root/Source/platform/text/SegmentedString.cpp

DEFINITIONS

1. length
2. setExcludeLineNumbers
3. clear
4. append
5. prepend
6. close
7. append
8. prepend
9. advanceSubstring
10. toString
11. advance
12. advance8
13. advance16
14. advanceAndUpdateLineNumber8
15. advanceAndUpdateLineNumber16
16. advanceSlowCase
17. advanceAndUpdateLineNumberSlowCase
18. advanceEmpty
19. updateSlowCaseFunctionPointers
20. currentLine
21. currentColumn
22. setCurrentPosition

/*
    Copyright (C) 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License as published by the Free Software Foundation; either
    version 2 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Library General Public License for more details.

    You should have received a copy of the GNU Library General Public License
    along with this library; see the file COPYING.LIB.  If not, write to
    the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
    Boston, MA 02110-1301, USA.
*/

#include "config.h"
#include "platform/text/SegmentedString.h"

namespace WebCore {

unsigned SegmentedString::length() const
{
    unsigned length = m_currentString.m_length;
    if (m_pushedChar1) {
        ++length;
        if (m_pushedChar2)
            ++length;
    }
    if (isComposite()) {
        Deque<SegmentedSubstring>::const_iterator it = m_substrings.begin();
        Deque<SegmentedSubstring>::const_iterator e = m_substrings.end();
        for (; it != e; ++it)
            length += it->m_length;
    }
    return length;
}

void SegmentedString::setExcludeLineNumbers()
{
    m_currentString.setExcludeLineNumbers();
    if (isComposite()) {
        Deque<SegmentedSubstring>::iterator it = m_substrings.begin();
        Deque<SegmentedSubstring>::iterator e = m_substrings.end();
        for (; it != e; ++it)
            it->setExcludeLineNumbers();
    }
}

void SegmentedString::clear()
{
    m_pushedChar1 = 0;
    m_pushedChar2 = 0;
    m_currentChar = 0;
    m_currentString.clear();
    m_numberOfCharactersConsumedPriorToCurrentString = 0;
    m_numberOfCharactersConsumedPriorToCurrentLine = 0;
    m_currentLine = 0;
    m_substrings.clear();
    m_closed = false;
    m_empty = true;
    m_fastPathFlags = NoFastPath;
    m_advanceFunc = &SegmentedString::advanceEmpty;
    m_advanceAndUpdateLineNumberFunc = &SegmentedString::advanceEmpty;
}

void SegmentedString::append(const SegmentedSubstring& s)
{
    ASSERT(!m_closed);
    if (!s.m_length)
        return;

    if (!m_currentString.m_length) {
        m_numberOfCharactersConsumedPriorToCurrentString += m_currentString.numberOfCharactersConsumed();
        m_currentString = s;
        updateAdvanceFunctionPointers();
    } else {
        m_substrings.append(s);
    }
    m_empty = false;
}

void SegmentedString::prepend(const SegmentedSubstring& s)
{
    ASSERT(!escaped());
    ASSERT(!s.numberOfCharactersConsumed());
    if (!s.m_length)
        return;

    // FIXME: We're assuming that the prepend were originally consumed by
    //        this SegmentedString. We're also ASSERTing that s is a fresh
    //        SegmentedSubstring. These assumptions are sufficient for our
    //        current use, but we might need to handle the more elaborate
    //        cases in the future.
    m_numberOfCharactersConsumedPriorToCurrentString += m_currentString.numberOfCharactersConsumed();
    m_numberOfCharactersConsumedPriorToCurrentString -= s.m_length;
    if (!m_currentString.m_length) {
        m_currentString = s;
        updateAdvanceFunctionPointers();
    } else {
        // Shift our m_currentString into our list.
        m_substrings.prepend(m_currentString);
        m_currentString = s;
        updateAdvanceFunctionPointers();
    }
    m_empty = false;
}

void SegmentedString::close()
{
    // Closing a stream twice is likely a coding mistake.
    ASSERT(!m_closed);
    m_closed = true;
}

void SegmentedString::append(const SegmentedString& s)
{
    ASSERT(!m_closed);
    ASSERT(!s.escaped());
    append(s.m_currentString);
    if (s.isComposite()) {
        Deque<SegmentedSubstring>::const_iterator it = s.m_substrings.begin();
        Deque<SegmentedSubstring>::const_iterator e = s.m_substrings.end();
        for (; it != e; ++it)
            append(*it);
    }
    m_currentChar = m_pushedChar1 ? m_pushedChar1 : (m_currentString.m_length ? m_currentString.getCurrentChar() : 0);
}

void SegmentedString::prepend(const SegmentedString& s)
{
    ASSERT(!escaped());
    ASSERT(!s.escaped());
    if (s.isComposite()) {
        Deque<SegmentedSubstring>::const_reverse_iterator it = s.m_substrings.rbegin();
        Deque<SegmentedSubstring>::const_reverse_iterator e = s.m_substrings.rend();
        for (; it != e; ++it)
            prepend(*it);
    }
    prepend(s.m_currentString);
    m_currentChar = m_pushedChar1 ? m_pushedChar1 : (m_currentString.m_length ? m_currentString.getCurrentChar() : 0);
}

void SegmentedString::advanceSubstring()
{
    if (isComposite()) {
        m_numberOfCharactersConsumedPriorToCurrentString += m_currentString.numberOfCharactersConsumed();
        m_currentString = m_substrings.takeFirst();
        // If we've previously consumed some characters of the non-current
        // string, we now account for those characters as part of the current
        // string, not as part of "prior to current string."
        m_numberOfCharactersConsumedPriorToCurrentString -= m_currentString.numberOfCharactersConsumed();
        updateAdvanceFunctionPointers();
    } else {
        m_currentString.clear();
        m_empty = true;
        m_fastPathFlags = NoFastPath;
        m_advanceFunc = &SegmentedString::advanceEmpty;
        m_advanceAndUpdateLineNumberFunc = &SegmentedString::advanceEmpty;
    }
}

String SegmentedString::toString() const
{
    StringBuilder result;
    if (m_pushedChar1) {
        result.append(m_pushedChar1);
        if (m_pushedChar2)
            result.append(m_pushedChar2);
    }
    m_currentString.appendTo(result);
    if (isComposite()) {
        Deque<SegmentedSubstring>::const_iterator it = m_substrings.begin();
        Deque<SegmentedSubstring>::const_iterator e = m_substrings.end();
        for (; it != e; ++it)
            it->appendTo(result);
    }
    return result.toString();
}

void SegmentedString::advance(unsigned count, UChar* consumedCharacters)
{
    ASSERT_WITH_SECURITY_IMPLICATION(count <= length());
    for (unsigned i = 0; i < count; ++i) {
        consumedCharacters[i] = currentChar();
        advance();
    }
}

void SegmentedString::advance8()
{
    ASSERT(!m_pushedChar1);
    decrementAndCheckLength();
    m_currentChar = m_currentString.incrementAndGetCurrentChar8();
}

void SegmentedString::advance16()
{
    ASSERT(!m_pushedChar1);
    decrementAndCheckLength();
    m_currentChar = m_currentString.incrementAndGetCurrentChar16();
}

void SegmentedString::advanceAndUpdateLineNumber8()
{
    ASSERT(!m_pushedChar1);
    ASSERT(m_currentString.getCurrentChar() == m_currentChar);
    if (m_currentChar == '\n') {
        ++m_currentLine;
        m_numberOfCharactersConsumedPriorToCurrentLine = numberOfCharactersConsumed() + 1;
    }
    decrementAndCheckLength();
    m_currentChar = m_currentString.incrementAndGetCurrentChar8();
}

void SegmentedString::advanceAndUpdateLineNumber16()
{
    ASSERT(!m_pushedChar1);
    ASSERT(m_currentString.getCurrentChar() == m_currentChar);
    if (m_currentChar == '\n') {
        ++m_currentLine;
        m_numberOfCharactersConsumedPriorToCurrentLine = numberOfCharactersConsumed() + 1;
    }
    decrementAndCheckLength();
    m_currentChar = m_currentString.incrementAndGetCurrentChar16();
}

void SegmentedString::advanceSlowCase()
{
    if (m_pushedChar1) {
        m_pushedChar1 = m_pushedChar2;
        m_pushedChar2 = 0;

        if (m_pushedChar1) {
            m_currentChar = m_pushedChar1;
            return;
        }

        updateAdvanceFunctionPointers();
    } else if (m_currentString.m_length) {
        if (!--m_currentString.m_length)
            advanceSubstring();
    } else if (!isComposite()) {
        m_currentString.clear();
        m_empty = true;
        m_fastPathFlags = NoFastPath;
        m_advanceFunc = &SegmentedString::advanceEmpty;
        m_advanceAndUpdateLineNumberFunc = &SegmentedString::advanceEmpty;
    }
    m_currentChar = m_currentString.m_length ? m_currentString.getCurrentChar() : 0;
}

void SegmentedString::advanceAndUpdateLineNumberSlowCase()
{
    if (m_pushedChar1) {
        m_pushedChar1 = m_pushedChar2;
        m_pushedChar2 = 0;

        if (m_pushedChar1) {
            m_currentChar = m_pushedChar1;
            return;
        }

        updateAdvanceFunctionPointers();
    } else if (m_currentString.m_length) {
        if (m_currentString.getCurrentChar() == '\n' && m_currentString.doNotExcludeLineNumbers()) {
            ++m_currentLine;
            // Plus 1 because numberOfCharactersConsumed value hasn't incremented yet; it does with m_length decrement below.
            m_numberOfCharactersConsumedPriorToCurrentLine = numberOfCharactersConsumed() + 1;
        }
        if (!--m_currentString.m_length)
            advanceSubstring();
        else
            m_currentString.incrementAndGetCurrentChar(); // Only need the ++
    } else if (!isComposite()) {
        m_currentString.clear();
        m_empty = true;
        m_fastPathFlags = NoFastPath;
        m_advanceFunc = &SegmentedString::advanceEmpty;
        m_advanceAndUpdateLineNumberFunc = &SegmentedString::advanceEmpty;
    }

    m_currentChar = m_currentString.m_length ? m_currentString.getCurrentChar() : 0;
}

void SegmentedString::advanceEmpty()
{
    ASSERT(!m_currentString.m_length && !isComposite());
    m_currentChar = 0;
}

void SegmentedString::updateSlowCaseFunctionPointers()
{
    m_fastPathFlags = NoFastPath;
    m_advanceFunc = &SegmentedString::advanceSlowCase;
    m_advanceAndUpdateLineNumberFunc = &SegmentedString::advanceAndUpdateLineNumberSlowCase;
}

OrdinalNumber SegmentedString::currentLine() const
{
    return OrdinalNumber::fromZeroBasedInt(m_currentLine);
}

OrdinalNumber SegmentedString::currentColumn() const
{
    int zeroBasedColumn = numberOfCharactersConsumed() - m_numberOfCharactersConsumedPriorToCurrentLine;
    return OrdinalNumber::fromZeroBasedInt(zeroBasedColumn);
}

void SegmentedString::setCurrentPosition(OrdinalNumber line, OrdinalNumber columnAftreProlog, int prologLength)
{
    m_currentLine = line.zeroBasedInt();
    m_numberOfCharactersConsumedPriorToCurrentLine = numberOfCharactersConsumed() + prologLength - columnAftreProlog.zeroBasedInt();
}

}