void VTTScanner::skipRun(const Run& run)
{
ASSERT(run.start() <= end());
ASSERT(run.end() >= run.start());
ASSERT(run.end() <= end());
seekTo(run.end());
}
inline bool
try_merge(Run& run, Iterator iter, Range const& range)
{
// if *iter intersects with, or is adjacent to, 'range'...
if (can_merge(*iter, range))
{
typedef typename Range::value_type value_type;
typedef integer_traits<value_type> integer_traits;
// merge range and *iter
merge(*iter, range);
// collapse all subsequent ranges that can merge with *iter:
Iterator i = iter+1;
// 1. skip subsequent ranges completely included in *iter
while (i != run.end() && i->last <= iter->last)
++i;
// 2. collapse next range if adjacent or overlapping with *iter
if (i != run.end() && i->first-1 <= iter->last)
{
iter->last = i->last;
++i;
}
// erase all ranges that were collapsed
run.erase(iter+1, i);
return true;
}
return false;
}
String VTTScanner::extractString(const Run& run)
{
ASSERT(run.start() == position());
ASSERT(run.start() <= end());
ASSERT(run.end() >= run.start());
ASSERT(run.end() <= end());
String s;
if (m_is8Bit)
s = String(m_data.characters8, run.length());
else
s = String(m_data.characters16, run.length());
seekTo(run.end());
return s;
}
bool VTTScanner::scanFloat(float& number)
{
Run integerRun = collectWhile<isASCIIDigit>();
seekTo(integerRun.end());
Run decimalRun(getPosition(), getPosition(), m_is8Bit);
if (scan('.')) {
decimalRun = collectWhile<isASCIIDigit>();
seekTo(decimalRun.end());
}
// At least one digit required.
if (integerRun.isEmpty() && decimalRun.isEmpty()) {
// Restore to starting position.
seekTo(integerRun.start());
return false;
}
size_t lengthOfFloat = Run(integerRun.start(), getPosition(), m_is8Bit).length();
bool validNumber;
if (m_is8Bit)
number = charactersToFloat(integerRun.start(), lengthOfFloat, &validNumber);
else
number = charactersToFloat(reinterpret_cast<const UChar*>(integerRun.start()), lengthOfFloat, &validNumber);
if (!validNumber)
number = std::numeric_limits<float>::max();
return true;
}
bool VTTScanner::scanRun(const Run& run, const String& toMatch)
{
ASSERT(run.start() == position());
ASSERT(run.start() <= end());
ASSERT(run.end() >= run.start());
ASSERT(run.end() <= end());
size_t matchLength = run.length();
if (toMatch.length() > matchLength)
return false;
bool matched;
if (m_is8Bit)
matched = WTF::equal(toMatch.impl(), m_data.characters8, matchLength);
else
matched = WTF::equal(toMatch.impl(), m_data.characters16, matchLength);
if (matched)
seekTo(run.end());
return matched;
}
unsigned VTTScanner::scanDigits(int& number)
{
Run runOfDigits = collectWhile<isASCIIDigit>();
if (runOfDigits.isEmpty()) {
number = 0;
return 0;
}
bool validNumber;
size_t numDigits = runOfDigits.length();
if (m_is8Bit)
number = charactersToIntStrict(m_data.characters8, numDigits, &validNumber);
else
number = charactersToIntStrict(m_data.characters16, numDigits, &validNumber);
// Since we know that scanDigits only scanned valid (ASCII) digits (and
// hence that's what got passed to charactersToInt()), the remaining
// failure mode for charactersToInt() is overflow, so if |validNumber| is
// not true, then set |number| to the maximum int value.
if (!validNumber)
number = std::numeric_limits<int>::max();
// Consume the digits.
seekTo(runOfDigits.end());
return numDigits;
}
