Function NewExprContext

pkg/expression/exprstatic/exprctx.go:151–190

NewExprContext creates a new ExprContext

(opts ...ExprCtxOption)

// NewExprContext creates a new ExprContext
func NewExprContext(opts ...ExprCtxOption) *ExprContext {
	cs, err := charset.GetCharsetInfo(mysql.DefaultCharset)
	intest.AssertNoError(err)

	ctx := &ExprContext{
		exprCtxState: exprCtxState{
			charset:                    cs.Name,
			collation:                  cs.DefaultCollation,
			defaultCollationForUTF8MB4: mysql.DefaultCollationName,
			blockEncryptionMode:        variable.DefBlockEncryptionMode,
			sysDateIsNow:               variable.DefSysdateIsNow,
			noopFuncsMode:              variable.TiDBOptOnOffWarn(variable.DefTiDBEnableNoopFuncs),
			windowingUseHighPrecision:  true,
			groupConcatMaxLen:          variable.DefGroupConcatMaxLen,
		},
	}
	for _, opt := range opts {
		opt(&ctx.exprCtxState)
	}

	if ctx.evalCtx == nil {
		ctx.evalCtx = NewEvalContext()
	}

	if ctx.rng == nil {
		ctx.rng = mathutil.NewWithTime()
	}

	if ctx.columnIDAllocator == nil {
		ctx.columnIDAllocator = exprctx.NewSimplePlanColumnIDAllocator(0)
	}

	if ctx.planCacheTracker == nil {
		cacheTracker := contextutil.NewPlanCacheTracker(ctx.evalCtx)
		ctx.planCacheTracker = &cacheTracker
		ctx.planCacheTracker.EnablePlanCache()
	}

	return ctx
}

// Apply returns a new `ExprContext` with the fields updated according to the given options.
func (ctx *ExprContext) Apply(opts ...ExprCtxOption) *ExprContext {