postgres

Documentation

Index

• Variables
• type Resource
  • func (r *Resource) Read() (string, shiftlock.FencingToken, error)
  • func (r *Resource) Write(token shiftlock.FencingToken, value string) error

Variables

var ErrStaleFencingToken = errors.New("fencing/postgres: stale fencing token")

ErrStaleFencingToken is returned when a mutation carries a stale token.

Types

type Resource

type Resource struct {
	DB    *sql.DB
	Table string
	Name  string
}

Resource is a fenced row helper. Table schema (caller migrates):

CREATE TABLE IF NOT EXISTS shiftlock_fenced (
  name TEXT PRIMARY KEY,
  fencing_token BIGINT NOT NULL DEFAULT 0,
  value TEXT NOT NULL DEFAULT ''
);

func (*Resource) Read

func (r *Resource) Read() (string, shiftlock.FencingToken, error)

Read returns value and token.

func (*Resource) Write

func (r *Resource) Write(token shiftlock.FencingToken, value string) error

Write updates value only if token >= stored fencing token (monotonic accept).