std::tuple<size_t, IOEvent> read_until_event(IInputStream& is, IOutputStream& os) {
if (os.is_write_nonblocking()) {
raise<IOError>("read_until_event will lose data if writing to non-blocking socket. Use a buffered approach instead.");
}
bool reading = true;
size_t total_read = 0;
size_t total_written = 0;
IOEvent reason;
byte buffer[1024];
while (reading) {
auto r = is.read(buffer, 1024);
either_switch(r,
[&](size_t n) {
total_written += n;
either_switch(os.write(buffer, n),
[&](size_t written) {
total_written += written;
},
[&](IOEvent wev) {
reason = wev;
reading = false;
}
);
},
[&](IOEvent event) {
reason = event;
reading = false;
}
);
}
return {total_written, reason};
}
void TBmpFileGray8Base::save_copy_line(IOutputStream& aOutputStream,const void* pixelsLine)const {
long BmpByteWidth=this->get_bmp_byte_width();
long pixelsWidth=this->get_width();
aOutputStream.write(pixelsLine,pixelsWidth);
if (pixelsWidth<BmpByteWidth)
aOutputStream.skip_fill(BmpByteWidth-pixelsWidth);
}
void TBmpFileBase::save_to(IOutputStream& aOutputStream) const
{
long BmpByteWidth=this->get_bmp_byte_width();
WORD bfType=csBmpTag;
//写入类型信息
aOutputStream.write(&bfType, sizeof(bfType));
//填充BITMAPFILEHEADER结构
BITMAPFILEHEADER_NO_TYPE bmFileHeader;//位图文件头结构和位图信息结构
memset(&bmFileHeader,0,sizeof(bmFileHeader));
DWORD dwDibBitsSize=this->get_height()*MyBase::abs(BmpByteWidth);
DWORD dwOffBits =sizeof(bfType)+ sizeof(BITMAPFILEHEADER_NO_TYPE) + sizeof(BITMAPINFOHEADER) +this->get_palette_byte_size();
DWORD dwFileSize = dwOffBits - dwDibBitsSize;
bmFileHeader.bfSize = dwFileSize;
bmFileHeader.bfReserved1 = 0;
bmFileHeader.bfReserved2 = 0;
bmFileHeader.bfOffBits = dwOffBits;
//写入文件头和位图信息
aOutputStream.write(&bmFileHeader, sizeof(BITMAPFILEHEADER_NO_TYPE));
//
BITMAPINFOHEADER bmpInfo;
memset(&bmpInfo,0,sizeof(bmpInfo));
bmpInfo.biSize= sizeof(BITMAPINFOHEADER);
bmpInfo.biWidth=this->get_width();
bmpInfo.biHeight=this->get_height();
bmpInfo.biPlanes=1;
bmpInfo.biBitCount=(WORD)this->get_bmp_bit_count();
bmpInfo.biCompression=0;
bmpInfo.biSizeImage=0;
bmpInfo.biXPelsPerMeter=0;
bmpInfo.biYPelsPerMeter=0;
bmpInfo.biClrUsed=0;
bmpInfo.biClrImportant=0;
aOutputStream.write(&bmpInfo, sizeof(BITMAPINFOHEADER));
this->write_palette(aOutputStream);
//写入数据
for (long y=bmpInfo.biHeight-1; y>=0; --y)
save_copy_line(aOutputStream,this->get_pixels_line(y));
}
long TBmpFileGray8Base::write_palette(IOutputStream& aOutputStream) const {
aOutputStream.write(gray_paltette256,256*4);
return 256*4;
}
void TBmpFileColor32Base::save_copy_line(IOutputStream& aOutputStream,const void* pixelsLine)const {
long BmpByteWidth=this->get_bmp_byte_width();
aOutputStream.write(pixelsLine,BmpByteWidth);
}
ssize_t
OutputStream_write(void *cookie, const char *buf, size_t size)
{
IOutputStream* output = (IOutputStream*)cookie;
return output->write(buf, size);
}