Function newFastValuesCtx

pkg/util/ctxutil/fast_value.go:168–185

newFastValuesCtx returns a new context with the given parent and the values from the ancestor. If the ancestor has an associated container that has free slots, it is used to avoid a new allocation.

(ancestor *fastValuesCtx, parent context.Context)

// If the ancestor has an associated container that has free slots, it is used
// to avoid a new allocation.
func newFastValuesCtx(ancestor *fastValuesCtx, parent context.Context) *fastValuesCtx {
	var ctx *fastValuesCtx
	var container *fastValuesContainer
	if ancestor != nil && ancestor.container != nil {
		// Try to use the container.
		var more bool
		ctx, more = ancestor.container.get()
		if more {
			container = ancestor.container
		} else if ctx == nil {
			ctx = &fastValuesCtx{}
		}
	} else {
		ctx = &fastValuesCtx{}
	}
	ctx.init(parent, container, ancestor)
	return ctx
}

// findFastValuesCtxAncestor returns the closest fastValuesCtx ancestor of the
// given parent context.