Golang influxql.NewMergeIterator函數代碼示例

func TestMergeIterator_Nil(t *testing.T) {
	itr := influxql.NewMergeIterator([]influxql.Iterator{nil}, influxql.IteratorOptions{}).(influxql.FloatIterator)
	if p := itr.Next(); p != nil {
		t.Fatalf("unexpected point: %#v", p)
	}
	itr.Close()
}

func (e *Engine) CreateIterator(opt influxql.IteratorOptions) (influxql.Iterator, error) {
	if call, ok := opt.Expr.(*influxql.Call); ok {
		refOpt := opt
		refOpt.Expr = call.Args[0].(*influxql.VarRef)
		inputs, err := e.createVarRefIterator(refOpt)
		if err != nil {
			return nil, err
		}

		input := influxql.NewMergeIterator(inputs, opt)
		if opt.InterruptCh != nil {
			input = influxql.NewInterruptIterator(input, opt.InterruptCh)
		}
		return influxql.NewCallIterator(input, opt)
	}

	itrs, err := e.createVarRefIterator(opt)
	if err != nil {
		return nil, err
	}
	itr := influxql.NewSortedMergeIterator(itrs, opt)
	if opt.InterruptCh != nil {
		itr = influxql.NewInterruptIterator(itr, opt.InterruptCh)
	}
	return itr, nil
}

func TestMergeIterator_Cast_Float(t *testing.T) {
	inputs := []influxql.Iterator{
		&IntegerIterator{Points: []influxql.IntegerPoint{
			{Name: "cpu", Tags: ParseTags("host=A"), Time: 0, Value: 1},
			{Name: "cpu", Tags: ParseTags("host=A"), Time: 12, Value: 3},
			{Name: "cpu", Tags: ParseTags("host=A"), Time: 30, Value: 4},
			{Name: "cpu", Tags: ParseTags("host=B"), Time: 1, Value: 2},
			{Name: "mem", Tags: ParseTags("host=B"), Time: 11, Value: 8},
		}},
		&FloatIterator{Points: []influxql.FloatPoint{
			{Name: "cpu", Tags: ParseTags("host=A"), Time: 20, Value: 7},
			{Name: "cpu", Tags: ParseTags("host=B"), Time: 11, Value: 5},
			{Name: "cpu", Tags: ParseTags("host=B"), Time: 13, Value: 6},
			{Name: "mem", Tags: ParseTags("host=A"), Time: 25, Value: 9},
		}},
	}

	itr := influxql.NewMergeIterator(inputs, influxql.IteratorOptions{
		Interval: influxql.Interval{
			Duration: 10 * time.Nanosecond,
		},
		Ascending: true,
	})
	if a, err := Iterators([]influxql.Iterator{itr}).ReadAll(); err != nil {
		t.Fatalf("unexpected error: %s", err)
	} else if !deep.Equal(a, [][]influxql.Point{
		{&influxql.FloatPoint{Name: "cpu", Tags: ParseTags("host=A"), Time: 0, Value: 1}},
		{&influxql.FloatPoint{Name: "cpu", Tags: ParseTags("host=A"), Time: 12, Value: 3}},
		{&influxql.FloatPoint{Name: "cpu", Tags: ParseTags("host=A"), Time: 20, Value: 7}},
		{&influxql.FloatPoint{Name: "cpu", Tags: ParseTags("host=A"), Time: 30, Value: 4}},
		{&influxql.FloatPoint{Name: "cpu", Tags: ParseTags("host=B"), Time: 1, Value: 2}},
		{&influxql.FloatPoint{Name: "cpu", Tags: ParseTags("host=B"), Time: 11, Value: 5}},
		{&influxql.FloatPoint{Name: "cpu", Tags: ParseTags("host=B"), Time: 13, Value: 6}},
		{&influxql.FloatPoint{Name: "mem", Tags: ParseTags("host=A"), Time: 25, Value: 9}},
		{&influxql.FloatPoint{Name: "mem", Tags: ParseTags("host=B"), Time: 11, Value: 8}},
	}) {
		t.Errorf("unexpected points: %s", spew.Sdump(a))
	}

	for i, input := range inputs {
		switch input := input.(type) {
		case *FloatIterator:
			if !input.Closed {
				t.Errorf("iterator %d not closed", i)
			}
		case *IntegerIterator:
			if !input.Closed {
				t.Errorf("iterator %d not closed", i)
			}
		}
	}
}

// Ensure that a set of iterators can be merged together, sorted by window and name/tag.
func TestMergeIterator_Boolean(t *testing.T) {
	inputs := []*BooleanIterator{
		{Points: []influxql.BooleanPoint{
			{Name: "cpu", Tags: ParseTags("host=A"), Time: 0, Value: true},
			{Name: "cpu", Tags: ParseTags("host=A"), Time: 12, Value: true},
			{Name: "cpu", Tags: ParseTags("host=A"), Time: 30, Value: false},
			{Name: "cpu", Tags: ParseTags("host=B"), Time: 1, Value: false},
			{Name: "mem", Tags: ParseTags("host=B"), Time: 11, Value: true},
		}},
		{Points: []influxql.BooleanPoint{
			{Name: "cpu", Tags: ParseTags("host=A"), Time: 20, Value: true},
			{Name: "cpu", Tags: ParseTags("host=B"), Time: 11, Value: true},
			{Name: "cpu", Tags: ParseTags("host=B"), Time: 13, Value: false},
			{Name: "mem", Tags: ParseTags("host=A"), Time: 25, Value: false},
		}},
		{Points: []influxql.BooleanPoint{}},
	}
	itr := influxql.NewMergeIterator(BooleanIterators(inputs), influxql.IteratorOptions{
		Interval: influxql.Interval{
			Duration: 10 * time.Nanosecond,
		},
		Ascending: true,
	})

	if a, err := Iterators([]influxql.Iterator{itr}).ReadAll(); err != nil {
		t.Fatalf("unexpected error: %s", err)
	} else if !deep.Equal(a, [][]influxql.Point{
		{&influxql.BooleanPoint{Name: "cpu", Tags: ParseTags("host=A"), Time: 0, Value: true}},
		{&influxql.BooleanPoint{Name: "cpu", Tags: ParseTags("host=A"), Time: 12, Value: true}},
		{&influxql.BooleanPoint{Name: "cpu", Tags: ParseTags("host=A"), Time: 20, Value: true}},
		{&influxql.BooleanPoint{Name: "cpu", Tags: ParseTags("host=A"), Time: 30, Value: false}},
		{&influxql.BooleanPoint{Name: "cpu", Tags: ParseTags("host=B"), Time: 1, Value: false}},
		{&influxql.BooleanPoint{Name: "cpu", Tags: ParseTags("host=B"), Time: 11, Value: true}},
		{&influxql.BooleanPoint{Name: "cpu", Tags: ParseTags("host=B"), Time: 13, Value: false}},
		{&influxql.BooleanPoint{Name: "mem", Tags: ParseTags("host=A"), Time: 25, Value: false}},
		{&influxql.BooleanPoint{Name: "mem", Tags: ParseTags("host=B"), Time: 11, Value: true}},
	}) {
		t.Errorf("unexpected points: %s", spew.Sdump(a))
	}

	for i, input := range inputs {
		if !input.Closed {
			t.Errorf("iterator %d not closed", i)
		}
	}
}

// createTagKeysIterator returns an iterator for all tag keys across measurements.
func (a Shards) createTagKeysIterator(opt influxql.IteratorOptions) (influxql.Iterator, error) {
	itrs := make([]influxql.Iterator, 0, len(a))
	if err := func() error {
		for _, sh := range a {
			itr, err := NewTagKeysIterator(sh, opt)
			if err != nil {
				return err
			}
			itrs = append(itrs, itr)
		}
		return nil
	}(); err != nil {
		influxql.Iterators(itrs).Close()
		return nil, err
	}
	return influxql.NewMergeIterator(itrs, opt), nil
}

// Ensure that a set of iterators can be merged together, sorted by window and name/tag.
func TestMergeIterator_Float(t *testing.T) {
	inputs := []*FloatIterator{
		{Points: []influxql.FloatPoint{
			{Name: "cpu", Tags: ParseTags("host=A"), Time: 0, Value: 1},
			{Name: "cpu", Tags: ParseTags("host=A"), Time: 12, Value: 3},
			{Name: "cpu", Tags: ParseTags("host=A"), Time: 30, Value: 4},
			{Name: "cpu", Tags: ParseTags("host=B"), Time: 1, Value: 2},
			{Name: "mem", Tags: ParseTags("host=B"), Time: 11, Value: 8},
		}},
		{Points: []influxql.FloatPoint{
			{Name: "cpu", Tags: ParseTags("host=A"), Time: 20, Value: 7},
			{Name: "cpu", Tags: ParseTags("host=B"), Time: 11, Value: 5},
			{Name: "cpu", Tags: ParseTags("host=B"), Time: 13, Value: 6},
			{Name: "mem", Tags: ParseTags("host=A"), Time: 25, Value: 9},
		}},
		{Points: []influxql.FloatPoint{}},
		{Points: []influxql.FloatPoint{}},
	}

	itr := influxql.NewMergeIterator(FloatIterators(inputs), influxql.IteratorOptions{
		Interval: influxql.Interval{
			Duration: 10 * time.Nanosecond,
		},
		Ascending: true,
	})
	if a := Iterators([]influxql.Iterator{itr}).ReadAll(); !deep.Equal(a, [][]influxql.Point{
		{&influxql.FloatPoint{Name: "cpu", Tags: ParseTags("host=A"), Time: 0, Value: 1}},
		{&influxql.FloatPoint{Name: "cpu", Tags: ParseTags("host=A"), Time: 12, Value: 3}},
		{&influxql.FloatPoint{Name: "cpu", Tags: ParseTags("host=A"), Time: 20, Value: 7}},
		{&influxql.FloatPoint{Name: "cpu", Tags: ParseTags("host=A"), Time: 30, Value: 4}},
		{&influxql.FloatPoint{Name: "cpu", Tags: ParseTags("host=B"), Time: 1, Value: 2}},
		{&influxql.FloatPoint{Name: "cpu", Tags: ParseTags("host=B"), Time: 11, Value: 5}},
		{&influxql.FloatPoint{Name: "cpu", Tags: ParseTags("host=B"), Time: 13, Value: 6}},
		{&influxql.FloatPoint{Name: "mem", Tags: ParseTags("host=A"), Time: 25, Value: 9}},
		{&influxql.FloatPoint{Name: "mem", Tags: ParseTags("host=B"), Time: 11, Value: 8}},
	}) {
		t.Errorf("unexpected points: %s", spew.Sdump(a))
	}

	for i, input := range inputs {
		if !input.Closed {
			t.Errorf("iterator %d not closed", i)
		}
	}
}

// createVarRefIterator creates an iterator for a variable reference.
func (e *Engine) createVarRefIterator(opt influxql.IteratorOptions) ([]influxql.Iterator, error) {
	ref, _ := opt.Expr.(*influxql.VarRef)

	var itrs []influxql.Iterator
	if err := func() error {
		mms := tsdb.Measurements(e.index.MeasurementsByName(influxql.Sources(opt.Sources).Names()))

		for _, mm := range mms {
			// Determine tagsets for this measurement based on dimensions and filters.
			tagSets, err := mm.TagSets(opt.Dimensions, opt.Condition)
			if err != nil {
				return err
			}

			// Calculate tag sets and apply SLIMIT/SOFFSET.
			tagSets = influxql.LimitTagSets(tagSets, opt.SLimit, opt.SOffset)

			for _, t := range tagSets {
				inputs, err := e.createTagSetIterators(ref, mm, t, opt)
				if err != nil {
					return err
				}

				if len(inputs) > 0 && (opt.Limit > 0 || opt.Offset > 0) {
					var itr influxql.Iterator
					if opt.MergeSorted() {
						itr = influxql.NewSortedMergeIterator(inputs, opt)
					} else {
						itr = influxql.NewMergeIterator(inputs, opt)
					}
					itrs = append(itrs, newLimitIterator(itr, opt))
				} else {
					itrs = append(itrs, inputs...)
				}
			}
		}
		return nil
	}(); err != nil {
		influxql.Iterators(itrs).Close()
		return nil, err
	}

	return itrs, nil
}

// Ensure that a set of iterators can be merged together, sorted by window and name/tag.
func TestMergeIterator_String(t *testing.T) {
	inputs := []*StringIterator{
		{Points: []influxql.StringPoint{
			{Name: "cpu", Tags: ParseTags("host=A"), Time: 0, Value: "a"},
			{Name: "cpu", Tags: ParseTags("host=A"), Time: 12, Value: "c"},
			{Name: "cpu", Tags: ParseTags("host=A"), Time: 30, Value: "d"},
			{Name: "cpu", Tags: ParseTags("host=B"), Time: 1, Value: "b"},
			{Name: "mem", Tags: ParseTags("host=B"), Time: 11, Value: "h"},
		}},
		{Points: []influxql.StringPoint{
			{Name: "cpu", Tags: ParseTags("host=A"), Time: 20, Value: "g"},
			{Name: "cpu", Tags: ParseTags("host=B"), Time: 11, Value: "e"},
			{Name: "cpu", Tags: ParseTags("host=B"), Time: 13, Value: "f"},
			{Name: "mem", Tags: ParseTags("host=A"), Time: 25, Value: "i"},
		}},
		{Points: []influxql.StringPoint{}},
	}
	itr := influxql.NewMergeIterator(StringIterators(inputs), influxql.IteratorOptions{
		Interval: influxql.Interval{
			Duration: 10 * time.Nanosecond,
		},
		Ascending: true,
	})

	if a := Iterators([]influxql.Iterator{itr}).ReadAll(); !deep.Equal(a, [][]influxql.Point{
		{&influxql.StringPoint{Name: "cpu", Tags: ParseTags("host=A"), Time: 0, Value: "a"}},
		{&influxql.StringPoint{Name: "cpu", Tags: ParseTags("host=A"), Time: 12, Value: "c"}},
		{&influxql.StringPoint{Name: "cpu", Tags: ParseTags("host=A"), Time: 20, Value: "g"}},
		{&influxql.StringPoint{Name: "cpu", Tags: ParseTags("host=A"), Time: 30, Value: "d"}},
		{&influxql.StringPoint{Name: "cpu", Tags: ParseTags("host=B"), Time: 1, Value: "b"}},
		{&influxql.StringPoint{Name: "cpu", Tags: ParseTags("host=B"), Time: 11, Value: "e"}},
		{&influxql.StringPoint{Name: "cpu", Tags: ParseTags("host=B"), Time: 13, Value: "f"}},
		{&influxql.StringPoint{Name: "mem", Tags: ParseTags("host=A"), Time: 25, Value: "i"}},
		{&influxql.StringPoint{Name: "mem", Tags: ParseTags("host=B"), Time: 11, Value: "h"}},
	}) {
		t.Errorf("unexpected points: %s", spew.Sdump(a))
	}

	for i, input := range inputs {
		if !input.Closed {
			t.Errorf("iterator %d not closed", i)
		}
	}
}

// CreateIterator returns a single combined iterator for the shards.
func (a Shards) CreateIterator(opt influxql.IteratorOptions) (influxql.Iterator, error) {
	if influxql.Sources(opt.Sources).HasSystemSource() {
		return a.createSystemIterator(opt)
	}

	// Create iterators for each shard.
	// Ensure that they are closed if an error occurs.
	itrs := make([]influxql.Iterator, 0, len(a))
	if err := func() error {
		for _, sh := range a {
			itr, err := sh.CreateIterator(opt)
			if err != nil {
				return err
			}
			itrs = append(itrs, itr)
		}
		return nil
	}(); err != nil {
		influxql.Iterators(itrs).Close()
		return nil, err
	}

	// Merge into a single iterator.
	if opt.MergeSorted() {
		return influxql.NewSortedMergeIterator(itrs, opt), nil
	}

	itr := influxql.NewMergeIterator(itrs, opt)
	if opt.Expr != nil {
		if expr, ok := opt.Expr.(*influxql.Call); ok && expr.Name == "count" {
			opt.Expr = &influxql.Call{
				Name: "sum",
				Args: expr.Args,
			}
		}
	}
	return influxql.NewCallIterator(itr, opt), nil
}

func TestMergeIterator_Nil(t *testing.T) {
	itr := influxql.NewMergeIterator([]influxql.Iterator{nil}, influxql.IteratorOptions{})
	if itr != nil {
		t.Fatalf("unexpected iterator: %#v", itr)
	}
}

// createVarRefIterator creates an iterator for a variable reference.
func (e *Engine) createVarRefIterator(opt influxql.IteratorOptions) ([]influxql.Iterator, error) {
	ref, _ := opt.Expr.(*influxql.VarRef)

	var itrs []influxql.Iterator
	if err := func() error {
		mms := tsdb.Measurements(e.index.MeasurementsByName(influxql.Sources(opt.Sources).Names()))

		// Retrieve the maximum number of fields (without time).
		conditionFields := make([]string, len(influxql.ExprNames(opt.Condition)))

		for _, mm := range mms {
			// Determine tagsets for this measurement based on dimensions and filters.
			tagSets, err := mm.TagSets(opt.Dimensions, opt.Condition)
			if err != nil {
				return err
			}

			// Calculate tag sets and apply SLIMIT/SOFFSET.
			tagSets = influxql.LimitTagSets(tagSets, opt.SLimit, opt.SOffset)

			for _, t := range tagSets {
				inputs := make([]influxql.Iterator, 0, len(t.SeriesKeys))
				for i, seriesKey := range t.SeriesKeys {
					fields := 0
					if t.Filters[i] != nil {
						// Retrieve non-time fields from this series filter and filter out tags.
						for _, f := range influxql.ExprNames(t.Filters[i]) {
							conditionFields[fields] = f
							fields++
						}
					}

					input, err := e.createVarRefSeriesIterator(ref, mm, seriesKey, t, t.Filters[i], conditionFields[:fields], opt)
					if err != nil {
						return err
					} else if input == nil {
						continue
					}
					inputs = append(inputs, input)
				}

				if len(inputs) > 0 && (opt.Limit > 0 || opt.Offset > 0) {
					var itr influxql.Iterator
					if opt.MergeSorted() {
						itr = influxql.NewSortedMergeIterator(inputs, opt)
					} else {
						itr = influxql.NewMergeIterator(inputs, opt)
					}
					itrs = append(itrs, newLimitIterator(itr, opt))
				} else {
					itrs = append(itrs, inputs...)
				}
			}
		}
		return nil
	}(); err != nil {
		influxql.Iterators(itrs).Close()
		return nil, err
	}

	return itrs, nil
}