OpenModem/bertos/io/kfile.h

/**
 * \file
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 * Copyright 2004 Develer S.r.l. (http://www.develer.com/)
 * Copyright 1999, 2000, 2001, 2003 Bernie Innocenti <bernie@codewiz.org>
 *
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 *
 * \defgroup io_kfile KFile interface
 * \ingroup core
 * \{
 *
 * \brief Virtual KFile I/O interface.
 *
 * KFile is a simple, generic interface for file I/O.  It uses an
 * object-oriented model to supply a device-neutral interface to
 * communicate with drivers.
 *
 * This module contains only definitions, the instance structure
 * and the common API.
 * Each KFile subclass can override one or more methods of the interface,
 * and can extend the base KFile structure with its own private data.
 * For instance, a serial driver might implement the KFile interface by
 * declaring a context structure like this:
 *
 * \code
 * typedef struct Serial
 * {
 *      // base class instance
 *      KFile fd;
 *
 *      // private instance data
 *      FIFOBuffer txfifo, rxfifo;
 * } Serial;
 * \endcode
 *
 * You should also supply a macro for casting KFile to Serial:
 *
 * \code
 * INLINE Serial * SERIAL_CAST(KFile *fd)
 * {
 *		ASSERT(fd->_type == KFT_SERIAL);
 *		return (Serial *)fd;
 * }
 * \endcode
 *
 * Then you can implement as many interface functions as needed
 * and leave the rest to NULL.
 *
 * Example implementation of the close KFile method for Serial:
 *
 * \code
 * static int ser_kfile_close(struct KFile *fd)
 * {
 *		Serial *fds = SERIAL_CAST(fd);
 *      // [driver specific code here]
 *		return 0;
 * }
 * \endcode
 *
 * The SERIAL_CAST() macro helps ensure that the passed object is
 * really of type Serial.
 *
 * The KFile interface does not supply an open function: this is deliberate,
 * because in embedded systems each device has its own init parameters.
 * For the same reason, specific device settings like, for example,
 * the baudrate, are not part of interface and should be handled by the
 * driver-specific API.
 *
 * \author Bernie Innocenti <bernie@codewiz.org>
 * \author Francesco Sacchi <batt@develer.com>
 * \author Daniele Basile <asterix@develer.com>
 *
 * $WIZ$ module_name = "kfile"
 * $WIZ$ module_configuration = "bertos/cfg/cfg_kfile.h"
 * $WIZ$ module_depends = "timer", "formatwr"
 */

#ifndef KERN_KFILE_H
#define KERN_KFILE_H

#include <cfg/compiler.h>
#include <cfg/debug.h>
#include <cfg/macros.h>

/* fwd decl */
struct KFile;

typedef int32_t kfile_off_t;     ///< KFile offset type, used by kfile_seek().

/**
 * Costants for repositioning read/write file offset.
 * These are needed because on some embedded platforms
 * ANSI I/O library may not be present.
 */
typedef enum KSeekMode
{
	KSM_SEEK_SET, ///< Seek from file beginning.
	KSM_SEEK_CUR, ///< Seek from file current position.
	KSM_SEEK_END, ///< Seek from file end.
} KSeekMode;

/*
 * Prototypes for KFile access functions.
 * I/O file functions must be ANSI compliant.
 * \note A KFile user can choose which function subset to implement,
 *       but has to set to NULL unimplemented features.
 */

/*
 * Read from file.
 * \return the number of bytes read.
 */
typedef size_t (*ReadFunc_t) (struct KFile *fd, void *buf, size_t size);

/*
 * Write to file.
 * \return the number of bytes written.
 */
typedef size_t (*WriteFunc_t) (struct KFile *fd, const void *buf, size_t size);

/*
 * Seek into file (if seekable).
 * \return the new file offset or EOF on errors.
 */
typedef kfile_off_t (*SeekFunc_t) (struct KFile *fd, kfile_off_t offset, KSeekMode whence);

/*
 * Close and reopen file \a fd.
 * The reopening is done with the former file parameters and access modes.
 */
typedef struct KFile * (*ReOpenFunc_t) (struct KFile *fd);

/*
 * Close file.
 * \return 0 on success, EOF on errors.
 */
typedef int (*CloseFunc_t) (struct KFile *fd);

/*
 * Flush file I/O.
 * \return 0 on success, EOF on errors.
 */
typedef int (*FlushFunc_t) (struct KFile *fd);

/*
 * Get file error mask.
 * \return 0 on success or file error code, device specific.
 */
typedef int (*ErrorFunc_t) (struct KFile *fd);

/*
 * Clear errors.
 */
typedef void (*ClearErrFunc_t) (struct KFile *fd);

/**
 * Context data for callback functions which operate on
 * pseudo files.
 *
 * \note Remember to add the corresponding accessor functions
 *       when extending this interface.
 */
typedef struct KFile
{
	ReadFunc_t     read;
	WriteFunc_t    write;
	ReOpenFunc_t   reopen;
	CloseFunc_t    close;
	SeekFunc_t     seek;
	FlushFunc_t    flush;
	ErrorFunc_t    error;
	ClearErrFunc_t clearerr;
	DB(id_t _type); // Used to keep track, at runtime, of the class type.

	/* NOTE: these must _NOT_ be size_t on 16bit CPUs! */
	kfile_off_t    seek_pos;
	kfile_off_t    size;
} KFile;

/*
 * Generic implementation of kfile_seek.
 */
kfile_off_t kfile_genericSeek(struct KFile *fd, kfile_off_t offset, KSeekMode whence);

/*
 * Generic implementation of kfile_reopen.
 */
struct KFile * kfile_genericReopen(struct KFile *fd);

int kfile_genericClose(struct KFile *fd);

/** @name KFile access functions
 * Interface functions for KFile access.
 * @{
 */

/**
 * Read \a size bytes from file \a fd into \a buf.
 *
 * This function reads at most the number of requested bytes into the
 * provided buffer.
 * The value returned may be less than the requested bytes in case EOF is
 * reached OR an error occurred. You need to check the error conditions
 * using kfile_error() to understand which case happened.
 *
 * \note This function will block if there are less than \a size bytes
 *       to read.
 *
 * \param fd KFile context.
 * \param buf User provided buffer.
 * \param size Number of bytes to read.
 * \return Number of bytes read.
 */
INLINE size_t kfile_read(struct KFile *fd, void *buf, size_t size)
{
	ASSERT(fd->read);
	return fd->read(fd, buf, size);
}
int kfile_gets(struct KFile *fd, char *buf, int size);
int kfile_gets_echo(struct KFile *fd, char *buf, int size, bool echo);

/**
 * Copy \a size bytes from file \a src to \a dst.
 *
 * \param src Source KFile.
 * \param dst Destionation KFile.
 * \param size number of bytes to copy.
 * \return the number of bytes copied.
 */
kfile_off_t kfile_copy(KFile *src, KFile *dst, kfile_off_t size);

/**
 * Write \a size bytes from buffer \a buf into KFile \a fd.
 *
 * Return value may be less than \a size.
 *
 * \param fd KFile context.
 * \param buf User provided data.
 * \param size Number of bytes to write.
 * \return Number of bytes written.
 */
INLINE size_t kfile_write(struct KFile *fd, const void *buf, size_t size)
{
	ASSERT(fd->write);
	return fd->write(fd, buf, size);
}

int kfile_printf(struct KFile *fd, const char *format, ...);
int kfile_print(struct KFile *fd, const char *s);

/**
 * Seek into file (if seekable).
 *
 * Move \a fd file seek position of \a offset bytes from \a whence.
 *
 * \param fd KFile context.
 * \param offset Offset bytes to move from position \a whence.
 * \param whence Position where to start the seek.
 * \return Current postion in the file.
 */
INLINE kfile_off_t kfile_seek(struct KFile *fd, kfile_off_t offset, KSeekMode whence)
{
	ASSERT(fd->seek);
	return fd->seek(fd, offset, whence);
}

/**
 * Close and reopen file \a fd.
 * The reopening is done with the former file parameters and access modes.
 */
INLINE KFile * kfile_reopen(struct KFile *fd)
{
	ASSERT(fd->reopen);
	return fd->reopen(fd);
}

/**
 * Close file.
 * \return 0 on success, EOF on errors.
 */
INLINE int kfile_close(struct KFile *fd)
{
	ASSERT(fd->close);
	return fd->close(fd);
}

/**
 * Flush file I/O.
 * \return 0 on success, EOF on errors.
 */
INLINE int kfile_flush(struct KFile *fd)
{
	ASSERT(fd->flush);
	return fd->flush(fd);
}

/**
 * Get file error mask.
 * \return 0 on success or file error code, device specific.
 */
INLINE int kfile_error(struct KFile *fd)
{
	ASSERT(fd->error);
	return fd->error(fd);
}

/**
 * Clear errors.
 */
INLINE void kfile_clearerr(struct KFile *fd)
{
	ASSERT(fd->clearerr);
	fd->clearerr(fd);
}

int kfile_putc(int c, struct KFile *fd); ///< Generic putc implementation using kfile_write.
int kfile_getc(struct KFile *fd);  ///< Generic getc implementation using kfile_read.
void kfile_resync(KFile *fd, mtime_t delay);
void kfile_init(struct KFile *fd);
/* @} */

/** \} */ //Defgroup io_kfile

/*
 * Kfile test function.
 */
int kfile_testSetup(void);
int kfile_testRun(void);
int kfile_testRunGeneric(KFile *fd, uint8_t *test_buf, uint8_t *save_buf, size_t size);
int kfile_testTearDown(void);


#endif /* KERN_KFILE_H */