metrics

type Fetch ¶

type Fetch func(Source, func(Sample) error) error

type Matcher ¶

type Matcher struct {
	Label string
	Op    string
	Value string
}

Matcher is one label predicate pushed down to a metric source, in Prometheus matcher terms: Op is "=", "!=", "=~" or "!~". Pushdown only narrows what a source fetches; SQLite still evaluates the full WHERE clause, so a source may ignore any matcher it cannot express.

type ProfileRows ¶

type ProfileRows func(name string) (ProfileTable, error)

ProfileRows executes the named profile for a `profiles.<name>` reference.

type ProfileTable ¶

type ProfileTable struct {
	Columns []string
	Rows    []map[string]any
}

ProfileTable is the result of a profile referenced as `profiles.<name>` in metric SQL: its column names and its rows.

type QueryPlan ¶

type QueryPlan struct {
	SQL        string
	Sources    []Source
	Prometheus bool
	Profiles   []string
}

QueryPlan is metric SQL rewritten onto its workspace tables. Prometheus reports a `prometheus(...)` reference; Profiles lists each `profiles.<name>` reference, loaded as table __profile_<index>.

func Plan(statement string) (QueryPlan, error)

type Range ¶

type Range struct {
	Start, End time.Time
	Step       time.Duration
}

Range is a PromQL range-query window.

type RangeQuery ¶

type RangeQuery struct {
	Window Range
	Fetch  func(expr string, r Range, emit func(Sample) error) error
}

RangeQuery lets metric SQL read `prometheus(query, [start, end, step])`. Window is the provider's request range, the default for omitted bounds; Fetch evaluates one expression over a range, emitting each sample.

type Request ¶

type Request struct {
	SQL      string
	Args     []any
	Labels   map[string]string
	Range    *RangeQuery
	Profiles ProfileRows
}

Request is one metric SQL statement. Range enables `prometheus(...)` and is nil for providers without range queries; Profiles enables `profiles.<name>` and is nil where no profile resolver is reachable.

type Sample ¶

type Sample struct {
	Time                               time.Time
	Value                              float64
	Labels                             map[string]string
	Metric, Namespace, Statistic, Unit string
}

type Source ¶

type Source struct {
	Name, Transform, Window string
	Filters                 []Matcher
	// contains filtered or unexported fields
}

Source is one `FROM <metric>` table. Filters are the WHERE predicates on its label columns, resolved against the request's parameters.