Merge branch 'main' into find2fdfind2fd

1 files changed, 68 insertions, 21 deletions

diff --git a/src/dir.h b/src/dir.h
index 69344c6..6d5c9c5 100644
--- a/src/dir.h
+++ b/src/dir.h
@@ -1,18 +1,5 @@
-/****************************************************************************
- * bfs                                                                      *
- * Copyright (C) 2021 Tavian Barnes <tavianator@tavianator.com>             *
- *                                                                          *
- * Permission to use, copy, modify, and/or distribute this software for any *
- * purpose with or without fee is hereby granted.                           *
- *                                                                          *
- * 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.           *
- ****************************************************************************/
+// Copyright © Tavian Barnes <tavianator@tavianator.com>
+// SPDX-License-Identifier: 0BSD
 
 /**
  * Directories and their contents.
@@ -21,9 +8,18 @@
 #ifndef BFS_DIR_H
 #define BFS_DIR_H
 
+#include "prelude.h"
 #include <sys/types.h>
 
 /**
+ * Whether the implementation uses the getdents() syscall directly, rather than
+ * libc's readdir().
+ */
+#if !defined(BFS_USE_GETDENTS) && (__linux__ || __FreeBSD__)
+#  define BFS_USE_GETDENTS (BFS_HAS_GETDENTS || BFS_HAS_GETDENTS64 | BFS_HAS_GETDENTS64_SYSCALL)
+#endif
+
+/**
  * A directory.
  */
 struct bfs_dir;
@@ -74,17 +70,49 @@ struct bfs_dirent {
 };
 
 /**
+ * Allocate space for a directory.
+ *
+ * @return
+ *         An allocated, unopen directory, or NULL on failure.
+ */
+struct bfs_dir *bfs_allocdir(void);
+
+struct arena;
+
+/**
+ * Initialize an arena for directories.
+ *
+ * @param arena
+ *         The arena to initialize.
+ */
+void bfs_dir_arena(struct arena *arena);
+
+/**
+ * bfs_opendir() flags.
+ */
+enum bfs_dir_flags {
+	/** Include whiteouts in the results. */
+	BFS_DIR_WHITEOUTS = 1 << 0,
+	/** @internal Start of private flags. */
+	BFS_DIR_PRIVATE   = 1 << 1,
+};
+
+/**
  * Open a directory.
  *
+ * @param dir
+ *         The allocated directory.
  * @param at_fd
  *         The base directory for path resolution.
  * @param at_path
  *         The path of the directory to open, relative to at_fd.  Pass NULL to
  *         open at_fd itself.
+ * @param flags
+ *         Flags that control which directory entries are listed.
  * @return
- *         The opened directory, or NULL on failure.
+ *         0 on success, or -1 on failure.
  */
-struct bfs_dir *bfs_opendir(int at_fd, const char *at_path);
+int bfs_opendir(struct bfs_dir *dir, int at_fd, const char *at_path, enum bfs_dir_flags flags);
 
 /**
  * Get the file descriptor for a directory.
@@ -92,6 +120,16 @@ struct bfs_dir *bfs_opendir(int at_fd, const char *at_path);
 int bfs_dirfd(const struct bfs_dir *dir);
 
 /**
+ * Performs any I/O necessary for the next bfs_readdir() call.
+ *
+ * @param dir
+ *         The directory to poll.
+ * @return
+ *         1 on success, 0 on EOF, or -1 on failure.
+ */
+int bfs_polldir(struct bfs_dir *dir);
+
+/**
  * Read a directory entry.
  *
  * @param dir
@@ -112,13 +150,22 @@ int bfs_readdir(struct bfs_dir *dir, struct bfs_dirent *de);
 int bfs_closedir(struct bfs_dir *dir);
 
 /**
- * Free a directory, keeping an open file descriptor to it.
+ * Whether the bfs_unwrapdir() function is supported.
+ */
+#ifndef BFS_USE_UNWRAPDIR
+#  define BFS_USE_UNWRAPDIR (BFS_USE_GETDENTS || BFS_HAS_FDCLOSEDIR)
+#endif
+
+#if BFS_USE_UNWRAPDIR
+/**
+ * Detach the file descriptor from an open directory.
  *
  * @param dir
- *         The directory to free.
+ *         The directory to detach.
  * @return
- *         The file descriptor on success, or -1 on failure.
+ *         The file descriptor of the directory.
  */
-int bfs_freedir(struct bfs_dir *dir);
+int bfs_unwrapdir(struct bfs_dir *dir);
+#endif
 
 #endif // BFS_DIR_H