Documentation

Overview

    Package state implements atomic file-based state management with support for advisory locking.

    Index

    Constants

    This section is empty.

    Variables

    View Source
    var ErrNoState = errors.New("no state exists")

      ErrNoState is returned when attempting to read a nonexistent state.

      Functions

      func Marshal

      func Marshal(prefix string, v interface{}) error

        Marshal opens a State, marshals v into it, and then closes it.

        func Unmarshal

        func Unmarshal(prefix string, v interface{}) error

          Unmarshal opens a State, unmarshals it into v, and then closes it.

          Types

          type File

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

            File implements file-based state management with support for advisory locking. It is also safe to use concurrently within a process.

            func Open

            func Open(prefix string) (*File, error)

              New creates and returns a new State at the given prefix. The following files are stored:

              - {prefix}.json: the current state
              - {prefix}.lock: the POSIX lock file
              - {prefix}.bak: the previous state
              

              func (*File) Close

              func (f *File) Close() error

                Close releases resources associated with this State instance.

                func (*File) Lock

                func (f *File) Lock() error

                  Lock locks the state, both inside of the process and outside. Lock relies on POSIX flock, which may not be available on all filesystems, notably NFS and SMB.

                  func (*File) LockLocal

                  func (f *File) LockLocal()

                    LockLocal locks local access to state.

                    func (*File) Marshal

                    func (f *File) Marshal(v interface{}) error

                      Marshal atomically stores the JSON-encoded representation of v to the current state. It is only stored when Marshal returns a nil error.

                      func (*File) Unlock

                      func (f *File) Unlock() error

                        Unlock unlocks the state.

                        func (*File) UnlockLocal

                        func (f *File) UnlockLocal()

                          UnlockLocal unlocks local access to state.

                          func (*File) Unmarshal

                          func (f *File) Unmarshal(v interface{}) error

                            Unmarshal decodes the current state into v. Unmarshal returns ErrNoState if no state is stored.

                            Source Files