Optimize memory usage

main.go

@@ -4,12 +4,20 @@ import (
 	"log"
 	"net"
 	"net/http"
+	"runtime/debug"
 	"time"
 
 	"golang.org/x/net/netutil"
 )
 
 func main() {
+	// Force garbage collection
+	go func() {
+		for _ = range time.Tick(time.Second) {
+			debug.FreeOSMemory()
+		}
+	}()
+
 	l, err := net.Listen("tcp", conf.Bind)
 	if err != nil {
 		log.Fatal(err)

process.go

@@ -176,6 +176,7 @@ func processImage(data []byte, imgtype imageType, po processingOptions) ([]byte,
 	err := C.int(0)
 
 	var img *C.struct__VipsImage
+	defer C.clear_image(&img)
 
 	defer C.vips_cleanup()
 
@@ -241,8 +242,11 @@ func processImage(data []byte, imgtype imageType, po processingOptions) ([]byte,
 	}
 
 	// Finally, save
-	imgsize := C.size_t(0)
 	var ptr unsafe.Pointer
+	defer C.g_free(C.gpointer(ptr))
+
+	imgsize := C.size_t(0)
+
 	switch po.format {
 	case JPEG:
 		err = C.vips_jpegsave_go(img, &ptr, &imgsize, 1, C.int(conf.Quality), 0)
@@ -255,10 +259,7 @@ func processImage(data []byte, imgtype imageType, po processingOptions) ([]byte,
 		return nil, vipsError()
 	}
 
-	C.g_object_unref(C.gpointer(img))
-
 	buf := C.GoBytes(ptr, C.int(imgsize))
-	C.g_free(C.gpointer(ptr))
 
 	return buf, nil
 }

vips.h

@@ -21,9 +21,14 @@ vips_initialize()
   return vips_init("imgproxy");
 }
 
+void
+clear_image(VipsImage **in) {
+  g_clear_object(in);
+}
+
 void
 swap_and_clear(VipsImage **in, VipsImage *out) {
-  g_object_unref((gpointer) *in);
+  clear_image(in);
   *in = out;
 }