pjs/xpcom/ds/nsSlidingString.cpp

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Executable File

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/*
* The contents of this file are subject to the Mozilla Public
* License Version 1.1 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of
* the License at http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS
* IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
* implied. See the License for the specific language governing
* rights and limitations under the License.
*
* The Original Code is Mozilla strings.
*
* The Initial Developer of the Original Code is Netscape
* Communications Corporation. Portions created by Netscape are
* Copyright (C) 2000 Netscape Communications Corporation. All
* Rights Reserved.
*
* Contributor(s):
* Scott Collins <scc@mozilla.org> (original author)
*
*/
#include "nsSlidingString.h"
void
nsSlidingSharedBufferList::DiscardUnreferencedPrefix( Buffer* aRecentlyReleasedBuffer )
{
if ( aRecentlyReleasedBuffer == mFirstBuffer )
{
while ( mFirstBuffer && !mFirstBuffer->IsReferenced() )
delete UnlinkBuffer(mFirstBuffer);
}
}
ptrdiff_t Distance( const nsSharedBufferList::Position&, const nsSharedBufferList::Position& );
ptrdiff_t
Distance( const nsSharedBufferList::Position& aStart, const nsSharedBufferList::Position& aEnd )
{
ptrdiff_t result = 0;
if ( aStart.mBuffer == aEnd.mBuffer )
result = aEnd.mPosInBuffer - aStart.mPosInBuffer;
else
{
result = aStart.mBuffer->DataEnd() - aStart.mPosInBuffer;
for ( nsSharedBufferList::Buffer* b = aStart.mBuffer->mNext; b != aEnd.mBuffer; b = b->mNext )
result += b->DataLength();
result += aEnd.mPosInBuffer - aEnd.mBuffer->DataStart();
}
return result;
}
nsSlidingSubstring::nsSlidingSubstring( const nsSlidingSubstring& aString )
: mStart(aString.mStart),
mEnd(aString.mEnd),
mBufferList(aString.mBufferList),
mLength(aString.mLength)
{
mBufferList.AcquireReference();
mStart.mBuffer->AcquireReference();
}
nsSlidingSubstring::nsSlidingSubstring( const nsSlidingSubstring& aString, const nsReadingIterator<PRUnichar>& aStart, const nsReadingIterator<PRUnichar>& aEnd )
: mStart(aStart),
mEnd(aEnd),
mBufferList(aString.mBufferList),
mLength(PRUint32(Distance(mStart, mEnd)))
{
mBufferList.AcquireReference();
mStart.mBuffer->AcquireReference();
}
nsSlidingSubstring::nsSlidingSubstring( nsSlidingSharedBufferList& aBufferList )
: mBufferList(aBufferList)
{
mBufferList.AcquireReference();
mStart.PointBefore(mBufferList.GetFirstBuffer());
mStart.mBuffer->AcquireReference();
mEnd.PointAfter(mBufferList.GetLastBuffer());
mLength = PRUint32(Distance(mStart, mEnd));
}
nsSlidingSubstring::~nsSlidingSubstring()
{
mStart.mBuffer->ReleaseReference();
mBufferList.DiscardUnreferencedPrefix(mStart.mBuffer);
mBufferList.ReleaseReference();
}
const PRUnichar*
nsSlidingSubstring::GetReadableFragment( nsReadableFragment<PRUnichar>& aFragment, nsFragmentRequest aRequest, PRUint32 aOffset ) const
{
const Buffer* result_buffer = 0;
switch ( aRequest )
{
case kPrevFragment:
{
const Buffer* current_buffer = NS_STATIC_CAST(const Buffer*, aFragment.mFragmentIdentifier);
if ( current_buffer != mStart.mBuffer )
result_buffer = current_buffer->mPrev;
}
break;
case kFirstFragment:
result_buffer = mStart.mBuffer;
break;
case kLastFragment:
result_buffer = mEnd.mBuffer;
break;
case kNextFragment:
{
const Buffer* current_buffer = NS_STATIC_CAST(const Buffer*, aFragment.mFragmentIdentifier);
if ( current_buffer != mEnd.mBuffer )
result_buffer = current_buffer->mNext;
}
break;
case kFragmentAt:
// ...work...
break;
}
if ( result_buffer )
{
if ( result_buffer == mStart.mBuffer )
aFragment.mStart = mStart.mPosInBuffer;
else
aFragment.mStart = result_buffer->DataStart();
if ( result_buffer == mEnd.mBuffer )
aFragment.mEnd = mEnd.mPosInBuffer;
else
aFragment.mEnd = result_buffer->DataEnd();
aFragment.mFragmentIdentifier = result_buffer;
return aFragment.mStart + aOffset;
}
return 0;
}
nsSlidingString::nsSlidingString( PRUnichar* aStorageStart, PRUnichar* aDataEnd, PRUnichar* aStorageEnd )
: nsSlidingSubstring(*(new nsSlidingSharedBufferList(nsSlidingSharedBufferList::NewWrappingBuffer(aStorageStart, aDataEnd, aStorageEnd))))
{
// nothing else to do here
}
void
nsSlidingString::AppendBuffer( PRUnichar* aStorageStart, PRUnichar* aDataEnd, PRUnichar* aStorageEnd )
{
Buffer* new_buffer = new Buffer(aStorageStart, aDataEnd, aStorageStart, aStorageEnd);
Buffer* old_last_buffer = mBufferList.GetLastBuffer();
mBufferList.LinkBuffer(old_last_buffer, new_buffer, 0);
mLength += new_buffer->DataLength();
mEnd.PointAfter(new_buffer);
}
void
nsSlidingString::DiscardPrefix( const nsReadingIterator<PRUnichar>& aIter )
{
Position old_start(mStart);
mStart = aIter;
mLength -= Distance(old_start, mStart);
mStart.mBuffer->AcquireReference();
old_start.mBuffer->ReleaseReference();
mBufferList.DiscardUnreferencedPrefix(old_start.mBuffer);
}