Wiser coders than myself have come to the conclusion that a `switch`
statement is almost always superior to a statement that includes any
`else if`.
The exceptions that I have found in our codebase are just these two:
* The `if else` is followed by an additional statement before the next
condition (separated by a `;`).
* The whole thing is within a `for` loop and `break` statements are
used. In this case, using `switch` would require tagging the `for`
loop, which probably tips the balance.
Why are `switch` statements more readable?
For one, fewer curly braces. But more importantly, the conditions all
have the same alignment, so the whole thing follows the natural flow
of going down a list of conditions. With `else if`, in contrast, all
conditions but the first are "hidden" behind `} else if `, harder to
spot and (for no good reason) presented differently from the first
condition.
I'm sure the aforemention wise coders can list even more reasons.
In any case, I like it so much that I have found myself recommending
it in code reviews. I would like to make it a habit in our code base,
without making it a hard requirement that we would test on the CI. But
for that, there has to be a role model, so this commit eliminates all
`if else` occurrences, unless it is autogenerated code or fits one of
the exceptions above.
Signed-off-by: beorn7 <beorn@grafana.com>
We haven't updated golint-ci in our CI yet, but this commit prepares
for that.
There are a lot of new warnings, and it is mostly because the "revive"
linter got updated. I agree with most of the new warnings, mostly
around not naming unused function parameters (although it is justified
in some cases for documentation purposes – while things like mocks are
a good example where not naming the parameter is clearer).
I'm pretty upset about the "empty block" warning to include `for`
loops. It's such a common pattern to do something in the head of the
`for` loop and then have an empty block. There is still an open issue
about this: https://github.com/mgechev/revive/issues/810 I have
disabled "revive" altogether in files where empty blocks are used
excessively, and I have made the effort to add individual
`// nolint:revive` where empty blocks are used just once or twice.
It's borderline noisy, though, but let's go with it for now.
I should mention that none of the "empty block" warnings for `for`
loop bodies were legitimate.
Signed-off-by: beorn7 <beorn@grafana.com>
It took a `Labels` where the memory could be re-used, but in practice
this hardly ever benefitted. Especially after converting `relabel.Process`
to `relabel.ProcessBuilder`.
Comparing the parameter to `nil` was a bug; `EmptyLabels` is not `nil`
so the slice was reallocated multiple times by `append`.
Lastly `Builder.Labels()` now estimates that the final size will depend
on labels added and deleted.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
In Thanos we would like to start experimenting with custom functions that are
currently not part of the PromQL spec. We would do this by adding an implementation
for those functions in the Thanos engine: https://github.com/thanos-community/promql-engine and allow
users to decide which engine they want to use on a per-query basis.
Since we use the PromQL parser from Prometheus, injecting functions in the global `Functions` variable
would mean they also become available for the Prometheus engine. To avoid this side-effect, this commit
exposes a Parser interface in which the supported functions can be injected as an option. If not functions
are injected, the parser implementation will default to the functions defined in the global Functions variable.
Signed-off-by: Filip Petkovski <filip.petkovsky@gmail.com>
We use `labels.Builder` to parse metrics, to avoid depending on the
internal implementation. This is not efficient, but the feature is only
used in tests. It wasn't efficient previously either - calling `Sort()`
after adding each label.
`createLabelsForAbsentFunction` also uses a Builder now, and gets
an extra `map` to replace the previous `Has()` usage.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
Fix up promql to compile with changes to Labels
* Switch from 'sanity' to more inclusive lanuage
"Removing ableist language in code is important; it helps to create and
maintain an environment that welcomes all developers of all backgrounds,
while emphasizing that we as developers select the most articulate,
precise, descriptive language we can rather than relying on metaphors.
The phrase sanity check is ableist, and unnecessarily references mental
health in our code bases. It denotes that people with mental illnesses
are inferior, wrong, or incorrect, and the phrase sanity continues to be
used by employers and other individuals to discriminate against these
people."
From https://gist.github.com/seanmhanson/fe370c2d8bd2b3228680e38899baf5cc
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
And a few cases of `EmptyLabels()`.
Replacing code which assumes the internal structure of `Labels`.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
* Update go to 1.19, set min version to 1.18
Signed-off-by: Julien Pivotto <roidelapluie@o11y.eu>
* Update golangci-lint
Signed-off-by: Julien Pivotto <roidelapluie@o11y.eu>
Signed-off-by: Julien Pivotto <roidelapluie@o11y.eu>
* Prettifier: Add spaces with non-callable keywords
I prefer to have a difference between, on one side: functions calls, end(), start(), and on the other side with, without, ignoring, by and group_rrigt, group_left.
The reasoning is that the former ones are not calls, while other are
functions. Additionally, it matches the examples in our documentation.
Signed-off-by: Julien Pivotto <roidelapluie@o11y.eu>
* Fix tests
Signed-off-by: Julien Pivotto <roidelapluie@o11y.eu>
* Implement Pretty() function for AST nodes.
Signed-off-by: Harkishen-Singh <harkishensingh@hotmail.com>
This commit adds .Pretty() for all nodes of PromQL AST.
Each .Pretty() prettifies the node it belongs to, and under
no circustance, the parent or child node is touch/prettified.
Read more in the "Approach" part in `prettier.go`
* Refactor functions between printer.go & prettier.go
Signed-off-by: Harkishen-Singh <harkishensingh@hotmail.com>
This commit removes redundancy between printer.go and prettier.go
by taking out the common code into separate private functions.
* Add more unit tests for Prettier.
Signed-off-by: Harkishen-Singh <harkishensingh@hotmail.com>
* Add support for spliting function calls with 1 arg & unary expressions.
Signed-off-by: Harkishen-Singh <harkishensingh@hotmail.com>
This commit does 2 things:
1. It adds support to split function calls that have 1 arg and exceeds the max_characters_per_line
to multiple lines.
2. Splits Unary expressions that exceed the max_characters_per_line. This is done by formatting the child node
and then removing the prefix indent, which is already applied before the unary operator.
This follow a simple function-based approach to access the count and
sum fields of a native Histogram. It might be more elegant to
implement “accessors” via the dot operator, as considered in the
brainstorming doc [1]. However, that would require the introduction of
a whole new concept in PromQL. For the PoC, we should be fine with the
function-based approch. Even the obvious inefficiencies (rate'ing a
whole histogram twice when we only want to rate each the count and the
sum once) could be optimized behind the scenes.
Note that the function-based approach elegantly solves the problem of
detecting counter resets in the sum of observations in the case of
negative observations. (Since the whole native Histogram is rate'd,
the counter reset is detected for the Histogram as a whole.)
We will decide later if an “accessor” approach is really needed. It
would change the example expression for average duration in
functions.md from
histogram_sum(rate(http_request_duration_seconds[10m]))
/
histogram_count(rate(http_request_duration_seconds[10m]))
to
rate(http_request_duration_seconds.sum[10m])
/
rate(http_request_duration_seconds.count[10m])
[1]: https://docs.google.com/document/d/1ch6ru8GKg03N02jRjYriurt-CZqUVY09evPg6yKTA1s/edit
Signed-off-by: beorn7 <beorn@grafana.com>
* Run gofumpt on all files
Getting golangci-lint errors when building on my laptop, possibly because I have newer version of gofumpt then what it was formatted with.
Run gofumpt -w -extra on all files as it will be needed in the future anyway.
* Update golangci-lint to v1.44.2
v1.44.0 upgraded gofumpt so bumping version in CI will help keep formatting correct for everyone
* Address golangci-lint error
Getting 'error-strings: error strings should not be capitalized or end with punctuation or a newline' from revive here.
Drop new line.
Signed-off-by: Łukasz Mierzwa <l.mierzwa@gmail.com>
This creates a new `model` directory and moves all data-model related
packages over there:
exemplar labels relabel rulefmt textparse timestamp value
All the others are more or less utilities and have been moved to `util`:
gate logging modetimevfs pool runtime
Signed-off-by: beorn7 <beorn@grafana.com>
* Allow VectorSelector.String() without matchers
Previously this method was panicking because it was trying to allocate a
slice with capacity -1. There's nothing saying that VectorSelector
should have matchers, and it's actually prepared to have zero matcher
strings, so it's worth checking instead of panicking.
Signed-off-by: Oleg Zaytsev <mail@olegzaytsev.com>
* PromQL: Fix start and end keywords masking label and metric names
This commit fixes an issue with the "at modifier" that introduced two
new keywords: `start` and `end`. In grouping options and in metric
names, these keywords took precedence over metric or label names, so
that those metrics and labels could no longer be referenced.
Signed-off-by: Clayton Peters <clayton.peters@man.com>
* Add in additional tests for metrics and/or labels called start/end.
Signed-off-by: Clayton Peters <clayton.peters@man.com>
* *: Cut 2.29.0-rc.0
Signed-off-by: Frederic Branczyk <fbranczyk@gmail.com>
* VERSION: bump to 2.29.0-rc.0
Signed-off-by: Frederic Branczyk <fbranczyk@gmail.com>
* Remove experimental wording on size-based retention
Followup of #9004
Signed-off-by: Julien Pivotto <roidelapluie@inuits.eu>
* Fix PR reference in changelog
Signed-off-by: George Brighton <george@gebn.co.uk>
* Describe EC2 availability zone IDs at most once per refresh (#9142)
Signed-off-by: George Brighton <george@gebn.co.uk>
* Describe EC2 availability zones at most once per SD load
Closes#9142.
Signed-off-by: George Brighton <george@gebn.co.uk>
* Incorporate feedback
Signed-off-by: George Brighton <george@gebn.co.uk>
* Integrate feedback
Signed-off-by: George Brighton <george@gebn.co.uk>
* Add a compatibility note for macOS users.
Signed-off-by: Julien Pivotto <roidelapluie@inuits.eu>
* *: Cut v2.29.0-rc.1
Signed-off-by: Frederic Branczyk <fbranczyk@gmail.com>
* Fix `kuma_sd` targetgroup reporting (#9157)
* Bundle all xDS targets into a single group
Signed-off-by: austin ce <austin.cawley@gmail.com>
* *: cut v2.29.0-rc.2
Signed-off-by: Frederic Branczyk <fbranczyk@gmail.com>
* Rename links
Signed-off-by: Levi Harrison <git@leviharrison.dev>
* bump codemirror-promql to 0.17.0
Signed-off-by: Augustin Husson <husson.augustin@gmail.com>
* *: cut v2.29.0
Signed-off-by: Frederic Branczyk <fbranczyk@gmail.com>
* tsdb: align atomically accessed int64 (#9192)
This prevents a panic in 32-bit archs:
https://pkg.go.dev/sync/atomic#pkg-note-BUGFixed#9190
Signed-off-by: Julien Pivotto <roidelapluie@inuits.eu>
* Release 2.29.1 (#9193)
Signed-off-by: Julien Pivotto <roidelapluie@inuits.eu>
Co-authored-by: Clayton Peters <clayton.peters@man.com>
Co-authored-by: Frederic Branczyk <fbranczyk@gmail.com>
Co-authored-by: George Brighton <george@gebn.co.uk>
Co-authored-by: Austin Cawley-Edwards <austin.cawley@gmail.com>
Co-authored-by: Levi Harrison <git@leviharrison.dev>
Co-authored-by: Augustin Husson <husson.augustin@gmail.com>
