dom/encoding/TextEncoder.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include "mozilla/dom/TextEncoder.h"
   8 #include "mozilla/CheckedInt.h"
   9 #include "mozilla/ErrorResult.h"
  10 #include "mozilla/UniquePtrExtensions.h"
  11 #include "nsReadableUtils.h"
  12
  13 namespace mozilla::dom {
  14
  15 void TextEncoder::Encode(JSContext* aCx, JS::Handle<JSObject*> aObj,
  16                          const nsACString& aUtf8String,
  17                          JS::MutableHandle<JSObject*> aRetval,
  18                          ErrorResult& aRv) {
  19   JSAutoRealm ar(aCx, aObj);
  20   JSObject* outView = Uint8Array::Create(aCx, aUtf8String, aRv);
  21   if (aRv.Failed()) {
  22     return;
  23   }
  24
  25   aRetval.set(outView);
  26 }
  27
  28 void TextEncoder::EncodeInto(JSContext* aCx, JS::Handle<JSString*> aSrc,
  29                              const Uint8Array& aDst,
  30                              TextEncoderEncodeIntoResult& aResult,
  31                              OOMReporter& aError) {
  32   DebugOnly<size_t> dstLength = 0;
  33   auto maybe = aDst.ProcessData(
  34       [&](const Span<uint8_t>& aData, JS::AutoCheckCannotGC&&) {
  35         dstLength = aData.Length();
  36         return JS_EncodeStringToUTF8BufferPartial(aCx, aSrc,
  37                                                   AsWritableChars(aData));
  38       });
  39   if (!maybe) {
  40     aError.ReportOOM();
  41     return;
  42   }
  43   size_t read;
  44   size_t written;
  45   std::tie(read, written) = *maybe;
  46   MOZ_ASSERT(written <= dstLength);
  47   aResult.mRead.Construct() = read;
  48   aResult.mWritten.Construct() = written;
  49 }
  50
  51 void TextEncoder::GetEncoding(nsACString& aEncoding) {
  52   aEncoding.AssignLiteral("utf-8");
  53 }
  54
  55 }  // namespace mozilla::dom