gecko-dev/xpcom/string/nsTSubstringTuple.cpp

97 строки
2.6 KiB
C++

/* -*- 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/CheckedInt.h"
/**
* computes the aggregate string length
*/
nsTSubstringTuple_CharT::size_type
nsTSubstringTuple_CharT::Length() const
{
mozilla::CheckedInt<size_type> len;
if (mHead) {
len = mHead->Length();
} else {
len = TO_SUBSTRING(mFragA).Length();
}
len += TO_SUBSTRING(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.
*/
void
nsTSubstringTuple_CharT::WriteTo(char_type* aBuf, uint32_t aBufLen) const
{
const substring_type& b = TO_SUBSTRING(mFragB);
MOZ_RELEASE_ASSERT(aBufLen >= b.Length(), "buffer too small");
uint32_t headLen = aBufLen - b.Length();
if (mHead) {
mHead->WriteTo(aBuf, headLen);
} else {
const substring_type& a = TO_SUBSTRING(mFragA);
MOZ_RELEASE_ASSERT(a.Length() == headLen, "buffer incorrectly sized");
char_traits::copy(aBuf, a.Data(), a.Length());
}
char_traits::copy(aBuf + headLen, b.Data(), b.Length());
#if 0
// we need to write out data into |aBuf|, ending at |aBuf + aBufLen|. So our
// data needs to precede |aBuf + aBufLen| exactly. We trust that the buffer
// was properly sized!
const substring_type& b = TO_SUBSTRING(mFragB);
NS_ASSERTION(aBufLen >= b.Length(), "buffer is too small");
char_traits::copy(aBuf + aBufLen - b.Length(), b.Data(), b.Length());
aBufLen -= b.Length();
if (mHead) {
mHead->WriteTo(aBuf, aBufLen);
} else {
const substring_type& a = TO_SUBSTRING(mFragA);
NS_ASSERTION(aBufLen == a.Length(), "buffer is too small");
char_traits::copy(aBuf, a.Data(), a.Length());
}
#endif
}
/**
* returns true if this tuple is dependent on (i.e., overlapping with)
* the given char sequence.
*/
bool
nsTSubstringTuple_CharT::IsDependentOn(const char_type* aStart,
const char_type* aEnd) const
{
// we aStart with the right-most fragment since it is faster to check.
if (TO_SUBSTRING(mFragB).IsDependentOn(aStart, aEnd)) {
return true;
}
if (mHead) {
return mHead->IsDependentOn(aStart, aEnd);
}
return TO_SUBSTRING(mFragA).IsDependentOn(aStart, aEnd);
}