This commit adds an alternate implementation for `labels.Labels`, behind
a build tag `stringlabels`.
Instead of storing label names and values as individual strings, they
are all concatenated into one string in this format:
[len][name0][len][value0][len][name1][len][value1]...
The lengths are varint encoded so usually a single byte.
The previous `[]string` had 24 bytes of overhead for the slice and 16
for each label name and value; this one has 16 bytes overhead plus 1
for each name and value.
In `ScratchBuilder.Overwrite` and `Labels.Hash` we use an unsafe
conversion from string to byte slice. `Overwrite` is explicitly unsafe,
but for `Hash` this is a pure performance hack.
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>
Without changing the definition of `labels.Labels`, add methods which
enable code using it to work without knowledge of the internals.
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
For performance reasons we may use a different implementation of Hash()
in future, so note this so callers can be warned.
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>
We know the max size of our map so we can create it with that information and avoid extra allocations
Signed-off-by: Łukasz Mierzwa <l.mierzwa@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>
