save

Documentation

Overview

Package save contains streaming, crash-safe document persistence.

Index

• func Atomic(path string, mode os.FileMode, prefix []byte, ...) (int64, error)
• func AtomicChecked(path string, mode os.FileMode, prefix []byte, ...) (int64, error)
• func SyncParent(path string) error
• type DurabilityError
  • func (e *DurabilityError) Committed() bool
  • func (e *DurabilityError) Error() string
  • func (e *DurabilityError) Unwrap() error

Functions

func Atomic

func Atomic(path string, mode os.FileMode, prefix []byte, writeContent func(io.Writer) (int64, error)) (int64, error)

Atomic streams content into a same-directory temporary file, flushes it, and atomically replaces path. The caller supplies an immutable document snapshot.

func AtomicChecked

func AtomicChecked(path string, mode os.FileMode, prefix []byte, writeContent func(io.Writer) (int64, error), beforeReplace func() error) (int64, error)

AtomicChecked performs a final conflict check after the potentially long stream write and immediately before replacing the original file.

func SyncParent

func SyncParent(path string) error

SyncParent retries durability of the directory entry containing path. It is a no-op on platforms whose replacement primitive already provides the required guarantee.

Types

type DurabilityError

type DurabilityError struct {
	Path string
	Err  error
}

DurabilityError means the target name was atomically replaced, but the platform could not confirm that the directory entry is durable across a power loss. Callers must treat the content as committed.

func (*DurabilityError) Committed

func (e *DurabilityError) Committed() bool

func (*DurabilityError) Error

func (e *DurabilityError) Error() string

func (*DurabilityError) Unwrap

func (e *DurabilityError) Unwrap() error