set log function (#3)

* gstreamer set log function

* missing parameters

* wrong object type

* spacing

* transfer

* nil check object

* add lock

* unset -> reset

* prevent data race

.gitignore

@@ -22,4 +22,5 @@ _bin/
 _rust/
 *.DS_Store*
 *.supp
-zzgenerated*
+zzgenerated*
+.idea/

go.sum

@@ -1,4 +1,4 @@
 github.com/mattn/go-pointer v0.0.1 h1:n+XhsuGeVO6MEAp7xyEukFINEa+Quek5psIR/ylA6o0=
 github.com/mattn/go-pointer v0.0.1/go.mod h1:2zXcozF6qYGgmsG+SeTZz3oAbFLdD3OWqnUbNvJZAlc=
-github.com/tinyzimmer/go-glib v0.0.24 h1:ktZZC22/9t88kGRgNEFV/SESgIWhGHE+q7Z7Qj++luw=
-github.com/tinyzimmer/go-glib v0.0.24/go.mod h1:ltV0gO6xNFzZhsIRbFXv8RTq9NGoNT2dmAER4YmZfaM=
+github.com/tinyzimmer/go-glib v0.0.25 h1:2GpumtkxA0wpXhCXP6D3ksb5pGMfo9WbhgLvEw8njK4=
+github.com/tinyzimmer/go-glib v0.0.25/go.mod h1:ltV0gO6xNFzZhsIRbFXv8RTq9NGoNT2dmAER4YmZfaM=

gst/cgo_exports.go

@@ -243,3 +243,34 @@ func goPluginInit(plugin *C.GstPlugin, userData C.gpointer) C.gboolean {
 func goGlobalPluginInit(plugin *C.GstPlugin) C.gboolean {
 	return gboolean(globalPluginInit(wrapPlugin(&glib.Object{GObject: glib.ToGObject(unsafe.Pointer(plugin))})))
 }
+
+//export goLogFunction
+func goLogFunction(
+	_ *C.GstDebugCategory,
+	level C.GstDebugLevel,
+	file *C.gchar,
+	function *C.gchar,
+	line C.gint,
+	object *C.GObject,
+	message *C.GstDebugMessage,
+	_ C.gpointer,
+) {
+	logFnMu.RLock()
+	f := customLogFunction
+	logFnMu.RUnlock()
+
+	if f != nil {
+		var obj *glib.Object
+		if object != nil {
+			obj = glib.TransferNone(unsafe.Pointer(object))
+		}
+		f(
+			DebugLevel(level),
+			C.GoString(file),
+			C.GoString(function),
+			int(line),
+			obj,
+			C.GoString(C.gst_debug_message_get(message)),
+		)
+	}
+}

gst/gst_debug.go

@@ -3,6 +3,15 @@ package gst
 /*
 #include "gst.go.h"
 
+extern void goLogFunction(GstDebugCategory * category,
+                          GstDebugLevel level,
+                          const gchar * file,
+                          const gchar * function,
+                          gint line,
+                          GObject * object,
+                          GstDebugMessage * message,
+                          gpointer user_data) G_GNUC_NO_INSTRUMENT;
+
 void cgoDebugLog (GstDebugCategory * category,
                	  GstDebugLevel level,
                   const gchar * file,
@@ -14,12 +23,27 @@ void cgoDebugLog (GstDebugCategory * category,
 	gst_debug_log(category, level, file, function, line, object, msg);
 }
 
+void cgoSetLogFunction()
+{
+	gst_debug_remove_log_function(gst_debug_log_default);
+	gst_debug_add_log_function(goLogFunction, NULL, NULL);
+}
+
+void cgoResetLogFunction()
+{
+	gst_debug_remove_log_function(goLogFunction);
+	gst_debug_add_log_function(gst_debug_log_default, NULL, NULL);
+}
+
 */
 import "C"
 import (
 	"path"
 	"runtime"
+	"sync"
 	"unsafe"
+
+	"github.com/tinyzimmer/go-glib/glib"
 )
 
 // DebugColorFlags are terminal style flags you can use when creating your debugging
@@ -164,3 +188,29 @@ func (d *DebugCategory) LogTrace(message string, obj ...*Object) {
 func (d *DebugCategory) LogMemDump(message string, obj ...*Object) {
 	d.logDepth(LevelMemDump, message, 2, getLogObj(obj...))
 }
+
+type LogFunction func(
+	level DebugLevel,
+	file string,
+	function string,
+	line int,
+	object *glib.Object,
+	message string,
+)
+
+var (
+	logFnMu           sync.RWMutex
+	customLogFunction LogFunction
+)
+
+func SetLogFunction(f LogFunction) {
+	logFnMu.Lock()
+	defer logFnMu.Unlock()
+
+	if f == nil {
+		C.cgoResetLogFunction()
+	} else if customLogFunction == nil {
+		C.cgoSetLogFunction()
+	}
+	customLogFunction = f
+}