Init

1 files changed, 321 insertions, 0 deletions

diff --git a/stdio/dirstream.c b/stdio/dirstream.c
new file mode 100644
index 0000000..77940a0
--- /dev/null
+++ b/stdio/dirstream.c
@@ -0,0 +1,321 @@
+/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
+│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
+╞══════════════════════════════════════════════════════════════════════════════╡
+│ Copyright 2020 Justine Alexandra Roberts Tunney                              │
+│                                                                              │
+│ Permission to use, copy, modify, and/or distribute this software for         │
+│ any purpose with or without fee is hereby granted, provided that the         │
+│ above copyright notice and this permission notice appear in all copies.      │
+│                                                                              │
+│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
+│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
+│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
+│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
+│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
+│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
+│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
+│ PERFORMANCE OF THIS SOFTWARE.                                                │
+╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/bits/bits.h"
+#include "libc/calls/internal.h"
+#include "libc/calls/struct/dirent.h"
+#include "libc/dce.h"
+#include "libc/macros.internal.h"
+#include "libc/mem/mem.h"
+#include "libc/nt/enum/fileflagandattributes.h"
+#include "libc/nt/enum/filetype.h"
+#include "libc/nt/files.h"
+#include "libc/nt/runtime.h"
+#include "libc/nt/struct/win32finddata.h"
+#include "libc/str/str.h"
+#include "libc/sysv/consts/dt.h"
+#include "libc/sysv/consts/o.h"
+#include "libc/sysv/errfuns.h"
+
+/**
+ * @fileoverview Directory Streams for Linux+Mac+Windows+FreeBSD+OpenBSD.
+ *
+ * System interfaces for listing the contents of file system directories
+ * are famously incompatible across platforms. Most native projects that
+ * have been around a long time implement wrappers for this. Normally it
+ * will only be for DOS or Windows support. So this is the first time it
+ * has been done for five platforms, having a remarkably tiny footprint.
+ */
+
+/**
+ * Directory stream object.
+ */
+struct dirstream {
+  int64_t fd;
+  int64_t tell;
+  struct dirent ent;
+  union {
+    struct {
+      unsigned buf_pos;
+      unsigned buf_end;
+      char buf[BUFSIZ];
+    };
+    struct {
+      bool isdone;
+      struct NtWin32FindData windata;
+    };
+  };
+};
+
+/**
+ * FreeBSD getdents() and XNU getdirentries() ABI.
+ */
+struct dirent_bsd {
+  uint32_t d_fileno;
+  uint16_t d_reclen;
+  uint8_t d_type;
+  uint8_t d_namlen;
+  char d_name[256];
+};
+
+/**
+ * OpenBSD getdents() ABI.
+ */
+struct dirent_openbsd {
+  uint64_t d_fileno;
+  int64_t d_off;
+  uint16_t d_reclen;
+  uint8_t d_type;
+  uint8_t d_namlen;
+  uint8_t __zomg[4];
+  char d_name[256];
+};
+
+/**
+ * NetBSD getdents().
+ */
+struct dirent_netbsd {
+  uint64_t d_fileno;
+  uint16_t d_reclen;
+  uint16_t d_namlen;
+  uint8_t d_type;
+  char d_name[512];
+};
+
+static textwindows DIR *opendir_nt_impl(char16_t name[PATH_MAX], size_t len) {
+  DIR *res;
+  if (len + 2 + 1 <= PATH_MAX) {
+    if (name[len - 1] != u'\\') name[len++] = u'\\';
+    name[len++] = u'*';
+    name[len] = u'\0';
+    if ((res = calloc(1, sizeof(DIR)))) {
+      if ((res->fd = FindFirstFile(name, &res->windata)) != -1) {
+        return res;
+      } else {
+        __winerr();
+      }
+      free(res);
+    }
+  } else {
+    enametoolong();
+  }
+  return NULL;
+}
+
+static textwindows noinline DIR *opendir_nt(const char *path) {
+  int len;
+  char16_t name[PATH_MAX];
+  if ((len = __mkntpath(path, name)) == -1) return NULL;
+  return opendir_nt_impl(name, len);
+}
+
+static textwindows noinline DIR *fdopendir_nt(int fd) {
+  DIR *res;
+  char16_t name[PATH_MAX];
+  if (__isfdkind(fd, kFdFile)) {
+    if ((res = opendir_nt_impl(
+             name, GetFinalPathNameByHandle(
+                       g_fds.p[fd].handle, name, ARRAYLEN(name),
+                       kNtFileNameNormalized | kNtVolumeNameDos)))) {
+      close(fd);
+      return res;
+    }
+  } else {
+    ebadf();
+  }
+  return NULL;
+}
+
+static textwindows noinline struct dirent *readdir_nt(DIR *dir) {
+  if (!dir->isdone) {
+    memset(&dir->ent, 0, sizeof(dir->ent));
+    dir->ent.d_ino = 0;
+    dir->ent.d_off = dir->tell++;
+    dir->ent.d_reclen = sizeof(dir->ent) +
+                        tprecode16to8(dir->ent.d_name, sizeof(dir->ent.d_name),
+                                      dir->windata.cFileName)
+                            .ax +
+                        1;
+    switch (dir->windata.dwFileType) {
+      case kNtFileTypeDisk:
+        dir->ent.d_type = DT_BLK;
+        break;
+      case kNtFileTypeChar:
+        dir->ent.d_type = DT_CHR;
+        break;
+      case kNtFileTypePipe:
+        dir->ent.d_type = DT_FIFO;
+        break;
+      default:
+        if (dir->windata.dwFileAttributes & kNtFileAttributeDirectory) {
+          dir->ent.d_type = DT_DIR;
+        } else {
+          dir->ent.d_type = DT_REG;
+        }
+        break;
+    }
+    dir->isdone = !FindNextFile(dir->fd, &dir->windata);
+    return &dir->ent;
+  } else {
+    return NULL;
+  }
+}
+
+/**
+ * Opens directory, e.g.
+ *
+ *     DIR *d;
+ *     struct dirent *e;
+ *     CHECK((d = opendir(path)));
+ *     while ((e = readdir(d))) {
+ *       printf("%s/%s\n", path, e->d_name);
+ *     }
+ *     LOGIFNEG1(closedir(d));
+ *
+ * @returns newly allocated DIR object, or NULL w/ errno
+ * @errors ENOENT, ENOTDIR, EACCES, EMFILE, ENFILE, ENOMEM
+ * @see glob()
+ */
+DIR *opendir(const char *name) {
+  int fd;
+  DIR *res;
+  if (!IsWindows()) {
+    res = NULL;
+    if ((fd = open(name, O_RDONLY | O_DIRECTORY | O_CLOEXEC)) != -1) {
+      if (!(res = fdopendir(fd))) close(fd);
+    }
+    return res;
+  } else {
+    return opendir_nt(name);
+  }
+}
+
+/**
+ * Creates directory object for file descriptor.
+ *
+ * @param fd gets owned by this function, if it succeeds
+ * @return new directory object, which must be freed by closedir(),
+ *     or NULL w/ errno
+ * @errors ENOMEM and fd is closed
+ */
+DIR *fdopendir(int fd) {
+  DIR *dir;
+  if (!IsWindows()) {
+    if (!(dir = calloc(1, sizeof(*dir)))) return NULL;
+    dir->fd = fd;
+    return dir;
+  } else {
+    return fdopendir_nt(fd);
+  }
+}
+
+/**
+ * Reads next entry from directory stream.
+ *
+ * This API doesn't define any particular ordering.
+ *
+ * @param dir is the object opendir() or fdopendir() returned
+ * @return next entry or NULL on end or error, which can be
+ *     differentiated by setting errno to 0 beforehand
+ */
+struct dirent *readdir(DIR *dir) {
+  int rc;
+  long basep;
+  struct dirent *ent;
+  struct dirent_bsd *bsd;
+  struct dirent_netbsd *nbsd;
+  struct dirent_openbsd *obsd;
+  if (!IsWindows()) {
+    if (dir->buf_pos >= dir->buf_end) {
+      basep = dir->tell; /* TODO(jart): what does xnu do */
+      rc = getdents(dir->fd, dir->buf, sizeof(dir->buf) - 256, &basep);
+      if (!rc || rc == -1) return NULL;
+      dir->buf_pos = 0;
+      dir->buf_end = rc;
+    }
+    if (IsLinux()) {
+      ent = (struct dirent *)(dir->buf + dir->buf_pos);
+      dir->buf_pos += ent->d_reclen;
+      dir->tell = ent->d_off;
+    } else if (IsOpenbsd()) {
+      obsd = (struct dirent_openbsd *)(dir->buf + dir->buf_pos);
+      dir->buf_pos += obsd->d_reclen;
+      ent = &dir->ent;
+      ent->d_ino = obsd->d_fileno;
+      ent->d_off = obsd->d_off;
+      ent->d_reclen = obsd->d_reclen;
+      ent->d_type = obsd->d_type;
+      memcpy(ent->d_name, obsd->d_name, obsd->d_namlen + 1);
+    } else if (IsNetbsd()) {
+      nbsd = (struct dirent_netbsd *)(dir->buf + dir->buf_pos);
+      dir->buf_pos += nbsd->d_reclen;
+      ent = &dir->ent;
+      ent->d_ino = nbsd->d_fileno;
+      ent->d_off = dir->tell++;
+      ent->d_reclen = nbsd->d_reclen;
+      ent->d_type = nbsd->d_type;
+      memcpy(ent->d_name, nbsd->d_name, MAX(256, nbsd->d_namlen + 1));
+    } else {
+      bsd = (struct dirent_bsd *)(dir->buf + dir->buf_pos);
+      dir->buf_pos += bsd->d_reclen;
+      ent = &dir->ent;
+      ent->d_ino = bsd->d_fileno;
+      ent->d_off = IsXnu() ? (dir->tell = basep) : dir->tell++;
+      ent->d_reclen = bsd->d_reclen;
+      ent->d_type = bsd->d_type;
+      memcpy(ent->d_name, bsd->d_name, bsd->d_namlen + 1);
+    }
+    return ent;
+  } else {
+    return readdir_nt(dir);
+  }
+}
+
+/**
+ * Closes directory object returned by opendir().
+ * @return 0 on success or -1 w/ errno
+ */
+int closedir(DIR *dir) {
+  int rc;
+  if (dir) {
+    if (!IsWindows()) {
+      rc = close(dir->fd);
+    } else {
+      rc = FindClose(dir->fd) ? 0 : __winerr();
+    }
+    free(dir);
+  } else {
+    rc = 0;
+  }
+  return rc;
+}
+
+/**
+ * Returns offset into directory data.
+ */
+long telldir(DIR *dir) {
+  return dir->tell;
+}
+
+/**
+ * Returns file descriptor associated with DIR object.
+ */
+int dirfd(DIR *dir) {
+  if (IsWindows()) return eopnotsupp();
+  return dir->fd;
+}