Diff: mbed/platform/DirHandle.h

Revision:

0:d383e2dee0f7

diff -r 000000000000 -r d383e2dee0f7 mbed/platform/DirHandle.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed/platform/DirHandle.h	Mon Jul 06 17:18:59 2020 +0530
@@ -0,0 +1,178 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2006-2013 ARM Limited
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#ifndef MBED_DIRHANDLE_H
+#define MBED_DIRHANDLE_H
+
+#include <stdint.h>
+#include "platform/platform.h"
+#include "platform/FileHandle.h"
+#include "platform/NonCopyable.h"
+
+namespace mbed {
+/** \addtogroup platform */
+/** @{*/
+/**
+ * \defgroup platform_DirHandle DirHandle functions
+ * @{
+ */
+
+
+/** Represents a directory stream. An opendir function returns
+ *  objects of this type. The core functions are read and seek,
+ *  but only a subset needs to be provided.
+ *
+ *  If a FileSystemLike class defines the opendir method, then you
+ *  can access the directories of an object of that type by either:
+ *  @code
+ *  DIR *d  = opendir("/example/directory");
+ *  @endcode
+ *  or
+ *  @code
+ *  DIR *d = opendir("/example");
+ *  @endcode
+ *  to open the root of the file system.
+ *
+ *  The root directory is considered to contain all FileHandle and
+ *  FileSystem objects, so the DIR pointer returned by opendir("/")
+ *  reflects this.
+ *
+ *  @note to create a directory, @see Dir
+ *  @note Synchronization level: Set by subclass
+ */
+class DirHandle : private NonCopyable<DirHandle> {
+public:
+    virtual ~DirHandle() {}
+
+    /** Read the next directory entry
+     *
+     *  @param ent      The directory entry to fill out
+     *  @return         1 on reading a filename, 0 at end of directory, negative error on failure
+     */
+    virtual ssize_t read(struct dirent *ent) = 0;
+
+    /** Close a directory
+     *
+     *  @return          0 on success, negative error code on failure
+     */
+    virtual int close() = 0;
+
+    /** Set the current position of the directory
+     *
+     *  @param offset   Offset of the location to seek to,
+     *                  must be a value returned from tell
+     */
+    virtual void seek(off_t offset) = 0;
+
+    /** Get the current position of the directory
+     *
+     *  @return         Position of the directory that can be passed to rewind
+     */
+    virtual off_t tell() = 0;
+
+    /** Rewind the current position to the beginning of the directory
+     */
+    virtual void rewind() = 0;
+
+    /** Get the sizeof the directory
+     *
+     *  @return         Number of files in the directory
+     */
+    virtual size_t size()
+    {
+        off_t off = tell();
+        size_t size = 0;
+        struct dirent *ent = new struct dirent;
+
+        rewind();
+        while (read(ent) > 0) {
+            size += 1;
+        }
+        seek(off);
+
+        delete ent;
+        return size;
+    }
+
+    /** Closes the directory.
+     *
+     *  @returns
+     *    0 on success,
+     *   -1 on error.
+     *  @deprecated Replaced by `int DirHandle::close()'
+     */
+    MBED_DEPRECATED_SINCE("mbed-os-5.4", "Replaced by DirHandle::close")
+    virtual int closedir()
+    {
+        return close();
+    };
+
+    /** Returns the directory entry at the current position, and
+     *  advances the position to the next entry.
+     *
+     * @returns
+     *  A pointer to a dirent structure representing the
+     *  directory entry at the current position, or NULL on reaching
+     *  end of directory or error.
+     * @deprecated Replaced by `ssize_t DirHandle::read(struct dirent *ent)
+     */
+    MBED_DEPRECATED_SINCE("mbed-os-5.4", "Replaced by DirHandle::read")
+    virtual struct dirent *readdir()
+    {
+        static struct dirent ent;
+        return (read(&ent) > 0) ? &ent : NULL;
+    }
+
+    /** Resets the position to the beginning of the directory.
+     * @deprecated Replaced by `void DirHandle::rewind()'
+     */
+    MBED_DEPRECATED_SINCE("mbed-os-5.4", "Replaced by DirHandle::rewind")
+    virtual void rewinddir()
+    {
+        rewind();
+    }
+
+    /** Returns the current position of the DirHandle.
+     *
+     * @returns
+     *   the current position,
+     *  -1 on error.
+     * @deprecated Replaced by `off_t DirHandle::tell()'
+     */
+    MBED_DEPRECATED_SINCE("mbed-os-5.4", "Replaced by DirHandle::tell")
+    virtual off_t telldir()
+    {
+        return tell();
+    }
+
+    /** Sets the position of the DirHandle.
+     *
+     *  @param location The location to seek to. Must be a value returned by telldir.
+     *  @deprecated Replaced by `void DirHandle::seek(off_t offset)'
+     */
+    MBED_DEPRECATED_SINCE("mbed-os-5.4", "Replaced by DirHandle::seek")
+    virtual void seekdir(off_t location)
+    {
+        seek(location);
+    }
+};
+
+/**@}*/
+
+/**@}*/
+} // namespace mbed
+
+#endif /* MBED_DIRHANDLE_H */