public unsafe void WriteBuffer(long position, byte *srcPosition, int sizeToWrite)
{
var offset = Convert.ToUInt64(sizeToWrite);
var result = Syscall.pwrite(_fd, srcPosition, (ulong)sizeToWrite, (long)offset);
if (result == -1)
{
var err = Marshal.GetLastWin32Error();
PosixHelper.ThrowLastError(err);
}
}
private unsafe void WriteFile(long position, byte *p, int numberOf4Kb)
{
if (numberOf4Kb == 0)
{
return; // nothing to do
}
var nNumberOfBytesToWrite = (ulong)numberOf4Kb * (4 * Constants.Size.Kilobyte);
long actuallyWritten = 0;
long result;
using (_options.IoMetrics.MeterIoRate(_filename.FullPath, IoMetrics.MeterType.JournalWrite, (long)nNumberOfBytesToWrite))
{
do
{
result = Syscall.pwrite(_fd, p, nNumberOfBytesToWrite - (ulong)actuallyWritten,
position * 4 * Constants.Size.Kilobyte);
if (result < 1)
{
break;
}
actuallyWritten += result;
p += actuallyWritten;
} while ((ulong)actuallyWritten < nNumberOfBytesToWrite);
}
if (result == -1)
{
var err = Marshal.GetLastWin32Error();
Syscall.ThrowLastError(err, "when writing to " + _filename);
}
else if (result == 0)
{
var err = Marshal.GetLastWin32Error();
throw new IOException($"pwrite reported zero bytes written, after write of {actuallyWritten} bytes out of {nNumberOfBytesToWrite}. lastErrNo={err} on {_filename}");
}
else if ((ulong)actuallyWritten != nNumberOfBytesToWrite)
{
var err = Marshal.GetLastWin32Error();
throw new IOException($"pwrite couln't write {nNumberOfBytesToWrite} to file. only {actuallyWritten} written. lastErrNo={err} on {_filename}");
}
}
