X-Git-Url: https://codewiz.org/gitweb?a=blobdiff_plain;f=fs%2Fbattfs.h;h=14728a8d2b199f82c36054fa9237bbdb1bc5904a;hb=75aa6c9fd80bb9d4bb3dc3ffb001a266915fe14f;hp=a3ef1cc654c623d93c2dcc68e8b9f9ed9ceed858;hpb=bafd7a54873af4dec7b7d3b94bf2cdfd0aa2d1b6;p=bertos.git

diff --git a/fs/battfs.h b/fs/battfs.h
index a3ef1cc6..14728a8d 100644
--- a/fs/battfs.h
+++ b/fs/battfs.h
@@ -43,13 +43,15 @@
 
 #include <cfg/compiler.h> // uintXX_t; STATIC_ASSERT
 #include <cpu/types.h> // CPU_BITS_PER_CHAR
+#include <algo/rotating_hash.h>
 
 typedef uint16_t fill_t;
+typedef fill_t   pgaddr_t;
 typedef uint16_t pgoff_t;
 typedef pgoff_t  mark_t;
 typedef uint8_t  inode_t;
 typedef uint8_t  seq_t;
-typedef uint16_t  fcs_t;
+typedef rotating_t fcs_t;
 
 /**
  * BattFS page header.
@@ -63,47 +65,79 @@ typedef struct BattFsPageHeader
 	mark_t   mark;  ///< Marker used to keep trace of free/used pages.
 	pgoff_t  pgoff; ///< Page offset inside file.
 	fill_t   fill;  ///< Filled bytes in page.
-	uint16_t rfu;  ///< Reserved for future use, 0xFFFF for now.
-	fcs_t    fcs;   ///< FCS (Frame Check Sequence) of the page header.
-} BattFsPageHeader;
+	uint16_t rfu;   ///< Reserved for future use, 0xFFFF for now.
 
+	/**
+	 * FCS (Frame Check Sequence) of the page header.
+	 * \note This field must be the last one!
+	 *       This is needed because if the page is only partially
+	 *       written, we can use this to detect it.
+	 */
+	fcs_t fcs;
+} BattFsPageHeader;
 /* Ensure structure has no padding added */
 STATIC_ASSERT(sizeof(BattFsPageHeader) == 12);
 
+
+/**
+ * Mark for valid pages.
+ * Simply set to 1 all field bits.
+ */
+#define MARK_PAGE_VALID ((1 << (CPU_BITS_PER_CHAR * sizeof(mark_t))) - 1)
+
+/**
+ * Max number of files.
+ */
+#define BATTFS_MAX_FILES (1 << (CPU_BITS_PER_CHAR * sizeof(inode_t)))
+
 /* Fwd decl */
 struct BattFsSuper;
 
 /**
  * Type for disk page addressing.
  */
-typedef uint32_t battfs_page_t;
+typedef uint16_t pgcnt_t;
+
+/**
+ * Sentinel used to keep trace of unset pages in disk->pag_array.
+ */
+#define PAGE_UNSET_SENTINEL ((1 << (CPU_BITS_PER_CHAR * sizeof(pgcnt_t))) - 1)
 
 /**
  * Type interface for disk init function.
  * \return true if all is ok, false otherwise.
  */
-typedef bool (*disk_init_t) (struct BattFsSuper *d);
+typedef bool (*disk_open_t) (struct BattFsSuper *d);
 
 /**
  * Type interface for disk page read function.
- * \a page is the page address, \a size the lenght to be read.
+ * \a page is the page address, \a addr the address inside the page,
+ * \a size the lenght to be read.
  * \return the number of bytes read.
  */
-typedef size_t (*disk_page_read_t) (struct BattFsSuper *d, void *buf, battfs_page_t page, size_t size);
+typedef size_t (*disk_page_read_t) (struct BattFsSuper *d, pgcnt_t page, pgaddr_t addr, void *buf, size_t);
 
 /**
  * Type interface for disk page write function.
- * \a page is the page address, \a size the lenght to be written.
+ * \a page is the page address, \a addr the address inside the page,
+ * \a size the lenght to be written.
  * \return the number of bytes written.
  */
-typedef size_t	(*disk_page_write_t) (struct BattFsSuper *d, const void *buf, battfs_page_t page, size_t size);
+typedef size_t	(*disk_page_write_t) (struct BattFsSuper *d, pgcnt_t page, pgaddr_t addr, void *buf, size_t);
 
 /**
  * Type interface for disk page erase function.
  * \a page is the page address.
  * \return true if all is ok, false otherwise.
  */
-typedef bool (*disk_page_erase_t) (struct BattFsSuper *d, battfs_page_t page);
+typedef bool (*disk_page_erase_t) (struct BattFsSuper *d, pgcnt_t page);
+
+/**
+ * Type interface for disk deinit function.
+ * \return true if all is ok, false otherwise.
+ */
+typedef bool (*disk_close_t) (struct BattFsSuper *d);
+
 
 typedef uint32_t disk_size_t; ///< Type for disk sizes.
 
@@ -114,14 +148,33 @@ typedef uint32_t disk_size_t; ///< Type for disk sizes.
  */
 typedef struct BattFsSuper
 {
-	disk_init_t init;        ///< Disk init.
+	disk_open_t open;        ///< Disk init.
 	disk_page_read_t  read;  ///< Page read.
 	disk_page_write_t write; ///< Page write.
 	disk_page_erase_t erase; ///< Page erase.
+	disk_close_t close;      ///< Disk deinit.
+
+	pgaddr_t page_size;      ///< Size of a disk page, in bytes.
+	pgcnt_t page_count;      ///< Number of pages on disk.
+
+	/**
+	 * Page allocation array.
+	 * This array must be allocated somewhere and
+	 * must have enough space for page_count elements.
+	 * Is used by the filesystem to represent
+	 * the entire disk in memory.
+	 */
+	pgcnt_t *page_array;
 
-	disk_size_t disk_size;   ///< Size of the disk, in bytes.
+	mark_t min_free; ///< Lowest sequence number of free page
+	mark_t max_free; ///< Highest sequence number of free page
+
+	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.
+	
 	/* TODO add other fields. */
 } BattFsSuper;
 
+bool battfs_init(struct BattFsSuper *d);
+
 #endif /* FS_BATTFS_H */