ref: e876447b7570808a97cbad6193b33c8af41552fe
dir: /sys/include/ndb.h/
#pragma src "/sys/src/libndb"
#pragma lib "libndb.a"
/*
* this include file requires includes of <u.h> and <bio.h>
*/
typedef struct Ndb Ndb;
typedef struct Ndbtuple Ndbtuple;
typedef struct Ndbhf Ndbhf;
typedef struct Ndbs Ndbs;
typedef struct Ndbcache Ndbcache;
#pragma incomplete Ndbhf
#pragma incomplete Ndbcache
enum
{
Ndbalen= 32, /* max attribute length */
Ndbvlen= 64, /* max value length */
};
/*
* the database
*/
struct Ndb
{
Ndb *next;
Biobufhdr b; /* buffered input file */
uchar buf[256]; /* and its buffer */
ulong mtime; /* mtime of db file */
Qid qid; /* qid of db file */
char file[128]; /* path name of db file */
ulong length; /* length of db file */
int nohash; /* don't look for hash files */
Ndbhf *hf; /* open hash files */
int ncache; /* size of tuple cache */
Ndbcache *cache; /* cached entries */
};
/*
* a parsed entry, doubly linked
*/
struct Ndbtuple
{
char attr[Ndbalen]; /* attribute name */
char *val; /* value(s) */
Ndbtuple *entry; /* next tuple in this entry */
Ndbtuple *line; /* next tuple on this line */
ulong ptr; /* (for the application - starts 0) */
char valbuf[Ndbvlen]; /* initial allocation for value */
};
/*
* each hash file is of the form
*
* +---------------------------------------+
* | mtime of db file (4 bytes) |
* +---------------------------------------+
* | size of table (in entries - 4 bytes) |
* +---------------------------------------+
* | hash table |
* +---------------------------------------+
* | hash chains |
* +---------------------------------------+
*
* hash collisions are resolved using chained entries added to the
* the end of the hash table.
*
* Hash entries are of the form
*
* +-------------------------------+
* | offset (3 bytes) |
* +-------------------------------+
*
* Chain entries are of the form
*
* +-------------------------------+
* | offset1 (3 bytes) |
* +-------------------------------+
* | offset2 (3 bytes) |
* +-------------------------------+
*
* The top bit of an offset set to 1 indicates a pointer to a hash chain entry.
*/
#define NDBULLEN 4 /* unsigned long length in bytes */
#define NDBPLEN 3 /* pointer length in bytes */
#define NDBHLEN (2*NDBULLEN) /* hash file header length in bytes */
/*
* finger pointing to current point in a search
*/
struct Ndbs
{
Ndb *db; /* data base file being searched */
Ndbhf *hf; /* hash file being searched */
int type;
ulong ptr; /* current pointer */
ulong ptr1; /* next pointer */
Ndbtuple *t; /* last attribute value pair found */
};
/*
* bit defs for pointers in hash files
*/
#define NDBSPEC (1<<23)
#define NDBCHAIN NDBSPEC /* points to a collision chain */
#define NDBNAP (NDBSPEC|1) /* not a pointer */
/*
* macros for packing and unpacking pointers
*/
#define NDBPUTP(v,a) { (a)[0] = v; (a)[1] = (v)>>8; (a)[2] = (v)>>16; }
#define NDBGETP(a) ((a)[0] | ((a)[1]<<8) | ((a)[2]<<16))
/*
* macros for packing and unpacking unsigned longs
*/
#define NDBPUTUL(v,a) { (a)[0] = v; (a)[1] = (v)>>8; (a)[2] = (v)>>16; (a)[3] = (v)>>24; }
#define NDBGETUL(a) ((a)[0] | ((a)[1]<<8) | ((a)[2]<<16) | ((a)[3]<<24))
#define NDB_IPlen 16
char* csgetvalue(char*, char*, char*, char*, Ndbtuple**);
Ndbtuple* csipinfo(char*, char*, char*, char**, int);
Ndbtuple* dnsquery(char*, char*, char*);
char* ipattr(char*);
Ndb* ndbcat(Ndb*, Ndb*);
int ndbchanged(Ndb*);
void ndbclose(Ndb*);
Ndbtuple* ndbconcatenate(Ndbtuple*, Ndbtuple*);
Ndbtuple* ndbdiscard(Ndbtuple*, Ndbtuple*);
void ndbfree(Ndbtuple*);
Ndbtuple* ndbgetipaddr(Ndb*, char*);
char* ndbgetvalue(Ndb*, Ndbs*, char*, char*, char*, Ndbtuple**);
Ndbtuple* ndbfindattr(Ndbtuple*, Ndbtuple*, char*);
ulong ndbhash(char*, int);
Ndbtuple* ndbipinfo(Ndb*, char*, char*, char**, int);
Ndbtuple* ndbnew(char*, char*);
Ndb* ndbopen(char*);
Ndbtuple* ndbparse(Ndb*);
int ndbreopen(Ndb*);
Ndbtuple* ndbreorder(Ndbtuple*, Ndbtuple*);
Ndbtuple* ndbsearch(Ndb*, Ndbs*, char*, char*);
void ndbsetval(Ndbtuple*, char*, int);
Ndbtuple* ndbsnext(Ndbs*, char*, char*);
Ndbtuple* ndbsubstitute(Ndbtuple*, Ndbtuple*, Ndbtuple*);
Ndbtuple* ndbdedup(Ndbtuple*);
void ndbsetmalloctag(Ndbtuple*, uintptr);