xref: /freebsd/contrib/llvm-project/libc/src/__support/File/dir.cpp (revision bb722a7d0f1642bff6487f943ad0427799a6e5bf)
1*bb722a7dSDimitry Andric //===--- Implementation of a platform independent Dir data structure ------===//
2*bb722a7dSDimitry Andric //
3*bb722a7dSDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4*bb722a7dSDimitry Andric // See https://llvm.org/LICENSE.txt for license information.
5*bb722a7dSDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6*bb722a7dSDimitry Andric //
7*bb722a7dSDimitry Andric //===----------------------------------------------------------------------===//
8*bb722a7dSDimitry Andric 
9*bb722a7dSDimitry Andric #include "dir.h"
10*bb722a7dSDimitry Andric 
11*bb722a7dSDimitry Andric #include "src/__support/CPP/mutex.h" // lock_guard
12*bb722a7dSDimitry Andric #include "src/__support/CPP/new.h"
13*bb722a7dSDimitry Andric #include "src/__support/error_or.h"
14*bb722a7dSDimitry Andric #include "src/__support/libc_errno.h" // For error macros
15*bb722a7dSDimitry Andric #include "src/__support/macros/config.h"
16*bb722a7dSDimitry Andric 
17*bb722a7dSDimitry Andric namespace LIBC_NAMESPACE_DECL {
18*bb722a7dSDimitry Andric 
open(const char * path)19*bb722a7dSDimitry Andric ErrorOr<Dir *> Dir::open(const char *path) {
20*bb722a7dSDimitry Andric   auto fd = platform_opendir(path);
21*bb722a7dSDimitry Andric   if (!fd)
22*bb722a7dSDimitry Andric     return LIBC_NAMESPACE::Error(fd.error());
23*bb722a7dSDimitry Andric 
24*bb722a7dSDimitry Andric   LIBC_NAMESPACE::AllocChecker ac;
25*bb722a7dSDimitry Andric   Dir *dir = new (ac) Dir(fd.value());
26*bb722a7dSDimitry Andric   if (!ac)
27*bb722a7dSDimitry Andric     return LIBC_NAMESPACE::Error(ENOMEM);
28*bb722a7dSDimitry Andric   return dir;
29*bb722a7dSDimitry Andric }
30*bb722a7dSDimitry Andric 
read()31*bb722a7dSDimitry Andric ErrorOr<struct ::dirent *> Dir::read() {
32*bb722a7dSDimitry Andric   cpp::lock_guard lock(mutex);
33*bb722a7dSDimitry Andric   if (readptr >= fillsize) {
34*bb722a7dSDimitry Andric     auto readsize = platform_fetch_dirents(fd, buffer);
35*bb722a7dSDimitry Andric     if (!readsize)
36*bb722a7dSDimitry Andric       return LIBC_NAMESPACE::Error(readsize.error());
37*bb722a7dSDimitry Andric     fillsize = readsize.value();
38*bb722a7dSDimitry Andric     readptr = 0;
39*bb722a7dSDimitry Andric   }
40*bb722a7dSDimitry Andric   if (fillsize == 0)
41*bb722a7dSDimitry Andric     return nullptr;
42*bb722a7dSDimitry Andric 
43*bb722a7dSDimitry Andric   struct ::dirent *d = reinterpret_cast<struct ::dirent *>(buffer + readptr);
44*bb722a7dSDimitry Andric #ifdef __linux__
45*bb722a7dSDimitry Andric   // The d_reclen field is available on Linux but not required by POSIX.
46*bb722a7dSDimitry Andric   readptr += d->d_reclen;
47*bb722a7dSDimitry Andric #else
48*bb722a7dSDimitry Andric   // Other platforms have to implement how the read pointer is to be updated.
49*bb722a7dSDimitry Andric #error "DIR read pointer update is missing."
50*bb722a7dSDimitry Andric #endif
51*bb722a7dSDimitry Andric   return d;
52*bb722a7dSDimitry Andric }
53*bb722a7dSDimitry Andric 
close()54*bb722a7dSDimitry Andric int Dir::close() {
55*bb722a7dSDimitry Andric   {
56*bb722a7dSDimitry Andric     cpp::lock_guard lock(mutex);
57*bb722a7dSDimitry Andric     int retval = platform_closedir(fd);
58*bb722a7dSDimitry Andric     if (retval != 0)
59*bb722a7dSDimitry Andric       return retval;
60*bb722a7dSDimitry Andric   }
61*bb722a7dSDimitry Andric   delete this;
62*bb722a7dSDimitry Andric   return 0;
63*bb722a7dSDimitry Andric }
64*bb722a7dSDimitry Andric 
65*bb722a7dSDimitry Andric } // namespace LIBC_NAMESPACE_DECL
66