Commit graph

44 commits

Author SHA1 Message Date
beorn7 4696b46dd5 storage: Fix mixed samples handling in sampleRing
Two issues are fixed here, that lead to the same problem:

1. If `newSampleRing` is called with an unknown ValueType including
   ValueNone, we have initialized the interface buffer (`iBuf`).
   However, we would still use a specialized buffer for the first
   sample, opportunistically assuming that we might still not
   encounter mixed samples and we should go down the more efficient
   road.

2. If the `sampleRing` is `reset`, we leave all buffers alone,
   including `iBuf`, which is generally fine, but not for `iBuf`, see
   below.

In both cases, `iBuf` already contains values, but we will fill one of
the specialized buffers first. Once we then actually encounter mixed
samples, the content of the specialized buffer is copied into `iBuf`
using `append`. That's by itself the right idea because `iBuf` might
be `nil`, and even if not, it might or might not have the right
capacity. However, this approach assumes that `iBuf` is empty, or more
precisely has a length of zero.

This commit makes sure that `iBuf` does not get needlessly initialized
in `newSampleRing` and that it is emptied upon `reset`.

A test case is added to demonstrate both issues above.

Signed-off-by: beorn7 <beorn@grafana.com>
2023-10-31 16:18:09 +01:00
Björn Rabenstein ade2ee3fe4
Merge pull request #12716 from bboreham/simplify-seek
storage: simplify Seek on BufferedSeriesIterator
2023-09-21 13:56:29 +02:00
beorn7 0521ec12af storage: remove obsolete TODO
This was solved one layer deeper with #11687.

Signed-off-by: beorn7 <beorn@grafana.com>
2023-09-13 15:10:22 +02:00
Justin Lei 8ef7dfdeeb
Add a chunk size limit in bytes (#12054)
Add a chunk size limit in bytes

This creates a hard cap for XOR chunks of 1024 bytes.

The limit for histogram chunk is also 1024 bytes, but it is a soft limit as a histogram has a dynamic size, and even a single one could be larger than 1024 bytes.

This also avoids cutting new histogram chunks if the existing chunk has fewer than 10 histograms yet. In that way, we are accepting "jumbo chunks" in order to have at least 10 histograms in a chunk, allowing compression to kick in.

Signed-off-by: Justin Lei <justin.lei@grafana.com>
2023-08-24 15:21:17 +02:00
Bryan Boreham a018a7ef53 storage: simplify Seek on BufferedSeriesIterator
Small tweak to call a simpler method

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
2023-08-17 07:42:18 +01:00
beorn7 b0272255b7 storage: optimise sampleRing
Replace many checks for the lengths of slices with a single tracking
variable.

Signed-off-by: beorn7 <beorn@grafana.com>
2023-05-03 20:09:29 +02:00
Sebastian Rabenhorst 5d4ec08a1f
Fixed sampleRingIterator for mixed histograms
Signed-off-by: Sebastian Rabenhorst <sebastian.rabenhorst@shopify.com>

Fixed sampleRingIterator for mixed histograms

Signed-off-by: Sebastian Rabenhorst <sebastian.rabenhorst@shopify.com>

Fixed lint
2023-04-14 12:45:36 +02:00
beorn7 717a3f8e25 storage: Manually expand genericAdd for specific types
This commit is doing what I would have expected that Go generics do
for me. However, the PromQL benchmarks show a significant runtime and
allocation increase with `genericAdd`, so this replaces it with
hand-coded non-generic versions of it.

Signed-off-by: beorn7 <beorn@grafana.com>
2023-04-13 19:25:24 +02:00
beorn7 817a2396cb Name float values as "floats", not as "values"
In the past, every sample value was a float, so it was fine to call a
variable holding such a float "value" or "sample". With native
histograms, a sample might have a histogram value. And a histogram
value is still a value. Calling a float value just "value" or "sample"
or "V" is therefore misleading. Over the last few commits, I already
renamed many variables, but this cleans up a few more places where the
changes are more invasive.

Note that we do not to attempt naming in the JSON APIs or in the
protobufs. That would be quite a disruption. However, internally, we
can call variables as we want, and we should go with the option of
avoiding misunderstandings.

Signed-off-by: beorn7 <beorn@grafana.com>
2023-04-13 19:25:24 +02:00
beorn7 462240bc78 storage: add specialized buffers to sampleRing
This utilizes the fact that most sampleRings will only contain samples
of one type. In this case, the generic interface is circumvented, and
a bespoke buffer for the one actually occurring sample type is
used. Should a sampleRing receive a sample of a different kind later,
it will transparently switch to the generic behavior.

Signed-off-by: beorn7 <beorn@grafana.com>
2023-04-13 19:25:24 +02:00
beorn7 630bcb494b storage: Use separate sample types for histogram vs. float
Previously, we had one “polymorphous” `sample` type in the `storage`
package. This commit breaks it up into `fSample`, `hSample`, and
`fhSample`, each still implementing the `tsdbutil.Sample` interface.

This reduces allocations in `sampleRing.Add` but inflicts the penalty
of the interface wrapper, which makes things worse in total.

This commit therefore just demonstrates the step taken. The next
commit will tackle the interface overhead problem.

Signed-off-by: beorn7 <beorn@grafana.com>
2023-04-13 19:25:24 +02:00
beorn7 d121db7a65
federate: Fix PeekBack usage
In most cases, there is no sample at `maxt`, so `PeekBack` has to be
used. So far, `PeekBack` did not return a float histogram, and we
disregarded even any returned normal histogram. This fixes both, and
also tweaks the unit test to discover the problem (by using an earlier
timestamp than "now" for the samples in the TSDB).

Signed-off-by: beorn7 <beorn@grafana.com>
2023-01-12 20:43:02 +05:30
Björn Rabenstein bd26ce440c
storage: Avoid duplicate function call in sampleRingIterator (#11502)
Signed-off-by: beorn7 <beorn@grafana.com>
2022-11-01 13:34:47 -04:00
beorn7 6f33ab2b35 Merge branch 'main' into sparsehistogram 2021-12-15 13:49:33 +01:00
detailyang 3e482c905f
fix:storage:avoid panic when iterater exhauested (#9945)
Signed-off-by: detailyang <detailyang@gmail.com>
2021-12-07 19:50:00 +05:30
beorn7 e4e24453fa Merge branch 'main' into beorn7/merge2 2021-11-30 17:19:06 +01:00
Björn Rabenstein 4ce01e9770
storage: Rename ...Values methods to At... (#9889)
This mirrors #9888 for the richer iterators we have with histograms in
the game.

Signed-off-by: beorn7 <beorn@grafana.com>
2021-11-29 16:23:04 +05:30
Björn Rabenstein d677aa4b29
storage: Consolidate iterator method names (Values -> At) (#9888)
`BufferedSeriesIterator` and `MemoizedSeriesIterator` use a method
called `Values` for exactly the purpose for which all other iterators
of the same kind use a method called `At`. That alone is confusing,
but on top of that, the `Values` method only returns a single sample,
not multiple values. I assume the naming has historical reasons. This
commit makes it more consistent. It is now easier to read, and now
`BufferedSeriesIterator` and `MemoizedSeriesIterator` implement
`chunkenc.Iterator` like many other iterators, too.

Signed-off-by: beorn7 <beorn@grafana.com>
2021-11-29 11:16:40 +01:00
Björn Rabenstein 7e42acd3b1
tsdb: Rework iterators (#9877)
- Pick At... method via return value of Next/Seek.
- Do not clobber returned buckets.
- Add partial FloatHistogram suppert.

Note that the promql package is now _only_ dealing with
FloatHistograms, following the idea that PromQL only knows float
values.

As a byproduct, I have removed the histogramSeries metric. In my
understanding, series can have both float and histogram samples, so
that metric doesn't make sense anymore.

As another byproduct, I have converged the sampleBuf and the
histogramSampleBuf in memSeries into one. The sample type stored in
the sampleBuf has been extended to also contain histograms even before
this commit.

Signed-off-by: beorn7 <beorn@grafana.com>
2021-11-29 13:24:23 +05:30
beorn7 5d4db805ac Merge branch 'main' into sparsehistogram 2021-11-17 19:57:31 +01:00
beorn7 4c28d9fac7 Move to histogram.Histogram pointers
This is to avoid copying the many fields of a histogram.Histogram all
the time.

This also fixes a bunch of formerly broken tests.

Signed-off-by: beorn7 <beorn@grafana.com>
2021-11-12 23:17:35 +01:00
beorn7 8f92c90897 Add TODOs and some minor tweaks
Signed-off-by: beorn7 <beorn@grafana.com>
2021-11-07 17:12:04 +01:00
Ganesh Vernekar c8b267efd6
Get histograms from TSDB to the rate() function implementation
Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>
2021-11-03 19:04:18 +05:30
Mateusz Gozdek 1a6c2283a3 Format Go source files using 'gofumpt -w -s -extra'
Part of #9557

Signed-off-by: Mateusz Gozdek <mgozdekof@gmail.com>
2021-11-02 19:52:34 +01:00
beorn7 7a8bb8222c Style cleanup of all the changes in sparsehistogram so far
A lot of this code was hacked together, literally during a
hackathon. This commit intends not to change the code substantially,
but just make the code obey the usual style practices.

A (possibly incomplete) list of areas:

* Generally address linter warnings.

* The `pgk` directory is deprecated as per dev-summit. No new packages should
  be added to it. I moved the new `pkg/histogram` package to `model`
  anticipating what's proposed in #9478.

* Make the naming of the Sparse Histogram more consistent. Including
  abbreviations, there were just too many names for it: SparseHistogram,
  Histogram, Histo, hist, his, shs, h. The idea is to call it "Histogram" in
  general. Only add "Sparse" if it is needed to avoid confusion with
  conventional Histograms (which is rare because the TSDB really has no notion
  of conventional Histograms). Use abbreviations only in local scope, and then
  really abbreviate (not just removing three out of seven letters like in
  "Histo"). This is in the spirit of
  https://github.com/golang/go/wiki/CodeReviewComments#variable-names

* Several other minor name changes.

* A lot of formatting of doc comments. For one, following
  https://github.com/golang/go/wiki/CodeReviewComments#comment-sentences
  , but also layout question, anticipating how things will look like
  when rendered by `godoc` (even where `godoc` doesn't render them
  right now because they are for unexported types or not a doc comment
  at all but just a normal code comment - consistency is queen!).

* Re-enabled `TestQueryLog` and `TestEndopints` (they pass now,
  leaving them disabled was presumably an oversight).

* Bucket iterator for histogram.Histogram is now created with a
  method.

* HistogramChunk.iterator now allows iterator recycling. (I think
  @dieterbe only commented it out because he was confused by the
  question in the comment.)

* HistogramAppender.Append panics now because we decided to treat
  staleness marker differently.

Signed-off-by: beorn7 <beorn@grafana.com>
2021-10-11 13:02:03 +02:00
Ganesh Vernekar f4d3af73f0
Query histograms from TSDB and unit test for append+query (#9022)
Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>
2021-06-30 20:18:13 +05:30
Ganesh Vernekar 04ad56d9b8
Append sparse histograms into the Head block (#9013)
* Append sparse histograms into the Head block

Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>

* Add AtHistogram() to Iterator interface. Make HistoChunk conform to Chunk interface.

Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>
2021-06-29 20:08:46 +05:30
Bartlomiej Plotka d5c33877f9
storage: Added Chunks{Queryable/Querier/SeriesSet/Series/Iteratable. Added generic Merge{SeriesSet/Querier} implementation. (#7005)
* storage: Added Chunks{Queryable/Querier/SeriesSet/Series/Iteratable. Added generic Merge{SeriesSet/Querier} implementation.

## Rationales:

In many places (e.g. chunk Remote read, Thanos Receive fetching chunk from TSDB), we operate on encoded chunks not samples.
This means that we unnecessary decode/encode, wasting CPU, time and memory.
This PR adds chunk iterator interfaces and makes the merge code to be reused between both seriesSets

I will make the use of it in following PR inside tsdb itself. For now fanout implements it and mergers.

All merges now also allows passing series mergers. This opens doors for custom deduplications other than TSDB vertical ones (e.g. offline one we have in Thanos).

## Changes

* Added Chunk versions of all iterating methods. It all starts in Querier/ChunkQuerier. The plan is that
Storage will implement both chunked and samples.
* Added Seek to chunks.Iterator interface for iterating over chunks.
* NewMergeChunkQuerier was added; Both this and NewMergeQuerier are now using generigMergeQuerier to share the code. Generic code was added.
* Improved tests.
* Added some TODO for further simplifications in next PRs.

Signed-off-by: Bartlomiej Plotka <bwplotka@gmail.com>

* Addressed Brian's comments.

Signed-off-by: Bartlomiej Plotka <bwplotka@gmail.com>

* Moved s/Labeled/SeriesLabels as per Krasi suggestion.

Signed-off-by: Bartlomiej Plotka <bwplotka@gmail.com>

* Addressed Krasi's comments.

Signed-off-by: Bartlomiej Plotka <bwplotka@gmail.com>

* Second iteration of Krasi comments.

Signed-off-by: Bartlomiej Plotka <bwplotka@gmail.com>

* Another round of comments.

Signed-off-by: Bartlomiej Plotka <bwplotka@gmail.com>
2020-03-24 20:15:47 +00:00
Bartlomiej Plotka cfba92a133 Addressed comments.
Signed-off-by: Bartlomiej Plotka <bwplotka@gmail.com>
2020-02-17 18:03:57 +00:00
Bartlomiej Plotka 34426766d8 Unify Iterator interfaces. All point to storage now.
This is part of https://github.com/prometheus/prometheus/pull/5882 that can be done to simplify things.
All todos I added will be fixed in follow up PRs.

* querier.Querier, querier.Appender, querier.SeriesSet, and querier.Series interfaces merged
with storage interface.go. All imports that.
* querier.SeriesIterator replaced by chunkenc.Iterator
* Added chunkenc.Iterator.Seek method and tests for xor implementation (?)
* Since we properly handle SelectParams for Select methods I adjusted min max
based on that. This should help in terms of performance for queries with functions like offset.
* added Seek to deletedIterator and test.
* storage/tsdb was removed as it was only a unnecessary glue with incompatible structs.

No logic was changed, only different source of abstractions, so no need for benchmarks.

Signed-off-by: Bartlomiej Plotka <bwplotka@gmail.com>
2020-02-17 18:03:54 +00:00
Alin Sinpalean 44bec482fb Minor optimization for BufferedSeriesIterator: actually drop the samples falling outside of the new delta from the underlying sampleRing, when ReduceDelta is called. (#4849)
Signed-off-by: Alin Sinpalean <alin.sinpalean@gmail.com>
2018-12-18 11:25:45 +00:00
Ben Kochie c6399296dc
Fix spelling/typos (#4921)
* Fix spelling/typos

Fix spelling/typos reported by codespell/misspell.
* UK -> US spelling changes.

Signed-off-by: Ben Kochie <superq@gmail.com>
2018-11-27 17:44:29 +01:00
yzpeninsula 4ae3bce260 Fix typo (#4497)
Signed-off-by: yzpeninsula <yzpeninsula@gmail.com>
2018-09-13 16:04:10 +05:30
Alin Sinpalean 372e7652b7 Reuse (copy) overlapping matrix samples between range evaluation steps (#4315)
* Reuse (copy) overlapping matrix samples between range evaluation steps.

Signed-off-by: Alin Sinpalean <alin.sinpalean@gmail.com>
2018-07-18 11:14:02 +01:00
Alin Sinpalean e3b775b78b Simplify BufferedSeriesIterator usage (#4294)
* Allow for BufferedSeriesIterator instances to be created without an underlying iterator, to simplify their usage.

Signed-off-by: Alin Sinpalean <alin.sinpalean@gmail.com>
2018-07-18 05:10:28 +01:00
Brian Brazil dd6781add2 Optimise PromQL (#3966)
* Move range logic to 'eval'

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Make aggregegate range aware

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* PromQL is statically typed, so don't eval to find the type.

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Extend rangewrapper to multiple exprs

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Start making function evaluation ranged

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Make instant queries a special case of range queries

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Eliminate evalString

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Evaluate range vector functions one series at a time

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Make unary operators range aware

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Make binops range aware

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Pass time to range-aware functions.

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Make simple _over_time functions range aware

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Reduce allocs when working with matrix selectors

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Add basic benchmark for range evaluation

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Reuse objects for function arguments

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Do dropmetricname and allocating output vector only once.

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Add range-aware support for range vector functions with params

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Optimise holt_winters, cut cpu and allocs by ~25%

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Make rate&friends range aware

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Make more functions range aware. Document calling convention.

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Make date functions range aware

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Make simple math functions range aware

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Convert more functions to be range aware

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Make more functions range aware

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Specialcase timestamp() with vector selector arg for range awareness

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Remove transition code for functions

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Remove the rest of the engine transition code

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Remove more obselete code

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Remove the last uses of the eval* functions

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Remove engine finalizers to prevent corruption

The finalizers set by matrixSelector were being called
just before the value they were retruning to the pool
was then being provided to the caller. Thus a concurrent query
could corrupt the data that the user has just been returned.

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Add new benchmark suite for range functinos

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Migrate existing benchmarks to new system

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Expand promql benchmarks

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Simply test by removing unused range code

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* When testing instant queries, check range queries too.

To protect against subsequent steps in a range query being
affected by the previous steps, add a test that evaluates
an instant query that we know works again as a range query
with the tiimestamp we care about not being the first step.

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Reuse ring for matrix iters. Put query results back in pool.

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Reuse buffer when iterating over matrix selectors

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Unary minus should remove metric name

Cut down benchmarks for faster runs.

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Reduce repetition in benchmark test cases

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Work series by series when doing normal vectorSelectors

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Optimise benchmark setup, cuts time by 60%

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Have rangeWrapper use an evalNodeHelper to cache across steps

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Use evalNodeHelper with functions

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Cache dropMetricName within a node evaluation.

This saves both the calculations and allocs done by dropMetricName
across steps.

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Reuse input vectors in rangewrapper

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Reuse the point slices in the matrixes input/output by rangeWrapper

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Make benchmark setup faster using AddFast

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Simplify benchmark code.

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Add caching in VectorBinop

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Use xor to have one-level resultMetric hash key

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Add more benchmarks

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Call Query.Close in apiv1

This allows point slices allocated for the response data
to be reused by later queries, saving allocations.

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Optimise histogram_quantile

It's now 5-10% faster with 97% less garbage generated for 1k steps

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Make the input collection in rangeVector linear rather than quadratic

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Optimise label_replace, for 1k steps 15x fewer allocs and 3x faster

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Optimise label_join, 1.8x faster and 11x less memory for 1k steps

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Expand benchmarks, cleanup comments, simplify numSteps logic.

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Address Fabian's comments

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Comments from Alin.

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Address jrv's comments

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Remove dead code

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Address Simon's comments.

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Rename populateIterators, pre-init some sizes

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Handle case where function has non-matrix args first

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Split rangeWrapper out to rangeEval function, improve comments

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Cleanup and make things more consistent

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Make EvalNodeHelper public

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

* Fabian's comments.

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>
2018-06-04 15:47:45 +02:00
Brian Brazil a8c22c85cc
Correctly handle pruning wraparound after ring expansion (#3942)
Fixes #3939
2018-03-12 13:16:59 +00:00
Goutham Veeramachaneni baf5b0f0fc Fix error where we look into the future. (#2829)
* Fix error where we look into the future.

So currently we are adding values that are in the future for an older
timestamp. For example, if we have [(1, 1), (150, 2)] we will end up
showing [(1, 1), (2,2)].

Further it is not advisable to call .At() after Next() returns false.

Signed-off-by: Goutham Veeramachaneni <cs14btech11014@iith.ac.in>

* Retuen early if done

Signed-off-by: Goutham Veeramachaneni <cs14btech11014@iith.ac.in>

* Handle Seek() where we reach the end of iterator

Signed-off-by: Goutham Veeramachaneni <cs14btech11014@iith.ac.in>

* Simplify code

Signed-off-by: Goutham Veeramachaneni <cs14btech11014@iith.ac.in>
2017-06-13 07:22:27 +02:00
Brian Brazil c02c25d5ba Allow peeking back further in buffer. 2017-05-24 14:27:17 +01:00
Brian Brazil 5c9a6ce747 Add license to files.
This should fix CI for dev-2.0.
2017-04-19 13:46:22 +01:00
Fabian Reinartz 0ecd205794 promql: Use buffer pool for matrix allocations 2017-03-14 10:57:34 +01:00
Fabian Reinartz bc20d93f0a storage: rename iterator value getters to At() 2017-01-02 13:33:37 +01:00
Fabian Reinartz fecf9532b9 *: fix misc compile errors 2016-12-25 11:42:57 +01:00
Fabian Reinartz 0492ddbd4d *: fully decouple tsdb, add new storage interfaces 2016-12-25 01:43:22 +01:00