ocaml/otherlibs/win32unix/read.c

55 lines
1.9 KiB
C

/***********************************************************************/
/* */
/* Objective Caml */
/* */
/* Xavier Leroy, projet Cristal, INRIA Rocquencourt */
/* */
/* Copyright 1996 Institut National de Recherche en Informatique et */
/* en Automatique. All rights reserved. This file is distributed */
/* under the terms of the GNU Library General Public License, with */
/* the special exception on linking described in file ../../LICENSE. */
/* */
/***********************************************************************/
/* $Id$ */
#include <string.h>
#include <mlvalues.h>
#include <memory.h>
#include <signals.h>
#include "unixsupport.h"
CAMLprim value unix_read(value fd, value buf, value ofs, value vlen)
{
intnat len;
DWORD numbytes, numread;
char iobuf[UNIX_BUFFER_SIZE];
DWORD err = 0;
Begin_root (buf);
len = Long_val(vlen);
numbytes = len > UNIX_BUFFER_SIZE ? UNIX_BUFFER_SIZE : len;
if (Descr_kind_val(fd) == KIND_SOCKET) {
int ret;
SOCKET s = Socket_val(fd);
enter_blocking_section();
ret = recv(s, iobuf, numbytes, 0);
if (ret == SOCKET_ERROR) err = WSAGetLastError();
leave_blocking_section();
numread = ret;
} else {
HANDLE h = Handle_val(fd);
enter_blocking_section();
if (! ReadFile(h, iobuf, numbytes, &numread, NULL))
err = GetLastError();
leave_blocking_section();
}
if (err) {
win32_maperr(err);
uerror("read", Nothing);
}
memmove (&Byte(buf, Long_val(ofs)), iobuf, numread);
End_roots();
return Val_int(numread);
}