160 lines
4.7 KiB
C
160 lines
4.7 KiB
C
/*
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* This file is part of the UCB release of Plan 9. It is subject to the license
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* terms in the LICENSE file found in the top-level directory of this
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* distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No
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* part of the UCB release of Plan 9, including this file, may be copied,
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* modified, propagated, or distributed except according to the terms contained
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* in the LICENSE file.
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*/
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/*
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* this include file requires includes of <u.h> and <bio.h>
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*/
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typedef struct Ndb Ndb;
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typedef struct Ndbtuple Ndbtuple;
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typedef struct Ndbhf Ndbhf;
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typedef struct Ndbs Ndbs;
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typedef struct Ndbcache Ndbcache;
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enum
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{
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Ndbalen= 32, /* max attribute length */
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Ndbvlen= 64, /* max value length */
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};
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/*
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* the database
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*/
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struct Ndb
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{
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Ndb *next;
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Biobufhdr b; /* buffered input file */
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uint8_t buf[256]; /* and its buffer */
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uint32_t mtime; /* mtime of db file */
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Qid qid; /* qid of db file */
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char file[128];/* path name of db file */
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uint32_t length; /* length of db file */
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int nohash; /* don't look for hash files */
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Ndbhf *hf; /* open hash files */
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int ncache; /* size of tuple cache */
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Ndbcache *cache; /* cached entries */
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};
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/*
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* a parsed entry, doubly linked
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*/
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struct Ndbtuple
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{
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char attr[Ndbalen]; /* attribute name */
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char *val; /* value(s) */
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Ndbtuple *entry; /* next tuple in this entry */
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Ndbtuple *line; /* next tuple on this line */
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uint32_t ptr; /* (for the application - starts 0) */
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char valbuf[Ndbvlen]; /* initial allocation for value */
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};
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/*
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* each hash file is of the form
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*
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* +---------------------------------------+
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* | mtime of db file (4 bytes) |
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* +---------------------------------------+
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* | size of table (in entries - 4 bytes) |
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* +---------------------------------------+
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* | hash table |
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* +---------------------------------------+
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* | hash chains |
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* +---------------------------------------+
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*
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* hash collisions are resolved using chained entries added to the
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* the end of the hash table.
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*
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* Hash entries are of the form
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*
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* +-------------------------------+
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* | offset (3 bytes) |
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* +-------------------------------+
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*
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* Chain entries are of the form
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*
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* +-------------------------------+
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* | offset1 (3 bytes) |
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* +-------------------------------+
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* | offset2 (3 bytes) |
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* +-------------------------------+
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*
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* The top bit of an offset set to 1 indicates a pointer to a hash chain entry.
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*/
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#define NDBULLEN 4 /* unsigned long length in bytes */
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#define NDBPLEN 3 /* pointer length in bytes */
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#define NDBHLEN (2*NDBULLEN) /* hash file header length in bytes */
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/*
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* finger pointing to current point in a search
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*/
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struct Ndbs
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{
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Ndb *db; /* data base file being searched */
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Ndbhf *hf; /* hash file being searched */
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int type;
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uint32_t ptr; /* current pointer */
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uint32_t ptr1; /* next pointer */
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Ndbtuple *t; /* last attribute value pair found */
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};
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/*
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* bit defs for pointers in hash files
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*/
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#define NDBSPEC (1<<23)
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#define NDBCHAIN NDBSPEC /* points to a collision chain */
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#define NDBNAP (NDBSPEC|1) /* not a pointer */
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/*
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* macros for packing and unpacking pointers
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*/
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#define NDBPUTP(v,a) { (a)[0] = (uint8_t)v; (a)[1] = (uint8_t)(v)>>8; (a)[2] = (uint8_t)(v)>>16; }
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#define NDBGETP(a) ((a)[0] | ((a)[1]<<8) | ((a)[2]<<16))
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/*
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* macros for packing and unpacking unsigned longs
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*/
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#define NDBPUTUL(v,a) { (a)[0] = (uint8_t)v; (a)[1] = (uint8_t)(v)>>8; (a)[2] = (uint8_t)(v)>>16; (a)[3] = (uint8_t)(v)>>24; }
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#define NDBGETUL(a) ((a)[0] | ((a)[1]<<8) | ((a)[2]<<16) | ((a)[3]<<24))
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#define NDB_IPlen 16
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Ndbtuple* csgetval(char*, char*, char*, char*, char*);
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char* csgetvalue(char*, char*, char*, char*,
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Ndbtuple**);
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Ndbtuple* csipinfo(char*, char*, char*, char**, int);
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Ndbtuple* dnsquery(char*, char*, char*);
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char* ipattr(char*);
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Ndb* ndbcat(Ndb*, Ndb*);
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int ndbchanged(Ndb*);
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void ndbclose(Ndb*);
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Ndbtuple* ndbconcatenate(Ndbtuple*, Ndbtuple*);
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Ndbtuple* ndbdiscard(Ndbtuple*, Ndbtuple*);
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void ndbfree(Ndbtuple*);
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Ndbtuple* ndbgetipaddr(Ndb*, char*);
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Ndbtuple* ndbgetval(Ndb*, Ndbs*, char*, char*, char*, char*);
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char* ndbgetvalue(Ndb*, Ndbs*, char*, char*, char*,
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Ndbtuple**);
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Ndbtuple* ndbfindattr(Ndbtuple*, Ndbtuple*, char*);
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uint32_t ndbhash(char*, int);
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Ndbtuple* ndbipinfo(Ndb*, char*, char*, char**, int);
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Ndbtuple* ndblookval(Ndbtuple*, Ndbtuple*, char*, char*);
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Ndbtuple* ndbnew(char*, char*);
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Ndb* ndbopen(char*);
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Ndbtuple* ndbparse(Ndb*);
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int ndbreopen(Ndb*);
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Ndbtuple* ndbreorder(Ndbtuple*, Ndbtuple*);
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Ndbtuple* ndbsearch(Ndb*, Ndbs*, char*, char*);
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void ndbsetval(Ndbtuple*, char*, int);
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Ndbtuple* ndbsnext(Ndbs*, char*, char*);
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Ndbtuple* ndbsubstitute(Ndbtuple*, Ndbtuple*, Ndbtuple*);
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void ndbsetmalloctag(Ndbtuple*, uintptr_t);
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