zbar.go

package zbar

import (
	"context"
	"image"
	"sync"

	_ "embed"

	"github.com/tetratelabs/wazero"
	"github.com/tetratelabs/wazero/api"
	"github.com/tetratelabs/wazero/imports/emscripten"
	"github.com/tetratelabs/wazero/imports/wasi_snapshot_preview1"
)

var (
	//go:embed zbar.wasm
	zbarWasm []byte
	ctx      = context.Background()
	pool     = sync.Pool{New: func() any { return NewScanner() }}
)

func newZbarInstance() (wazero.Runtime, api.Module) {
	r := wazero.NewRuntime(ctx)
	wasi_snapshot_preview1.MustInstantiate(ctx, r)
	emscripten.MustInstantiate(ctx, r)

	zbar := must(r.Instantiate(ctx, zbarWasm))
	return r, zbar
}

func ReadAll(img image.Image) ([][]byte, error) {
	s := pool.Get().(*Scanner)
	defer pool.Put(s)

	return s.ReadAll(img)
}

func Read(img image.Image) (*Reader, error) {
	s := pool.Get().(*Scanner)
	defer pool.Put(s)

	return s.Reader(img)
}

func must[T any](v T, err error) T {
	if err != nil {
		panic(err)
	}
	return v
}