tiffstream.cpp

TIFF文件格式读取及生成的源代码

// tiff stream interface class implementation

#include "tiffstream.h"

const char* TiffStream::m_name = "TiffStream";

TiffStream::TiffStream()
{
    m_tif = NULL;


    m_inStream = NULL;
	m_outStream = NULL;
	m_ioStream = NULL;

	m_streamLength = 0;

	m_this = reinterpret_cast<thandle_t>(this);
};

TiffStream::~TiffStream()
{
    if(m_tif != NULL) TIFFClose(m_tif);
}

TIFF*
TiffStream::makeFileStream(istream* str)
{
    m_inStream = str;
	m_outStream = NULL;
	m_ioStream = NULL;
    m_streamLength = getSize(m_this);

    m_tif =  TIFFClientOpen(m_name, 
                           "r",
						   m_this,
						   read,
						   write,
						   seek,
						   close,
						   size,
						   map,
						   unmap);
    return m_tif;
}

TIFF*
TiffStream::makeFileStream(ostream* str)
{
	m_inStream = NULL;
    m_outStream = str;
	m_ioStream = NULL;
	m_streamLength = getSize(m_this);

	m_tif =  TIFFClientOpen(m_name, 
                           "w",
						   m_this,
						   read,
						   write,
						   seek,
						   close,
						   size,
						   map,
						   unmap);
    return m_tif;
}

TIFF*
TiffStream::makeFileStream(iostream* str)
{
	m_inStream = NULL;
	m_outStream = NULL;
    m_ioStream = str;
	m_streamLength = getSize(m_this);

    m_tif =  TIFFClientOpen(m_name, 
	                       "r+w",
						   m_this,
						   read,
						   write,
						   seek,
						   close,
						   size,
						   map,
						   unmap);
    return m_tif;
}

tsize_t
TiffStream::read(thandle_t fd, tdata_t buf, tsize_t size)
{
	istream* istr;
	TiffStream* ts = reinterpret_cast<TiffStream*>(fd);
    if(ts->m_inStream != NULL) {
	    istr = ts->m_inStream;
	} else if(ts->m_ioStream != NULL) {
	    istr = ts->m_ioStream;
	}

	int remain = ts->m_streamLength - ts->tell(fd);
	int actual = remain < size ? remain : size;
	istr->read(reinterpret_cast<char*>(buf), actual);
    return istr->gcount();
}

tsize_t
TiffStream::write(thandle_t fd, tdata_t buf, tsize_t size)
{
	TiffStream* ts = reinterpret_cast<TiffStream*>(fd);
	ostream* ostr;
	if(ts->m_outStream != NULL) {
	    ostr = ts->m_outStream;
	} else if(ts->m_ioStream != NULL) {
	    ostr = ts->m_ioStream;
	}

	streampos start = ostr->tellp();
	ostr->write(reinterpret_cast<const char*>(buf), size);
	return ostr->tellp() - start;
}

toff_t
TiffStream::seek(thandle_t fd, toff_t offset, int origin)
{
    TiffStream* ts = reinterpret_cast<TiffStream*>(fd);
    if(ts->seekInt(fd, offset, origin) == true) return offset;
	else return -1;
}

int
TiffStream::close(thandle_t fd)
{
    TiffStream* ts = reinterpret_cast<TiffStream*>(fd);
	if(ts->m_inStream != NULL) {
		ts->m_inStream = NULL;
		return 0;
	} else if(ts->m_outStream != NULL) {
		ts->m_outStream = NULL;
		return 0;
	} else if(ts->m_ioStream != NULL) {
		ts->m_ioStream = NULL;
		return 0;
	}
    return -1;
}

toff_t
TiffStream::size(thandle_t fd)
{
    TiffStream* ts = reinterpret_cast<TiffStream*>(fd);
    return ts->getSize(fd);
}

int 
TiffStream::map(thandle_t fd, tdata_t* phase, toff_t* psize)
{
    return 0;
}

void
TiffStream::unmap(thandle_t fd, tdata_t base, tsize_t size)
{
}

unsigned int
TiffStream::getSize(thandle_t fd)
{
	if(!isOpen(fd)) return 0;

    unsigned int pos = tell(fd);
	seekInt(fd, 0, end);
	unsigned int size = tell(fd);
	seekInt(fd, pos, beg);

	return size;
}

unsigned int
TiffStream::tell(thandle_t fd)
{
    TiffStream* ts = reinterpret_cast<TiffStream*>(fd);
    if(ts->m_inStream != NULL) {
	    return ts->m_inStream->tellg();
	} else if(ts->m_outStream != NULL) {
	    return ts->m_outStream->tellp();
	} else if(ts->m_ioStream != NULL) {
		return ts->m_ioStream->tellg();
	}
	return 0;
}

bool
TiffStream::seekInt(thandle_t fd, unsigned int offset, int origin)
{
	if(!isOpen(fd)) return false;

	ios::seek_dir org;
	switch(origin) {
	case beg: 
		org = ios::beg;
		break;
	case cur: 
		org = ios::cur;
		break;
	case end: 
		org = ios::end;
		break;
	}

	TiffStream* ts = reinterpret_cast<TiffStream*>(fd);
    if(ts->m_inStream != NULL) {
	    ts->m_inStream->seekg(offset, org);
		return true;
	} else if(ts->m_outStream != NULL) {
	    ts->m_outStream->seekp(offset, org);
		return true;
	} else if(ts->m_ioStream != NULL) {
	    ts->m_ioStream->seekg(offset, org);
		ts->m_ioStream->seekp(offset, org);
		return true;
	}
    return false;
}

bool
TiffStream::isOpen(thandle_t fd)
{
	TiffStream* ts = reinterpret_cast<TiffStream*>(fd);
	return (ts->m_inStream != NULL ||
		   ts->m_outStream != NULL ||
		   ts->m_ioStream != NULL);
}