dbz.h

linux下的BBS

#ifndef __DBZ_H__
#define __DBZ_H__

#ifndef TRUE
# define TRUE                   1
#endif
#ifndef FALSE
# define FALSE                  0
#endif
typedef int BOOL;

#define OFFSET_T        off_t
#define NOTFOUND        ((OFFSET_T)-1)
typedef struct {
  char hash[16];
} HASH;
typedef caddr_t MMAP_PTR;
typedef void *POINTER;

#define NEW(T, c)               malloc(sizeof(T) * (c))
#define DISPOSE(p)              free(p)



/* This is the number of bytes of the md5 to actually store in
 * the .pag file.  This number directly effects the collision
 * rate and memory usage.  You can probably set this number as
 * low as 5 w/o problems and some sites may want to set it as
 * high as 8.  Anything higher than that is probably not useful.
 * Note at the internal hash size isn't the only factor that
 * effects collision rate.  The table index is used as an implicit
 * part of the hash value stored also.
 */
#ifdef	DO_TAGGED_HASH
#define DBZMAXKEY	255
#define DBZ_INTERNAL_HASH_SIZE   4
#else
#define DBZ_INTERNAL_HASH_SIZE   6
#endif

typedef enum { INCORE_NO, INCORE_MEM, INCORE_MMAP } dbz_incore_val;

typedef struct {
  /* Whether to write to the filesystem in addition to updating the incore
     copy.  This will replace a single large write to disk when dbzsync is
     called.  */
  BOOL writethrough;
  /* Whether to do hash lookups from disk, memory or a mmap'ed file */
#ifdef	DO_TAGGED_HASH
  dbz_incore_val pag_incore;
#else
  dbz_incore_val idx_incore;
#endif
  dbz_incore_val exists_incore;
  /* Whether dbzstore should update the database async or sync.  This
     is only applicable if you're not mmaping the database */
  BOOL nonblock;
} dbzoptions;

/* standard dbm functions */
extern BOOL dbminit (const char *name);
extern BOOL dbmclose (void);

/* new stuff for dbz */
extern BOOL dbzfresh (const char *name, const long size,
  const int fillpercent);
extern BOOL dbzagain (const char *name, const char *oldname);
extern BOOL dbzexists (const HASH key);
extern OFFSET_T dbzfetch (const HASH key);
extern BOOL dbzstore (const HASH key, const OFFSET_T data);
extern BOOL dbzsync (void);
extern long dbzsize (const long contents);
extern BOOL dbzdebug (const int value);
extern void dbzsetoptions (const dbzoptions options);
extern void dbzgetoptions (dbzoptions * options);

#endif /* __DBZ_H__ */