mysql

Documentation

Index

• Constants
• type Datastore
  • func NewMySQLDatastore(uri string, options ...Option) (*Datastore, error)
  • func (mds *Datastore) CheckRevision(ctx context.Context, revision datastore.Revision) error
  • func (mds *Datastore) Close() error
  • func (mds *Datastore) DeleteBeforeTx(ctx context.Context, txID uint64) (removed common.DeletionCounts, err error)
  • func (mds *Datastore) Features(ctx context.Context) (*datastore.Features, error)
  • func (mds *Datastore) HeadRevision(ctx context.Context) (datastore.Revision, error)
  • func (mds *Datastore) IsReady(ctx context.Context) (bool, error)
  • func (mds *Datastore) Now(ctx context.Context) (time.Time, error)
  • func (mds *Datastore) ReadWriteTx(ctx context.Context, fn datastore.TxUserFunc) (datastore.Revision, error)
  • func (mds *Datastore) SnapshotReader(rev datastore.Revision) datastore.Reader
  • func (mds *Datastore) Statistics(ctx context.Context) (datastore.Stats, error)
  • func (mds *Datastore) TxIDBefore(ctx context.Context, before time.Time) (uint64, error)
  • func (mds *Datastore) Watch(ctx context.Context, afterRevision datastore.Revision) (<-chan *datastore.RevisionChanges, <-chan error)
• type Option
  • func ConnMaxIdleTime(idle time.Duration) Option
  • func ConnMaxLifetime(lifetime time.Duration) Option
  • func DebugAnalyzeBeforeStatistics() Option
  • func GCInterval(interval time.Duration) Option
  • func GCWindow(window time.Duration) Option
  • func MaxOpenConns(conns int) Option
  • func MaxRetries(maxRetries uint8) Option
  • func MaxRevisionStalenessPercent(stalenessPercent float64) Option
  • func OverrideLockWaitTimeout(seconds uint8) Option
  • func RevisionQuantization(quantization time.Duration) Option
  • func TablePrefix(prefix string) Option
  • func WatchBufferLength(watchBufferLength uint16) Option
  • func WithEnablePrometheusStats(enablePrometheusStats bool) Option
• type QueryBuilder
  • func NewQueryBuilder(driver *migrations.MySQLDriver) *QueryBuilder

Constants

const (
	Engine = "mysql"
)

Types

type Datastore

type Datastore struct {
	*QueryBuilder
	*revisions.CachedOptimizedRevisions
	// contains filtered or unexported fields
}

Datastore is a MySQL-based implementation of the datastore.Datastore interface

func NewMySQLDatastore

func NewMySQLDatastore(uri string, options ...Option) (*Datastore, error)

NewMySQLDatastore creates a new mysql.Datastore value configured with the MySQL instance specified in through the URI parameter. Supports customization via the various options available in this package.

URI: [scheme://][user[:[password]]@]host[:port][/schema][?attribute1=value1&attribute2=value2... See https://dev.mysql.com/doc/refman/8.0/en/connecting-using-uri-or-key-value-pairs.html

func (*Datastore) CheckRevision

func (mds *Datastore) CheckRevision(ctx context.Context, revision datastore.Revision) error

func (*Datastore) Close

func (mds *Datastore) Close() error

Close closes the data store.

func (*Datastore) DeleteBeforeTx

func (mds *Datastore) DeleteBeforeTx(ctx context.Context, txID uint64) (removed common.DeletionCounts, err error)

TODO (@vroldanbet) dupe from postgres datastore - need to refactor - implementation misses metrics

func (*Datastore) Features

func (mds *Datastore) Features(ctx context.Context) (*datastore.Features, error)

func (*Datastore) HeadRevision

func (mds *Datastore) HeadRevision(ctx context.Context) (datastore.Revision, error)

func (*Datastore) IsReady

func (mds *Datastore) IsReady(ctx context.Context) (bool, error)

IsReady returns whether the datastore is ready to accept data. Datastores that require database schema creation will return false until the migrations have been run to create the necessary tables.

fundamentally different from PSQL implementation:

• checking if the current migration version is compatible is implemented with IsHeadCompatible
• Database seeding is handled here, so that we can decouple schema migration from data migration and support skeema-based migrations.

func (*Datastore) Now

func (mds *Datastore) Now(ctx context.Context) (time.Time, error)

TODO (@vroldanbet) dupe from postgres datastore - need to refactor

func (*Datastore) ReadWriteTx

func (mds *Datastore) ReadWriteTx(
	ctx context.Context,
	fn datastore.TxUserFunc,
) (datastore.Revision, error)

TODO (@vroldanbet) dupe from postgres datastore - need to refactor ReadWriteTx starts a read/write transaction, which will be committed if no error is returned and rolled back if an error is returned.

func (*Datastore) SnapshotReader

func (mds *Datastore) SnapshotReader(rev datastore.Revision) datastore.Reader

TODO (@vroldanbet) dupe from postgres datastore - need to refactor

func (*Datastore) Statistics

func (mds *Datastore) Statistics(ctx context.Context) (datastore.Stats, error)

func (*Datastore) TxIDBefore

func (mds *Datastore) TxIDBefore(ctx context.Context, before time.Time) (uint64, error)

TODO (@vroldanbet) dupe from postgres datastore - need to refactor - main difference is how the PSQL driver handles null values

func (*Datastore) Watch

func (mds *Datastore) Watch(ctx context.Context, afterRevision datastore.Revision) (<-chan *datastore.RevisionChanges, <-chan error)

Watch notifies the caller about all changes to tuples.

All events following afterRevision will be sent to the caller.

TODO (@vroldanbet) dupe from postgres datastore - need to refactor

type Option

type Option func(*mysqlOptions)

Option provides the facility to configure how clients within the MySQL datastore interact with the running MySQL database.

func ConnMaxIdleTime

func ConnMaxIdleTime(idle time.Duration) Option

ConnMaxIdleTime is the duration after which an idle connection will be automatically closed. See https://pkg.go.dev/database/sql#DB.SetConnMaxIdleTime/

This value defaults to having no maximum.

func ConnMaxLifetime

func ConnMaxLifetime(lifetime time.Duration) Option

ConnMaxLifetime is the duration since creation after which a connection will be automatically closed. See https://pkg.go.dev/database/sql#DB.SetConnMaxLifetime

This value defaults to having no maximum.

func DebugAnalyzeBeforeStatistics

func DebugAnalyzeBeforeStatistics() Option

DebugAnalyzeBeforeStatistics signals to the Statistics method that it should run Analyze Table on the relationships table before returning statistics. This should only be used for debug and testing.

Disabled by default.

func GCInterval

func GCInterval(interval time.Duration) Option

GCInterval is the interval at which garbage collection will occur.

This value defaults to 3 minutes.

func GCWindow

func GCWindow(window time.Duration) Option

GCWindow is the maximum age of a passed revision that will be considered valid.

This value defaults to 24 hours.

func MaxOpenConns

func MaxOpenConns(conns int) Option

MaxOpenConns is the maximum size of the connection pool. See https://pkg.go.dev/database/sql#DB.SetMaxOpenConns

This value defaults to having no maximum.

func MaxRetries

func MaxRetries(maxRetries uint8) Option

MaxRetries is the maximum number of times a retriable transaction will be client-side retried. Default: 10

func MaxRevisionStalenessPercent

func MaxRevisionStalenessPercent(stalenessPercent float64) Option

MaxRevisionStalenessPercent is the amount of time, expressed as a percentage of the revision quantization window, that a previously computed rounded revision can still be advertised after the next rounded revision would otherwise be ready.

This value defaults to 0.1 (10%).

func OverrideLockWaitTimeout

func OverrideLockWaitTimeout(seconds uint8) Option

OverrideLockWaitTimeout sets the lock wait timeout on each new connection established with the databases. As an OLTP service, the default of 50s is unbearably long to block a write for our service, so we suggest setting this value to the minimum of 1 second.

Uses server default by default.

func RevisionQuantization

func RevisionQuantization(quantization time.Duration) Option

RevisionQuantization is the time bucket size to which advertised revisions will be rounded.

This value defaults to 5 seconds.

func TablePrefix

func TablePrefix(prefix string) Option

TablePrefix allows defining a MySQL table name prefix.

No prefix is set by default

func WatchBufferLength

func WatchBufferLength(watchBufferLength uint16) Option

WatchBufferLength is the number of entries that can be stored in the watch buffer while awaiting read by the client.

This value defaults to 128.

func WithEnablePrometheusStats

func WithEnablePrometheusStats(enablePrometheusStats bool) Option

WithEnablePrometheusStats marks whether Prometheus metrics provided by Go's database/sql package are enabled.

Prometheus metrics are disabled by default.

type QueryBuilder

type QueryBuilder struct {
	GetLastRevision  sq.SelectBuilder
	GetRevisionRange sq.SelectBuilder

	WriteNamespaceQuery        sq.InsertBuilder
	ReadNamespaceQuery         sq.SelectBuilder
	DeleteNamespaceQuery       sq.UpdateBuilder
	DeleteNamespaceTuplesQuery sq.UpdateBuilder

	QueryTupleIdsQuery    sq.SelectBuilder
	QueryTuplesQuery      sq.SelectBuilder
	DeleteTupleQuery      sq.UpdateBuilder
	QueryTupleExistsQuery sq.SelectBuilder
	WriteTupleQuery       sq.InsertBuilder
	QueryChangedQuery     sq.SelectBuilder
	CountTupleQuery       sq.SelectBuilder
}

QueryBuilder captures all parameterizable queries used by the MySQL datastore implementation

func NewQueryBuilder

func NewQueryBuilder(driver *migrations.MySQLDriver) *QueryBuilder

NewQueryBuilder returns a new QueryBuilder instance. The migration driver is used to determine the names of the tables.