diff options
Diffstat (limited to 'ext/sdbm/sdbm.h')
-rw-r--r-- | ext/sdbm/sdbm.h | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/ext/sdbm/sdbm.h b/ext/sdbm/sdbm.h new file mode 100644 index 0000000000..ce8f54c4d4 --- /dev/null +++ b/ext/sdbm/sdbm.h @@ -0,0 +1,84 @@ +/* + * sdbm - ndbm work-alike hashed database library + * based on Per-Ake Larson's Dynamic Hashing algorithms. BIT 18 (1978). + * author: [email protected] + * status: public domain. + */ +#ifndef _SDBM_H_ +#define _SDBM_H_ + +#define DBLKSIZ 4096 +#define PBLKSIZ 1024 +#define PAIRMAX 1008 /* arbitrary on PBLKSIZ-N */ +#define SPLTMAX 10 /* maximum allowed splits */ + /* for a single insertion */ +#define DIRFEXT ".dir" +#define PAGFEXT ".pag" + +typedef struct { + int dirf; /* directory file descriptor */ + int pagf; /* page file descriptor */ + int flags; /* status/error flags, see below */ + long maxbno; /* size of dirfile in bits */ + long curbit; /* current bit number */ + long hmask; /* current hash mask */ + long blkptr; /* current block for nextkey */ + int keyptr; /* current key for nextkey */ + long blkno; /* current page to read/write */ + long pagbno; /* current page in pagbuf */ + char pagbuf[PBLKSIZ]; /* page file block buffer */ + long dirbno; /* current block in dirbuf */ + char dirbuf[DBLKSIZ]; /* directory file block buffer */ +} DBM; + +#define DBM_RDONLY 0x1 /* data base open read-only */ +#define DBM_IOERR 0x2 /* data base I/O error */ + +/* + * utility macros + */ +#define sdbm_rdonly(db) ((db)->flags & DBM_RDONLY) +#define sdbm_error(db) ((db)->flags & DBM_IOERR) + +#define sdbm_clearerr(db) ((db)->flags &= ~DBM_IOERR) /* ouch */ + +#define sdbm_dirfno(db) ((db)->dirf) +#define sdbm_pagfno(db) ((db)->pagf) + +typedef struct { + char *dptr; + int dsize; +} datum; + +extern datum nullitem; + +#if defined(__STDC__) || defined(MSDOS) +#define proto(p) p +#else +#define proto(p) () +#endif + +/* + * flags to sdbm_store + */ +#define DBM_INSERT 0 +#define DBM_REPLACE 1 + +/* + * ndbm interface + */ +extern DBM *sdbm_open proto((char *, int, int)); +extern void sdbm_close proto((DBM *)); +extern datum sdbm_fetch proto((DBM *, datum)); +extern int sdbm_delete proto((DBM *, datum)); +extern int sdbm_store proto((DBM *, datum, datum, int)); +extern datum sdbm_firstkey proto((DBM *)); +extern datum sdbm_nextkey proto((DBM *)); + +/* + * other + */ +extern DBM *sdbm_prep proto((char *, char *, int, int)); +extern long sdbm_hash proto((char *, int)); + +#endif /* _SDBM_H_ */ |