src/include/utils/rel.h

   1 /*-------------------------------------------------------------------------
   2  *
   3  * rel.h
   4  *        POSTGRES relation descriptor (a/k/a relcache entry) definitions.
   5  *
   6  *
   7  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
   8  * Portions Copyright (c) 1994, Regents of the University of California
   9  *
  10  * $Id: rel.h,v 1.38 2000/06/18 22:44:34 tgl Exp $
  11  *
  12  *-------------------------------------------------------------------------
  13  */
  14 #ifndef REL_H
  15 #define REL_H
  16
  17 #include "access/strat.h"
  18 #include "access/tupdesc.h"
  19 #include "catalog/pg_am.h"
  20 #include "catalog/pg_class.h"
  21 #include "rewrite/prs2lock.h"
  22 #include "storage/fd.h"
  23
  24 /* added to prevent circular dependency.  bjm 1999/11/15 */
  25 extern char *get_temp_rel_by_physicalname(const char *relname);
  26
  27 /*
  28  * LockRelId and LockInfo really belong to lmgr.h, but it's more convenient
  29  * to declare them here so we can have a LockInfoData field in a Relation.
  30  */
  31
  32 typedef struct LockRelId
  33 {
  34         Oid                     relId;                  /* a relation identifier */
  35         Oid                     dbId;                   /* a database identifier */
  36 } LockRelId;
  37
  38 typedef struct LockInfoData
  39 {
  40         LockRelId       lockRelId;
  41 } LockInfoData;
  42
  43 typedef LockInfoData *LockInfo;
  44
  45 /*
  46  * Likewise, this struct really belongs to trigger.h, but for convenience
  47  * we put it here.
  48  */
  49
  50 typedef struct Trigger
  51 {
  52         Oid                     tgoid;
  53         char       *tgname;
  54         Oid                     tgfoid;
  55         FmgrInfo        tgfunc;
  56         int16           tgtype;
  57         bool            tgenabled;
  58         bool            tgisconstraint;
  59         bool            tgdeferrable;
  60         bool            tginitdeferred;
  61         int16           tgnargs;
  62         int16           tgattr[FUNC_MAX_ARGS];
  63         char      **tgargs;
  64 } Trigger;
  65
  66 typedef struct TriggerDesc
  67 {
  68         /* index data to identify which triggers are which */
  69         uint16          n_before_statement[4];
  70         uint16          n_before_row[4];
  71         uint16          n_after_row[4];
  72         uint16          n_after_statement[4];
  73         Trigger   **tg_before_statement[4];
  74         Trigger   **tg_before_row[4];
  75         Trigger   **tg_after_row[4];
  76         Trigger   **tg_after_statement[4];
  77         /* the actual array of triggers is here */
  78         Trigger    *triggers;
  79         int                     numtriggers;
  80 } TriggerDesc;
  81
  82 /*
  83  * Here are the contents of a relation cache entry.
  84  */
  85
  86 typedef struct RelationData
  87 {
  88         File            rd_fd;                  /* open file descriptor */
  89         int                     rd_nblocks;             /* number of blocks in rel */
  90         uint16          rd_refcnt;              /* reference count */
  91         bool            rd_myxactonly;  /* rel uses the local buffer mgr */
  92         bool            rd_isnailed;    /* rel is nailed in cache */
  93         bool            rd_unlinked;    /* rel already unlinked or not created yet */
  94         bool            rd_indexfound;  /* true if rd_indexlist is valid */
  95         Form_pg_am      rd_am;                  /* AM tuple */
  96         Form_pg_class rd_rel;           /* RELATION tuple */
  97         Oid                     rd_id;                  /* relation's object id */
  98         List       *rd_indexlist;       /* list of OIDs of indexes on relation */
  99         LockInfoData rd_lockInfo;       /* lock mgr's info for locking relation */
 100         TupleDesc       rd_att;                 /* tuple descriptor */
 101         RuleLock   *rd_rules;           /* rewrite rules */
 102         IndexStrategy rd_istrat;        /* info needed if rel is an index */
 103         RegProcedure *rd_support;
 104         TriggerDesc *trigdesc;          /* Trigger info, or NULL if rel has none */
 105 } RelationData;
 106
 107 typedef RelationData *Relation;
 108
 109
 110 /* ----------------
 111  *              RelationPtr is used in the executor to support index scans
 112  *              where we have to keep track of several index relations in an
 113  *              array.  -cim 9/10/89
 114  * ----------------
 115  */
 116 typedef Relation *RelationPtr;
 117
 118
 119 /*
 120  * RelationIsValid
 121  *              True iff relation descriptor is valid.
 122  */
 123 #define RelationIsValid(relation) PointerIsValid(relation)
 124
 125 #define InvalidRelation ((Relation) NULL)
 126
 127 /*
 128  * RelationHasReferenceCountZero
 129  *              True iff relation reference count is zero.
 130  *
 131  * Note:
 132  *              Assumes relation descriptor is valid.
 133  */
 134 #define RelationHasReferenceCountZero(relation) \
 135                 ((bool)((relation)->rd_refcnt == 0))
 136
 137 /*
 138  * RelationSetReferenceCount
 139  *              Sets relation reference count.
 140  */
 141 #define RelationSetReferenceCount(relation,count) \
 142         ((relation)->rd_refcnt = (count))
 143
 144 /*
 145  * RelationIncrementReferenceCount
 146  *              Increments relation reference count.
 147  */
 148 #define RelationIncrementReferenceCount(relation) \
 149         ((relation)->rd_refcnt += 1)
 150
 151 /*
 152  * RelationDecrementReferenceCount
 153  *              Decrements relation reference count.
 154  */
 155 #define RelationDecrementReferenceCount(relation) \
 156         (AssertMacro((relation)->rd_refcnt > 0), \
 157          (relation)->rd_refcnt -= 1)
 158
 159 /*
 160  * RelationGetForm
 161  *              Returns pg_class tuple for a relation.
 162  *
 163  * Note:
 164  *              Assumes relation descriptor is valid.
 165  */
 166 #define RelationGetForm(relation) ((relation)->rd_rel)
 167
 168 /*
 169  * RelationGetRelid
 170  *
 171  *      returns the OID of the relation
 172  */
 173 #define RelationGetRelid(relation) ((relation)->rd_id)
 174
 175 /*
 176  * RelationGetFile
 177  *
 178  *        Returns the open file descriptor for the rel
 179  */
 180 #define RelationGetFile(relation) ((relation)->rd_fd)
 181
 182 /*
 183  * RelationGetRelationName
 184  *
 185  *        Returns a Relation Name
 186  */
 187 #define RelationGetRelationName(relation) \
 188 (\
 189         (strncmp(RelationGetPhysicalRelationName(relation), \
 190          "pg_temp.", strlen("pg_temp.")) != 0) \
 191         ? \
 192                 RelationGetPhysicalRelationName(relation) \
 193         : \
 194                 get_temp_rel_by_physicalname( \
 195                         RelationGetPhysicalRelationName(relation)) \
 196 )
 197
 198
 199 /*
 200  * RelationGetPhysicalRelationName
 201  *
 202  *        Returns a Relation Name
 203  */
 204 #define RelationGetPhysicalRelationName(relation) \
 205         (NameStr((relation)->rd_rel->relname))
 206
 207 /*
 208  * RelationGetNumberOfAttributes
 209  *
 210  *        Returns the number of attributes.
 211  */
 212 #define RelationGetNumberOfAttributes(relation) ((relation)->rd_rel->relnatts)
 213
 214 /*
 215  * RelationGetDescr
 216  *              Returns tuple descriptor for a relation.
 217  */
 218 #define RelationGetDescr(relation) ((relation)->rd_att)
 219
 220 /*
 221  * RelationGetIndexStrategy
 222  *              Returns index strategy for a relation.
 223  *
 224  * Note:
 225  *              Assumes relation descriptor is valid.
 226  *              Assumes relation descriptor is for an index relation.
 227  */
 228 #define RelationGetIndexStrategy(relation) ((relation)->rd_istrat)
 229
 230 /*
 231  * Routines in utils/cache/rel.c
 232  */
 233 extern void RelationSetIndexSupport(Relation relation,
 234                                                                         IndexStrategy strategy,
 235                                                                         RegProcedure *support);
 236
 237 #endif   /* REL_H */