NewCachingIndexer returns a new instance of the CachingIndexer.

Equal is "=" in PromQL.

NotEqual is "!=" in PromQL.

RegexMatch is "=~" in PromQL.

RegexNoMatch is "!~" in PromQL.

CachingIndexer remembers when a metric was indexed last, if it is beyond a provided duration, then the provided Writer is called to write the metric and the time of the write is stored in CachingIndexer.

CachingIndexerConfig represents the configuration of a CachingIndexer object.

Match represents the PromQL matching function and on what label name to operate.

DatapointReader is an interface that wraps the ReadDatapoints method.

Resolver is a interface that wraps a database that can answer questions on what metrics exist.

SampleIndexer is an interface that wraps the methods of a Prometheus Collector interface and IndexSample method.

SampleWriter is an interface that wraps methods needed to write to the database of the storage layer.

MatchType is an enum representing a PromQL label match from "=", "!=", "=~" or "!~".