util

Documentation

Index

• Constants
• func DelKeyWithPrefix(rm kv.RetrieverMutator, prefix kv.Key) error
• func GetStack() []byte
• func RandomBuf(size int) []byte
• func RowKeyPrefixFilter(rowKeyPrefix kv.Key) kv.FnKeyCmp
• func RunWithRetry(retryCnt int, backoff uint64, f func() (bool, error)) (err error)
• func ScanMetaWithPrefix(retriever kv.Retriever, prefix kv.Key, filter func(kv.Key, []byte) bool) error
• func WithRecovery(exec func(), recoverFn func(r interface{}))
• type ProcessInfo
• type SessionManager

Constants

const (
	// DefaultMaxRetries indicates the max retry count.
	DefaultMaxRetries = 30
	// RetryInterval indicates retry interval.
	RetryInterval uint64 = 500
)

Functions

func DelKeyWithPrefix

func DelKeyWithPrefix(rm kv.RetrieverMutator, prefix kv.Key) error

DelKeyWithPrefix deletes keys with prefix.

func GetStack

func GetStack() []byte

GetStack gets the stacktrace.

func RandomBuf

func RandomBuf(size int) []byte

RandomBuf generates a random string using ASCII characters but avoid separator character. See https://github.com/mysql/mysql-server/blob/5.7/mysys_ssl/crypt_genhash_impl.cc#L435

func RowKeyPrefixFilter

func RowKeyPrefixFilter(rowKeyPrefix kv.Key) kv.FnKeyCmp

RowKeyPrefixFilter returns a function which checks whether currentKey has decoded rowKeyPrefix as prefix.

func RunWithRetry

func RunWithRetry(retryCnt int, backoff uint64, f func() (bool, error)) (err error)

RunWithRetry will run the f with backoff and retry. retryCnt: Max retry count backoff: When run f failed, it will sleep backoff * triedCount time.Millisecond. Function f should have two return value. The first one is an bool which indicate if the err if retryable. The second is if the f meet any error.

func ScanMetaWithPrefix

func ScanMetaWithPrefix(retriever kv.Retriever, prefix kv.Key, filter func(kv.Key, []byte) bool) error

ScanMetaWithPrefix scans metadata with the prefix.

func WithRecovery

func WithRecovery(exec func(), recoverFn func(r interface{}))

WithRecovery wraps goroutine startup call with force recovery. it will dump current goroutine stack into log if catch any recover result.

exec:      execute logic function.
recoverFn: handler will be called after recover and before dump stack, passing `nil` means noop.

Types

type ProcessInfo

type ProcessInfo struct {
	ID      uint64
	User    string
	Host    string
	DB      string
	Command string
	Time    time.Time
	State   uint16
	Info    string
	Mem     int64
}

ProcessInfo is a struct used for show processlist statement.

type SessionManager

type SessionManager interface {
	// ShowProcessList returns map[connectionID]ProcessInfo
	ShowProcessList() map[uint64]ProcessInfo
	Kill(connectionID uint64, query bool)
}

SessionManager is an interface for session manage. Show processlist and kill statement rely on this interface.