FileSystem: Reintegrated FileSystemLike interface

Required for other representations of FileSystems, ie LocalFileSystem

Introduces FileSystemHandle for the same behaviour as FileHandle and
DirHandle.

Requires the following to hook into file/dir lookup:
```
int open(FileHandle **file, const char *filename, int flags)
int open(DirHandle **dir, const char *path)
```

This hook is provided by the FileSystem class, so requires no changes
from implementations.

Author: geky

features/filesystem/FileSystem.cpp

@@ -21,7 +21,7 @@
 
 
 FileSystem::FileSystem(const char *name)
-    : FileBase(name, FileSystemPathType)
+    : FileSystemLike(name)
 {
 }
 
@@ -109,3 +109,37 @@ size_t FileSystem::dir_size(fs_dir_t dir)
     return size;
 }
 
+template <typename F>
+class Managed : public F {
+public:
+    virtual int close() {
+        int err = F::close();
+        delete this;
+        return err;
+    }
+};
+
+int FileSystem::open(FileHandle **file, const char *path, int flags)
+{
+    File *f = new Managed<File>;
+    int err = f->open(this, path, flags);
+    if (err) {
+        delete f;
+        return err;
+    }
+
+    *file = f;
+    return 0;
+}
+
+int FileSystem::open(DirHandle **dir, const char *path) {
+    Dir *d = new Managed<Dir>;
+    int err = d->open(this, path);
+    if (err) {
+        delete d;
+        return err;
+    }
+
+    *dir = d;
+    return 0;
+}

features/filesystem/FileSystem.h

@@ -20,6 +20,9 @@
 #include "platform/platform.h"
 
 #include "platform/FileBase.h"
+#include "platform/FileHandle.h"
+#include "platform/DirHandle.h"
+#include "platform/FileSystemLike.h"
 #include "BlockDevice.h"
 
 namespace mbed {
@@ -31,15 +34,19 @@ namespace mbed {
 typedef void *fs_file_t;
 typedef void *fs_dir_t;
 
-/** A filesystem-like object is one that can be used to open files
- *  though it by fopen("/name/filename", flags)
+// Predeclared classes
+class Dir;
+class File;
+
+/** A filesystem object provides filesystem operations and file operations
+ *  for the File and Dir classes on a block device.
  *
- *  Implementations must define at least open (the default definitions
- *  of the rest of the functions just return error values).
+ *  Implementations must provide at minimum file operations and mount
+ *  operations for block devices.
  *
- * @Note Synchronization level: Set by subclass
+ *  @Note Synchronization level: Set by subclass
  */
-class FileSystem : public FileBase {
+class FileSystem : public FileSystemLike {
 public:
     /** FileSystem lifetime
      */
@@ -227,6 +234,13 @@ class FileSystem : public FileBase {
      *  @return         Number of files in the directory
      */
     virtual size_t dir_size(fs_dir_t dir);
+
+protected:
+    // Hooks for FileSystemHandle
+    virtual int open(File *file, const char *path, int flags);
+    virtual int open(Dir *dir, const char *path);
+    virtual int open(FileHandle **file, const char *path, int flags);
+    virtual int open(DirHandle **dir, const char *path);
 };
 
 

mbed.h

@@ -86,6 +86,9 @@
 #include "platform/mbed_rtc_time.h"
 #include "platform/mbed_poll.h"
 #include "platform/ATCmdParser.h"
+#include "platform/FileSystemHandle.h"
+#include "platform/FileHandle.h"
+#include "platform/DirHandle.h"
 
 // mbed Non-hardware components
 #include "platform/Callback.h"

platform/FilePath.cpp

@@ -49,9 +49,9 @@ bool FilePath::isFileSystem(void) {
     return (fb->getPathType() == FileSystemPathType);
 }
 
-FileSystem* FilePath::fileSystem(void) {
+FileSystemLike* FilePath::fileSystem(void) {
     if (isFileSystem()) {
-        return (FileSystem*)fb;
+        return static_cast<FileSystemLike*>(fb);
     }
     return NULL;
 }

platform/FilePath.h

@@ -37,7 +37,7 @@ class FilePath {
     const char* fileName(void);
 
     bool          isFileSystem(void);
-    FileSystem* fileSystem(void);
+    FileSystemLike* fileSystem(void);
 
     bool    isFile(void);
     FileLike* file(void);

platform/FileSystemHandle.cpp

@@ -0,0 +1,44 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2006-2013 ARM Limited
+ *
+ * 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.
+ */
+
+#include "mbed.h"
+#include "FileSystemHandle.h"
+#include <errno.h>
+
+int FileSystemHandle::open(DirHandle **dir, const char *path)
+{
+    return -ENOSYS;
+}
+
+int FileSystemHandle::remove(const char *path)
+{
+    return -ENOSYS;
+}
+
+int FileSystemHandle::rename(const char *path, const char *newpath)
+{
+    return -ENOSYS;
+}
+
+int FileSystemHandle::stat(const char *path, struct stat *st)
+{
+    return -ENOSYS;
+}
+
+int FileSystemHandle::mkdir(const char *path, mode_t mode)
+{
+    return -ENOSYS;
+}

platform/FileSystemHandle.h

@@ -0,0 +1,99 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2006-2013 ARM Limited
+ *
+ * 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_FILESYSTEMHANDLE_H
+#define MBED_FILESYSTEMHANDLE_H
+
+#include "platform/platform.h"
+
+#include "platform/FileBase.h"
+#include "platform/FileHandle.h"
+#include "platform/DirHandle.h"
+
+namespace mbed {
+/** \addtogroup drivers */
+/** @{*/
+
+
+/** A filesystem-like object is one that can be used to open file-like
+ *  objects though it by fopen("/name/filename", mode)
+ *
+ *  Implementations must define at least open (the default definitions
+ *  of the rest of the functions just return error values).
+ *
+ * @Note Synchronization level: Set by subclass
+ */
+class FileSystemHandle {
+public:
+    /** FileSystemHandle lifetime
+     */
+    virtual ~FileSystemHandle() {}
+
+    /** Open a file on the filesystem
+     *
+     *  @param file     Destination for the handle to a newly created file
+     *  @param path     The name of the file to open
+     *  @param flags    The flags to open the file in, one of O_RDONLY, O_WRONLY, O_RDWR,
+     *                  bitwise or'd with one of O_CREAT, O_TRUNC, O_APPEND
+     *  @return         0 on success, negative error code on failure
+     */
+    virtual int open(FileHandle **file, const char *filename, int flags) = 0;
+
+    /** Open a directory on the filesystem
+     *
+     *  @param dir      Destination for the handle to the directory
+     *  @param path     Name of the directory to open
+     *  @return         0 on success, negative error code on failure
+     */
+    virtual int open(DirHandle **dir, const char *path);
+
+    /** Remove a file from the filesystem.
+     *
+     *  @param path     The name of the file to remove.
+     *  @return         0 on success, negative error code on failure
+     */
+    virtual int remove(const char *path);
+
+    /** Rename a file in the filesystem.
+     *
+     *  @param path     The name of the file to rename.
+     *  @param newpath  The name to rename it to
+     *  @return         0 on success, negative error code on failure
+     */
+    virtual int rename(const char *path, const char *newpath);
+
+    /** Store information about the file in a stat structure
+     *
+     *  @param path     The name of the file to find information about
+     *  @param st       The stat buffer to write to
+     *  @return         0 on success, negative error code on failure
+     */
+    virtual int stat(const char *path, struct stat *st);
+
+    /** Create a directory in the filesystem.
+     *
+     *  @param path     The name of the directory to create.
+     *  @param mode     The permissions with which to create the directory
+     *  @return         0 on success, negative error code on failure
+     */
+    virtual int mkdir(const char *path, mode_t mode);
+};
+
+
+} // namespace mbed
+
+#endif
+
+/** @}*/