Module readings 

The console’s readings (SRV-015 R1): numbers the map can be wired to, on their own subject, console.readings.

A source is a named kind of number about one kind of target (a device, a station or a line), offered by the server or by a participant. A reading is one source’s number for one target. Every console.readings record is the whole current set, so, as on console.topology, a reader’s snapshot is the subject’s latest record; console.topology itself never carries a reading (SRV-015 R1 and R4, amended 7 Oct 14:30).

No source is required. A source nothing measures is absent, and an absent reading means no reading, never zero (Tom 7 Oct 13:56: “we don’t want to sort of require like CPU and temperature”).

Structs

Reading

One source’s number for one target.

ReadingValue

A reading’s number: always finite, with one zero, so two readings compare equal exactly when they are the same number.

ReadingsRecord

One console.readings record: every source and reading as they stand.

Source

A named kind of number about one kind of target.

Enums

Origin

Who offers a source: the server, from what it measures itself, or the participant that first published it.

TargetKind

What a source’s readings are about.

Constants

READINGS_SUBJECT

The subject the readings records go out on.