type LocalFilesystem struct {
	Type     string
	DeviceId uint64
}

type LocalTree interface {
	// Root returns the root entry of this tree.
	Root() Entry
}

type Mode uint32

type PathError interface {
	error
	Path() string
}

type RemoteTree interface {
	Tree

	// RemoteScan issues a scan on the other end, and returns a reader for the
	// newly created .dtsync file.
	//
	// Implementations may either scan the whole tree and return once finished,
	// or start scanning while returning the data as far as they've scanned.
	//
	// The sendOptions are sent to the remote scanner (scan will start once
	// received), and recvOptions is a channel from which the options sent by
	// the remote can be read.
	RemoteScan(extraOptions *ScanOptions, sendOptions, recvOptions chan *ScanOptions, progress chan<- *ScanProgress, cancel chan struct{}) (io.ReadCloser, error)

	// SendStatus is used to overwrite the status file on the remote. Data (in
	// e.g. protobuf format) can be written to the Copier.
	SendStatus() (Copier, error)

	// Use the rsync algorithm (librsync) to send only small changes in files.
	// RsyncSrc sends a signature and receives the binary delta.
	RsyncSrc(file FileInfo, signature io.Reader) (delta io.ReadCloser, err error)
	// RsyncDst receives a signature and sends the binary delta.
	RsyncDst(file, source FileInfo) (signature io.Reader, delta Copier, err error)
}

type RsyncBasis interface {
	io.Reader
	io.ReaderAt
	io.Closer
}

type ScanOptions struct {
	Exclude []string
	Include []string
	Follow  []string
	Perms   Mode
	Replica string
}

type ScanProgress struct {
	Total uint64
	Done  uint64
	Path  []string
}

type TestTree interface {
	FileTree

	// ReadInfo returns the FileInfo (with hash) for a particular path.
	ReadInfo(path []string) (FileInfo, error)

	// PutFileTest sets the file at the path to the specified contents. The
	// FileInfo returned does not have to contain the hash.
	PutFileTest(path []string, contents []byte) (FileInfo, error)
}

type Tester interface {
	Error(...interface{})
	Errorf(string, ...interface{})
	Fatal(...interface{})
	Fatalf(string, ...interface{})
	FailNow()
}

type Tree interface {
	// Close clears all resources allocated for this tree, if any. For example,
	// it closes a network connection.
	Close() error

	// mkdir: create a directory in this directory with the given name. The
	// modification time is unknown and will likely be the current time.
	CreateDir(name string, parent, source FileInfo) (FileInfo, error) // TODO update parent mtime
	// Remove removes the indicated file, but checks the fingerprint first. It
	// returns ErrChanged if the metadata does not match, or another error if
	// the remove failed.
	Remove(file FileInfo) (parentInfo FileInfo, err error)
	// Chmod updates the mode (permission) bits of a file. The newly returned
	// FileInfo contains the new mode.
	Chmod(target, source FileInfo) (FileInfo, error)
}

type Type int

type UpdateStats struct {
	ToSource int64
	ToTarget int64
}