File base class (work in progress)

teensy3/FS.h

-/* Experimental File & Dir base classes.  VERY experimental!
-
-   These are intended to someday allow libraries using files,
-   such as a JPEG decoder, to accept a File object from SD,
-   Bridge, USB Host, ESP SPIFFS, and others.  Perhaps only a
-   distant dream at this point, but maybe someday....
+/* Experimental File & FS base classes.
 */
 
-
 #ifndef FS_H
 #define FS_H
 #ifdef __cplusplus
 
-#include "Stream.h"
-#include "WString.h"
+#include <Arduino.h>
+
+#define FILE_READ  0
+#define FILE_WRITE 1
+
+enum SeekMode {
+	SeekSet = 0,
+	SeekCur = 1,
+	SeekEnd = 2
+};
+
+class File;
 
 class File : public Stream {
 public:
-	constexpr File() {}
-	enum SeekMode {
-		SeekSet = 0,
-		SeekCur = 1,
-		SeekEnd = 2
-	};
+	constexpr File() : f(nullptr) { }
+	constexpr File(const File &file) : f(file.f) { }
+	virtual ~File();
 	virtual size_t read(void *buf, size_t nbyte);
 	virtual size_t write(const void *buf, size_t size);
 	virtual int available();
 	virtual uint32_t size() const;
 	virtual void close();
 	virtual operator bool() const;
-	//virtual const char* name() const; // why does ESP have this in File?
+	virtual const char* name();
+	virtual bool isDirectory();
+	virtual File openNextFile(uint8_t mode=0);
+	virtual void rewindDirectory(void);
 
-	bool seek(uint32_t pos) {
+	virtual bool seek(uint32_t pos) {
 		return seek(pos, SeekSet);
 	}
-	size_t write(uint8_t b) {
+	virtual size_t write(uint8_t b) {
 		return write(&b, 1);
 	}
-	size_t write(const char *str) {
+	virtual size_t write(const char *str) {
 		return write(str, strlen(str));
 	}
-	size_t readBytes(char *buffer, size_t length) {
+	virtual size_t readBytes(char *buffer, size_t length) {
 		return read(buffer, length);
 	}
-
-	// needed for compatiblity with Arduino's SD & Bridge libs
-	virtual const char* name();
-	virtual bool isDirectory();
-	virtual File openNextFile(uint8_t mode=0);
-	virtual void rewindDirectory(void);
+	virtual void whoami(); // testing only
+//protected:
+	File *f; // points to actual implementing class, or nullptr
 };
 
-class Dir {
+
+class FS
+{
 public:
-	constexpr Dir() {}
-	virtual const char *name(); // from SD's File (and ESP's File)
-	virtual uint32_t fileSize();
-	virtual bool isDirectory(); // from SD, not in ESP
-	virtual File openFile(const char *mode);
-	virtual bool next();
-	String fileName() {
-		return String(name());
-	}
+	FS() {}
+	File open(const char *filename, uint8_t mode = FILE_READ);
+	bool exists(const char *filepath);
+	bool mkdir(const char *filepath);
+	bool remove(const char *filepath);
+	bool rmdir(const char *filepath);
 };
 
+
 #endif // __cplusplus
 #endif // FS_H