Metriche repository
- Star
- (284 stelle)
- Metriche merge PR
- (Merge medio 11h 57m) (69 PR mergiate in 30 g)
Descrizione
File I/O is slow in CP/M.
This is because for each BIOS read sector:
- The file is opened
- The sector is read
- The file is closed.
A similar pattern is done for the other methods I list below, it's very atomic, but very slow.
Calls to OpenFile() in lib/runcpm/disk.h call _sys_openfile(): https://github.com/FujiNetWIFI/fujinet-firmware/blob/master/lib/runcpm/abstraction_fujinet.h#L153 and read sequential: https://github.com/FujiNetWIFI/fujinet-firmware/blob/master/lib/runcpm/abstraction_fujinet.h#L223 and write sequential: https://github.com/FujiNetWIFI/fujinet-firmware/blob/master/lib/runcpm/abstraction_fujinet.h#L263 and read random: https://github.com/FujiNetWIFI/fujinet-firmware/blob/master/lib/runcpm/abstraction_fujinet.h#L293 and write random: https://github.com/FujiNetWIFI/fujinet-firmware/blob/master/lib/runcpm/abstraction_fujinet.h#L339
This needs to be extended to hold onto the file handle, and not open the file again if it has already been opened, thus avoiding the file_open call if needed, and finding out when to best close the file when it is no longer needed (so we don't leak file descriptors! A timer?)
-Thom