/* -*- 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/. */
// We can compute the length without replacement, because the // the replacement is only one byte long and a mappable character // would always output something, i.e. at least one byte. // When encoding to ISO-2022-JP, unmappables shouldn't be able // to cause more escape sequences to be emitted than the mappable // worst case where every input character causes an escape into // a different state.
CheckedInt<size_t> needed =
mEncoder->MaxBufferLengthFromUTF16WithoutReplacement(aSrc.Length()); if (!needed.isValid() || needed.value() > UINT32_MAX) { return NS_ERROR_OUT_OF_MEMORY;
}
auto dstChars = _retval.GetMutableData(needed.value(), fallible); if (!dstChars) { return NS_ERROR_OUT_OF_MEMORY;
}
auto src = Span(aSrc); auto dst = AsWritableBytes(*dstChars);
size_t totalWritten = 0; for (;;) { auto [result, read, written] =
mEncoder->EncodeFromUTF16WithoutReplacement(src, dst, false); if (result != kInputEmpty && result != kOutputFull) {
MOZ_RELEASE_ASSERT(written < dst.Length(), "Unmappables with one-byte replacement should not " "exceed mappable worst case.");
dst[written++] = '?';
}
totalWritten += written; if (result == kInputEmpty) {
MOZ_ASSERT(totalWritten <= UINT32_MAX); if (!_retval.SetLength(totalWritten, fallible)) { return NS_ERROR_OUT_OF_MEMORY;
} return NS_OK;
}
src = src.From(read);
dst = dst.From(written);
}
}
NS_IMETHODIMP
nsScriptableUnicodeConverter::Finish(nsACString& _retval) { // The documentation for this method says it should be called after // ConvertFromUnicode(). However, our own tests called it after // convertFromByteArray(), i.e. when *decoding*. // Assuming that there exists extensions that similarly call // this at the wrong time, let's deal. In general, it is a design // error for this class to handle conversions in both directions. if (!mEncoder) {
_retval.Truncate();
mDecoder->Encoding()->NewDecoderWithBOMRemovalInto(*mDecoder); return NS_OK;
} // If we are encoding to ISO-2022-JP, potentially // transition back to the ASCII state. The buffer // needs to be large enough for an additional NCR, // though.
_retval.SetLength(13); auto dst = AsWritableBytes(_retval.GetMutableData(13));
Span<char16_t> src(nullptr);
uint32_t result;
size_t read;
size_t written;
std::tie(result, read, written, std::ignore) =
mEncoder->EncodeFromUTF16(src, dst, true);
MOZ_ASSERT(!read);
MOZ_ASSERT(result == kInputEmpty);
_retval.SetLength(written);
auto dst = _retval.GetMutableData(needed.value(), fallible); if (!dst) { return NS_ERROR_OUT_OF_MEMORY;
}
auto src =
Span(reinterpret_cast<const uint8_t*>(aSrc.BeginReading()), length);
uint32_t result;
size_t read;
size_t written; // The UTF-8 decoder used to throw regardless of the error behavior. // Simulating the old behavior for compatibility with legacy callers. // If callers want control over the behavior, they should switch to // TextDecoder. if (mDecoder->Encoding() == UTF_8_ENCODING) {
std::tie(result, read, written) =
mDecoder->DecodeToUTF16WithoutReplacement(src, *dst, false); if (result != kInputEmpty) { return NS_ERROR_UDEC_ILLEGALINPUT;
}
} else {
std::tie(result, read, written, std::ignore) =
mDecoder->DecodeToUTF16(src, *dst, false);
}
MOZ_ASSERT(result == kInputEmpty);
MOZ_ASSERT(read == length);
MOZ_ASSERT(written <= needed.value()); if (!_retval.SetLength(written, fallible)) { return NS_ERROR_OUT_OF_MEMORY;
} return NS_OK;
}
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