nuttx/fs/spiffs/src/spiffs_cache.h

/****************************************************************************
 * fs/spiffs.h/spiffs_cache.h
 *
 *   Copyright (C) 2018 Gregory Nutt. All rights reserved.
 *   Author: Gregory Nutt <gnutt@nuttx.org>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name NuttX nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 ****************************************************************************/

#ifndef __FS_SPIFFS_SRC_SPIFFS_CACHE_H
#define __FS_SPIFFS_SRC_SPIFFS_CACHE_H

#if defined(__cplusplus)
extern "C"
{
#endif

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <nuttx/config.h>

#include <stdint.h>

/****************************************************************************
 * Pre-processor Definitions
 ****************************************************************************/

#define SPIFFS_CACHE_FLAG_DIRTY       (1 << 0)
#define SPIFFS_CACHE_FLAG_WRTHRU      (1 << 1)
#define SPIFFS_CACHE_FLAG_OBJLU       (1 << 2)
#define SPIFFS_CACHE_FLAG_OBJIX       (1 << 3)
#define SPIFFS_CACHE_FLAG_DATA        (1 << 4)
#define SPIFFS_CACHE_FLAG_TYPE_WR     (1 << 7)

#define SPIFFS_CACHE_PAGE_SIZE(fs) \
  (sizeof(struct spiffs_cache_page_s) + SPIFFS_GEO_PAGE_SIZE(fs))

#define spiffs_get_cache(fs) \
  ((FAR struct spiffs_cache_s *)((fs)->cache))

#define spiffs_get_cache_page_hdr(fs, c, cpndx) \
  ((FAR struct spiffs_cache_page_s *)(&((c)->cpages[(cpndx) * \
  SPIFFS_CACHE_PAGE_SIZE(fs)])))

#define spiffs_get_cache_page(fs, c, cpndx) \
  ((FAR uint8_t *)(&((c)->cpages[(cpndx) * SPIFFS_CACHE_PAGE_SIZE(fs)])) + \
  sizeof(struct spiffs_cache_page_s))

/* Debug */

#ifdef CONFIG_SPIFFS_CACHEDBG
#  ifdef CONFIG_CPP_HAVE_VARARGS
#    define spiffs_cacheinfo(format, ...)   _info(format, ##__VA_ARGS__)
#  else
#    define spiffs_cacheinfo                _info
#  endif
#else
#  ifdef CONFIG_CPP_HAVE_VARARGS
#    define spiffs_cacheinfo(format, ...)
#  else
#    define spiffs_cacheinfo                (void)
#  endif
#endif

/****************************************************************************
 * Public Types
 ****************************************************************************/

/* cache page struct */

struct spiffs_cache_page_s
{
  uint8_t flags;             /* Cache flags */
  uint8_t cpndx;             /* Cache page index */
  uint32_t last_access;      /* Last access of this cache page */
  union
    {
      struct                 /* Type read cache */
        {
          int16_t pgndx;     /* Read cache page index */
        };

      struct                 /* Type write cache */
        {
          int16_t objid;     /* Write cache */
          uint32_t offset;   /* Offset in cache page */
          uint16_t size;     /* Size of cache page */
        };
    };
};

/* Cache structure */

struct spiffs_cache_s
{
  uint8_t cpage_count;
  uint32_t last_access;
  uint32_t cpage_use_map;
  uint32_t cpage_use_mask;
  FAR uint8_t *cpages;
};

/****************************************************************************
 * Public Function Prototypes
 ****************************************************************************/

struct spiffs_s;  /* Forward reference */

/****************************************************************************
 * Name: spiffs_cache_initialize
 *
 * Description:
 *   Initializes the cache
 *
 * Input Parameters:
 *   fs  - A reference to the SPIFFS volume object instance
 *   cp  - The cache page to be released
 *
 * Returned Value:
 *   None
 *
 ****************************************************************************/

void spiffs_cache_initialize(FAR struct spiffs_s *fs);

/****************************************************************************
 * Name: spiffs_cache_drop_page
 *
 * Description:
 *   Drops the cache page for give page index
 *
 * Input Parameters:
 *   fs    - A reference to the SPIFFS volume object instance
 *   pgndx - Page index to be dropped
 *
 * Returned Value:
 *   None
 *
 ****************************************************************************/

void spiffs_cache_drop_page(FAR struct spiffs_s *fs, int16_t pgndx);

/****************************************************************************
 * Name: spiffs_cache_read
 *
 * Description:
 *   Reads from SPI FLASH or the cache
 *
 * Input Parameters:
 *   fs    - A reference to the SPIFFS volume object instance
 *   op    - Read options
 *   objid - File object ID to read
 *   addr  - Address to read from
 *   len   - The number of bytes to be read
 *   dest  - The location in which the read data is to be returned.
 *
 * Returned Value:
 *   The number of bytes read (len) is returned on success; A negated
 *   errno value is returned on any failure.
 *
 ****************************************************************************/

ssize_t spiffs_cache_read(FAR struct spiffs_s *fs, uint8_t op, int16_t objid,
                          off_t addr, size_t len, FAR uint8_t *dest);

/****************************************************************************
 * Name: spiffs_cache_write
 *
 * Description:
 *   Writes to SPI FLASH and/or the cache
 *
 * Input Parameters:
 *   fs    - A reference to the SPIFFS volume object instance
 *   op    - Write options
 *   objid - File object ID to write
 *   addr  - Address to write to
 *   len   - The number of bytes to be write
 *   dest  - The location that provide the data to be written.
 *
 * Returned Value:
 *   The number of bytes written (len) is returned on success; A negated
 *   errno value is returned on any failure.
 *
 ****************************************************************************/

size_t spiffs_cache_write(FAR struct spiffs_s *fs, uint8_t op, int16_t objid,
                          off_t addr, size_t len, FAR uint8_t *src);

/****************************************************************************
 * Name: spiffs_cache_write
 *
 * Description:
 *   Returns the cache page that this file object refers to (or NULL if
 *   there is no cache page
 *
 * Input Parameters:
 *   fs    - A reference to the SPIFFS volume object instance
 *   fobj  - The file object instance
 *
 * Returned Value:
 *   Returns the cache page that this file object refers to (or NULL if
 *   there is no cache page
 *
 ****************************************************************************/

FAR struct spiffs_cache_page_s *
  spiffs_cache_page_get_byobjid(FAR struct spiffs_s *fs,
                                FAR struct spiffs_file_s *fobj);

/****************************************************************************
 * Name: spiffs_cache_page_allocate_byobjid
 *
 * Description:
 *   Allocates a new cache page and refers this to given object ID.  It
 *   flushes an old cache page if all cache pages are busy
 *
 * Input Parameters:
 *   fs    - A reference to the SPIFFS volume object instance
 *   fobj  - The file object instance
 *
 * Returned Value:
 *   Returns the allocated cache page(or NULL if the cache page could not
 *   be allocated).
 *
 ****************************************************************************/

FAR struct spiffs_cache_page_s *
  spiffs_cache_page_allocate_byobjid(FAR struct spiffs_s *fs,
                                     FAR struct spiffs_file_s *fobj);

/****************************************************************************
 * Name: spiffs_cache_page_release
 *
 * Description:
 *   "Unrefers" all file objects that this cache page refers to and releases
 *   the cache page
 *
 * Input Parameters:
 *   fs  - A reference to the SPIFFS volume object instance
 *   cp  - The cache page to be released
 *
 * Returned Value:
 *   None
 *
 ****************************************************************************/

void spiffs_cache_page_release(FAR struct spiffs_s *fs,
                               FAR struct spiffs_cache_page_s *cp);

#if defined(__cplusplus)
}
#endif

#endif  /* __FS_SPIFFS_SRC_SPIFFS_CACHE_H */