1 files changed, 114 insertions, 0 deletions
diff --git a/dom/encoding/TextDecoder.h b/dom/encoding/TextDecoder.h
new file mode 100644
index 0000000000..39ba8ed1f8
--- /dev/null
+++ b/dom/encoding/TextDecoder.h
@@ -0,0 +1,114 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_dom_textdecoder_h_
+#define mozilla_dom_textdecoder_h_
+
+#include "mozilla/dom/NonRefcountedDOMObject.h"
+#include "mozilla/dom/TextDecoderBinding.h"
+#include "mozilla/dom/TypedArray.h"
+#include "mozilla/Encoding.h"
+#include "mozilla/ErrorResult.h"
+#include "mozilla/UniquePtr.h"
+
+namespace mozilla::dom {
+
+class ArrayBufferViewOrArrayBuffer;
+
+class TextDecoderCommon {
+ public:
+  /**
+   * Decodes incoming byte stream of characters in charset indicated by
+   * encoding.
+   *
+   * The encoding algorithm state is reset if aOptions.mStream is not set.
+   *
+   * If the fatal flag is set then a decoding error will throw EncodingError.
+   * Else the decoder will return a decoded string with replacement
+   * character(s) for unidentified character(s).
+   *
+   * @param      aInput, incoming byte stream of characters to be decoded to
+   *                    to UTF-16 code points.
+   * @param      aStream, indicates if streaming or not.
+   * @param      aOutDecodedString, decoded string of UTF-16 code points.
+   * @param      aRv, error result.
+   */
+  void DecodeNative(mozilla::Span<const uint8_t> aInput, const bool aStream,
+                    nsAString& aOutDecodedString, ErrorResult& aRv);
+
+  /**
+   * Return the encoding name.
+   *
+   * @param aEncoding, current encoding.
+   */
+  void GetEncoding(nsAString& aEncoding);
+
+  bool Fatal() const { return mFatal; }
+
+  bool IgnoreBOM() const { return mIgnoreBOM; }
+
+ protected:
+  mozilla::UniquePtr<mozilla::Decoder> mDecoder;
+  nsCString mEncoding;
+  bool mFatal = false;
+  bool mIgnoreBOM = false;
+};
+
+class TextDecoder final : public NonRefcountedDOMObject,
+                          public TextDecoderCommon {
+ public:
+  // The WebIDL constructor.
+  static TextDecoder* Constructor(const GlobalObject& aGlobal,
+                                  const nsAString& aEncoding,
+                                  const TextDecoderOptions& aOptions,
+                                  ErrorResult& aRv) {
+    auto txtDecoder = MakeUnique<TextDecoder>();
+    txtDecoder->Init(aEncoding, aOptions, aRv);
+    if (aRv.Failed()) {
+      return nullptr;
+    }
+    return txtDecoder.release();
+  }
+
+  TextDecoder() { MOZ_COUNT_CTOR(TextDecoder); }
+
+  MOZ_COUNTED_DTOR(TextDecoder)
+
+  bool WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto,
+                  JS::MutableHandle<JSObject*> aReflector) {
+    return TextDecoder_Binding::Wrap(aCx, this, aGivenProto, aReflector);
+  }
+
+  /**
+   * Validates provided label and throws an exception if invalid label.
+   *
+   * @param aLabel       The encoding label (case insensitive) provided.
+   * @param aOptions     The TextDecoderOptions to use.
+   * @return aRv         EncodingError exception else null.
+   */
+  void Init(const nsAString& aLabel, const TextDecoderOptions& aOptions,
+            ErrorResult& aRv);
+
+  /**
+   * Performs initialization with a Gecko-canonical encoding name (as opposed
+   * to a label.)
+   *
+   * @param aEncoding    An Encoding object
+   * @param aOptions     The TextDecoderOptions to use.
+   */
+  void InitWithEncoding(NotNull<const Encoding*> aEncoding,
+                        const TextDecoderOptions& aOptions);
+
+  void Decode(const Optional<ArrayBufferViewOrArrayBuffer>& aBuffer,
+              const TextDecodeOptions& aOptions, nsAString& aOutDecodedString,
+              ErrorResult& aRv);
+
+ private:
+};
+
+}  // namespace mozilla::dom
+
+#endif  // mozilla_dom_textdecoder_h_