gecko-dev/dom/encoding/TextEncoder.cpp

101 lines
2.8 KiB
C++

/* 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/dom/EncodingUtils.h"
#include "nsContentUtils.h"
namespace mozilla {
namespace dom {
void
TextEncoder::Init(const nsAString& aEncoding, ErrorResult& aRv)
{
nsAutoString label(aEncoding);
EncodingUtils::TrimSpaceCharacters(label);
// Let encoding be the result of getting an encoding from label.
// If encoding is failure, or is none of utf-8, utf-16, and utf-16be,
// throw a TypeError.
if (!EncodingUtils::FindEncodingForLabel(label, mEncoding)) {
aRv.ThrowTypeError(MSG_ENCODING_NOT_SUPPORTED, &label);
return;
}
if (!mEncoding.EqualsLiteral("UTF-8") &&
!mEncoding.EqualsLiteral("UTF-16LE") &&
!mEncoding.EqualsLiteral("UTF-16BE")) {
aRv.ThrowTypeError(MSG_DOM_ENCODING_NOT_UTF);
return;
}
// Create an encoder object for mEncoding.
mEncoder = EncodingUtils::EncoderForEncoding(mEncoding);
}
JSObject*
TextEncoder::Encode(JSContext* aCx,
JS::Handle<JSObject*> aObj,
const nsAString& aString,
const bool aStream,
ErrorResult& aRv)
{
// Run the steps of the encoding algorithm.
int32_t srcLen = aString.Length();
int32_t maxLen;
const PRUnichar* data = PromiseFlatString(aString).get();
nsresult rv = mEncoder->GetMaxLength(data, srcLen, &maxLen);
if (NS_FAILED(rv)) {
aRv.Throw(rv);
return nullptr;
}
// Need a fallible allocator because the caller may be a content
// and the content can specify the length of the string.
static const fallible_t fallible = fallible_t();
nsAutoArrayPtr<char> buf(new (fallible) char[maxLen + 1]);
if (!buf) {
aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
return nullptr;
}
int32_t dstLen = maxLen;
rv = mEncoder->Convert(data, &srcLen, buf, &dstLen);
// If the internal streaming flag is not set, then reset
// the encoding algorithm state to the default values for encoding.
if (!aStream) {
int32_t finishLen = maxLen - dstLen;
rv = mEncoder->Finish(buf + dstLen, &finishLen);
if (NS_SUCCEEDED(rv)) {
dstLen += finishLen;
}
}
JSObject* outView = nullptr;
if (NS_SUCCEEDED(rv)) {
buf[dstLen] = '\0';
outView = Uint8Array::Create(aCx, aObj, dstLen,
reinterpret_cast<uint8_t*>(buf.get()));
if (!outView) {
aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
return nullptr;
}
}
if (NS_FAILED(rv)) {
aRv.Throw(rv);
}
return outView;
}
void
TextEncoder::GetEncoding(nsAString& aEncoding)
{
CopyASCIItoUTF16(mEncoding, aEncoding);
nsContentUtils::ASCIIToLower(aEncoding);
}
} // dom
} // mozilla