schema

Documentation

Index

• Constants
• Variables
• type Engine
  • func NewEngine(checker connpool.MySQLChecker, config tabletenv.TabletConfig) *Engine
  • func NewEngineForTests() *Engine
  • func (se *Engine) Close()
  • func (se *Engine) GetSchema() map[string]*Table
  • func (se *Engine) GetTable(tableName sqlparser.TableIdent) *Table
  • func (se *Engine) InitDBConfig(dbcfgs *dbconfigs.DBConfigs)
  • func (se *Engine) MakeNonMaster()
  • func (se *Engine) Open() error
  • func (se *Engine) RegisterNotifier(name string, f notifier)
  • func (se *Engine) Reload(ctx context.Context) error
  • func (se *Engine) ReloadTime() time.Duration
  • func (se *Engine) ServeHTTP(response http.ResponseWriter, request *http.Request)
  • func (se *Engine) SetReloadTime(reloadTime time.Duration)
  • func (se *Engine) SetTableForTests(table *Table)
  • func (se *Engine) UnregisterNotifier(name string)
• type Index
  • func NewIndex(name string, unique bool) *Index
  • func (idx *Index) AddColumn(name string, cardinality uint64)
  • func (idx *Index) FindColumn(name sqlparser.ColIdent) int
• type MessageInfo
• type SequenceInfo
• type Table
  • func LoadTable(conn *connpool.DBConn, tableName string, tableType string, comment string) (*Table, error)
  • func NewTable(name string) *Table
  • func (ta *Table) AddColumn(name string, columnType querypb.Type, defval sqltypes.Value, extra string)
  • func (ta *Table) AddIndex(name string, unique bool) (index *Index)
  • func (ta *Table) Done()
  • func (ta *Table) FindColumn(name sqlparser.ColIdent) int
  • func (ta *Table) GetPKColumn(index int) *TableColumn
  • func (ta *Table) HasPrimary() bool
  • func (ta *Table) SetMysqlStats(tr, dl, il, df, mdl sqltypes.Value)
  • func (ta *Table) UniqueIndexes() int
• type TableColumn
  • func (c *TableColumn) String() string

Constants

const (
	NoType = iota
	Sequence
	Message
)

Table types

Variables

var TypeNames = []string{
	"none",
	"sequence",
	"message",
}

TypeNames allows to fetch a the type name for a table. Count must match the number of table types.

Types

type Engine

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

Engine stores the schema info and performs operations that keep itself up-to-date.

func NewEngine

func NewEngine(checker connpool.MySQLChecker, config tabletenv.TabletConfig) *Engine

NewEngine creates a new Engine.

func NewEngineForTests

func NewEngineForTests() *Engine

NewEngineForTests creates a new engine, that can't query the database, and will not send notifications. It starts opened, and doesn't reload. Use SetTableForTests to set table schema.

func (*Engine) Close

func (se *Engine) Close()

Close shuts down Engine and is idempotent. It can be re-opened after Close.

func (*Engine) GetSchema

func (se *Engine) GetSchema() map[string]*Table

GetSchema returns the current The Tables are a shared data structure and must be treated as read-only.

func (*Engine) GetTable

func (se *Engine) GetTable(tableName sqlparser.TableIdent) *Table

GetTable returns the info for a table.

func (*Engine) InitDBConfig

func (se *Engine) InitDBConfig(dbcfgs *dbconfigs.DBConfigs)

InitDBConfig must be called before Open.

func (*Engine) MakeNonMaster

func (se *Engine) MakeNonMaster()

MakeNonMaster clears the sequence caches to make sure that they don't get accidentally reused after losing mastership.

func (*Engine) Open

func (se *Engine) Open() error

Open initializes the Engine. Calling Open on an already open engine is a no-op.

func (*Engine) RegisterNotifier

func (se *Engine) RegisterNotifier(name string, f notifier)

RegisterNotifier registers the function for schema change notification. It also causes an immediate notification to the caller. The notified function must not change the map or its contents. The only exception is the sequence table where the values can be changed using the lock.

func (*Engine) Reload

func (se *Engine) Reload(ctx context.Context) error

Reload reloads the schema info from the db. Any tables that have changed since the last load are updated. This is a no-op if the Engine is closed.

func (*Engine) ReloadTime

func (se *Engine) ReloadTime() time.Duration

ReloadTime returns schema info reload time.

func (*Engine) ServeHTTP

func (se *Engine) ServeHTTP(response http.ResponseWriter, request *http.Request)

func (*Engine) SetReloadTime

func (se *Engine) SetReloadTime(reloadTime time.Duration)

SetReloadTime changes how often the schema is reloaded. This call also triggers an immediate reload.

func (*Engine) SetTableForTests

func (se *Engine) SetTableForTests(table *Table)

SetTableForTests puts a Table in the map directly.

func (*Engine) UnregisterNotifier

func (se *Engine) UnregisterNotifier(name string)

UnregisterNotifier unregisters the notifier function.

type Index

type Index struct {
	Name   sqlparser.ColIdent
	Unique bool
	// Columns are the columns comprising the index.
	Columns []sqlparser.ColIdent
	// Cardinality[i] is the number of distinct values of Columns[i] in the
	// table.
	Cardinality []uint64
}

Index contains info about a table index.

func NewIndex

func NewIndex(name string, unique bool) *Index

NewIndex creates a new Index.

func (*Index) AddColumn

func (idx *Index) AddColumn(name string, cardinality uint64)

AddColumn adds a column to the index.

func (*Index) FindColumn

func (idx *Index) FindColumn(name sqlparser.ColIdent) int

FindColumn finds a column in the index. It returns the index if found. Otherwise, it returns -1.

type MessageInfo

type MessageInfo struct {
	// IDPKIndex is the index of the ID column
	// in PKvalues. This is used to extract the ID
	// value for message tables to discard items
	// from the cache.
	IDPKIndex int

	// Fields stores the field info to be
	// returned for subscribers.
	Fields []*querypb.Field

	// AckWaitDuration specifies how long to wait after
	// the message was first sent. The back-off doubles
	// every attempt.
	AckWaitDuration time.Duration

	// PurgeAfterDuration specifies the time after which
	// a successfully acked message can be deleted.
	PurgeAfterDuration time.Duration

	// BatchSize specifies the max number of events to
	// send per response.
	BatchSize int

	// CacheSize specifies the number of messages to keep
	// in cache. Anything that cannot fit in the cache
	// is sent as best effort.
	CacheSize int

	// PollInterval specifies the polling frequency to
	// look for messages to be sent.
	PollInterval time.Duration
}

MessageInfo contains info specific to message tables.

type SequenceInfo

type SequenceInfo struct {
	sync.Mutex
	NextVal int64
	LastVal int64
}

SequenceInfo contains info specific to sequence tabels. It must be locked before accessing the values inside. If CurVal==LastVal, we have to cache new values. When the schema is first loaded, the values are all 0, which will trigger caching on first use.

type Table

type Table struct {
	Name      sqlparser.TableIdent
	Columns   []TableColumn
	Indexes   []*Index
	PKColumns []int
	Type      int

	// SequenceInfo contains info for sequence tables.
	SequenceInfo *SequenceInfo

	// MessageInfo contains info for message tables.
	MessageInfo *MessageInfo

	// These vars can be accessed concurrently.
	TableRows     sync2.AtomicInt64
	DataLength    sync2.AtomicInt64
	IndexLength   sync2.AtomicInt64
	DataFree      sync2.AtomicInt64
	MaxDataLength sync2.AtomicInt64
}

Table contains info about a table.

func LoadTable

func LoadTable(conn *connpool.DBConn, tableName string, tableType string, comment string) (*Table, error)

LoadTable creates a Table from the schema info in the database.

func NewTable

func NewTable(name string) *Table

NewTable creates a new Table.

func (*Table) AddColumn

func (ta *Table) AddColumn(name string, columnType querypb.Type, defval sqltypes.Value, extra string)

AddColumn adds a column to the Table.

func (*Table) AddIndex

func (ta *Table) AddIndex(name string, unique bool) (index *Index)

AddIndex adds an index to the table.

func (*Table) Done

func (ta *Table) Done()

Done must be called after columns and indexes are added to the table. It will build additional metadata like PKColumns.

func (*Table) FindColumn

func (ta *Table) FindColumn(name sqlparser.ColIdent) int

FindColumn finds a column in the table. It returns the index if found. Otherwise, it returns -1.

func (*Table) GetPKColumn

func (ta *Table) GetPKColumn(index int) *TableColumn

GetPKColumn returns the pk column specified by the index.

func (*Table) HasPrimary

func (ta *Table) HasPrimary() bool

HasPrimary returns true if the table has a primary key.

func (*Table) SetMysqlStats

func (ta *Table) SetMysqlStats(tr, dl, il, df, mdl sqltypes.Value)

SetMysqlStats receives the values found in the mysql information_schema.tables table

func (*Table) UniqueIndexes

func (ta *Table) UniqueIndexes() int

UniqueIndexes returns the number of unique indexes on the table

type TableColumn

type TableColumn struct {
	Name    sqlparser.ColIdent
	Type    querypb.Type
	IsAuto  bool
	Default sqltypes.Value
}

TableColumn contains info about a table's column.

func (*TableColumn) String

func (c *TableColumn) String() string

String() pretty-prints TableColumn into a string.