postgres

Documentation

Overview

Package postgres provides native durable fenced leases for PostgreSQL.

Index

• func GoMigration() (migrations.Migration, error)
• type Migration
  • func SchemaMigration() Migration
• type Store
  • func New(pool *pgxpool.Pool) (*Store, error)
  • func (store *Store) Cleanup(ctx context.Context, batch uint32) (uint32, error)
  • func (store *Store) Release(ctx context.Context, owned lease.Record) error
  • func (store *Store) Renew(ctx context.Context, owned lease.Record, ttl time.Duration) (lease.Record, error)
  • func (store *Store) TryAcquire(ctx context.Context, key lease.Key, owner string, ttl time.Duration) (lease.Record, error)
  • func (store *Store) Validate(ctx context.Context, owned lease.Record) (lease.Record, error)

Functions

func GoMigration

func GoMigration() (migrations.Migration, error)

GoMigration returns the schema in migrations' immutable format.

Types

type Migration

type Migration struct {
	Version uint
	Name    string
	Up      string
	Down    string
}

Migration describes the reversible PostgreSQL schema contract.

func SchemaMigration

func SchemaMigration() Migration

SchemaMigration returns the durable lease and persistent-fence schema.

type Store

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

Store persists leases and fencing counters in PostgreSQL server time.

func New

func New(pool *pgxpool.Pool) (*Store, error)

New constructs a PostgreSQL backend from a caller-owned pgx pool.

func (*Store) Cleanup

func (store *Store) Cleanup(ctx context.Context, batch uint32) (uint32, error)

Cleanup removes a bounded batch of old inactive lease rows. Fence rows are deliberately retained so cleanup cannot reset monotonic continuity.

func (*Store) Release

func (store *Store) Release(ctx context.Context, owned lease.Record) error

Release atomically deactivates only a matching owner and token.

func (*Store) Renew

func (store *Store) Renew(
	ctx context.Context,
	owned lease.Record,
	ttl time.Duration,
) (lease.Record, error)

Renew atomically compares owner and token before extending backend expiry.

func (*Store) TryAcquire

func (store *Store) TryAcquire(
	ctx context.Context,
	key lease.Key,
	owner string,
	ttl time.Duration,
) (lease.Record, error)

TryAcquire atomically advances the durable fence and installs an owner.

func (*Store) Validate

func (store *Store) Validate(ctx context.Context, owned lease.Record) (lease.Record, error)

Validate checks current owner, token, active state, and backend deadline.