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-rw-r--r--dom/encoding/TextDecoder.cpp147
1 files changed, 147 insertions, 0 deletions
diff --git a/dom/encoding/TextDecoder.cpp b/dom/encoding/TextDecoder.cpp
new file mode 100644
index 000000000..24f7ec166
--- /dev/null
+++ b/dom/encoding/TextDecoder.cpp
@@ -0,0 +1,147 @@
+/* -*- 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/TextDecoder.h"
+#include "mozilla/dom/EncodingUtils.h"
+#include "mozilla/dom/UnionTypes.h"
+#include "mozilla/UniquePtrExtensions.h"
+#include "nsContentUtils.h"
+#include <stdint.h>
+
+namespace mozilla {
+namespace dom {
+
+static const char16_t kReplacementChar = static_cast<char16_t>(0xFFFD);
+
+void
+TextDecoder::Init(const nsAString& aLabel, const bool aFatal,
+ ErrorResult& aRv)
+{
+ nsAutoCString encoding;
+ // Let encoding be the result of getting an encoding from label.
+ // If encoding is failure or replacement, throw a RangeError
+ // (https://encoding.spec.whatwg.org/#dom-textdecoder).
+ if (!EncodingUtils::FindEncodingForLabelNoReplacement(aLabel, encoding)) {
+ nsAutoString label(aLabel);
+ EncodingUtils::TrimSpaceCharacters(label);
+ aRv.ThrowRangeError<MSG_ENCODING_NOT_SUPPORTED>(label);
+ return;
+ }
+ InitWithEncoding(encoding, aFatal);
+}
+
+void
+TextDecoder::InitWithEncoding(const nsACString& aEncoding, const bool aFatal)
+{
+ mEncoding = aEncoding;
+ // If the constructor is called with an options argument,
+ // and the fatal property of the dictionary is set,
+ // set the internal fatal flag of the decoder object.
+ mFatal = aFatal;
+
+ // Create a decoder object for mEncoding.
+ mDecoder = EncodingUtils::DecoderForEncoding(mEncoding);
+
+ if (mFatal) {
+ mDecoder->SetInputErrorBehavior(nsIUnicodeDecoder::kOnError_Signal);
+ }
+}
+
+void
+TextDecoder::Decode(const char* aInput, const int32_t aLength,
+ const bool aStream, nsAString& aOutDecodedString,
+ ErrorResult& aRv)
+{
+ aOutDecodedString.Truncate();
+
+ // Run or resume the decoder algorithm of the decoder object's encoder.
+ int32_t outLen;
+ nsresult rv = mDecoder->GetMaxLength(aInput, aLength, &outLen);
+ 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.
+ auto buf = MakeUniqueFallible<char16_t[]>(outLen + 1);
+ if (!buf) {
+ aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
+ return;
+ }
+
+ int32_t length = aLength;
+ rv = mDecoder->Convert(aInput, &length, buf.get(), &outLen);
+ MOZ_ASSERT(mFatal || rv != NS_ERROR_ILLEGAL_INPUT);
+ buf[outLen] = 0;
+
+ if (!aOutDecodedString.Append(buf.get(), outLen, fallible)) {
+ aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
+ return;
+ }
+
+ // If the internal streaming flag of the decoder object is not set,
+ // then reset the encoding algorithm state to the default values
+ if (!aStream) {
+ mDecoder->Reset();
+ if (rv == NS_OK_UDEC_MOREINPUT) {
+ if (mFatal) {
+ aRv.ThrowTypeError<MSG_DOM_DECODING_FAILED>();
+ } else {
+ // Need to emit a decode error manually
+ // to simulate the EOF handling of the Encoding spec.
+ aOutDecodedString.Append(kReplacementChar);
+ }
+ }
+ }
+
+ if (NS_FAILED(rv)) {
+ aRv.ThrowTypeError<MSG_DOM_DECODING_FAILED>();
+ }
+}
+
+void
+TextDecoder::Decode(const Optional<ArrayBufferViewOrArrayBuffer>& aBuffer,
+ const TextDecodeOptions& aOptions,
+ nsAString& aOutDecodedString,
+ ErrorResult& aRv)
+{
+ if (!aBuffer.WasPassed()) {
+ Decode(nullptr, 0, aOptions.mStream, aOutDecodedString, aRv);
+ return;
+ }
+ const ArrayBufferViewOrArrayBuffer& buf = aBuffer.Value();
+ uint8_t* data;
+ uint32_t length;
+ if (buf.IsArrayBufferView()) {
+ buf.GetAsArrayBufferView().ComputeLengthAndData();
+ data = buf.GetAsArrayBufferView().Data();
+ length = buf.GetAsArrayBufferView().Length();
+ } else {
+ MOZ_ASSERT(buf.IsArrayBuffer());
+ buf.GetAsArrayBuffer().ComputeLengthAndData();
+ data = buf.GetAsArrayBuffer().Data();
+ length = buf.GetAsArrayBuffer().Length();
+ }
+ // The other Decode signature takes a signed int, because that's
+ // what nsIUnicodeDecoder::Convert takes as the length. Throw if
+ // our length is too big.
+ if (length > INT32_MAX) {
+ aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
+ return;
+ }
+ Decode(reinterpret_cast<char*>(data), length, aOptions.mStream,
+ aOutDecodedString, aRv);
+}
+
+void
+TextDecoder::GetEncoding(nsAString& aEncoding)
+{
+ CopyASCIItoUTF16(mEncoding, aEncoding);
+ nsContentUtils::ASCIIToLower(aEncoding);
+}
+
+} // namespace dom
+} // namespace mozilla