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/* -*- 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 "nsTSubstringTuple.h"
#include "mozilla/CheckedInt.h"
/**
* computes the aggregate string length
*/
template <typename T>
typename nsTSubstringTuple<T>::size_type nsTSubstringTuple<T>::Length() const {
mozilla::CheckedInt<size_type> len;
if (mHead) {
len = mHead->Length();
} else {
len = mFragA->Length();
}
len += mFragB->Length();
MOZ_RELEASE_ASSERT(len.isValid(), "Substring tuple length is invalid");
return len.value();
}
/**
* writes the aggregate string to the given buffer. aBufLen is assumed
* to be equal to or greater than the value returned by the Length()
* method. the string written to |aBuf| is not null-terminated.
*/
template <typename T>
void nsTSubstringTuple<T>::WriteTo(char_type* aBuf, uint32_t aBufLen) const {
MOZ_RELEASE_ASSERT(aBufLen >= mFragB->Length(), "buffer too small");
uint32_t headLen = aBufLen - mFragB->Length();
if (mHead) {
mHead->WriteTo(aBuf, headLen);
} else {
MOZ_RELEASE_ASSERT(mFragA->Length() == headLen, "buffer incorrectly sized");
char_traits::copy(aBuf, mFragA->Data(), mFragA->Length());
}
char_traits::copy(aBuf + headLen, mFragB->Data(), mFragB->Length());
}
/**
* returns true if this tuple is dependent on (i.e., overlapping with)
* the given char sequence.
*/
template <typename T>
bool nsTSubstringTuple<T>::IsDependentOn(const char_type* aStart,
const char_type* aEnd) const {
// we start with the right-most fragment since it is faster to check.
if (mFragB->IsDependentOn(aStart, aEnd)) {
return true;
}
if (mHead) {
return mHead->IsDependentOn(aStart, aEnd);
}
return mFragA->IsDependentOn(aStart, aEnd);
}
template <typename T>
auto nsTSubstringTuple<T>::IsDependentOnWithLength(const char_type* aStart,
const char_type* aEnd) const
-> std::pair<bool, size_type> {
// we start with the right-most fragment since it is faster to check for
// dependency.
const bool rightDependentOn = mFragB->IsDependentOn(aStart, aEnd);
if (rightDependentOn) {
return {true, Length()};
}
const auto [leftDependentOn, leftLen] =
mHead ? mHead->IsDependentOnWithLength(aStart, aEnd)
: std::pair{mFragA->IsDependentOn(aStart, aEnd), mFragA->Length()};
const auto checkedLen =
mozilla::CheckedInt<size_type>{leftLen} + mFragB->Length();
MOZ_RELEASE_ASSERT(checkedLen.isValid(), "Substring tuple length is invalid");
return {leftDependentOn, checkedLen.value()};
}
template class nsTSubstringTuple<char>;
template class nsTSubstringTuple<char16_t>;