private unsafe string GetModelJSON(int startIteration, int numIteration)
{
long bufLen = 2L << 15;
byte[] buffer = new byte[bufLen];
long size = 0L;
fixed(byte *ptr = buffer)
PInvokeException.Check(PInvoke.BoosterDumpModel(Handle, startIteration, numIteration, bufLen, ref size, ptr),
nameof(PInvoke.BoosterDumpModel));
// If buffer size is not enough, reallocate buffer and get again.
if (size > bufLen)
{
bufLen = size;
buffer = new byte[bufLen];
fixed(byte *ptr = buffer)
PInvokeException.Check(PInvoke.BoosterDumpModel(Handle, startIteration, numIteration, bufLen, ref size, ptr),
nameof(PInvoke.BoosterDumpModel));
}
byte[] content = new byte[size];
Array.Copy(buffer, content, size);
fixed(byte *ptr = content)
return(Marshal.PtrToStringAnsi((IntPtr)ptr));
}