Very preliminary: remove from BattFS the LRU of free blocks; now the old blocks are...

[bertos.git] / bertos / fs / battfs.h

diff --git a/bertos/fs/battfs.h b/bertos/fs/battfs.h
index d75bd6452fc941c26e74c1f2aa6d4a248d4e56bf..0422c43a7497181a5d03264c123bf9cf39a655ff 100644 (file)
--- a/bertos/fs/battfs.h
+++ b/bertos/fs/battfs.h
@@ -51,7 +51,6 @@ typedef uint16_t fill_t;    ///< Type for keeping trace of space filled inside a
 typedef fill_t   pgaddr_t;  ///< Type for addressing space inside a page
 typedef uint16_t pgcnt_t;   ///< Type for counting pages on disk
 typedef pgcnt_t  pgoff_t;   ///< Type for counting pages inside a file
-typedef uint32_t mark_t;    ///< Type for marking pages as free
 typedef uint8_t  inode_t;   ///< Type for file inodes
 typedef uint8_t  seq_t;     ///< Type for page seq number
 typedef rotating_t fcs_t;   ///< Type for header FCS.
@@ -60,7 +59,7 @@ typedef rotating_t fcs_t;   ///< Type for header FCS.
  * Size required for free block allocation is at least 1 bit more
  * than page addressing.
  */
-STATIC_ASSERT(sizeof(mark_t) > sizeof(pgcnt_t));
+STATIC_ASSERT(sizeof(seq_t) > sizeof(pgcnt_t));
 
 /**
  * BattFS page header, used to represent a page
@@ -72,16 +71,9 @@ STATIC_ASSERT(sizeof(mark_t) > sizeof(pgcnt_t));
 typedef struct BattFsPageHeader
 {
        inode_t  inode; ///< File inode (file identifier).
-       seq_t    seq;   ///< Page sequence number.
        fill_t   fill;  ///< Filled bytes in page.
        pgoff_t  pgoff; ///< Page offset inside file.
-       mark_t   mark;  ///< Marker used to keep trace of free/used pages.
-
-       /**
-        * FCS (Frame Check Sequence) of the page header once the page
-        * as been marked as free.
-        */
-       fcs_t fcs_free;
+       seq_t    seq;   ///< Page sequence number.
 
        /**
         * FCS (Frame Check Sequence) of the page header.
@@ -94,23 +86,18 @@ typedef struct BattFsPageHeader
  * \see battfs_to_disk
  * \see disk_to_battfs
  */
-#define BATTFS_HEADER_LEN 12
+#define BATTFS_HEADER_LEN 10
 
 /**
- * Marks for valid pages.
- * Simply set to 1 all field bits.
- * \{
+ * Half-size of page sequence numer.
  */
-#define MARK_PAGE_VALID ((1 << (CPU_BITS_PER_CHAR * sizeof(pgcnt_t) + 1)) - 1)
-#define FCS_FREE_VALID  ((1 << (CPU_BITS_PER_CHAR * sizeof(fcs_t))) - 1)
-/* \} */
-
+#define HALF_SEQ (1 << (CPU_BITS_PER_CHAR * sizeof(pgcnt_t)))
 
 /**
- * Half-size of free page marker.
- * Used to keep trace of free marker wrap-arounds.
+ * Max sequence number.
  */
-#define MARK_HALF_SIZE (1 << (CPU_BITS_PER_CHAR * sizeof(pgcnt_t) + 1))
+#define MAX_SEQ ((1 << (CPU_BITS_PER_CHAR * sizeof(pgcnt_t) + 1)) - 1)
+
 
 /**
  * Maximum page address.
@@ -130,6 +117,9 @@ struct BattFsSuper;
  */
 #define PAGE_UNSET_SENTINEL ((1 << (CPU_BITS_PER_CHAR * sizeof(pgcnt_t))) - 1)
 
+/** Also used as an error marker sometimes */
+#define PAGE_ERROR PAGE_UNSET_SENTINEL
+
 /**
  * Type interface for disk init function.
  * \return true if all is ok, false otherwise.
@@ -193,17 +183,11 @@ typedef struct BattFsSuper
         */
        pgcnt_t *page_array;
 
-        /**
-        * Lowest free page counter.
-        * This is the counter of the first availble free page.
-        */
-       mark_t free_start;
-
-        /**
-        * Highest free page counter.
-        * This value is the next to be used to mark a block as free.
+       /**
+        * Lowest address, in page array, for free pages.
+        * Pages above this element are free for use.
         */
-       mark_t free_next;
+       pgcnt_t free_page_start;
 
        disk_size_t disk_size;   ///< Size of the disk, in bytes (page_count * page_size).
        disk_size_t free_bytes;  ///< Free space on the disk.
@@ -228,7 +212,7 @@ typedef uint32_t file_size_t; ///< Type for file sizes.
 /**
  * Describe a BattFs file usign a KFile.
  */
-typedef struct BattFS
+typedef struct BattFs
 {
        KFile fd;           ///< KFile context
        Node link;          ///< Link for inserting in opened file list
@@ -236,7 +220,7 @@ typedef struct BattFS
        BattFsSuper *disk;  ///< Disk context
        filemode_t mode;    ///< File open mode
        pgcnt_t *start;     ///< Pointer to page_array file start position.
-} BattFS;
+} BattFs;
 
 /**
  * Id for battfs file descriptors.
@@ -247,18 +231,17 @@ typedef struct BattFS
  * Macro used to cast a KFile to a BattFS.
  * Also perform dynamic type check.
  */
-INLINE BattFS * BATTFSKFILE(KFile *fd)
+INLINE BattFs * BATTFS_CAST(KFile *fd)
 {
        ASSERT(fd->_type == KFT_BATTFS);
-       return (BattFS *)fd;
+       return (BattFs *)fd;
 }
 
 bool battfs_init(struct BattFsSuper *d);
 bool battfs_close(struct BattFsSuper *disk);
 
 bool battfs_fileExists(BattFsSuper *disk, inode_t inode);
-bool battfs_fileopen(BattFsSuper *disk, BattFS *fd, inode_t inode, filemode_t mode);
-
-bool battfs_writeTestBlock(struct BattFsSuper *disk, pgcnt_t page, inode_t inode, seq_t seq, fill_t fill, pgoff_t pgoff, mark_t mark);
+bool battfs_fileopen(BattFsSuper *disk, BattFs *fd, inode_t inode, filemode_t mode);
 
+bool battfs_writeTestBlock(struct BattFsSuper *disk, pgcnt_t page, inode_t inode, seq_t seq, fill_t fill, pgoff_t pgoff, seq_t seq);
 #endif /* FS_BATTFS_H */