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// Copyright 2017 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package tsdb
import (
"fmt"
"sort"
"strings"
"github.com/pkg/errors"
"github.com/prometheus/tsdb/chunkenc"
"github.com/prometheus/tsdb/chunks"
"github.com/prometheus/tsdb/index"
"github.com/prometheus/tsdb/labels"
)
// Querier provides querying access over time series data of a fixed
// time range.
type Querier interface {
// Select returns a set of series that matches the given label matchers.
Select(...labels.Matcher) (SeriesSet, error)
// LabelValues returns all potential values for a label name.
LabelValues(string) ([]string, error)
// LabelValuesFor returns all potential values for a label name.
// under the constraint of another label.
LabelValuesFor(string, labels.Label) ([]string, error)
// LabelNames returns all the unique label names present in the block in sorted order.
LabelNames() ([]string, error)
// Close releases the resources of the Querier.
Close() error
}
// Series exposes a single time series.
type Series interface {
// Labels returns the complete set of labels identifying the series.
Labels() labels.Labels
// Iterator returns a new iterator of the data of the series.
Iterator() SeriesIterator
}
// querier aggregates querying results from time blocks within
// a single partition.
type querier struct {
blocks []Querier
}
func (q *querier) LabelValues(n string) ([]string, error) {
return q.lvals(q.blocks, n)
}
// LabelNames returns all the unique label names present querier blocks.
func (q *querier) LabelNames() ([]string, error) {
labelNamesMap := make(map[string]struct{})
for _, b := range q.blocks {
names, err := b.LabelNames()
if err != nil {
return nil, errors.Wrap(err, "LabelNames() from Querier")
}
for _, name := range names {
labelNamesMap[name] = struct{}{}
}
}
labelNames := make([]string, 0, len(labelNamesMap))
for name := range labelNamesMap {
labelNames = append(labelNames, name)
}
sort.Strings(labelNames)
return labelNames, nil
}
func (q *querier) lvals(qs []Querier, n string) ([]string, error) {
if len(qs) == 0 {
return nil, nil
}
if len(qs) == 1 {
return qs[0].LabelValues(n)
}
l := len(qs) / 2
s1, err := q.lvals(qs[:l], n)
if err != nil {
return nil, err
}
s2, err := q.lvals(qs[l:], n)
if err != nil {
return nil, err
}
return mergeStrings(s1, s2), nil
}
func (q *querier) LabelValuesFor(string, labels.Label) ([]string, error) {
return nil, fmt.Errorf("not implemented")
}
func (q *querier) Select(ms ...labels.Matcher) (SeriesSet, error) {
return q.sel(q.blocks, ms)
}
func (q *querier) sel(qs []Querier, ms []labels.Matcher) (SeriesSet, error) {
if len(qs) == 0 {
return EmptySeriesSet(), nil
}
if len(qs) == 1 {
return qs[0].Select(ms...)
}
l := len(qs) / 2
a, err := q.sel(qs[:l], ms)
if err != nil {
return nil, err
}
b, err := q.sel(qs[l:], ms)
if err != nil {
return nil, err
}
return newMergedSeriesSet(a, b), nil
}
func (q *querier) Close() error {
var merr MultiError
for _, bq := range q.blocks {
merr.Add(bq.Close())
}
return merr.Err()
}
// NewBlockQuerier returns a querier against the reader.
func NewBlockQuerier(b BlockReader, mint, maxt int64) (Querier, error) {
indexr, err := b.Index()
if err != nil {
return nil, errors.Wrapf(err, "open index reader")
}
chunkr, err := b.Chunks()
if err != nil {
indexr.Close()
return nil, errors.Wrapf(err, "open chunk reader")
}
tombsr, err := b.Tombstones()
if err != nil {
indexr.Close()
chunkr.Close()
return nil, errors.Wrapf(err, "open tombstone reader")
}
return &blockQuerier{
mint: mint,
maxt: maxt,
index: indexr,
chunks: chunkr,
tombstones: tombsr,
}, nil
}
// blockQuerier provides querying access to a single block database.
type blockQuerier struct {
index IndexReader
chunks ChunkReader
tombstones TombstoneReader
mint, maxt int64
}
func (q *blockQuerier) Select(ms ...labels.Matcher) (SeriesSet, error) {
base, err := LookupChunkSeries(q.index, q.tombstones, ms...)
if err != nil {
return nil, err
}
return &blockSeriesSet{
set: &populatedChunkSeries{
set: base,
chunks: q.chunks,
mint: q.mint,
maxt: q.maxt,
},
mint: q.mint,
maxt: q.maxt,
}, nil
}
func (q *blockQuerier) LabelValues(name string) ([]string, error) {
tpls, err := q.index.LabelValues(name)
if err != nil {
return nil, err
}
res := make([]string, 0, tpls.Len())
for i := 0; i < tpls.Len(); i++ {
vals, err := tpls.At(i)
if err != nil {
return nil, err
}
res = append(res, vals[0])
}
return res, nil
}
func (q *blockQuerier) LabelNames() ([]string, error) {
return q.index.LabelNames()
}
func (q *blockQuerier) LabelValuesFor(string, labels.Label) ([]string, error) {
return nil, fmt.Errorf("not implemented")
}
func (q *blockQuerier) Close() error {
var merr MultiError
merr.Add(q.index.Close())
merr.Add(q.chunks.Close())
merr.Add(q.tombstones.Close())
return merr.Err()
}
// PostingsForMatchers assembles a single postings iterator against the index reader
// based on the given matchers. It returns a list of label names that must be manually
// checked to not exist in series the postings list points to.
func PostingsForMatchers(ix IndexReader, ms ...labels.Matcher) (index.Postings, error) {
var its []index.Postings
for _, m := range ms {
it, err := postingsForMatcher(ix, m)
if err != nil {
return nil, err
}
its = append(its, it)
}
return ix.SortedPostings(index.Intersect(its...)), nil
}
func postingsForMatcher(ix IndexReader, m labels.Matcher) (index.Postings, error) {
// If the matcher selects an empty value, it selects all the series which don't
// have the label name set too. See: https://github.com/prometheus/prometheus/issues/3575
// and https://github.com/prometheus/prometheus/pull/3578#issuecomment-351653555
if m.Matches("") {
return postingsForUnsetLabelMatcher(ix, m)
}
// Fast-path for equal matching.
if em, ok := m.(*labels.EqualMatcher); ok {
it, err := ix.Postings(em.Name(), em.Value())
if err != nil {
return nil, err
}
return it, nil
}
tpls, err := ix.LabelValues(m.Name())
if err != nil {
return nil, err
}
var res []string
for i := 0; i < tpls.Len(); i++ {
vals, err := tpls.At(i)
if err != nil {
return nil, err
}
if m.Matches(vals[0]) {
res = append(res, vals[0])
}
}
if len(res) == 0 {
return index.EmptyPostings(), nil
}
var rit []index.Postings
for _, v := range res {
it, err := ix.Postings(m.Name(), v)
if err != nil {
return nil, err
}
rit = append(rit, it)
}
return index.Merge(rit...), nil
}
func postingsForUnsetLabelMatcher(ix IndexReader, m labels.Matcher) (index.Postings, error) {
tpls, err := ix.LabelValues(m.Name())
if err != nil {
return nil, err
}
var res []string
for i := 0; i < tpls.Len(); i++ {
vals, err := tpls.At(i)
if err != nil {
return nil, err
}
if !m.Matches(vals[0]) {
res = append(res, vals[0])
}
}
var rit []index.Postings
for _, v := range res {
it, err := ix.Postings(m.Name(), v)
if err != nil {
return nil, err
}
rit = append(rit, it)
}
allPostings, err := ix.Postings(index.AllPostingsKey())
if err != nil {
return nil, err
}
return index.Without(allPostings, index.Merge(rit...)), nil
}
func mergeStrings(a, b []string) []string {
maxl := len(a)
if len(b) > len(a) {
maxl = len(b)
}
res := make([]string, 0, maxl*10/9)
for len(a) > 0 && len(b) > 0 {
d := strings.Compare(a[0], b[0])
if d == 0 {
res = append(res, a[0])
a, b = a[1:], b[1:]
} else if d < 0 {
res = append(res, a[0])
a = a[1:]
} else if d > 0 {
res = append(res, b[0])
b = b[1:]
}
}
// Append all remaining elements.
res = append(res, a...)
res = append(res, b...)
return res
}
// SeriesSet contains a set of series.
type SeriesSet interface {
Next() bool
At() Series
Err() error
}
var emptySeriesSet = errSeriesSet{}
// EmptySeriesSet returns a series set that's always empty.
func EmptySeriesSet() SeriesSet {
return emptySeriesSet
}
// mergedSeriesSet takes two series sets as a single series set. The input series sets
// must be sorted and sequential in time, i.e. if they have the same label set,
// the datapoints of a must be before the datapoints of b.
type mergedSeriesSet struct {
a, b SeriesSet
cur Series
adone, bdone bool
}
// NewMergedSeriesSet takes two series sets as a single series set. The input series sets
// must be sorted and sequential in time, i.e. if they have the same label set,
// the datapoints of a must be before the datapoints of b.
func NewMergedSeriesSet(a, b SeriesSet) SeriesSet {
return newMergedSeriesSet(a, b)
}
func newMergedSeriesSet(a, b SeriesSet) *mergedSeriesSet {
s := &mergedSeriesSet{a: a, b: b}
// Initialize first elements of both sets as Next() needs
// one element look-ahead.
s.adone = !s.a.Next()
s.bdone = !s.b.Next()
return s
}
func (s *mergedSeriesSet) At() Series {
return s.cur
}
func (s *mergedSeriesSet) Err() error {
if s.a.Err() != nil {
return s.a.Err()
}
return s.b.Err()
}
func (s *mergedSeriesSet) compare() int {
if s.adone {
return 1
}
if s.bdone {
return -1
}
return labels.Compare(s.a.At().Labels(), s.b.At().Labels())
}
func (s *mergedSeriesSet) Next() bool {
if s.adone && s.bdone || s.Err() != nil {
return false
}
d := s.compare()
// Both sets contain the current series. Chain them into a single one.
if d > 0 {
s.cur = s.b.At()
s.bdone = !s.b.Next()
} else if d < 0 {
s.cur = s.a.At()
s.adone = !s.a.Next()
} else {
s.cur = &chainedSeries{series: []Series{s.a.At(), s.b.At()}}
s.adone = !s.a.Next()
s.bdone = !s.b.Next()
}
return true
}
// ChunkSeriesSet exposes the chunks and intervals of a series instead of the
// actual series itself.
type ChunkSeriesSet interface {
Next() bool
At() (labels.Labels, []chunks.Meta, Intervals)
Err() error
}
// baseChunkSeries loads the label set and chunk references for a postings
// list from an index. It filters out series that have labels set that should be unset.
type baseChunkSeries struct {
p index.Postings
index IndexReader
tombstones TombstoneReader
lset labels.Labels
chks []chunks.Meta
intervals Intervals
err error
}
// LookupChunkSeries retrieves all series for the given matchers and returns a ChunkSeriesSet
// over them. It drops chunks based on tombstones in the given reader.
func LookupChunkSeries(ir IndexReader, tr TombstoneReader, ms ...labels.Matcher) (ChunkSeriesSet, error) {
if tr == nil {
tr = newMemTombstones()
}
p, err := PostingsForMatchers(ir, ms...)
if err != nil {
return nil, err
}
return &baseChunkSeries{
p: p,
index: ir,
tombstones: tr,
}, nil
}
func (s *baseChunkSeries) At() (labels.Labels, []chunks.Meta, Intervals) {
return s.lset, s.chks, s.intervals
}
func (s *baseChunkSeries) Err() error { return s.err }
func (s *baseChunkSeries) Next() bool {
var (
lset = make(labels.Labels, len(s.lset))
chkMetas = make([]chunks.Meta, len(s.chks))
err error
)
for s.p.Next() {
ref := s.p.At()
if err := s.index.Series(ref, &lset, &chkMetas); err != nil {
// Postings may be stale. Skip if no underlying series exists.
if errors.Cause(err) == ErrNotFound {
continue
}
s.err = err
return false
}
s.lset = lset
s.chks = chkMetas
s.intervals, err = s.tombstones.Get(s.p.At())
if err != nil {
s.err = errors.Wrap(err, "get tombstones")
return false
}
if len(s.intervals) > 0 {
// Only those chunks that are not entirely deleted.
chks := make([]chunks.Meta, 0, len(s.chks))
for _, chk := range s.chks {
if !(Interval{chk.MinTime, chk.MaxTime}.isSubrange(s.intervals)) {
chks = append(chks, chk)
}
}
s.chks = chks
}
return true
}
if err := s.p.Err(); err != nil {
s.err = err
}
return false
}
// populatedChunkSeries loads chunk data from a store for a set of series
// with known chunk references. It filters out chunks that do not fit the
// given time range.
type populatedChunkSeries struct {
set ChunkSeriesSet
chunks ChunkReader
mint, maxt int64
err error
chks []chunks.Meta
lset labels.Labels
intervals Intervals
}
func (s *populatedChunkSeries) At() (labels.Labels, []chunks.Meta, Intervals) {
return s.lset, s.chks, s.intervals
}
func (s *populatedChunkSeries) Err() error { return s.err }
func (s *populatedChunkSeries) Next() bool {
for s.set.Next() {
lset, chks, dranges := s.set.At()
for len(chks) > 0 {
if chks[0].MaxTime >= s.mint {
break
}
chks = chks[1:]
}
// This is to delete in place while iterating.
for i, rlen := 0, len(chks); i < rlen; i++ {
j := i - (rlen - len(chks))
c := &chks[j]
// Break out at the first chunk that has no overlap with mint, maxt.
if c.MinTime > s.maxt {
chks = chks[:j]
break
}
c.Chunk, s.err = s.chunks.Chunk(c.Ref)
if s.err != nil {
// This means that the chunk has be garbage collected. Remove it from the list.
if s.err == ErrNotFound {
s.err = nil
// Delete in-place.
s.chks = append(chks[:j], chks[j+1:]...)
}
return false
}
}
if len(chks) == 0 {
continue
}
s.lset = lset
s.chks = chks
s.intervals = dranges
return true
}
if err := s.set.Err(); err != nil {
s.err = err
}
return false
}
// blockSeriesSet is a set of series from an inverted index query.
type blockSeriesSet struct {
set ChunkSeriesSet
err error
cur Series
mint, maxt int64
}
func (s *blockSeriesSet) Next() bool {
for s.set.Next() {
lset, chunks, dranges := s.set.At()
s.cur = &chunkSeries{
labels: lset,
chunks: chunks,
mint: s.mint,
maxt: s.maxt,
intervals: dranges,
}
return true
}
if s.set.Err() != nil {
s.err = s.set.Err()
}
return false
}
func (s *blockSeriesSet) At() Series { return s.cur }
func (s *blockSeriesSet) Err() error { return s.err }
// chunkSeries is a series that is backed by a sequence of chunks holding
// time series data.
type chunkSeries struct {
labels labels.Labels
chunks []chunks.Meta // in-order chunk refs
mint, maxt int64
intervals Intervals
}
func (s *chunkSeries) Labels() labels.Labels {
return s.labels
}
func (s *chunkSeries) Iterator() SeriesIterator {
return newChunkSeriesIterator(s.chunks, s.intervals, s.mint, s.maxt)
}
// SeriesIterator iterates over the data of a time series.
type SeriesIterator interface {
// Seek advances the iterator forward to the given timestamp.
// If there's no value exactly at t, it advances to the first value
// after t.
Seek(t int64) bool
// At returns the current timestamp/value pair.
At() (t int64, v float64)
// Next advances the iterator by one.
Next() bool
// Err returns the current error.
Err() error
}
// chainedSeries implements a series for a list of time-sorted series.
// They all must have the same labels.
type chainedSeries struct {
series []Series
}
func (s *chainedSeries) Labels() labels.Labels {
return s.series[0].Labels()
}
func (s *chainedSeries) Iterator() SeriesIterator {
return newChainedSeriesIterator(s.series...)
}
// chainedSeriesIterator implements a series iterater over a list
// of time-sorted, non-overlapping iterators.
type chainedSeriesIterator struct {
series []Series // series in time order
i int
cur SeriesIterator
}
func newChainedSeriesIterator(s ...Series) *chainedSeriesIterator {
return &chainedSeriesIterator{
series: s,
i: 0,
cur: s[0].Iterator(),
}
}
func (it *chainedSeriesIterator) Seek(t int64) bool {
// We just scan the chained series sequentially as they are already
// pre-selected by relevant time and should be accessed sequentially anyway.
for i, s := range it.series[it.i:] {
cur := s.Iterator()
if !cur.Seek(t) {
continue
}
it.cur = cur
it.i += i
return true
}
return false
}
func (it *chainedSeriesIterator) Next() bool {
if it.cur.Next() {
return true
}
if err := it.cur.Err(); err != nil {
return false
}
if it.i == len(it.series)-1 {
return false
}
it.i++
it.cur = it.series[it.i].Iterator()
return it.Next()
}
func (it *chainedSeriesIterator) At() (t int64, v float64) {
return it.cur.At()
}
func (it *chainedSeriesIterator) Err() error {
return it.cur.Err()
}
// chunkSeriesIterator implements a series iterator on top
// of a list of time-sorted, non-overlapping chunks.
type chunkSeriesIterator struct {
chunks []chunks.Meta
i int
cur chunkenc.Iterator
maxt, mint int64
intervals Intervals
}
func newChunkSeriesIterator(cs []chunks.Meta, dranges Intervals, mint, maxt int64) *chunkSeriesIterator {
it := cs[0].Chunk.Iterator()
if len(dranges) > 0 {
it = &deletedIterator{it: it, intervals: dranges}
}
return &chunkSeriesIterator{
chunks: cs,
i: 0,
cur: it,
mint: mint,
maxt: maxt,
intervals: dranges,
}
}
func (it *chunkSeriesIterator) Seek(t int64) (ok bool) {
if t > it.maxt {
return false
}
// Seek to the first valid value after t.
if t < it.mint {
t = it.mint
}
for ; it.chunks[it.i].MaxTime < t; it.i++ {
if it.i == len(it.chunks)-1 {
return false
}
}
it.cur = it.chunks[it.i].Chunk.Iterator()
if len(it.intervals) > 0 {
it.cur = &deletedIterator{it: it.cur, intervals: it.intervals}
}
for it.cur.Next() {
t0, _ := it.cur.At()
if t0 >= t {
return true
}
}
return false
}
func (it *chunkSeriesIterator) At() (t int64, v float64) {
return it.cur.At()
}
func (it *chunkSeriesIterator) Next() bool {
if it.cur.Next() {
t, _ := it.cur.At()
if t < it.mint {
if !it.Seek(it.mint) {
return false
}
t, _ = it.At()
return t <= it.maxt
}
if t > it.maxt {
return false
}
return true
}
if err := it.cur.Err(); err != nil {
return false
}
if it.i == len(it.chunks)-1 {
return false
}
it.i++
it.cur = it.chunks[it.i].Chunk.Iterator()
if len(it.intervals) > 0 {
it.cur = &deletedIterator{it: it.cur, intervals: it.intervals}
}
return it.Next()
}
func (it *chunkSeriesIterator) Err() error {
return it.cur.Err()
}
// deletedIterator wraps an Iterator and makes sure any deleted metrics are not
// returned.
type deletedIterator struct {
it chunkenc.Iterator
intervals Intervals
}
func (it *deletedIterator) At() (int64, float64) {
return it.it.At()
}
func (it *deletedIterator) Next() bool {
Outer:
for it.it.Next() {
ts, _ := it.it.At()
for _, tr := range it.intervals {
if tr.inBounds(ts) {
continue Outer
}
if ts > tr.Maxt {
it.intervals = it.intervals[1:]
continue
}
return true
}
return true
}
return false
}
func (it *deletedIterator) Err() error {
return it.it.Err()
}
type errSeriesSet struct {
err error
}
func (s errSeriesSet) Next() bool { return false }
func (s errSeriesSet) At() Series { return nil }
func (s errSeriesSet) Err() error { return s.err }