/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

/* 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 RangeError (https://encoding.spec.whatwg.org/#dom-textencoder).

if (!EncodingUtils::FindEncodingForLabel(label, mEncoding)) {

aRv.ThrowRangeError(MSG_ENCODING_NOT_SUPPORTED, &label);

return;

}

if (!mEncoding.EqualsLiteral("UTF-8") &&

!mEncoding.EqualsLiteral("UTF-16LE") &&

!mEncoding.EqualsLiteral("UTF-16BE")) {

aRv.ThrowRangeError(MSG_DOM_ENCODING_NOT_UTF);

return;

}

// Create an encoder object for mEncoding.

mEncoder = EncodingUtils::EncoderForEncoding(mEncoding);

}

void

TextEncoder::Encode(JSContext* aCx,

JS::Handle<JSObject*> aObj,

const nsAString& aString,

JS::MutableHandle<JSObject*> aRetval,

ErrorResult& aRv)

{

// Run the steps of the encoding algorithm.

int32_t srcLen = aString.Length();

int32_t maxLen;

const char16_t* data = PromiseFlatString(aString).get();

nsresult rv = mEncoder->GetMaxLength(data, srcLen, &maxLen);

if (NS_FAILED(rv)) {

aRv.Throw(rv);

return;

}

// Need a fallible allocator because the caller may be a content

// and the content can specify the length of the string.

nsAutoArrayPtr<char> buf(new (fallible) char[maxLen + 1]);

if (!buf) {

aRv.Throw(NS_ERROR_OUT_OF_MEMORY);

return;

}

int32_t dstLen = maxLen;

rv = mEncoder->Convert(data, &srcLen, buf, &dstLen);

// Now reset the encoding algorithm state to the default values for encoding.

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';

JSAutoCompartment ac(aCx, aObj);

outView = Uint8Array::Create(aCx, dstLen,

reinterpret_cast<uint8_t*>(buf.get()));

if (!outView) {

aRv.Throw(NS_ERROR_OUT_OF_MEMORY);

return;

}

}

if (NS_FAILED(rv)) {

aRv.Throw(rv);

}

aRetval.set(outView);

}

void

TextEncoder::GetEncoding(nsAString& aEncoding)

{

CopyASCIItoUTF16(mEncoding, aEncoding);

nsContentUtils::ASCIIToLower(aEncoding);

}

} // dom

} // mozilla