globalconn

Documentation

Index

• Constants
• type AutoIncPool
  • func (p *AutoIncPool) Get() (id uint64, ok bool)
  • func (p *AutoIncPool) Init(sizeInBits uint32)
  • func (p *AutoIncPool) InitExt(sizeInBits uint32, checkExisted bool, tryCnt int)
  • func (p *AutoIncPool) Len() int
  • func (p *AutoIncPool) Put(id uint64) (ok bool)
  • func (p AutoIncPool) String() string
• type IDPool
• type LockFreeCircularPool
  • func (p *LockFreeCircularPool) Get() (val uint64, ok bool)
  • func (p *LockFreeCircularPool) Init(sizeInBits uint32)
  • func (p *LockFreeCircularPool) InitExt(sizeInBits uint32, fillCount uint32)
  • func (p *LockFreeCircularPool) InitForTest(head uint32, fillCount uint32)
  • func (p *LockFreeCircularPool) Len() int
  • func (p *LockFreeCircularPool) Put(val uint64) (ok bool)
  • func (p *LockFreeCircularPool) String() string

Constants

const (
	// MaxServerID32 is maximum serverID for 32bits global connection ID.
	MaxServerID32 = 1<<11 - 1
	// LocalConnIDBits32 is the number of bits of localConnID for 32bits global connection ID.
	LocalConnIDBits32 = 20
	// MaxLocalConnID32 is maximum localConnID for 32bits global connection ID.
	MaxLocalConnID32 = 1<<LocalConnIDBits32 - 1

	// MaxServerID64 is maximum serverID for 64bits global connection ID.
	MaxServerID64 = 1<<22 - 1
	// LocalConnIDBits64 is the number of bits of localConnID for 64bits global connection ID.
	LocalConnIDBits64 = 40
	// MaxLocalConnID64 is maximum localConnID for 64bits global connection ID.
	MaxLocalConnID64 = 1<<LocalConnIDBits64 - 1
)

GlobalConnID is the global connection ID, providing UNIQUE connection IDs across the whole TiDB cluster. Used when GlobalKill feature is enable. See https://github.com/pingcap/tidb/blob/master/docs/design/2020-06-01-global-kill.md 32 bits version:

 31    21 20               1    0
+--------+------------------+------+
|serverID|   local connID   |markup|
| (11b)  |       (20b)      |  =0  |
+--------+------------------+------+

64 bits version:

 63 62                 41 40                                   1   0
+--+---------------------+--------------------------------------+------+
|  |      serverId       |             local connId             |markup|
|=0|       (22b)         |                 (40b)                |  =1  |
+--+---------------------+--------------------------------------+------+

const (
	// IDPoolInvalidValue indicates invalid value from IDPool.
	IDPoolInvalidValue = math.MaxUint64
)

Types

type AutoIncPool

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

AutoIncPool simply do auto-increment to allocate ID. Wrapping will happen.

func (*AutoIncPool) Get

func (p *AutoIncPool) Get() (id uint64, ok bool)

Get id by auto-increment.

func (*AutoIncPool) Init

func (p *AutoIncPool) Init(sizeInBits uint32)

Init initiates AutoIncPool.

func (*AutoIncPool) InitExt

func (p *AutoIncPool) InitExt(sizeInBits uint32, checkExisted bool, tryCnt int)

InitExt initiates AutoIncPool with more parameters.

func (*AutoIncPool) Len

func (p *AutoIncPool) Len() int

Len implements IDPool interface.

func (*AutoIncPool) Put

func (p *AutoIncPool) Put(id uint64) (ok bool)

Put id back to pool.

func (AutoIncPool) String

func (p AutoIncPool) String() string

String implements IDPool interface.

type IDPool

type IDPool interface {
	fmt.Stringer
	// Init initiates pool.
	Init(sizeInBits uint32)
	// Len returns length of available id's in pool.
	// Note that Len() would return -1 when this method is NOT supported.
	Len() int
	// Put puts value to pool. "ok" is false when pool is full.
	Put(val uint64) (ok bool)
	// Get gets value from pool. "ok" is false when pool is empty.
	Get() (val uint64, ok bool)
}

IDPool is the pool allocating & deallocating IDs.

type LockFreeCircularPool

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

LockFreeCircularPool is a lock-free circular implementation of IDPool. Note that to reduce memory usage, LockFreeCircularPool supports 32bits IDs ONLY.

func (*LockFreeCircularPool) Get

func (p *LockFreeCircularPool) Get() (val uint64, ok bool)

Get implements IDPool interface.

func (*LockFreeCircularPool) Init

func (p *LockFreeCircularPool) Init(sizeInBits uint32)

Init implements IDPool interface.

func (*LockFreeCircularPool) InitExt

func (p *LockFreeCircularPool) InitExt(sizeInBits uint32, fillCount uint32)

InitExt initializes LockFreeCircularPool with more parameters. fillCount: fills pool with [1, min(fillCount, 1<<(sizeInBits-1)]. Pass "math.MaxUint32" to fulfill the pool.

func (*LockFreeCircularPool) InitForTest

func (p *LockFreeCircularPool) InitForTest(head uint32, fillCount uint32)

InitForTest used to unit test overflow of head & tail.

func (*LockFreeCircularPool) Len

func (p *LockFreeCircularPool) Len() int

Len implements IDPool interface.

func (*LockFreeCircularPool) Put

func (p *LockFreeCircularPool) Put(val uint64) (ok bool)

Put implements IDPool interface.

func (*LockFreeCircularPool) String

func (p *LockFreeCircularPool) String() string

String implements IDPool interface. Notice: NOT thread safe.