Files
lambda/internal/plugins/performance.go
M.V. Hutz bcc0331149 refactor: move event system to reducer, remove engine package
Move the event emitter and lifecycle events from the engine into the reducer,
making the reducer the single point of orchestration for reduction.
This eliminates the engine package entirely.

- Add events.go to pkg/reducer with Start, Step, and Stop events.
- Extend Reducer interface to embed Emitter and add Expression() method.
- Update NormalOrderReducer to embed BaseEmitter and emit lifecycle events.
- Update all plugins to attach to Reducer instead of Engine.
- Remove internal/engine package.
- Add Off() method to BaseEmitter to complete Emitter interface.
- Fix Emitter.On signature to use generic type E instead of string.
2026-01-16 18:50:52 -05:00

60 lines
1.1 KiB
Go

// Package "performance" provides a tracker to observe CPU performance during
// execution.
package plugins
import (
"os"
"path/filepath"
"runtime/pprof"
"git.maximhutz.com/max/lambda/pkg/reducer"
)
// Observes a reduction process, and publishes a CPU performance profile on
// completion.
type Performance struct {
File string
filePointer *os.File
Error error
}
// Create a performance tracker that outputs a profile to "file".
func NewPerformance(file string, r reducer.Reducer) *Performance {
plugin := &Performance{File: file}
r.On(reducer.StartEvent, plugin.Start)
r.On(reducer.StopEvent, plugin.Stop)
return plugin
}
// Begin profiling.
func (t *Performance) Start() {
var absPath string
absPath, t.Error = filepath.Abs(t.File)
if t.Error != nil {
return
}
t.Error = os.MkdirAll(filepath.Dir(absPath), 0777)
if t.Error != nil {
return
}
t.filePointer, t.Error = os.Create(absPath)
if t.Error != nil {
return
}
t.Error = pprof.StartCPUProfile(t.filePointer)
if t.Error != nil {
return
}
}
// Stop profiling.
func (t *Performance) Stop() {
pprof.StopCPUProfile()
t.filePointer.Close()
}