D4rtProfiler class

Compile-time-gated profiler for D4rt's initialization path.

This profiler measures the one-time setup work that happens when a D4rt runner is constructed and prepared for a run — bridge finalization, warm-parent environment assembly, stdlib registration, module-loader construction, and the declaration/registration passes that precede the actual main() call. It is not a profiler for the interpreter's hot path; instrumentation deliberately stops at the point where script interpretation begins.

Zero runtime cost when disabled

enabled is a static const bool. Every measurement site is written as an if (D4rtProfiler.enabled) { ... } guard (or a D4rtProfiler.enabled ? ... : null ternary). When enabled is false the Dart compiler (VM TFA / AOT / dart2js) constant-folds the condition and eliminates the guarded code entirely — no Stopwatch allocation, no map lookup, and no call overhead in a normal run.

CRITICAL — never publish with enabled == true

Flip enabled to true only for a local profiling session, then revert it before committing or publishing the package. A true value would leave the instrumentation live in shipped builds. A guard test (test/profiler_disabled_test.dart) asserts it stays false.

Twin of tom_d4rt/lib/src/profiler.dart — keep both in sync.

Properties

hashCode → int

The hash code for this object.

no setter, inherited

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

Methods

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

toString() → String

A string representation of this object.

inherited

Operators

operator ==(Object other) → bool

The equality operator.

inherited

Static Properties

hasData → bool

Whether any spans have been recorded.

no setter

Static Methods

record(String name, int micros) → void

Records an elapsed micros span under name.

report({String title = 'D4rt init profile'}) → String

Human-readable multi-line report, longest span first.

reset() → void

Clears all recorded spans (e.g. between profiling runs).

snapshot() → Map<String, dynamic>

JSON-serializable snapshot: {name: {us, ms, n}} in record order.

Constants

enabled → const bool

Master compile-time switch. MUST remain false in published code.