dblock

README

DBLock

A simple distributed locking library for Go. Heavily inspired by cirello.io/pglock, but built on top of ent instead for better database compatibility.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/shivanshvij/dblock. For more contribution information check out the contribution guide.

License

This project is available as open source under the terms of the Apache License, Version 2.0.

Code of Conduct

Everyone interacting in this project's codebases, issue trackers, chat rooms and mailing lists is expected to follow the CNCF Code of Conduct.

Documentation

Index

• Constants
• Variables
• type DBLock
  • func New(options *Options) (*DBLock, error)
  • func (db *DBLock) Acquire(l *Lock, failIfLocked ...bool) error
  • func (db *DBLock) Lock(id string) *Lock
  • func (db *DBLock) Release(l *Lock) error
  • func (db *DBLock) Stop() error
• type DBType
• type Lock
  • func (l *Lock) Acquire(failIfLocked ...bool) error
  • func (l *Lock) ID() string
  • func (l *Lock) IsReleased() bool
  • func (l *Lock) Release() error
  • func (l *Lock) Version() uuid.UUID
• type Options
  • func (o *Options) Validate() error

Constants

const PGQuery = `
INSERT INTO ` + lock.Table + `("` + lock.FieldID + `", "` + lock.FieldVersion + `", "` + lock.FieldOwner + `") 
VALUES($1, $2, $3) 
ON CONFLICT ("` + lock.FieldID + `") DO 
UPDATE SET "` + lock.FieldVersion + `" = $2, "` + lock.FieldOwner + `" = $3 
WHERE ` + lock.Table + `."` + lock.FieldVersion + `" IS NULL OR ` + lock.Table + `."` + lock.FieldVersion + `" = $4`

const SQLiteQuery = `
INSERT INTO ` + lock.Table + ` ("` + lock.FieldID + `", "` + lock.FieldVersion + `", "` + lock.FieldOwner + `")
VALUES( ?, ?, ? )
ON CONFLICT ("` + lock.FieldID + `") DO 
UPDATE SET "` + lock.FieldVersion + `" = ?, "` + lock.FieldOwner + `" = ? 
WHERE ` + lock.Table + `."` + lock.FieldVersion + `" IS NULL OR ` + lock.Table + `."` + lock.FieldVersion + `" = ?`

Variables

var (
	ErrInvalidOptions    = errors.New("invalid options")
	ErrOpeningDatabase   = errors.New("failed opening connection to database")
	ErrRunningMigrations = errors.New("failed running database migrations")
	ErrClosingDatabase   = errors.New("failed closing connection to database")

	ErrNotAcquired = errors.New("lock not acquired")
	ErrNotReleased = errors.New("lock not released")

	ErrCreateTransaction = errors.New("cannot create transaction")
	ErrCommitTransaction = errors.New("cannot commit transaction")

	ErrSerializationError  = errors.New("serialization error")
	ErrRefreshLease        = errors.New("cannot refresh lease")
	ErrLockAlreadyReleased = errors.New("lock already released")
)

var (
	ErrInvalidOwner                 = errors.New("invalid owner")
	ErrInvalidDBType                = errors.New("invalid database type")
	ErrInvalidDatabaseURL           = errors.New("invalid database URL")
	ErrInvalidLeaseDuration         = errors.New("invalid lease duration")
	ErrInvalidLeaseRefreshFrequency = errors.New("invalid lease refresh frequency")
)

Types

type DBLock

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

func New

func New(options *Options) (*DBLock, error)

func (*DBLock) Acquire

func (db *DBLock) Acquire(l *Lock, failIfLocked ...bool) error

func (*DBLock) Lock

func (db *DBLock) Lock(id string) *Lock

func (*DBLock) Release

func (db *DBLock) Release(l *Lock) error

func (*DBLock) Stop

func (db *DBLock) Stop() error

type DBType

type DBType int

const (
	Undefined DBType = iota
	Postgres
	SQLite
)

type Lock

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

func (*Lock) Acquire

func (l *Lock) Acquire(failIfLocked ...bool) error

func (*Lock) ID

func (l *Lock) ID() string

func (*Lock) IsReleased

func (l *Lock) IsReleased() bool

func (*Lock) Release

func (l *Lock) Release() error

func (*Lock) Version

func (l *Lock) Version() uuid.UUID

type Options

type Options struct {
	Logger                types.SubLogger
	Owner                 string
	DBType                DBType
	DatabaseURL           string
	LeaseDuration         time.Duration
	LeaseRefreshFrequency time.Duration
}

func (*Options) Validate

func (o *Options) Validate() error