postgres

Documentation

Index

• Constants
• Variables
• func GormTransaction(ctx context.Context, db *gorm.DB, fc func(tx *gorm.DB) error, ...) (err error)
• func IsSerializationAnomaly(err error) bool
• func NewEventBroadcaster(uri string, minReconnectInterval time.Duration, ...) *eventBroadcaster
• type AdvisoryLocker
  • func NewAdvisoryLock(uri string) AdvisoryLocker
• type Event
• type EventBroadcaster
• type NullAdvisoryLocker
  • func (n *NullAdvisoryLocker) Close() error
  • func (*NullAdvisoryLocker) Unlock(ctx context.Context, classID int32, objectID int32) error
  • func (*NullAdvisoryLocker) WithAdvisoryLock(ctx context.Context, classID int32, objectID int32, f func() error) error
• type Subscription

Constants

const (
	AdvisoryLockClassID_EthBroadcaster int32 = 0
	AdvisoryLockClassID_JobSpawner     int32 = 1
	AdvisoryLockClassID_EthConfirmer   int32 = 2

	// ORM takes lock on 1027321974924625846 which splits into ClassID 239192036, ObjID 2840971190
	AdvisoryLockClassID_ORM int32 = 239192036

	AdvisoryLockObjectID_EthConfirmer int32 = 0
)

NOTE: All advisory lock class IDs used by the Seerlink application MUST be kept here to avoid accidental re-use

const (
	ChannelJobCreated   = "insert_on_jobs"
	ChannelJobDeleted   = "delete_from_jobs"
	ChannelRunStarted   = "pipeline_run_started"
	ChannelRunCompleted = "pipeline_run_completed"

	// Postgres channel to listen for new eth_txes
	ChannelInsertOnEthTx = "insert_on_eth_txes"
)

const (
	// LockTimeout controls the max time we will wait for any kind of database lock.
	// It's good to set this to _something_ because waiting for locks forever is really bad.
	LockTimeout = 1 * time.Minute
	// IdleInTxSessionTimeout controls the max time we leave a transaction open and idle.
	// It's good to set this to _something_ because leaving transactions open forever is really bad.
	IdleInTxSessionTimeout = 1 * time.Hour
)

NOTE: In an ideal world the timeouts below would be set to something sane in the postgres configuration by the user. Since we do not live in an ideal world, it is necessary to override them here.

They cannot easily be set at a session level due to how Go's connection pooling works.

Variables

var (
	DefaultSqlTxOptions = sql.TxOptions{

		Isolation: sql.LevelReadCommitted,
	}
)

Functions

func GormTransaction

func GormTransaction(ctx context.Context, db *gorm.DB, fc func(tx *gorm.DB) error, txOptss ...sql.TxOptions) (err error)

func IsSerializationAnomaly

func IsSerializationAnomaly(err error) bool

func NewEventBroadcaster

func NewEventBroadcaster(uri string, minReconnectInterval time.Duration, maxReconnectDuration time.Duration) *eventBroadcaster

Types

type AdvisoryLocker

type AdvisoryLocker interface {
	Unlock(ctx context.Context, classID int32, objectID int32) error
	WithAdvisoryLock(ctx context.Context, classID int32, objectID int32, f func() error) error
	Close() error
}

func NewAdvisoryLock

func NewAdvisoryLock(uri string) AdvisoryLocker

type Event

type Event struct {
	Channel string
	Payload string
}

type EventBroadcaster

type EventBroadcaster interface {
	Start() error
	Stop() error
	Subscribe(channel, payloadFilter string) (Subscription, error)
	Notify(channel string, payload string) error
	NotifyInsideGormTx(tx *gorm.DB, channel string, payload string) error
}

EventBroadcaster opaquely manages a collection of Postgres event listeners and broadcasts events to subscribers (with an optional payload filter).

type NullAdvisoryLocker

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

func (*NullAdvisoryLocker) Close

func (n *NullAdvisoryLocker) Close() error

func (*NullAdvisoryLocker) Unlock

func (*NullAdvisoryLocker) Unlock(ctx context.Context, classID int32, objectID int32) error

func (*NullAdvisoryLocker) WithAdvisoryLock

func (*NullAdvisoryLocker) WithAdvisoryLock(ctx context.Context, classID int32, objectID int32, f func() error) error

type Subscription

type Subscription interface {
	Events() <-chan Event
	Close()
	// contains filtered or unexported methods
}

Subscription represents a subscription to a Postgres event channel