示例#1
0
func ExampleIts() {
	var its []x.Instruction

	for t := 0; t < 10; t++ {
		var i x.Instruction
		i.NanoTs = int64(100 - t)
		its = append(its, i)
	}

	sort.Sort(x.Its(its))
	fmt.Println(its[0].NanoTs)
	// Output: 91
}
示例#2
0
文件: query.go 项目: postfix/gocrud
func (q *Query) doRun(c *req.Context, level, max int, ch chan runResult) {
	log.Debugf("Query: %+v", q)
	its, err := c.Store.GetEntity(c.TablePrefix, q.id)
	if err != nil {
		x.LogErr(log, err).Error("While retrieving: ", q.id)
		ch <- runResult{Result: nil, Err: err}
		return
	}
	if len(its) == 0 {
		ch <- runResult{Result: new(Result), Err: nil}
		return
	}
	sort.Sort(x.Its(its))

	follow := make(map[string]*Query)
	for _, child := range q.children {
		follow[child.kind] = child
		log.WithField("kind", child.kind).WithField("child", child).Debug("Following")
	}

	result := new(Result)
	result.Columns = make(map[string]Object)
	it := its[0]
	result.Id = it.SubjectId
	result.Kind = it.SubjectType

	waitTimes := 0
	childChan := make(chan runResult)
	for _, it := range its {
		if it.Predicate == "_delete_" {
			// If marked as deleted, don't return this node.
			log.WithField("id", result.Id).
				WithField("kind", result.Kind).
				WithField("_delete_", true).
				Debug("Discarding due to delete bit")
			ch <- runResult{Result: new(Result), Err: nil}
			return
		}

		if _, fout := q.filterOut[it.Predicate]; fout {
			log.WithField("id", result.Id).
				WithField("kind", result.Kind).
				WithField("predicate", it.Predicate).
				Debug("Discarding due to predicate filter")
			ch <- runResult{Result: new(Result), Err: nil}
			return
		}

		if len(it.ObjectId) == 0 {
			o := Object{NanoTs: it.NanoTs, Source: it.Source}
			if err := json.Unmarshal(it.Object, &o.Value); err != nil {
				x.LogErr(log, err).Error("While unmarshal")
				ch <- runResult{Result: nil, Err: err}
				return
			}

			result.Columns[it.Predicate] = o
			continue
		}

		if childq, fw := follow[it.Predicate]; fw {
			nchildq := new(Query)
			*nchildq = *childq // This is important, otherwise id gets overwritten
			nchildq.id = it.ObjectId

			// Use child's maxDepth here, instead of parent's.
			waitTimes += 1
			log.WithField("child_id", nchildq.id).
				WithField("child_kind", nchildq.kind).Debug("Go routine for child")
			go nchildq.doRun(c, 0, nchildq.maxDepth, childChan)
			continue
		}

		if len(it.ObjectId) > 0 && level < max {
			child := new(Query)
			child.id = it.ObjectId

			waitTimes += 1
			log.WithField("child_id", child.id).WithField("level", level+1).
				Debug("Go routine for child one level deeper")
			go child.doRun(c, level+1, max, childChan)
		}
	}

	// Wait for all those subroutines
	for i := 0; i < waitTimes; i++ {
		log.Debugf("Waiting for children subroutines: %v/%v", i, waitTimes-1)
		rr := <-childChan
		log.Debugf("Waiting done")
		if rr.Err != nil {
			x.LogErr(log, err).Error("While child doRun")
		} else {
			if len(rr.Result.Id) > 0 && len(rr.Result.Kind) > 0 {
				log.WithField("result", *rr.Result).Debug("Appending child")
				result.Children = append(result.Children, rr.Result)
			}
		}
	}

	ch <- runResult{Result: result, Err: nil}
	return
}