gecko-dev/dom/encoding/TextEncoder.cpp

82 строки
2.5 KiB
C++

/* -*- 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/. */
#include "mozilla/dom/TextEncoder.h"
#include "mozilla/CheckedInt.h"
#include "mozilla/UniquePtrExtensions.h"
#include "nsReadableUtils.h"
namespace mozilla {
namespace dom {
void TextEncoder::Encode(JSContext* aCx, JS::Handle<JSObject*> aObj,
JS::Handle<JSString*> aString,
JS::MutableHandle<JSObject*> aRetval,
ErrorResult& aRv) {
CheckedInt<size_t> bufLen(JS::GetStringLength(aString));
bufLen *= 3; // from the contract for JS_EncodeStringToUTF8BufferPartial
// Uint8Array::Create takes uint32_t as the length.
if (!bufLen.isValid() || bufLen.value() > UINT32_MAX) {
aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
return;
}
// TODO: Avoid malloc and use a stack-allocated buffer if bufLen
// is small.
auto data = mozilla::MakeUniqueFallible<uint8_t[]>(bufLen.value());
if (!data) {
aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
return;
}
size_t read;
size_t written;
auto maybe = JS_EncodeStringToUTF8BufferPartial(
aCx, aString, AsWritableChars(MakeSpan(data.get(), bufLen.value())));
if (!maybe) {
aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
return;
}
Tie(read, written) = *maybe;
MOZ_ASSERT(written <= bufLen.value());
MOZ_ASSERT(read == JS::GetStringLength(aString));
JSAutoRealm ar(aCx, aObj);
JSObject* outView = Uint8Array::Create(aCx, written, data.get());
if (!outView) {
aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
return;
}
aRetval.set(outView);
}
void TextEncoder::EncodeInto(JSContext* aCx, JS::Handle<JSString*> aSrc,
const Uint8Array& aDst,
TextEncoderEncodeIntoResult& aResult,
OOMReporter& aError) {
aDst.ComputeLengthAndData();
size_t read;
size_t written;
auto maybe = JS_EncodeStringToUTF8BufferPartial(
aCx, aSrc, AsWritableChars(MakeSpan(aDst.Data(), aDst.Length())));
if (!maybe) {
aError.ReportOOM();
return;
}
Tie(read, written) = *maybe;
MOZ_ASSERT(written <= aDst.Length());
aResult.mRead.Construct() = read;
aResult.mWritten.Construct() = written;
}
void TextEncoder::GetEncoding(nsACString& aEncoding) {
aEncoding.AssignLiteral("utf-8");
}
} // namespace dom
} // namespace mozilla