navidrome/plugins/manager_plugin.go

package plugins

import (
	"context"
	"crypto/rand"
	"errors"
	"io"

	extism "github.com/extism/go-sdk"
	"github.com/tetratelabs/wazero"
)

// plugin represents a loaded plugin
type plugin struct {
	name         string // Plugin name (from filename)
	path         string // Path to the wasm file
	manifest     *Manifest
	compiled     *extism.CompiledPlugin
	capabilities []Capability // Auto-detected capabilities based on exported functions
	closers      []io.Closer  // Cleanup functions to call on unload
	metrics      PluginMetricsRecorder
}

// instance creates a new plugin instance for the given context.
// The context is used for cancellation - if cancelled during a call,
// the module will be terminated and the instance becomes unusable.
func (p *plugin) instance(ctx context.Context) (*extism.Plugin, error) {
	instance, err := p.compiled.Instance(ctx, extism.PluginInstanceConfig{
		ModuleConfig: wazero.NewModuleConfig().WithSysWalltime().WithRandSource(rand.Reader),
	})
	if err != nil {
		return nil, err
	}
	instance.SetLogger(extismLogger(p.name))
	return instance, nil
}

func (p *plugin) Close() error {
	var errs []error
	for _, f := range p.closers {
		err := f.Close()
		if err != nil {
			errs = append(errs, err)
		}
	}
	return errors.Join(errs...)
}