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/*
* Copyright (C) 2010 Google, Inc. All Rights Reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "core/html/parser/HTMLEntitySearch.h"
#include "core/html/parser/HTMLEntityTable.h"
namespace blink {
static const HTMLEntityTableEntry* halfway(const HTMLEntityTableEntry* left, const HTMLEntityTableEntry* right)
{
return &left[(right - left) / 2];
}
HTMLEntitySearch::HTMLEntitySearch()
: m_currentLength(0)
, m_mostRecentMatch(0)
, m_first(HTMLEntityTable::firstEntry())
, m_last(HTMLEntityTable::lastEntry())
{
}
HTMLEntitySearch::CompareResult HTMLEntitySearch::compare(const HTMLEntityTableEntry* entry, UChar nextCharacter) const
{
if (entry->length < m_currentLength + 1)
return Before;
const LChar* entityString = HTMLEntityTable::entityString(*entry);
UChar entryNextCharacter = entityString[m_currentLength];
if (entryNextCharacter == nextCharacter)
return Prefix;
return entryNextCharacter < nextCharacter ? Before : After;
}
const HTMLEntityTableEntry* HTMLEntitySearch::findFirst(UChar nextCharacter) const
{
const HTMLEntityTableEntry* left = m_first;
const HTMLEntityTableEntry* right = m_last;
if (left == right)
return left;
CompareResult result = compare(left, nextCharacter);
if (result == Prefix)
return left;
if (result == After)
return right;
while (left + 1 < right) {
const HTMLEntityTableEntry* probe = halfway(left, right);
result = compare(probe, nextCharacter);
if (result == Before)
left = probe;
else {
ASSERT(result == After || result == Prefix);
right = probe;
}
}
ASSERT(left + 1 == right);
return right;
}
const HTMLEntityTableEntry* HTMLEntitySearch::findLast(UChar nextCharacter) const
{
const HTMLEntityTableEntry* left = m_first;
const HTMLEntityTableEntry* right = m_last;
if (left == right)
return right;
CompareResult result = compare(right, nextCharacter);
if (result == Prefix)
return right;
if (result == Before)
return left;
while (left + 1 < right) {
const HTMLEntityTableEntry* probe = halfway(left, right);
result = compare(probe, nextCharacter);
if (result == After)
right = probe;
else {
ASSERT(result == Before || result == Prefix);
left = probe;
}
}
ASSERT(left + 1 == right);
return left;
}
void HTMLEntitySearch::advance(UChar nextCharacter)
{
ASSERT(isEntityPrefix());
if (!m_currentLength) {
m_first = HTMLEntityTable::firstEntryStartingWith(nextCharacter);
m_last = HTMLEntityTable::lastEntryStartingWith(nextCharacter);
if (!m_first || !m_last)
return fail();
} else {
m_first = findFirst(nextCharacter);
m_last = findLast(nextCharacter);
if (m_first == m_last && compare(m_first, nextCharacter) != Prefix)
return fail();
}
++m_currentLength;
if (m_first->length != m_currentLength) {
return;
}
m_mostRecentMatch = m_first;
}
} // namespace blink