Class: Kobako::Usage

Inherits:

Object

• Object
• Kobako::Usage

Defined in:

lib/kobako/usage.rb

Overview

Per-last-invocation resource accounting for a Kobako::Sandbox. Carries two readers populated by every #eval / #run invocation:

* +wall_time+ — the Float number of seconds the guest export call
  spent inside wasmtime during the most recent invocation. The
  measurement bracket aligns with the +timeout+ deadline; time spent
  in host Service callbacks is included, but everything that runs
  after the guest export returns — the post-export
  +OUTCOME_BUFFER+ fetch and decode, plus stdout / stderr capture
  readout — is excluded.
* +memory_peak+ — the Integer high-water mark, in bytes, of the
  per-invocation +memory.grow+ delta past the linear-memory size
  captured at invocation entry. Same baseline accounting as
  +memory_limit+: the mruby image's initial allocation and any
  prior-invocation watermark sit outside the measurement. On
  +MemoryLimitError+ +memory_peak+ never exceeds the configured
  cap because the rejected +desired+ value is not promoted into
  the high-water.

Both readers are populated on every outcome, including TrapError branches, so the Host App can read Sandbox#usage after rescuing a trap to diagnose how much of the budget the failing invocation consumed. Before the first invocation Sandbox#usage returns the pre-invocation sentinel Kobako::Usage::EMPTY.

Built on the class X < Data.define(…) subclass form (the Steep-friendly shape — see lib/kobako/outcome/panic.rb).

Constant Summary

EMPTY =

Pre-invocation sentinel. Reused by Sandbox before any invocation has run so callers do not need to handle a nil #usage.

new(wall_time: 0.0, memory_peak: 0)