go: allow set a flash_attn option in Go binding, better sugar apis

bindings/go/context_params.go

@@ -1,20 +1,5 @@
 package whisper
 
-type (
-	contextParamsOption     interface{ apply(*ContextParams) }
-	contextParamsOptionFunc func(*ContextParams)
-)
-
-func (fn contextParamsOptionFunc) apply(to *ContextParams) {
-	fn(to)
-}
-
-func WithUseGPU(v bool) contextParamsOption {
-	return contextParamsOptionFunc(func(p *ContextParams) {
-		p.SetUseGPU(v)
-	})
-}
-
 func (p *ContextParams) UseGPU() bool {
 	return bool(p.use_gpu)
 }
@@ -22,3 +7,11 @@ func (p *ContextParams) UseGPU() bool {
 func (p *ContextParams) SetUseGPU(v bool) {
 	p.use_gpu = toBool(v)
 }
+
+func (p *ContextParams) UseFlashAttention() bool {
+	return bool(p.flash_attn)
+}
+
+func (p *ContextParams) SetUseFlashAttention(v bool) {
+	p.flash_attn = toBool(v)
+}

bindings/go/pkg/whisper/model.go

@@ -23,19 +23,21 @@ var _ Model = (*model)(nil)
 ///////////////////////////////////////////////////////////////////////////////
 // LIFECYCLE
 
-func New(path string) (Model, error) {
-	model := new(model)
+func New(path string, options ...modelOption) (Model, error) {
 	if _, err := os.Stat(path); err != nil {
 		return nil, err
-	} else if ctx := whisper.Whisper_init(path); ctx == nil {
-		return nil, ErrUnableToLoadModel
-	} else {
-		model.ctx = ctx
-		model.path = path
 	}
 
-	// Return success
-	return model, nil
+	params := whisper.DefaultContextParams()
+	for _, option := range options {
+		option.apply(&params)
+	}
+
+	if ctx := whisper.Whisper_init_with_params(path, params); ctx != nil {
+		return &model{path, ctx}, nil
+	}
+
+	return nil, ErrUnableToLoadModel
 }
 
 func (model *model) Close() error {

bindings/go/pkg/whisper/model_option.go

@@ -0,0 +1,26 @@
+package whisper
+
+import whisper "github.com/ggerganov/whisper.cpp/bindings/go"
+
+type ContextParams = whisper.ContextParams
+
+type (
+	modelOption     interface{ apply(*ContextParams) }
+	modelOptionFunc func(*ContextParams)
+)
+
+func (fn modelOptionFunc) apply(to *ContextParams) {
+	fn(to)
+}
+
+func WithUseGPU(v bool) modelOption {
+	return modelOptionFunc(func(p *ContextParams) {
+		p.SetUseGPU(v)
+	})
+}
+
+func WithUseFlashAttention(v bool) modelOption {
+	return modelOptionFunc(func(p *ContextParams) {
+		p.SetUseFlashAttention(v)
+	})
+}

bindings/go/whisper.go

@@ -102,13 +102,13 @@ var (
 
 // Allocates all memory needed for the model and loads the model from the given file.
 // Returns NULL on failure.
-func Whisper_init(path string, options ...contextParamsOption) *Context {
+func Whisper_init(path string) *Context {
+	return Whisper_init_with_params(path, DefaultContextParams())
+}
+
+func Whisper_init_with_params(path string, params ContextParams) *Context {
 	cPath := C.CString(path)
 	defer C.free(unsafe.Pointer(cPath))
-	params := ContextParams(C.whisper_context_default_params())
-	for _, o := range options {
-		o.apply(&params)
-	}
 	if ctx := C.whisper_init_from_file_with_params(cPath, (C.struct_whisper_context_params)(params)); ctx != nil {
 		return (*Context)(ctx)
 	} else {
@@ -116,6 +116,10 @@ func Whisper_init(path string, options ...contextParamsOption) *Context {
 	}
 }
 
+func DefaultContextParams() ContextParams {
+	return ContextParams(C.whisper_context_default_params())
+}
+
 // Frees all memory allocated by the model.
 func (ctx *Context) Whisper_free() {
 	C.whisper_free((*C.struct_whisper_context)(ctx))