M.V. Hutz
1974ad582f
## Description This PR completes the MVC-inspired refactoring by moving the event system from the engine into the reducer. The engine package is now removed entirely, as the reducer handles both reduction logic and lifecycle events. - Add `pkg/reducer/events.go` with `StartEvent`, `StepEvent`, and `StopEvent`. - Extend `Reducer` interface to embed `Emitter[Event]` and add `Expression()` method. - Update `NormalOrderReducer` to embed `BaseEmitter` and emit lifecycle events during reduction. - Update all plugins to attach to `Reducer` instead of `Engine`. - Remove `internal/engine` package entirely. - Add `Off()` method to `BaseEmitter` to complete the `Emitter` interface. - Fix `Emitter.On` signature to use generic type `E` instead of `string`. ### Decisions - The `Reducer` interface now combines reduction logic with event emission, making it the single orchestration point. - Plugins attach directly to the reducer, simplifying the architecture. - The `Expression()` method on `Reducer` provides access to current state for plugins. ## Benefits - Simpler architecture with one fewer abstraction layer. - Plugins are now mode-agnostic - they work with any `Reducer` implementation. - Cleaner separation: reducers handle reduction, plugins observe via events. - Easier to add new evaluation modes - just implement `Reducer` with embedded emitter. ## Checklist - [x] Code follows conventional commit format. - [x] Branch follows naming convention (`<type>/<description>`). - [x] Tests pass (if applicable). - [ ] Documentation updated (if applicable). Reviewed-on: #32 Co-authored-by: M.V. Hutz <git@maximhutz.me> Co-committed-by: M.V. Hutz <git@maximhutz.me>
45 lines
821 B
Go
45 lines
821 B
Go
package plugins
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import (
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"fmt"
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"os"
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"time"
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"git.maximhutz.com/max/lambda/internal/statistics"
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"git.maximhutz.com/max/lambda/pkg/reducer"
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)
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// An observer, to track reduction performance.
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type Statistics struct {
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start time.Time
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steps uint64
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}
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// Create a new reduction performance Statistics.
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func NewStatistics(r reducer.Reducer) *Statistics {
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plugin := &Statistics{}
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r.On(reducer.StartEvent, plugin.Start)
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r.On(reducer.StepEvent, plugin.Step)
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r.On(reducer.StopEvent, plugin.Stop)
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return plugin
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}
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func (t *Statistics) Start() {
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t.start = time.Now()
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t.steps = 0
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}
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func (t *Statistics) Step() {
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t.steps++
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}
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func (t *Statistics) Stop() {
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results := statistics.Results{
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StepsTaken: t.steps,
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TimeElapsed: uint64(time.Since(t.start).Milliseconds()),
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}
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fmt.Fprint(os.Stderr, results.String())
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}
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