This function is called very frequently when executing PromQL functions,
and we can do it much more efficiently inside Labels.
In the common case that `__name__` comes first in the labels, we simply
re-point to start at the next label, which is nearly free.
`DropMetricName` is now so cheap I removed the cache - benchmarks show
everything still goes faster.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
Inline one call to `decodeString`, and skip decoding the value string
until we find a match for the name.
Do a quick check on the first character in each string,
and exit early if we've gone past - labels are sorted in order.
Also improve tests and benchmark:
* labels: test Get with varying lengths - it's not typical for Prometheus labels to all be the same length.
* extend benchmark with label not found
---------
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
Instead of unpacking every individual string, we skip to the point
where there is a difference, going 8 bytes at a time where possible.
Add benchmark for Compare; extend tests too.
---------
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
Co-authored-by: Oleg Zaytsev <mail@olegzaytsev.com>
* labels: respect Set after Del in Builder
The implementations are not symmetric between `Set()` and `Del()`, so
we must be careful. Add tests for this, both in labels and in relabel
where the issue was reported.
Also make the slice implementation consistent re `slices.Contains`.
Signed-off-by: Bryan Boreham <bjboreham@gmail.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>
Instead of passing in a `ScratchBuilder` and `Labels`, just pass the
builder and the caller can extract labels from it. In many cases the
caller didn't use the Labels value anyway.
Now in `Labels.ScratchBuilder` we need a slightly different API: one
to assign what will be the result, instead of overwriting some other
`Labels`. This is safer and easier to reason about.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
Replacing code which assumes the internal structure of `Labels`.
Add a convenience function `EmptyLabels()` which is more efficient than
calling `New()`.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
* model/relabel: Add benchmark
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
* model/relabel: re-use Builder across relabels
Saves memory allocations.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
* labels.Builder: allow re-use of result slice
This reduces memory allocations where the caller has a suitable slice available.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
* model/relabel: re-use source values slice
To reduce memory allocations.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
* Unwind one change causing test failures
Restore original behaviour in PopulateLabels, where we must not overwrite the input set.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
* relabel: simplify values optimisation
Use a stack-based array for up to 16 source labels, which will be the
vast majority of cases.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
* lint
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
* Labels: create signature with/without labels
Instead of creating a new Labels slice then converting to signature,
go directly to the signature and save time.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
* Labels: refactor Builder tests
Have one test with a range of cases, and have them check the final
output rather than checking the internal structure of the Builder.
Also add a couple of cases where the value is "", which should be
interpreted as 'delete'.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
* Labels: add 'Keep' function to Builder
This lets us replace `Labels.WithLabels` with the more general `Builder`.
In `engine.resultMetric()` we can call `Keep()` instead of checking
and calling `Del()`.
Avoid calling `Sort()` in `Builder.Labels()` if we didn't add anything,
so that `Keep()` has the same performance as `WithLabels()`.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
* labels.Equal benchmark for equal, not equal, and differing lengths
Signed-off-by: Nick Pillitteri <nick.pillitteri@grafana.com>
* Compare equality of label.Label structs directly
Compare the structs using `==` instead of the name and value
of each label. This is functionally equivalent and about ~10%
faster in my testing.
Signed-off-by: Nick Pillitteri <nick.pillitteri@grafana.com>
* Use longer more realistic names and values in benchmark
Signed-off-by: Nick Pillitteri <nick.pillitteri@grafana.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>
