github.com/m3db/m3@v1.5.0/src/query/test/test_series_iterator.go

// Copyright (c) 2018 Uber Technologies, Inc.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

package test

import (
	"fmt"
	"sort"
	"time"

	"github.com/m3db/m3/src/dbnode/encoding"
	"github.com/m3db/m3/src/dbnode/encoding/m3tsz"
	"github.com/m3db/m3/src/dbnode/namespace"
	"github.com/m3db/m3/src/dbnode/ts"
	"github.com/m3db/m3/src/dbnode/x/xio"
	"github.com/m3db/m3/src/query/models"
	"github.com/m3db/m3/src/x/checked"
	"github.com/m3db/m3/src/x/ident"
	xtime "github.com/m3db/m3/src/x/time"
)

var (
	// SeriesNamespace is the expected namespace for the generated series
	SeriesNamespace string
	// TestTags is the expected tags for the generated series
	TestTags map[string]string
	// BlockSize is the expected block size for the generated series
	BlockSize time.Duration
	// Start is the expected start time for the first block in the generated series
	Start xtime.UnixNano
	// SeriesStart is the expected start time for the generated series
	SeriesStart xtime.UnixNano
	// Middle is the expected end for the first block, and start of the second block
	Middle xtime.UnixNano
	// End is the expected end time for the generated series
	End xtime.UnixNano

	testIterAlloc func(r xio.Reader64, d namespace.SchemaDescr) encoding.ReaderIterator
)

func init() {
	SeriesNamespace = "namespace"

	TestTags = map[string]string{"foo": "bar", "baz": "qux"}

	BlockSize = time.Hour / 2

	Start = xtime.Now().Truncate(time.Hour)
	SeriesStart = Start.Add(2 * time.Minute)
	Middle = Start.Add(BlockSize)
	End = Middle.Add(BlockSize)

	testIterAlloc = m3tsz.DefaultReaderIteratorAllocFn(encoding.NewOptions())
}

// Builds a MultiReaderIterator representing a single replica
// with two segments, one merged with values from 1->30, and
// one which is unmerged with 2 segments from 101->130
// with one of the unmerged containing even points, other containing odd
func buildReplica() (encoding.MultiReaderIterator, error) {
	// Build a merged BlockReader
	encoder := m3tsz.NewEncoder(Start, checked.NewBytes(nil, nil), true, encoding.NewOptions())
	i := 0
	for at := time.Duration(0); at < BlockSize; at += time.Minute {
		i++
		datapoint := ts.Datapoint{TimestampNanos: Start.Add(at), Value: float64(i)}
		err := encoder.Encode(datapoint, xtime.Second, nil)
		if err != nil {
			return nil, err
		}
	}
	segment := encoder.Discard()
	mergedReader := xio.BlockReader{
		SegmentReader: xio.NewSegmentReader(segment),
		Start:         Start,
		BlockSize:     BlockSize,
	}

	// Build two unmerged BlockReaders
	i = 100
	encoder = m3tsz.NewEncoder(Middle, checked.NewBytes(nil, nil), true, encoding.NewOptions())
	encoderTwo := m3tsz.NewEncoder(Middle, checked.NewBytes(nil, nil), true, encoding.NewOptions())
	useFirstEncoder := true

	for at := time.Duration(0); at < BlockSize; at += time.Minute {
		i++
		datapoint := ts.Datapoint{TimestampNanos: Middle.Add(at), Value: float64(i)}
		var err error
		if useFirstEncoder {
			err = encoder.Encode(datapoint, xtime.Second, nil)
		} else {
			err = encoderTwo.Encode(datapoint, xtime.Second, nil)
		}
		if err != nil {
			return nil, err
		}
		useFirstEncoder = !useFirstEncoder
	}

	segment = encoder.Discard()
	segmentTwo := encoderTwo.Discard()
	unmergedReaders := []xio.BlockReader{
		{
			SegmentReader: xio.NewSegmentReader(segment),
			Start:         Middle,
			BlockSize:     BlockSize,
		},
		{
			SegmentReader: xio.NewSegmentReader(segmentTwo),
			Start:         Middle,
			BlockSize:     BlockSize,
		},
	}

	multiReader := encoding.NewMultiReaderIterator(testIterAlloc, nil)
	sliceOfSlicesIter := xio.NewReaderSliceOfSlicesFromBlockReadersIterator([][]xio.BlockReader{
		{mergedReader},
		unmergedReaders,
	})
	multiReader.ResetSliceOfSlices(sliceOfSlicesIter, nil)
	return multiReader, nil
}

type sortableTags []ident.Tag

func (a sortableTags) Len() int           { return len(a) }
func (a sortableTags) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
func (a sortableTags) Less(i, j int) bool { return a[i].Name.String() < a[j].Name.String() }

// BuildTestSeriesIterator creates a sample SeriesIterator
// This series iterator has two identical replicas.
// Each replica has two blocks.
// The first block in each replica is merged and has values 1->30
// The values 1 and 2 appear before the SeriesIterator start time, and are not expected
// to appear when reading through the iterator
// The second block is unmerged; when it was merged, it has values 101 -> 130
// from two readers, one with even values and other with odd values
// Expected data points for reading through the iterator: [3..30,101..130], 58 in total
// SeriesIterator ID is given, namespace is 'namespace'
// Tags are "foo": "bar" and "baz": "qux"
func BuildTestSeriesIterator(id string) (encoding.SeriesIterator, error) {
	replicaOne, err := buildReplica()
	if err != nil {
		return nil, err
	}
	replicaTwo, err := buildReplica()
	if err != nil {
		return nil, err
	}

	sortTags := make(sortableTags, 0, len(TestTags))
	for name, value := range TestTags {
		sortTags = append(sortTags, ident.StringTag(name, value))
	}

	sort.Sort(sortTags)
	tags := ident.Tags{}
	for _, t := range sortTags {
		tags.Append(t)
	}

	return encoding.NewSeriesIterator(
		encoding.SeriesIteratorOptions{
			ID:             ident.StringID(id),
			Namespace:      ident.StringID(SeriesNamespace),
			Tags:           ident.NewTagsIterator(tags),
			StartInclusive: SeriesStart,
			EndExclusive:   End,
			Replicas: []encoding.MultiReaderIterator{
				replicaOne,
				replicaTwo,
			},
		}, nil), nil
}

// Datapoint is a datapoint with a value and an offset for building a custom iterator
type Datapoint struct {
	Value  float64
	Offset time.Duration
}

// BuildCustomIterator builds a custom iterator with bounds
func BuildCustomIterator(
	dps [][]Datapoint,
	testTags map[string]string,
	seriesID, seriesNamespace string,
	start xtime.UnixNano,
	blockSize, stepSize time.Duration,
) (encoding.SeriesIterator, models.Bounds, error) {
	// Build a merged BlockReader
	readers := make([][]xio.BlockReader, 0, len(dps))
	currentStart := start
	for _, datapoints := range dps {
		encoder := m3tsz.NewEncoder(currentStart, checked.NewBytes(nil, nil), true, encoding.NewOptions())
		// NB: empty datapoints should skip this block reader but still increase time
		if len(datapoints) > 0 {
			for _, dp := range datapoints {
				offset := dp.Offset
				if offset > blockSize {
					return nil, models.Bounds{},
						fmt.Errorf("custom series iterator offset is larger than blockSize")
				}

				if offset < 0 {
					return nil, models.Bounds{},
						fmt.Errorf("custom series iterator offset is negative")
				}

				tsDp := ts.Datapoint{
					Value:          dp.Value,
					TimestampNanos: currentStart.Add(offset),
				}

				err := encoder.Encode(tsDp, xtime.Second, nil)
				if err != nil {
					return nil, models.Bounds{}, err
				}
			}

			segment := encoder.Discard()
			readers = append(readers, []xio.BlockReader{{
				SegmentReader: xio.NewSegmentReader(segment),
				Start:         currentStart,
				BlockSize:     blockSize,
			}})
		}

		currentStart = currentStart.Add(blockSize)
	}

	multiReader := encoding.NewMultiReaderIterator(testIterAlloc, nil)
	sliceOfSlicesIter := xio.NewReaderSliceOfSlicesFromBlockReadersIterator(readers)
	multiReader.ResetSliceOfSlices(sliceOfSlicesIter, nil)

	tags := ident.Tags{}
	for name, value := range testTags {
		tags.Append(ident.StringTag(name, value))
	}

	return encoding.NewSeriesIterator(
			encoding.SeriesIteratorOptions{
				ID:             ident.StringID(seriesID),
				Namespace:      ident.StringID(seriesNamespace),
				Tags:           ident.NewTagsIterator(tags),
				StartInclusive: start,
				EndExclusive:   currentStart.Add(blockSize),
				Replicas: []encoding.MultiReaderIterator{
					multiReader,
				},
			}, nil),
		models.Bounds{
			Start:    start,
			Duration: blockSize * time.Duration(len(dps)),
			StepSize: stepSize,
		},
		nil
}