/** \brief Create a virtual seeker.
*
* This constructor defines a virtual seeker start and end offsets
* on initialization. By default it is initialized to a transparent
* seeker since the start and end are set to zero.
*
* \note
* If the offsets are left undefined (both set to zero) then the virtual
* seeker is viewed as a transparent seeker, meaning that it seeks in
* the input streams as if it did not exist.
*
* \warning
* The virtual seek end offset is quite peculiar in that it is defined
* as a POSITIVE number from the end of the file, going backward. The
* normal seekg() command expects a negative number of an offset to be
* applied from the end of the file.
*
* \warning
* The class is not attached to one specific input stream so there is no
* way to verify that the offsets are valid (i.e. not representing an
* empty virtual file or having offsets completely outside of the available
* range.)
*
* \exception InvalidException
* The two offsets must be positive.
*
* \param[in] start_offset The start offset of the embedded file.
* \param[in] end_offset The end offset of the embedded file.
*/
VirtualSeeker::VirtualSeeker(offset_t start_offset, offset_t end_offset)
: m_start_offset(start_offset)
, m_end_offset(end_offset)
{
if(m_start_offset < 0
|| m_end_offset < 0)
{
throw InvalidException("VirtualSeeker::VirtualSeeker(): the start and end offsets cannot be negative.");
}
}
Regex::Result
Regex::match(const char * str, bool copyStr, std::size_t count) const
{
if (freed)
throw InvalidException();
auto maxMatches = exp.re_nsub + 1;
auto size = count < maxMatches ? count : maxMatches;
Result ret(str, copyStr, size);
ret.matched = regexec(&exp, str, size, ret.matches.data(), 0) == 0;
return ret;
}
/** \brief Set the offsets of the virtual seeker.
*
* This function can be used to change the virtual seeker offsets.
*
* \exception InvalidException
* The start offset must be before or equal to the end offset or
* this exception is raised.
*
* \param[in] start_offset The new start offset.
* \param[in] end_offset The new end offset.
*/
void VirtualSeeker::setOffsets(offset_t start_offset, offset_t end_offset)
{
if(start_offset < 0
|| end_offset < 0)
{
throw InvalidException("VirtualSeeker::VirtualSeeker(): the start and end offsets cannot be negative.");
}
m_start_offset = start_offset;
m_end_offset = end_offset;
}
