Deallocate jsencoding::Decoder instances (#195)

Call jsencoding::decoder_free() for jsencoding::decoder instances

Author: andreiltd

builtins/web/blob.cpp

@@ -419,11 +419,14 @@ bool Blob::text(JSContext *cx, HandleObject self, MutableHandleValue rval) {
   auto encoding = const_cast<jsencoding::Encoding *>(jsencoding::encoding_for_label_no_replacement(
       reinterpret_cast<uint8_t *>(const_cast<char *>("UTF-8")), 5));
 
-  auto decoder = jsencoding::encoding_new_decoder_with_bom_removal(encoding);
+  auto deleter = [&](jsencoding::Decoder *dec) { jsencoding::decoder_free(dec); };
+  std::unique_ptr<jsencoding::Decoder, decltype(deleter)> decoder(
+      jsencoding::encoding_new_decoder_with_bom_removal(encoding), deleter);
+
   MOZ_ASSERT(decoder);
 
   auto src_len = src->length();
-  auto dst_len = jsencoding::decoder_max_utf16_buffer_length(decoder, src_len);
+  auto dst_len = jsencoding::decoder_max_utf16_buffer_length(decoder.get(), src_len);
 
   JS::UniqueTwoByteChars dst(new char16_t[dst_len + 1]);
   if (!dst) {
@@ -434,8 +437,8 @@ bool Blob::text(JSContext *cx, HandleObject self, MutableHandleValue rval) {
   bool had_replacements;
   auto dst_data = reinterpret_cast<uint16_t *>(dst.get());
 
-  jsencoding::decoder_decode_to_utf16(decoder, src->begin(), &src_len, dst_data, &dst_len, true,
-                                      &had_replacements);
+  jsencoding::decoder_decode_to_utf16(decoder.get(), src->begin(), &src_len, dst_data, &dst_len,
+                                      true, &had_replacements);
 
   JS::RootedString str(cx, JS_NewUCString(cx, std::move(dst), dst_len));
   if (!str) {

builtins/web/text-codec/text-decoder.cpp

@@ -247,6 +247,15 @@ bool TextDecoder::init_class(JSContext *cx, JS::HandleObject global) {
   return init_class_impl(cx, global);
 }
 
+void TextDecoder::finalize(JS::GCContext *gcx, JSObject *self) {
+  auto decoder = reinterpret_cast<jsencoding::Decoder *>(
+      JS::GetReservedSlot(self, static_cast<uint32_t>(TextDecoder::Slots::Decoder)).toPrivate());
+
+  if (decoder) {
+    jsencoding::decoder_free(decoder);
+  }
+}
+
 } // namespace text_codec
 } // namespace web
 } // namespace builtins

builtins/web/text-codec/text-decoder.h

@@ -7,7 +7,7 @@ namespace builtins {
 namespace web {
 namespace text_codec {
 
-class TextDecoder final : public BuiltinImpl<TextDecoder> {
+class TextDecoder final : public FinalizableBuiltinImpl<TextDecoder> {
   static bool decode(JSContext *cx, unsigned argc, JS::Value *vp);
   static bool encoding_get(JSContext *cx, unsigned argc, JS::Value *vp);
   static bool fatal_get(JSContext *cx, unsigned argc, JS::Value *vp);
@@ -33,6 +33,7 @@ class TextDecoder final : public BuiltinImpl<TextDecoder> {
 
   static bool init_class(JSContext *cx, JS::HandleObject global);
   static bool constructor(JSContext *cx, unsigned argc, JS::Value *vp);
+  static void finalize(JS::GCContext *gcx, JSObject *self);
 };
 
 } // namespace text_codec