Module series 

The metrics read path: match metrics, gather points, group into series.

A different shape from crate::query::search, and deliberately a separate function rather than a mode of it. A log search filters one root table and returns rows newest-first; a metrics query filters a descriptor table, gathers points from four point tables that share one id space, and then regroups them by a key that has to be stable across blocks. Folding both into one code path would mean inventing the abstraction that both are special cases of, which is a planner.

The grouping key is the hard part and the reason this is not trivial. Ids are rebased per block — that is what makes the attribute joins array stores — so nothing block-local can identify a series across two blocks. The key is built from values instead: the metric’s name, unit and kind, plus the merged attribute map from all four levels. That is one string built per point, which is the honest cost of a layout optimized for writing and pruning rather than for grouping.

What V0 returns

Gauges and sums come back as their own value. Histograms, exponential histograms and summaries come back as two derived series each, <name>.count and <name>.sum — the same convention Prometheus uses, and the same two numbers that answer “how often” and “how much”. Bucket and quantile maths is not here: it is a heatmap feature, it needs the UI to exist first, and shipping it wrong would be worse than shipping it later. Everything needed for it is on disk already — bucket_counts, bounds_id, scale, quantile — so this is a read-path gap, not a storage one.

Blocking: mmaps and page-faults, same as search. Callers on an async runtime must use spawn_blocking.

Structs

Series 🔒

SeriesQuery

A metrics query.

Enums

Pt 🔒

One point. Integers stay integers: an OTLP as_int is sfixed64, and a counter past 2^53 pushed through an f64 loses its low bits — which is exactly the moment a counter is interesting.

Values 🔒

Which columns of a point table carry chartable values, resolved once per table instead of per row.

Constants

COUNT 🔒

The suffixes a histogram’s or summary’s name is derived with. Named rather than written twice, because the name filter has to accept back exactly the names the renderer hands out and two literal lists would drift apart.

DERIVED 🔒

DP_TABLES 🔒

The four point tables, and how many name suffixes each contributes.

MAX_EXEMPLARS 🔒

Exemplars kept per series.

SUM 🔒

Functions

bound 🔒

Hold out to max_series entries by evicting its largest key.

collect_attrs 🔒

The rows one parent owns, rendered.

collect_block 🔒

dedup_last 🔒

describe 🔒

The descriptor’s identity as rendered JSON members, without the trailing comma. Doubles as the stable half of the series key.

dict_str 🔒

exemplar_time 🔒

index_by_parent 🔒

Child rows grouped by parent_id, indexed by it.

kind_name 🔒

load 🔒

merge 🔒

Render the union of two sorted attribute lists as a JSON object, own winning on collision. A merge, not a concatenation and a re-sort: upper is already sorted and shared by every point of the metric.

names

Every metric name present in the window, with its unit and kind.

names_open

As names, but also reads the open block’s snapshot. A metric name that has only ever been written to the open block is exactly the one a dropdown must not omit — it is the new one.

own_attrs 🔒

series

series_open

As series, but also reads the open block’s snapshot — see crate::query::search_open, which this mirrors exactly.

u8_col 🔒

upper_attrs 🔒

Attributes from the metric, resource and scope levels, sorted and deduped with the most specific level winning.

with_suffix 🔒

describe with the derived-series suffix folded into the name, so a .count series reports the name a caller can query it back by.

Type Aliases

Attr 🔒

One attribute as (key, rendered JSON value). Rendered once and carried as a string because the same value is written into both the grouping key and the response.

Prefix 🔒

A descriptor row’s cached contribution: its rendered JSON members, and the attributes every point beneath it inherits.