Skip to content

feat(metrics/family): 🍭 len() returns the number of metrics#246

Merged
mxinden merged 1 commit intoprometheus:masterfrom
cratelyn:family-len
Jan 29, 2026
Merged

feat(metrics/family): 🍭 len() returns the number of metrics#246
mxinden merged 1 commit intoprometheus:masterfrom
cratelyn:family-len

Conversation

@cratelyn
Copy link
Copy Markdown
Contributor

this commit introduces a len() method to Family<S, M, C>, which returns the number of series within a metric family.

see also #245, which allows callers to check if a family contains() a given label set.

@cratelyn cratelyn changed the title feat(metrics/family): len() returns the number of metrics feat(metrics/family): 🍭 len() returns the number of metrics Nov 18, 2024
@cratelyn
Copy link
Copy Markdown
Contributor Author

cratelyn commented Sep 2, 2025

my understanding is that this could be added behind the test-util flag proposed in #283.

Copy link
Copy Markdown
Member

@mxinden mxinden left a comment

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Looks good to me. Thanks. Once #242 is merged, we can proceed here.

Comment thread src/metrics/family.rs
Comment thread CHANGELOG.md
Copy link
Copy Markdown
Member

@mxinden mxinden left a comment

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Thanks.

Comment thread CHANGELOG.md Outdated
@mxinden
Copy link
Copy Markdown
Member

mxinden commented Jan 23, 2026

@cratelyn can you resolve the merge conflict? A bit tricky via GitHub UI.

this commit introduces a `len()` method to `Family<S, M, C>`, which
returns the number of series within a metric family.

see also prometheus#245, which allows callers to check if a family `contains()` a
given label set.

```shell
$ cargo clippy --all-features --all-targets --tests
   Compiling prometheus-client v0.23.0 (/path/to/prometheus-client)
warning: struct `Family` has a public `len` method, but no `is_empty` method
   --> src/metrics/family.rs:309:5
    |
309 |     pub fn len(&self) -> usize {
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#len_without_is_empty
    = note: `#[warn(clippy::len_without_is_empty)]` on by default

warning: `prometheus-client` (lib) generated 1 warning
warning: `prometheus-client` (lib test) generated 1 warning (1 duplicate)
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.63s
```

Signed-off-by: katelyn martin <git@katelyn.world>
Comment thread CHANGELOG.md
@cratelyn
Copy link
Copy Markdown
Contributor Author

@cratelyn can you resolve the merge conflict? A bit tricky via GitHub UI.

yes, of course!

i've rebased this on master, and pushed a clean commit. thank you for spotting the changelog typo as well.

@mxinden mxinden added this pull request to the merge queue Jan 29, 2026
Merged via the queue into prometheus:master with commit 3942d06 Jan 29, 2026
10 checks passed
eleboucher pushed a commit to eleboucher/towonel that referenced this pull request Apr 18, 2026
This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| [prometheus-client](https://github.com/prometheus/client_rust) | workspace.dependencies | minor | `0.22` → `0.24` |

---

### Release Notes

<details>
<summary>prometheus/client_rust (prometheus-client)</summary>

### [`v0.24.1`](https://github.com/prometheus/client_rust/blob/HEAD/CHANGELOG.md#0241)

[Compare Source](prometheus/client_rust@v0.24.0...v0.24.1)

##### Added

- `EncodeGaugeValue` is implemented for `usize` and `isize`, and
  `EncodeCounterValue` is implemented for `usize`. See [PR 282].

##### Fixed

- `EncodeGaugeValue`, `EncodeCounterValue` and `EncodeExemplarValue` now use
  fewer `as` casts in their implementation. This caught an issue where
  `EncodeGaugeValue` would not error when encoding some `u64`s that don't fit
  in a `i64`. See [PR 281].
- Filter out empty metric families, to match the go client. See [PR 279].
- `Histogram` now exposes `count()` and `sum()` methods when the `test-util`
  feature is enabled. See [PR 242].
- `Family` now exposes a `contains()` method when the `test-util` feature
  is enabled. See [PR 245].
- `Family` now exposes `len()` and `is_empty()` methods when the
  `test-util` feature is enabled. See [PR 246].

[PR 279]: prometheus/client_rust#279

[PR 281]: prometheus/client_rust#281

[PR 242]: prometheus/client_rust#242

[PR 245]: prometheus/client_rust#245

[PR 246]: prometheus/client_rust#246

[PR 281]: prometheus/client_rust#281

[PR 282]: prometheus/client_rust#282

### [`v0.24.0`](https://github.com/prometheus/client_rust/blob/HEAD/CHANGELOG.md#0240)

[Compare Source](prometheus/client_rust@v0.23.1...v0.24.0)

##### Added

- `EncodeLabelSet` is now implemented for tuples `(A: EncodeLabelSet, B: EncodeLabelSet)`.
  See [PR 257].

- `Family::get_or_create_owned` can access a metric in a labeled family. This
  method avoids the risk of runtime deadlocks at the expense of creating an
  owned type. See [PR 244].

- `impl<T: Collector> Collector for std::sync::Arc<T>`.
  See [PR 273].

[PR 244]: prometheus/client_rust#244

[PR 257]: prometheus/client_rust#257

[PR 273]: prometheus/client_rust#273

##### Changed

- `EncodeLabelSet::encode()` now accepts a mutable reference to its encoder parameter.
- Exemplar timestamps can now be passed, which are required for `convert_classic_histograms_to_nhcb: true`
  in Prometheus scraping. See [PR 276].

[PR 276]: prometheus/client_rust#276

### [`v0.23.1`](https://github.com/prometheus/client_rust/blob/HEAD/CHANGELOG.md#0231)

[Compare Source](prometheus/client_rust@v0.23.0...v0.23.1)

##### Changed

- `Histogram::new` now accepts an `IntoIterator` argument, rather than an `Iterator`.
  See [PR 243].

[PR 243]: prometheus/client_rust#243

### [`v0.23.0`](https://github.com/prometheus/client_rust/blob/HEAD/CHANGELOG.md#0230)

[Compare Source](prometheus/client_rust@v0.22.3...v0.23.0)

##### Changed

- `ConstCounter::new` now requires specifying the type of literal arguments, like this: `ConstCounter::new(42u64);`.
  See [PR 173].

- Update `prost` dependencies to `v0.12`.
  See [PR 198].

- Implement `Atomic<u64>` for `AtomicU64` for gauges.
  See [PR 226].

- Implement `EnableLabelValue` for `bool`.
  See [PR 237]

[PR 173]: prometheus/client_rust#173

[PR 198]: prometheus/client_rust#198

[PR 226]: prometheus/client_rust#226

[PR 237]: prometheus/client_rust#237

##### Added

- Support `i32`/`f32` for `Gauge` and `u32`/`f32` for `Counter`/`CounterWithExemplar`.
  See [PR 173] and [PR 216].

- Supoort `Arc<String>` for `EncodeLabelValue`.
  See [PR 217].

- Add `histogram::exponential_buckets_range`.
  See [PR 233].

- Added `get` method to `Family`.
  See [PR 234].

[PR 173]: prometheus/client_rust#173

[PR 216]: prometheus/client_rust#216

[PR 217]: prometheus/client_rust#217

[PR 233]: prometheus/client_rust#233

[PR 234]: prometheus/client_rust#234

##### Fixed

- Don't prepend `,` when encoding empty family label set.
  See [PR 175].

[PR 175]: prometheus/client_rust#175

</details>

---

### Configuration

📅 **Schedule**: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined).

🚦 **Automerge**: Disabled by config. Please merge this manually once you are satisfied.

♻ **Rebasing**: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.

🔕 **Ignore**: Close this PR and you won't be reminded about this update again.

---

 - [ ] <!-- rebase-check -->If you want to rebase/retry this PR, check this box

---

This PR has been generated by [Renovate Bot](https://github.com/renovatebot/renovate).
<!--renovate-debug:eyJjcmVhdGVkSW5WZXIiOiI0My4xMDEuMSIsInVwZGF0ZWRJblZlciI6IjQzLjEwMS4xIiwidGFyZ2V0QnJhbmNoIjoibWFpbiIsImxhYmVscyI6WyJ0eXBlL21pbm9yIl19-->

Reviewed-on: https://git.erwanleboucher.dev/eleboucher/towonel/pulls/7
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Labels

None yet

Projects

None yet

Development

Successfully merging this pull request may close these issues.

2 participants