Golang value.AnnotatedValue类代码示例

func (this *IntersectScan) processKey(item value.AnnotatedValue, context *Context) bool {
	m := item.GetAttachment("meta")
	meta, ok := m.(map[string]interface{})
	if !ok {
		context.Error(errors.NewError(nil,
			fmt.Sprintf("Missing or invalid meta %v of type %T.", m, m)))
		return false
	}

	k := meta["id"]
	key, ok := k.(string)
	if !ok {
		context.Error(errors.NewError(nil,
			fmt.Sprintf("Missing or invalid primary key %v of type %T.", k, k)))
		return false
	}

	count := this.counts[key]
	this.counts[key] = count + 1

	if count+1 == len(this.scans) {
		delete(this.values, key)
		return this.sendItem(item)
	}

	if count == 0 {
		this.values[key] = item
	}

	return true
}

func (this *Clone) processItem(item value.AnnotatedValue, context *Context) bool {
	target, ok := item.GetAttachment("target").(value.Value)
	if !ok {
		target = item
	}

	item.SetAttachment("clone", target.CopyForUpdate())
	return this.sendItem(item)
}

func (this *FinalProject) processItem(item value.AnnotatedValue, context *Context) bool {
	pv := item.GetAttachment("projection")
	if pv != nil {
		v := pv.(value.Value)
		return this.sendItem(value.NewAnnotatedValue(v))
	}

	return this.sendItem(item)
}

func (this *Distinct) processItem(item value.AnnotatedValue, context *Context) bool {
	p := item.GetAttachment("projection")
	if p == nil {
		p = item
	}

	this.set.Put(p.(value.Value), item)
	return true
}

func (this *Collect) processItem(item value.AnnotatedValue, context *Context) bool {
	if len(this.values) == cap(this.values) {
		values := make([]interface{}, len(this.values), len(this.values)<<1)
		copy(values, this.values)
		this.values = values
	}

	this.values = append(this.values, item.Actual())
	return true
}

// The item may have been wrapped in a top-level object by a previous
// operator (key scan, primary scan) - take the inner value if so, as
// we do not want to write the top-level value to the datastore
func (this *SendUpdate) unwrapTop(item value.AnnotatedValue) value.Value {
	top := this.plan.Alias()
	value := item.GetValue()
	inner_value, ok := value.Field(top)

	if ok {
		return inner_value
	}
	return item
}

func (this *Merge) processMatch(item value.AnnotatedValue,
	context *Context, update, delete, insert Operator) bool {
	kv, e := this.plan.Key().Evaluate(item, context)
	if e != nil {
		context.Error(errors.NewError(e, "Error evaluatating MERGE key."))
		return false
	}

	ka := kv.Actual()
	k, ok := ka.(string)
	if !ok {
		context.Error(errors.NewError(nil,
			fmt.Sprintf("Invalid MERGE key %v of type %T.", ka, ka)))
		return false
	}

	bvs, err := this.plan.Keyspace().Fetch([]string{k})
	if err != nil {
		context.Error(err)
		return false
	}

	if len(bvs) > 0 {
		bv := bvs[0].Value

		// Matched; join source and target
		if update != nil {
			item.SetAttachment("target", bv)
		}

		abv := value.NewAnnotatedValue(bv)
		item.SetField(this.plan.KeyspaceRef().Alias(), abv)

		// Perform UPDATE and/or DELETE
		if update != nil {
			update.Input().ItemChannel() <- item
		}

		if delete != nil {
			delete.Input().ItemChannel() <- item
		}
	} else {
		// Not matched; INSERT
		if insert != nil {
			insert.Input().ItemChannel() <- item
		}
	}

	return true
}

func (this *Unset) processItem(item value.AnnotatedValue, context *Context) bool {
	clone, ok := item.GetAttachment("clone").(value.AnnotatedValue)
	if !ok {
		context.Error(errors.NewError(nil,
			fmt.Sprintf("Invalid UPDATE clone of type %T.", clone)))
		return false
	}

	for _, t := range this.plan.Node().Terms() {
		unsetPath(t, clone, context)
	}

	return this.sendItem(item)
}

func (this *InitialProject) processTerms(item value.AnnotatedValue, context *Context) bool {
	n := len(this.plan.Terms())

	var f map[string]interface{}
	if item.Type() == value.OBJECT {
		f = item.Copy().Fields()
	}

	if f == nil {
		f = make(map[string]interface{}, n)
	}

	pv := value.NewAnnotatedValue(f)
	pv.SetAttachments(item.Attachments())

	p := value.NewValue(make(map[string]interface{}, n+32))
	pv.SetAttachment("projection", p)

	for _, term := range this.plan.Terms() {
		if term.Result().Alias() != "" {
			v, err := term.Result().Expression().Evaluate(item, context)
			if err != nil {
				context.Error(errors.NewError(err, "Error evaluating projection."))
				return false
			}

			p.SetField(term.Result().Alias(), v)

			// Explicit aliases override data
			if term.Result().As() != "" {
				pv.SetField(term.Result().As(), v)
			}
		} else {
			// Star
			starval := item.GetValue()
			if term.Result().Expression() != nil {
				var err error
				starval, err = term.Result().Expression().Evaluate(item, context)
				if err != nil {
					context.Error(errors.NewError(err, "Error evaluating projection."))
					return false
				}
			}

			// Latest star overwrites previous star
			switch sa := starval.Actual().(type) {
			case map[string]interface{}:
				for k, v := range sa {
					p.SetField(k, v)
				}
			}
		}
	}

	return this.sendItem(pv)
}

func (this *InitialProject) processItem(item value.AnnotatedValue, context *Context) bool {
	terms := this.plan.Terms()
	n := len(terms)

	if n > 1 {
		return this.processTerms(item, context)
	}

	if n == 0 {
		return this.sendItem(item)
	}

	// n == 1

	result := terms[0].Result()
	expr := result.Expression()

	if expr == nil {
		// Unprefixed star
		if item.Type() == value.OBJECT {
			return this.sendItem(item)
		} else {
			return this.sendItem(_EMPTY_ANNOTATED_VALUE)
		}
	} else if this.plan.Projection().Raw() {
		// Raw projection of an expression
		v, err := expr.Evaluate(item, context)
		if err != nil {
			context.Error(errors.NewError(err, "Error evaluating projection."))
			return false
		}

		if result.As() == "" {
			return this.sendItem(value.NewAnnotatedValue(v))
		}

		sv := value.NewScopeValue(make(map[string]interface{}, 1), item)
		sv.SetField(result.As(), v)
		av := value.NewAnnotatedValue(sv)
		av.SetAttachment("projection", v)
		return this.sendItem(av)
	} else {
		// Any other projection
		return this.processTerms(item, context)
	}
}

func (this *Let) processItem(item value.AnnotatedValue, context *Context) bool {
	n := len(this.plan.Bindings())
	cv := value.NewScopeValue(make(map[string]interface{}, n), item)
	lv := value.NewAnnotatedValue(cv)
	lv.SetAttachments(item.Attachments())

	for _, b := range this.plan.Bindings() {
		v, e := b.Expression().Evaluate(item, context)
		if e != nil {
			context.Error(errors.NewError(e, "Error evaluating LET."))
			return false
		}

		lv.SetField(b.Variable(), v)
	}

	return this.sendItem(lv)
}

func (this *Set) processItem(item value.AnnotatedValue, context *Context) bool {
	clone, ok := item.GetAttachment("clone").(value.AnnotatedValue)
	if !ok {
		context.Error(errors.NewError(nil,
			fmt.Sprintf("Invalid UPDATE clone of type %T.", clone)))
		return false
	}

	var e error
	for _, t := range this.plan.Node().Terms() {
		clone, e = setPath(t, clone, item, context)
		if e != nil {
			context.Error(errors.NewError(e, "Error evaluating SET clause."))
			return false
		}
	}

	item.SetAttachment("clone", clone)
	return this.sendItem(item)
}

func (this *Unnest) processItem(item value.AnnotatedValue, context *Context) bool {
	ev, err := this.plan.Term().Expression().Evaluate(item, context)
	if err != nil {
		context.Error(errors.NewError(err, "Error evaluating UNNEST path."))
		return false
	}

	actuals := ev.Actual()
	switch actuals.(type) {
	case []interface{}:
	case nil:
		actuals = []interface{}(nil)
	default:
		actuals = []interface{}{actuals}
	}

	acts := actuals.([]interface{})
	if len(acts) == 0 {
		// Outer unnest
		return !this.plan.Term().Outer() || this.sendItem(item)
	}

	// Attach and send
	for i, act := range acts {
		var av value.AnnotatedValue
		if i < len(acts)-1 {
			av = value.NewAnnotatedValue(item.Copy())
		} else {
			av = item
		}

		av.SetField(this.plan.Alias(), value.NewValue(act))

		if !this.sendItem(av) {
			return false
		}
	}

	return true
}

func setPath(t *algebra.SetTerm, clone, item value.AnnotatedValue, context *Context) (value.AnnotatedValue, error) {
	if t.UpdateFor() != nil {
		return setFor(t, clone, item, context)
	}

	v, err := t.Value().Evaluate(item, context)
	if err != nil {
		return nil, err
	}

	if v.Type() == value.MISSING {
	}

	if t.Path() != nil {
		t.Path().Set(clone, v, context)
		return clone, nil
	} else {
		av := value.NewAnnotatedValue(v)
		av.SetAttachments(clone.Attachments())
		return av, nil
	}
}

func (this *UnionScan) processKey(item value.AnnotatedValue, context *Context) bool {
	m := item.GetAttachment("meta")
	meta, ok := m.(map[string]interface{})
	if !ok {
		context.Error(errors.NewError(nil,
			fmt.Sprintf("Missing or invalid meta %v of type %T.", m, m)))
		return false
	}

	k := meta["id"]
	key, ok := k.(string)
	if !ok {
		context.Error(errors.NewError(nil,
			fmt.Sprintf("Missing or invalid primary key %v of type %T.", k, k)))
		return false
	}

	if this.values[key] != nil {
		return true
	}

	this.values[key] = item
	return this.sendItem(item)
}