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yap-6.3/packages/semweb/rdf_db.h

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/* $Id$
Part of SWI-Prolog
Author: Jan Wielemaker
E-mail: wielemak@science.uva.nl
WWW: http://www.swi-prolog.org
Copyright (C): 1985-2007, University of Amsterdam
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifndef RDFDB_H_INCLUDED
#define RDFDB_H_INCLUDED
#include "avl.h"
#ifdef WITH_MD5
#include "md5.h"
#endif
#include "lock.h"
#define RDF_VERSION 20800 /* 2.8.0 */
#define URL_subPropertyOf \
"http://www.w3.org/2000/01/rdf-schema#subPropertyOf"
/*******************************
* C *
*******************************/
/* Keep consistent with md5_type[] in rdf_db.c! */
#define OBJ_UNTYPED 0x0 /* partial: don't know */
#define OBJ_INTEGER 0x1
#define OBJ_DOUBLE 0x2
#define OBJ_STRING 0x3
#define OBJ_TERM 0x4
#define Q_NONE 0x0
#define Q_TYPE 0x1
#define Q_LANG 0x2
#define BY_NONE 0x00 /* 0 */
#define BY_S 0x01 /* 1 */
#define BY_P 0x02 /* 2 */
#define BY_O 0x04 /* 4 */
#define BY_SP (BY_S|BY_P) /* 3 */
#define BY_SO (BY_S|BY_O) /* 5 */
#define BY_OP (BY_P|BY_O) /* 6 */
#define BY_SPO (BY_S|BY_P|BY_O) /* 7 */
#define INDEX_TABLES 7
#define INITIAL_TABLE_SIZE 8*1024
#define INITIAL_PREDICATE_TABLE_SIZE 1024
#define INITIAL_GRAPH_TABLE_SIZE 64
#define MAX_HASH_FACTOR 8 /* factor to trigger re-hash */
#define MIN_HASH_FACTOR 4 /* factor after re-hash */
#define NO_LINE (0)
typedef struct cell
{ void * value; /* represented resource */
struct cell *next; /* next in chain */
} cell;
typedef struct list
{ cell *head; /* first in list */
cell *tail; /* tail of list */
} list;
typedef struct bitmatrix
{ size_t width;
size_t heigth;
int bits[1];
} bitmatrix;
#define DISTINCT_DIRECT 0 /* for ->distinct_subjects, etc */
#define DISTINCT_SUB 1
typedef struct predicate
{ atom_t name; /* name of the predicate */
struct predicate *next; /* next in hash-table */
/* hierarchy */
list subPropertyOf; /* the one I'm subPropertyOf */
list siblings; /* reverse of subPropertyOf */
int label; /* Numeric label in cloud */
struct predicate_cloud *cloud; /* cloud I belong to */
unsigned int hash; /* key used for hashing
(=hash if ->cloud is up-to-date) */
/* properties */
struct predicate *inverse_of; /* my inverse predicate */
unsigned transitive : 1; /* P(a,b)&P(b,c) --> P(a,c) */
/* statistics */
long triple_count; /* # triples on this predicate */
long distinct_updated[2];/* Is count still valid? */
long distinct_count[2]; /* Triple count at last update */
long distinct_subjects[2];/* # distinct subject values */
long distinct_objects[2];/* # distinct object values */
} predicate;
typedef struct predicate_cloud
{ predicate **members; /* member predicates */
unsigned int hash; /* hash-code */
size_t size; /* size of the cloud */
size_t deleted; /* See erase_predicates() */
bitmatrix *reachable; /* cloud reachability matrix */
unsigned dirty : 1; /* predicate hash not synchronised */
} predicate_cloud;
typedef struct graph
{ struct graph *next; /* next in table */
atom_t name; /* name of the graph */
atom_t source; /* URL graph was loaded from */
double modified; /* Modified time of source URL */
int triple_count; /* # triples associated to it */
#ifdef WITH_MD5
unsigned md5 : 1; /* do/don't record MD5 */
md5_byte_t digest[16]; /* MD5 digest */
#endif
} graph;
typedef struct literal
{ union
{ atom_t string;
int64_t integer;
double real;
struct
{ record_t record;
size_t len;
} term; /* external record */
} value;
atom_t type_or_lang; /* Type or language for literals */
unsigned int hash; /* saved hash */
unsigned objtype : 3;
unsigned qualifier : 2; /* Lang/Type qualifier */
unsigned shared : 1; /* member of shared table */
unsigned term_loaded : 1; /* OBJ_TERM from quick save file */
unsigned atoms_locked : 1; /* Atoms have been locked */
unsigned references : 24; /* # references to me */
} literal;
#define t_match next[0]
typedef struct triple
{ atom_t subject;
union
{ predicate* r; /* resolved: normal DB */
atom_t u; /* used by rdf_load_db_/3 */
} predicate;
union
{ literal * literal;
atom_t resource;
} object;
atom_t graph; /* where it comes from */
unsigned long line; /* graph-line number */
/* indexing */
struct triple*next[INDEX_TABLES]; /* hash-table next links */
/* flags */
unsigned object_is_literal : 1; /* Object is a literal */
unsigned resolve_pred : 1; /* predicates needs to be resolved */
unsigned indexed : 3; /* Partials: BY_* */
unsigned erased : 1; /* If TRUE, triple is erased */
unsigned first : 1; /* I'm the first on subject */
unsigned match : 3; /* How to match literals */
unsigned inversed : 1; /* Partials: using inverse match */
unsigned is_duplicate : 1; /* I'm a duplicate */
unsigned allocated : 1; /* Triple is allocated */
unsigned atoms_locked : 1; /* Atoms have been locked */
unsigned duplicates : 16; /* Duplicate count */
/* Total: 32 */
} triple;
typedef enum
{ TR_MARK, /* mark start for nesting */
TR_SUB_START, /* start nested transaction */
TR_SUB_END, /* end nested transaction */
TR_ASSERT, /* rdf_assert */
TR_RETRACT, /* rdf_retractall */
TR_UPDATE, /* rdf_update */
TR_UPDATE_SRC, /* rdf_update */
TR_UPDATE_MD5, /* update md5 src */
TR_RESET, /* rdf_reset_db */
TR_VOID /* no-op */
} tr_type;
typedef struct transaction_record
{ struct transaction_record *previous;
struct transaction_record *next;
tr_type type;
triple *triple; /* new/deleted triple */
union
{ triple *triple; /* used for update */
struct
{ atom_t atom;
unsigned long line;
} src;
struct
{ graph *graph;
md5_byte_t *digest;
} md5;
record_t transaction_id;
} update;
} transaction_record;
typedef struct active_transaction
{ struct active_transaction *parent;
term_t id;
} active_transaction;
typedef struct rdf_db
{ triple *by_none, *by_none_tail;
triple **table[INDEX_TABLES];
triple **tail[INDEX_TABLES];
int *counts[INDEX_TABLES];
int table_size[INDEX_TABLES];
long created; /* #triples created */
long erased; /* #triples erased */
long freed; /* #triples actually erased */
long subjects; /* subjects (unique first) */
long indexed[8]; /* Count calls */
int rehash_count; /* # rehashes */
int gc_count; /* # garbage collections */
int gc_blocked; /* GC is blocked; */
double rehash_time; /* time spent in rehash */
double gc_time; /* time spent in GC */
size_t core; /* core in use */
predicate **pred_table; /* Hash-table of predicates */
int pred_table_size; /* #entries in the table */
int pred_count; /* #predicates */
unsigned long next_hash; /* cloud hash keys */
int active_queries; /* Calls with choicepoints */
int need_update; /* We need to update */
long agenda_created; /* #visited nodes in agenda */
long duplicates; /* #duplicate triples */
long generation; /* generation-id of the database */
graph **graph_table; /* Hash table of sources */
int graph_table_size; /* Entries in table */
graph *last_graph; /* last accessed graph */
active_transaction *tr_active; /* open transactions */
transaction_record *tr_first; /* first transaction record */
transaction_record *tr_last; /* last transaction record */
int tr_nesting; /* nesting depth of transactions */
int tr_reset; /* transaction contains reset */
int resetting; /* We are in rdf_reset_db() */
rwlock lock; /* threaded access */
avl_tree literals;
} rdf_db;
#endif /*RDFDB_H_INCLUDED*/