2002-09-02 02:47:07 +00:00

3222 lines
92 KiB
C

/*-------------------------------------------------------------------------
*
* relcache.c
* POSTGRES relation descriptor cache code
*
* Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/utils/cache/relcache.c,v 1.174 2002/09/02 02:47:05 momjian Exp $
*
*-------------------------------------------------------------------------
*/
/*
* INTERFACE ROUTINES
* RelationCacheInitialize - initialize relcache
* RelationCacheInitializePhase2 - finish initializing relcache
* RelationIdGetRelation - get a reldesc by relation id
* RelationSysNameGetRelation - get a reldesc by system rel name
* RelationIdCacheGetRelation - get a cached reldesc by relid
* RelationClose - close an open relation
*
* NOTES
* The following code contains many undocumented hacks. Please be
* careful....
*/
#include "postgres.h"
#include <errno.h>
#include <sys/file.h>
#include <fcntl.h>
#include <unistd.h>
#include "access/genam.h"
#include "access/heapam.h"
#include "access/istrat.h"
#include "catalog/catalog.h"
#include "catalog/catname.h"
#include "catalog/indexing.h"
#include "catalog/namespace.h"
#include "catalog/pg_amop.h"
#include "catalog/pg_amproc.h"
#include "catalog/pg_attrdef.h"
#include "catalog/pg_attribute.h"
#include "catalog/pg_constraint.h"
#include "catalog/pg_index.h"
#include "catalog/pg_namespace.h"
#include "catalog/pg_opclass.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_rewrite.h"
#include "catalog/pg_type.h"
#include "commands/trigger.h"
#include "miscadmin.h"
#include "storage/smgr.h"
#include "utils/builtins.h"
#include "utils/catcache.h"
#include "utils/fmgroids.h"
#include "utils/inval.h"
#include "utils/lsyscache.h"
#include "utils/relcache.h"
#include "utils/syscache.h"
/*
* name of relcache init file, used to speed up backend startup
*/
#define RELCACHE_INIT_FILENAME "pg_internal.init"
/*
* hardcoded tuple descriptors. see include/catalog/pg_attribute.h
*/
static FormData_pg_attribute Desc_pg_class[Natts_pg_class] = {Schema_pg_class};
static FormData_pg_attribute Desc_pg_attribute[Natts_pg_attribute] = {Schema_pg_attribute};
static FormData_pg_attribute Desc_pg_proc[Natts_pg_proc] = {Schema_pg_proc};
static FormData_pg_attribute Desc_pg_type[Natts_pg_type] = {Schema_pg_type};
/*
* Hash tables that index the relation cache
*
* Relations are looked up two ways, by OID and by name,
* thus there are two hash tables for referencing them.
*
* The OID index covers all relcache entries. The name index
* covers *only* system relations (only those in PG_CATALOG_NAMESPACE).
*/
static HTAB *RelationIdCache;
static HTAB *RelationSysNameCache;
/*
* Bufmgr uses RelFileNode for lookup. Actually, I would like to do
* not pass Relation to bufmgr & beyond at all and keep some cache
* in smgr, but no time to do it right way now. -- vadim 10/22/2000
*/
static HTAB *RelationNodeCache;
/*
* This flag is false until we have prepared the critical relcache entries
* that are needed to do indexscans on the tables read by relcache building.
*/
bool criticalRelcachesBuilt = false;
/*
* This flag is set if we discover that we need to write a new relcache
* cache file at the end of startup.
*/
static bool needNewCacheFile = false;
/*
* This counter counts relcache inval events received since backend startup
* (but only for rels that are actually in cache). Presently, we use it only
* to detect whether data about to be written by write_relcache_init_file()
* might already be obsolete.
*/
static long relcacheInvalsReceived = 0L;
/*
* This list remembers the OIDs of the relations cached in the relcache
* init file.
*/
static List *initFileRelationIds = NIL;
/*
* RelationBuildDescInfo exists so code can be shared
* between RelationIdGetRelation() and RelationSysNameGetRelation()
*/
typedef struct RelationBuildDescInfo
{
int infotype; /* lookup by id or by name */
#define INFO_RELID 1
#define INFO_RELNAME 2
union
{
Oid info_id; /* relation object id */
char *info_name; /* system relation name */
} i;
} RelationBuildDescInfo;
typedef struct relidcacheent
{
Oid reloid;
Relation reldesc;
} RelIdCacheEnt;
typedef struct relnamecacheent
{
NameData relname;
Relation reldesc;
} RelNameCacheEnt;
typedef struct relnodecacheent
{
RelFileNode relnode;
Relation reldesc;
} RelNodeCacheEnt;
/*
* macros to manipulate the lookup hashtables
*/
#define RelationCacheInsert(RELATION) \
do { \
RelIdCacheEnt *idhentry; RelNodeCacheEnt *nodentry; bool found; \
idhentry = (RelIdCacheEnt*)hash_search(RelationIdCache, \
(void *) &(RELATION->rd_id), \
HASH_ENTER, \
&found); \
if (idhentry == NULL) \
elog(ERROR, "out of memory for relation descriptor cache"); \
/* used to give notice if found -- now just keep quiet */ \
idhentry->reldesc = RELATION; \
nodentry = (RelNodeCacheEnt*)hash_search(RelationNodeCache, \
(void *) &(RELATION->rd_node), \
HASH_ENTER, \
&found); \
if (nodentry == NULL) \
elog(ERROR, "out of memory for relation descriptor cache"); \
/* used to give notice if found -- now just keep quiet */ \
nodentry->reldesc = RELATION; \
if (IsSystemNamespace(RelationGetNamespace(RELATION))) \
{ \
char *relname = RelationGetRelationName(RELATION); \
RelNameCacheEnt *namehentry; \
namehentry = (RelNameCacheEnt*)hash_search(RelationSysNameCache, \
relname, \
HASH_ENTER, \
&found); \
if (namehentry == NULL) \
elog(ERROR, "out of memory for relation descriptor cache"); \
/* used to give notice if found -- now just keep quiet */ \
namehentry->reldesc = RELATION; \
} \
} while(0)
#define RelationIdCacheLookup(ID, RELATION) \
do { \
RelIdCacheEnt *hentry; \
hentry = (RelIdCacheEnt*)hash_search(RelationIdCache, \
(void *)&(ID), HASH_FIND,NULL); \
if (hentry) \
RELATION = hentry->reldesc; \
else \
RELATION = NULL; \
} while(0)
#define RelationSysNameCacheLookup(NAME, RELATION) \
do { \
RelNameCacheEnt *hentry; \
hentry = (RelNameCacheEnt*)hash_search(RelationSysNameCache, \
(void *) (NAME), HASH_FIND,NULL); \
if (hentry) \
RELATION = hentry->reldesc; \
else \
RELATION = NULL; \
} while(0)
#define RelationNodeCacheLookup(NODE, RELATION) \
do { \
RelNodeCacheEnt *hentry; \
hentry = (RelNodeCacheEnt*)hash_search(RelationNodeCache, \
(void *)&(NODE), HASH_FIND,NULL); \
if (hentry) \
RELATION = hentry->reldesc; \
else \
RELATION = NULL; \
} while(0)
#define RelationCacheDelete(RELATION) \
do { \
RelIdCacheEnt *idhentry; RelNodeCacheEnt *nodentry; \
idhentry = (RelIdCacheEnt*)hash_search(RelationIdCache, \
(void *)&(RELATION->rd_id), \
HASH_REMOVE, NULL); \
if (idhentry == NULL) \
elog(WARNING, "trying to delete a rd_id reldesc that does not exist."); \
nodentry = (RelNodeCacheEnt*)hash_search(RelationNodeCache, \
(void *)&(RELATION->rd_node), \
HASH_REMOVE, NULL); \
if (nodentry == NULL) \
elog(WARNING, "trying to delete a rd_node reldesc that does not exist."); \
if (IsSystemNamespace(RelationGetNamespace(RELATION))) \
{ \
char *relname = RelationGetRelationName(RELATION); \
RelNameCacheEnt *namehentry; \
namehentry = (RelNameCacheEnt*)hash_search(RelationSysNameCache, \
relname, \
HASH_REMOVE, NULL); \
if (namehentry == NULL) \
elog(WARNING, "trying to delete a relname reldesc that does not exist."); \
} \
} while(0)
/*
* Special cache for opclass-related information
*/
typedef struct opclasscacheent
{
Oid opclassoid; /* lookup key: OID of opclass */
bool valid; /* set TRUE after successful fill-in */
StrategyNumber numStrats; /* max # of strategies (from pg_am) */
StrategyNumber numSupport; /* max # of support procs (from pg_am) */
Oid *operatorOids; /* strategy operators' OIDs */
RegProcedure *operatorProcs; /* strategy operators' procs */
RegProcedure *supportProcs; /* support procs */
} OpClassCacheEnt;
static HTAB *OpClassCache = NULL;
/* non-export function prototypes */
static void RelationClearRelation(Relation relation, bool rebuild);
#ifdef ENABLE_REINDEX_NAILED_RELATIONS
static void RelationReloadClassinfo(Relation relation);
#endif /* ENABLE_REINDEX_NAILED_RELATIONS */
static void RelationFlushRelation(Relation relation);
static Relation RelationSysNameCacheGetRelation(const char *relationName);
static bool load_relcache_init_file(void);
static void write_relcache_init_file(void);
static void formrdesc(const char *relationName, int natts,
FormData_pg_attribute *att);
static HeapTuple ScanPgRelation(RelationBuildDescInfo buildinfo);
static Relation AllocateRelationDesc(Relation relation, Form_pg_class relp);
static void RelationBuildTupleDesc(RelationBuildDescInfo buildinfo,
Relation relation);
static Relation RelationBuildDesc(RelationBuildDescInfo buildinfo,
Relation oldrelation);
static void AttrDefaultFetch(Relation relation);
static void CheckConstraintFetch(Relation relation);
static List *insert_ordered_oid(List *list, Oid datum);
static void IndexSupportInitialize(Form_pg_index iform,
IndexStrategy indexStrategy,
Oid *indexOperator,
RegProcedure *indexSupport,
StrategyNumber maxStrategyNumber,
StrategyNumber maxSupportNumber,
AttrNumber maxAttributeNumber);
static OpClassCacheEnt *LookupOpclassInfo(Oid operatorClassOid,
StrategyNumber numStrats,
StrategyNumber numSupport);
/*
* ScanPgRelation
*
* this is used by RelationBuildDesc to find a pg_class
* tuple matching either a relation name or a relation id
* as specified in buildinfo.
*
* NB: the returned tuple has been copied into palloc'd storage
* and must eventually be freed with heap_freetuple.
*/
static HeapTuple
ScanPgRelation(RelationBuildDescInfo buildinfo)
{
HeapTuple pg_class_tuple;
Relation pg_class_desc;
const char *indexRelname;
SysScanDesc pg_class_scan;
ScanKeyData key[2];
int nkeys;
/*
* form a scan key
*/
switch (buildinfo.infotype)
{
case INFO_RELID:
ScanKeyEntryInitialize(&key[0], 0,
ObjectIdAttributeNumber,
F_OIDEQ,
ObjectIdGetDatum(buildinfo.i.info_id));
nkeys = 1;
indexRelname = ClassOidIndex;
break;
case INFO_RELNAME:
ScanKeyEntryInitialize(&key[0], 0,
Anum_pg_class_relname,
F_NAMEEQ,
NameGetDatum(buildinfo.i.info_name));
ScanKeyEntryInitialize(&key[1], 0,
Anum_pg_class_relnamespace,
F_OIDEQ,
ObjectIdGetDatum(PG_CATALOG_NAMESPACE));
nkeys = 2;
indexRelname = ClassNameNspIndex;
break;
default:
elog(ERROR, "ScanPgRelation: bad buildinfo");
return NULL; /* keep compiler quiet */
}
/*
* Open pg_class and fetch a tuple. Force heap scan if we haven't
* yet built the critical relcache entries (this includes initdb
* and startup without a pg_internal.init file).
*/
pg_class_desc = heap_openr(RelationRelationName, AccessShareLock);
pg_class_scan = systable_beginscan(pg_class_desc, indexRelname,
criticalRelcachesBuilt,
SnapshotNow,
nkeys, key);
pg_class_tuple = systable_getnext(pg_class_scan);
/*
* Must copy tuple before releasing buffer.
*/
if (HeapTupleIsValid(pg_class_tuple))
pg_class_tuple = heap_copytuple(pg_class_tuple);
/* all done */
systable_endscan(pg_class_scan);
heap_close(pg_class_desc, AccessShareLock);
return pg_class_tuple;
}
/*
* AllocateRelationDesc
*
* This is used to allocate memory for a new relation descriptor
* and initialize the rd_rel field.
*
* If 'relation' is NULL, allocate a new RelationData object.
* If not, reuse the given object (that path is taken only when
* we have to rebuild a relcache entry during RelationClearRelation).
*/
static Relation
AllocateRelationDesc(Relation relation, Form_pg_class relp)
{
MemoryContext oldcxt;
Form_pg_class relationForm;
/* Relcache entries must live in CacheMemoryContext */
oldcxt = MemoryContextSwitchTo(CacheMemoryContext);
/*
* allocate space for new relation descriptor, if needed
*/
if (relation == NULL)
relation = (Relation) palloc(sizeof(RelationData));
/*
* clear all fields of reldesc
*/
MemSet((char *) relation, 0, sizeof(RelationData));
relation->rd_targblock = InvalidBlockNumber;
/* make sure relation is marked as having no open file yet */
relation->rd_fd = -1;
/*
* Copy the relation tuple form
*
* We only allocate space for the fixed fields, ie, CLASS_TUPLE_SIZE.
* relacl is NOT stored in the relcache --- there'd be little point in
* it, since we don't copy the tuple's nullvalues bitmap and hence
* wouldn't know if the value is valid ... bottom line is that relacl
* *cannot* be retrieved from the relcache. Get it from the syscache
* if you need it.
*/
relationForm = (Form_pg_class) palloc(CLASS_TUPLE_SIZE);
memcpy((char *) relationForm, (char *) relp, CLASS_TUPLE_SIZE);
/* initialize relation tuple form */
relation->rd_rel = relationForm;
/* and allocate attribute tuple form storage */
relation->rd_att = CreateTemplateTupleDesc(relationForm->relnatts,
relationForm->relhasoids);
MemoryContextSwitchTo(oldcxt);
return relation;
}
/*
* RelationBuildTupleDesc
*
* Form the relation's tuple descriptor from information in
* the pg_attribute, pg_attrdef & pg_constraint system catalogs.
*/
static void
RelationBuildTupleDesc(RelationBuildDescInfo buildinfo,
Relation relation)
{
HeapTuple pg_attribute_tuple;
Relation pg_attribute_desc;
SysScanDesc pg_attribute_scan;
ScanKeyData skey[2];
int need;
TupleConstr *constr;
AttrDefault *attrdef = NULL;
int ndef = 0;
relation->rd_att->tdhasoid = RelationGetForm(relation)->relhasoids;
constr = (TupleConstr *) MemoryContextAlloc(CacheMemoryContext,
sizeof(TupleConstr));
constr->has_not_null = false;
/*
* Form a scan key that selects only user attributes (attnum > 0).
* (Eliminating system attribute rows at the index level is lots
* faster than fetching them.)
*/
ScanKeyEntryInitialize(&skey[0], 0,
Anum_pg_attribute_attrelid,
F_OIDEQ,
ObjectIdGetDatum(RelationGetRelid(relation)));
ScanKeyEntryInitialize(&skey[1], 0,
Anum_pg_attribute_attnum,
F_INT2GT,
Int16GetDatum(0));
/*
* Open pg_attribute and begin a scan. Force heap scan if we haven't
* yet built the critical relcache entries (this includes initdb
* and startup without a pg_internal.init file).
*/
pg_attribute_desc = heap_openr(AttributeRelationName, AccessShareLock);
pg_attribute_scan = systable_beginscan(pg_attribute_desc,
AttributeRelidNumIndex,
criticalRelcachesBuilt,
SnapshotNow,
2, skey);
/*
* add attribute data to relation->rd_att
*/
need = relation->rd_rel->relnatts;
while (HeapTupleIsValid(pg_attribute_tuple = systable_getnext(pg_attribute_scan)))
{
Form_pg_attribute attp;
attp = (Form_pg_attribute) GETSTRUCT(pg_attribute_tuple);
if (attp->attnum <= 0 ||
attp->attnum > relation->rd_rel->relnatts)
elog(ERROR, "Bogus attribute number %d for %s",
attp->attnum, RelationGetRelationName(relation));
relation->rd_att->attrs[attp->attnum - 1] =
(Form_pg_attribute) MemoryContextAlloc(CacheMemoryContext,
ATTRIBUTE_TUPLE_SIZE);
memcpy((char *) (relation->rd_att->attrs[attp->attnum - 1]),
(char *) attp,
ATTRIBUTE_TUPLE_SIZE);
/* Update constraint/default info */
if (attp->attnotnull)
constr->has_not_null = true;
if (attp->atthasdef)
{
if (attrdef == NULL)
{
attrdef = (AttrDefault *)
MemoryContextAlloc(CacheMemoryContext,
relation->rd_rel->relnatts *
sizeof(AttrDefault));
MemSet(attrdef, 0,
relation->rd_rel->relnatts * sizeof(AttrDefault));
}
attrdef[ndef].adnum = attp->attnum;
attrdef[ndef].adbin = NULL;
ndef++;
}
need--;
if (need == 0)
break;
}
/*
* end the scan and close the attribute relation
*/
systable_endscan(pg_attribute_scan);
heap_close(pg_attribute_desc, AccessShareLock);
if (need != 0)
elog(ERROR, "catalog is missing %d attribute(s) for relid %u",
need, RelationGetRelid(relation));
/*
* The attcacheoff values we read from pg_attribute should all be -1
* ("unknown"). Verify this if assert checking is on. They will be
* computed when and if needed during tuple access.
*/
#ifdef USE_ASSERT_CHECKING
{
int i;
for (i = 0; i < relation->rd_rel->relnatts; i++)
Assert(relation->rd_att->attrs[i]->attcacheoff == -1);
}
#endif
/*
* However, we can easily set the attcacheoff value for the first
* attribute: it must be zero. This eliminates the need for special
* cases for attnum=1 that used to exist in fastgetattr() and
* index_getattr().
*/
relation->rd_att->attrs[0]->attcacheoff = 0;
/*
* Set up constraint/default info
*/
if (constr->has_not_null || ndef > 0 || relation->rd_rel->relchecks)
{
relation->rd_att->constr = constr;
if (ndef > 0) /* DEFAULTs */
{
if (ndef < relation->rd_rel->relnatts)
constr->defval = (AttrDefault *)
repalloc(attrdef, ndef * sizeof(AttrDefault));
else
constr->defval = attrdef;
constr->num_defval = ndef;
AttrDefaultFetch(relation);
}
else
constr->num_defval = 0;
if (relation->rd_rel->relchecks > 0) /* CHECKs */
{
constr->num_check = relation->rd_rel->relchecks;
constr->check = (ConstrCheck *)
MemoryContextAlloc(CacheMemoryContext,
constr->num_check * sizeof(ConstrCheck));
MemSet(constr->check, 0, constr->num_check * sizeof(ConstrCheck));
CheckConstraintFetch(relation);
}
else
constr->num_check = 0;
}
else
{
pfree(constr);
relation->rd_att->constr = NULL;
}
}
/*
* RelationBuildRuleLock
*
* Form the relation's rewrite rules from information in
* the pg_rewrite system catalog.
*
* Note: The rule parsetrees are potentially very complex node structures.
* To allow these trees to be freed when the relcache entry is flushed,
* we make a private memory context to hold the RuleLock information for
* each relcache entry that has associated rules. The context is used
* just for rule info, not for any other subsidiary data of the relcache
* entry, because that keeps the update logic in RelationClearRelation()
* manageable. The other subsidiary data structures are simple enough
* to be easy to free explicitly, anyway.
*/
static void
RelationBuildRuleLock(Relation relation)
{
MemoryContext rulescxt;
MemoryContext oldcxt;
HeapTuple rewrite_tuple;
Relation rewrite_desc;
TupleDesc rewrite_tupdesc;
SysScanDesc rewrite_scan;
ScanKeyData key;
RuleLock *rulelock;
int numlocks;
RewriteRule **rules;
int maxlocks;
/*
* Make the private context. Parameters are set on the assumption
* that it'll probably not contain much data.
*/
rulescxt = AllocSetContextCreate(CacheMemoryContext,
RelationGetRelationName(relation),
0, /* minsize */
1024, /* initsize */
1024); /* maxsize */
relation->rd_rulescxt = rulescxt;
/*
* allocate an array to hold the rewrite rules (the array is extended if
* necessary)
*/
maxlocks = 4;
rules = (RewriteRule **)
MemoryContextAlloc(rulescxt, sizeof(RewriteRule *) * maxlocks);
numlocks = 0;
/*
* form a scan key
*/
ScanKeyEntryInitialize(&key, 0,
Anum_pg_rewrite_ev_class,
F_OIDEQ,
ObjectIdGetDatum(RelationGetRelid(relation)));
/*
* open pg_rewrite and begin a scan
*
* Note: since we scan the rules using RewriteRelRulenameIndex,
* we will be reading the rules in name order, except possibly
* during emergency-recovery operations (ie, IsIgnoringSystemIndexes).
* This in turn ensures that rules will be fired in name order.
*/
rewrite_desc = heap_openr(RewriteRelationName, AccessShareLock);
rewrite_tupdesc = RelationGetDescr(rewrite_desc);
rewrite_scan = systable_beginscan(rewrite_desc,
RewriteRelRulenameIndex,
true, SnapshotNow,
1, &key);
while (HeapTupleIsValid(rewrite_tuple = systable_getnext(rewrite_scan)))
{
Form_pg_rewrite rewrite_form = (Form_pg_rewrite) GETSTRUCT(rewrite_tuple);
bool isnull;
Datum ruleaction;
Datum rule_evqual;
char *ruleaction_str;
char *rule_evqual_str;
RewriteRule *rule;
rule = (RewriteRule *) MemoryContextAlloc(rulescxt,
sizeof(RewriteRule));
rule->ruleId = HeapTupleGetOid(rewrite_tuple);
rule->event = rewrite_form->ev_type - '0';
rule->attrno = rewrite_form->ev_attr;
rule->isInstead = rewrite_form->is_instead;
/* Must use heap_getattr to fetch ev_qual and ev_action */
ruleaction = heap_getattr(rewrite_tuple,
Anum_pg_rewrite_ev_action,
rewrite_tupdesc,
&isnull);
Assert(!isnull);
ruleaction_str = DatumGetCString(DirectFunctionCall1(textout,
ruleaction));
oldcxt = MemoryContextSwitchTo(rulescxt);
rule->actions = (List *) stringToNode(ruleaction_str);
MemoryContextSwitchTo(oldcxt);
pfree(ruleaction_str);
rule_evqual = heap_getattr(rewrite_tuple,
Anum_pg_rewrite_ev_qual,
rewrite_tupdesc,
&isnull);
Assert(!isnull);
rule_evqual_str = DatumGetCString(DirectFunctionCall1(textout,
rule_evqual));
oldcxt = MemoryContextSwitchTo(rulescxt);
rule->qual = (Node *) stringToNode(rule_evqual_str);
MemoryContextSwitchTo(oldcxt);
pfree(rule_evqual_str);
if (numlocks >= maxlocks)
{
maxlocks *= 2;
rules = (RewriteRule **)
repalloc(rules, sizeof(RewriteRule *) * maxlocks);
}
rules[numlocks++] = rule;
}
/*
* end the scan and close the attribute relation
*/
systable_endscan(rewrite_scan);
heap_close(rewrite_desc, AccessShareLock);
/*
* form a RuleLock and insert into relation
*/
rulelock = (RuleLock *) MemoryContextAlloc(rulescxt, sizeof(RuleLock));
rulelock->numLocks = numlocks;
rulelock->rules = rules;
relation->rd_rules = rulelock;
}
/*
* equalRuleLocks
*
* Determine whether two RuleLocks are equivalent
*
* Probably this should be in the rules code someplace...
*/
static bool
equalRuleLocks(RuleLock *rlock1, RuleLock *rlock2)
{
int i;
/*
* As of 7.3 we assume the rule ordering is repeatable,
* because RelationBuildRuleLock should read 'em in a
* consistent order. So just compare corresponding slots.
*/
if (rlock1 != NULL)
{
if (rlock2 == NULL)
return false;
if (rlock1->numLocks != rlock2->numLocks)
return false;
for (i = 0; i < rlock1->numLocks; i++)
{
RewriteRule *rule1 = rlock1->rules[i];
RewriteRule *rule2 = rlock2->rules[i];
if (rule1->ruleId != rule2->ruleId)
return false;
if (rule1->event != rule2->event)
return false;
if (rule1->attrno != rule2->attrno)
return false;
if (rule1->isInstead != rule2->isInstead)
return false;
if (!equal(rule1->qual, rule2->qual))
return false;
if (!equal(rule1->actions, rule2->actions))
return false;
}
}
else if (rlock2 != NULL)
return false;
return true;
}
/* ----------------------------------
* RelationBuildDesc
*
* Build a relation descriptor --- either a new one, or by
* recycling the given old relation object. The latter case
* supports rebuilding a relcache entry without invalidating
* pointers to it.
* --------------------------------
*/
static Relation
RelationBuildDesc(RelationBuildDescInfo buildinfo,
Relation oldrelation)
{
Relation relation;
Oid relid;
HeapTuple pg_class_tuple;
Form_pg_class relp;
MemoryContext oldcxt;
/*
* find the tuple in pg_class corresponding to the given relation id
*/
pg_class_tuple = ScanPgRelation(buildinfo);
/*
* if no such tuple exists, return NULL
*/
if (!HeapTupleIsValid(pg_class_tuple))
return NULL;
/*
* get information from the pg_class_tuple
*/
relid = HeapTupleGetOid(pg_class_tuple);
relp = (Form_pg_class) GETSTRUCT(pg_class_tuple);
/*
* allocate storage for the relation descriptor, and copy
* pg_class_tuple to relation->rd_rel.
*/
relation = AllocateRelationDesc(oldrelation, relp);
/*
* now we can free the memory allocated for pg_class_tuple
*/
heap_freetuple(pg_class_tuple);
/*
* initialize the relation's relation id (relation->rd_id)
*/
RelationGetRelid(relation) = relid;
/*
* initialize relation->rd_refcnt
*/
RelationSetReferenceCount(relation, 1);
/*
* normal relations are not nailed into the cache; nor can a pre-existing
* relation be new. It could be temp though. (Actually, it could be new
* too, but it's okay to forget that fact if forced to flush the entry.)
*/
relation->rd_isnailed = false;
relation->rd_isnew = false;
relation->rd_istemp = isTempNamespace(relation->rd_rel->relnamespace);
/*
* initialize the tuple descriptor (relation->rd_att).
*/
RelationBuildTupleDesc(buildinfo, relation);
/*
* Fetch rules and triggers that affect this relation
*/
if (relation->rd_rel->relhasrules)
RelationBuildRuleLock(relation);
else
{
relation->rd_rules = NULL;
relation->rd_rulescxt = NULL;
}
if (relation->rd_rel->reltriggers > 0)
RelationBuildTriggers(relation);
else
relation->trigdesc = NULL;
/*
* if it's an index, initialize index-related information
*/
if (OidIsValid(relation->rd_rel->relam))
RelationInitIndexAccessInfo(relation);
/*
* initialize the relation lock manager information
*/
RelationInitLockInfo(relation); /* see lmgr.c */
if (relation->rd_rel->relisshared)
relation->rd_node.tblNode = InvalidOid;
else
relation->rd_node.tblNode = MyDatabaseId;
relation->rd_node.relNode = relation->rd_rel->relfilenode;
/* make sure relation is marked as having no open file yet */
relation->rd_fd = -1;
/*
* Insert newly created relation into relcache hash tables.
*/
oldcxt = MemoryContextSwitchTo(CacheMemoryContext);
RelationCacheInsert(relation);
MemoryContextSwitchTo(oldcxt);
/*
* If it's a temp rel, RelationGetNumberOfBlocks will assume that
* rd_nblocks is correct. Must forcibly update the block count when
* creating the relcache entry. But if we are doing a rebuild, don't
* do this yet; leave it to RelationClearRelation to do at the end.
* (Otherwise, an elog in RelationUpdateNumberOfBlocks would leave us
* with inconsistent relcache state.)
*/
if (relation->rd_istemp && oldrelation == NULL)
RelationUpdateNumberOfBlocks(relation);
return relation;
}
/*
* Initialize index-access-method support data for an index relation
*/
void
RelationInitIndexAccessInfo(Relation relation)
{
HeapTuple tuple;
Size iformsize;
Form_pg_index iform;
Form_pg_am aform;
MemoryContext indexcxt;
IndexStrategy strategy;
Oid *operator;
RegProcedure *support;
FmgrInfo *supportinfo;
int natts;
uint16 amstrategies;
uint16 amsupport;
/*
* Make a copy of the pg_index entry for the index. Note that this
* is a variable-length tuple.
*/
tuple = SearchSysCache(INDEXRELID,
ObjectIdGetDatum(RelationGetRelid(relation)),
0, 0, 0);
if (!HeapTupleIsValid(tuple))
elog(ERROR, "RelationInitIndexAccessInfo: no pg_index entry for index %u",
RelationGetRelid(relation));
iformsize = tuple->t_len - tuple->t_data->t_hoff;
iform = (Form_pg_index) MemoryContextAlloc(CacheMemoryContext, iformsize);
memcpy(iform, GETSTRUCT(tuple), iformsize);
ReleaseSysCache(tuple);
relation->rd_index = iform;
/*
* Make a copy of the pg_am entry for the index's access method
*/
tuple = SearchSysCache(AMOID,
ObjectIdGetDatum(relation->rd_rel->relam),
0, 0, 0);
if (!HeapTupleIsValid(tuple))
elog(ERROR, "RelationInitIndexAccessInfo: cache lookup failed for AM %u",
relation->rd_rel->relam);
aform = (Form_pg_am) MemoryContextAlloc(CacheMemoryContext, sizeof *aform);
memcpy(aform, GETSTRUCT(tuple), sizeof *aform);
ReleaseSysCache(tuple);
relation->rd_am = aform;
natts = relation->rd_rel->relnatts;
amstrategies = aform->amstrategies;
amsupport = aform->amsupport;
/*
* Make the private context to hold index access info. The reason we
* need a context, and not just a couple of pallocs, is so that we
* won't leak any subsidiary info attached to fmgr lookup records.
*
* Context parameters are set on the assumption that it'll probably not
* contain much data.
*/
indexcxt = AllocSetContextCreate(CacheMemoryContext,
RelationGetRelationName(relation),
0, /* minsize */
512, /* initsize */
1024); /* maxsize */
relation->rd_indexcxt = indexcxt;
/*
* Allocate arrays to hold data
*/
if (amstrategies > 0)
{
int noperators = natts * amstrategies;
Size stratSize;
stratSize = AttributeNumberGetIndexStrategySize(natts, amstrategies);
strategy = (IndexStrategy) MemoryContextAlloc(indexcxt, stratSize);
MemSet(strategy, 0, stratSize);
operator = (Oid *)
MemoryContextAlloc(indexcxt, noperators * sizeof(Oid));
MemSet(operator, 0, noperators * sizeof(Oid));
}
else
{
strategy = NULL;
operator = NULL;
}
if (amsupport > 0)
{
int nsupport = natts * amsupport;
support = (RegProcedure *)
MemoryContextAlloc(indexcxt, nsupport * sizeof(RegProcedure));
MemSet(support, 0, nsupport * sizeof(RegProcedure));
supportinfo = (FmgrInfo *)
MemoryContextAlloc(indexcxt, nsupport * sizeof(FmgrInfo));
MemSet(supportinfo, 0, nsupport * sizeof(FmgrInfo));
}
else
{
support = NULL;
supportinfo = NULL;
}
relation->rd_istrat = strategy;
relation->rd_operator = operator;
relation->rd_support = support;
relation->rd_supportinfo = supportinfo;
/*
* Fill the strategy map and the support RegProcedure arrays.
* (supportinfo is left as zeroes, and is filled on-the-fly when used)
*/
IndexSupportInitialize(iform,
strategy, operator, support,
amstrategies, amsupport, natts);
}
/*
* IndexSupportInitialize
* Initializes an index strategy and associated support procedures,
* given the index's pg_index tuple.
*
* Data is returned into *indexStrategy, *indexOperator, and *indexSupport,
* all of which are objects allocated by the caller.
*
* The caller also passes maxStrategyNumber, maxSupportNumber, and
* maxAttributeNumber, since these indicate the size of the arrays
* it has allocated --- but in practice these numbers must always match
* those obtainable from the system catalog entries for the index and
* access method.
*/
static void
IndexSupportInitialize(Form_pg_index iform,
IndexStrategy indexStrategy,
Oid *indexOperator,
RegProcedure *indexSupport,
StrategyNumber maxStrategyNumber,
StrategyNumber maxSupportNumber,
AttrNumber maxAttributeNumber)
{
int attIndex;
maxStrategyNumber = AMStrategies(maxStrategyNumber);
/*
* XXX note that the following assumes the INDEX tuple is well formed
* and that the *key and *class are 0 terminated.
*/
for (attIndex = 0; attIndex < maxAttributeNumber; attIndex++)
{
OpClassCacheEnt *opcentry;
if (iform->indkey[attIndex] == InvalidAttrNumber ||
!OidIsValid(iform->indclass[attIndex]))
elog(ERROR, "IndexSupportInitialize: bogus pg_index tuple");
/* look up the info for this opclass, using a cache */
opcentry = LookupOpclassInfo(iform->indclass[attIndex],
maxStrategyNumber,
maxSupportNumber);
/* load the strategy information for the index operators */
if (maxStrategyNumber > 0)
{
StrategyMap map;
Oid *opers;
StrategyNumber strategy;
map = IndexStrategyGetStrategyMap(indexStrategy,
maxStrategyNumber,
attIndex + 1);
opers = &indexOperator[attIndex * maxStrategyNumber];
for (strategy = 0; strategy < maxStrategyNumber; strategy++)
{
ScanKey mapentry;
mapentry = StrategyMapGetScanKeyEntry(map, strategy + 1);
if (RegProcedureIsValid(opcentry->operatorProcs[strategy]))
{
MemSet(mapentry, 0, sizeof(*mapentry));
mapentry->sk_flags = 0;
mapentry->sk_procedure = opcentry->operatorProcs[strategy];
/*
* Mark mapentry->sk_func invalid, until and unless
* someone sets it up.
*/
mapentry->sk_func.fn_oid = InvalidOid;
}
else
ScanKeyEntrySetIllegal(mapentry);
opers[strategy] = opcentry->operatorOids[strategy];
}
}
/* if support routines exist for this access method, load them */
if (maxSupportNumber > 0)
{
RegProcedure *procs;
StrategyNumber support;
procs = &indexSupport[attIndex * maxSupportNumber];
for (support = 0; support < maxSupportNumber; ++support)
procs[support] = opcentry->supportProcs[support];
}
}
}
/*
* LookupOpclassInfo
*
* This routine maintains a per-opclass cache of the information needed
* by IndexSupportInitialize(). This is more efficient than relying on
* the catalog cache, because we can load all the info about a particular
* opclass in a single indexscan of pg_amproc or pg_amop.
*
* The information from pg_am about expected range of strategy and support
* numbers is passed in, rather than being looked up, mainly because the
* caller will have it already.
*
* XXX There isn't any provision for flushing the cache. However, there
* isn't any provision for flushing relcache entries when opclass info
* changes, either :-(
*/
static OpClassCacheEnt *
LookupOpclassInfo(Oid operatorClassOid,
StrategyNumber numStrats,
StrategyNumber numSupport)
{
OpClassCacheEnt *opcentry;
bool found;
Relation pg_amop_desc;
Relation pg_amproc_desc;
SysScanDesc pg_amop_scan;
SysScanDesc pg_amproc_scan;
ScanKeyData key;
HeapTuple htup;
bool indexOK;
if (OpClassCache == NULL)
{
/* First time through: initialize the opclass cache */
HASHCTL ctl;
if (!CacheMemoryContext)
CreateCacheMemoryContext();
MemSet(&ctl, 0, sizeof(ctl));
ctl.keysize = sizeof(Oid);
ctl.entrysize = sizeof(OpClassCacheEnt);
ctl.hash = tag_hash;
OpClassCache = hash_create("Operator class cache", 64,
&ctl, HASH_ELEM | HASH_FUNCTION);
}
opcentry = (OpClassCacheEnt *) hash_search(OpClassCache,
(void *) &operatorClassOid,
HASH_ENTER, &found);
if (opcentry == NULL)
elog(ERROR, "out of memory for operator class cache");
if (found && opcentry->valid)
{
/* Already made an entry for it */
Assert(numStrats == opcentry->numStrats);
Assert(numSupport == opcentry->numSupport);
return opcentry;
}
/* Need to fill in new entry */
opcentry->valid = false; /* until known OK */
opcentry->numStrats = numStrats;
opcentry->numSupport = numSupport;
if (numStrats > 0)
{
opcentry->operatorOids = (Oid *)
MemoryContextAlloc(CacheMemoryContext,
numStrats * sizeof(Oid));
MemSet(opcentry->operatorOids, 0, numStrats * sizeof(Oid));
opcentry->operatorProcs = (RegProcedure *)
MemoryContextAlloc(CacheMemoryContext,
numStrats * sizeof(RegProcedure));
MemSet(opcentry->operatorProcs, 0, numStrats * sizeof(RegProcedure));
}
else
{
opcentry->operatorOids = NULL;
opcentry->operatorProcs = NULL;
}
if (numSupport > 0)
{
opcentry->supportProcs = (RegProcedure *)
MemoryContextAlloc(CacheMemoryContext,
numSupport * sizeof(RegProcedure));
MemSet(opcentry->supportProcs, 0, numSupport * sizeof(RegProcedure));
}
else
opcentry->supportProcs = NULL;
/*
* To avoid infinite recursion during startup, force a heap scan if
* we're looking up info for the opclasses used by the indexes we
* would like to reference here.
*/
indexOK = criticalRelcachesBuilt ||
(operatorClassOid != OID_BTREE_OPS_OID &&
operatorClassOid != INT2_BTREE_OPS_OID);
/*
* Scan pg_amop to obtain operators for the opclass
*/
if (numStrats > 0)
{
ScanKeyEntryInitialize(&key, 0,
Anum_pg_amop_amopclaid,
F_OIDEQ,
ObjectIdGetDatum(operatorClassOid));
pg_amop_desc = heap_openr(AccessMethodOperatorRelationName,
AccessShareLock);
pg_amop_scan = systable_beginscan(pg_amop_desc,
AccessMethodStrategyIndex,
indexOK,
SnapshotNow,
1, &key);
while (HeapTupleIsValid(htup = systable_getnext(pg_amop_scan)))
{
Form_pg_amop amopform = (Form_pg_amop) GETSTRUCT(htup);
if (amopform->amopstrategy <= 0 ||
(StrategyNumber) amopform->amopstrategy > numStrats)
elog(ERROR, "Bogus amopstrategy number %d for opclass %u",
amopform->amopstrategy, operatorClassOid);
opcentry->operatorOids[amopform->amopstrategy - 1] =
amopform->amopopr;
opcentry->operatorProcs[amopform->amopstrategy - 1] =
get_opcode(amopform->amopopr);
}
systable_endscan(pg_amop_scan);
heap_close(pg_amop_desc, AccessShareLock);
}
/*
* Scan pg_amproc to obtain support procs for the opclass
*/
if (numSupport > 0)
{
ScanKeyEntryInitialize(&key, 0,
Anum_pg_amproc_amopclaid,
F_OIDEQ,
ObjectIdGetDatum(operatorClassOid));
pg_amproc_desc = heap_openr(AccessMethodProcedureRelationName,
AccessShareLock);
pg_amproc_scan = systable_beginscan(pg_amproc_desc,
AccessMethodProcedureIndex,
indexOK,
SnapshotNow,
1, &key);
while (HeapTupleIsValid(htup = systable_getnext(pg_amproc_scan)))
{
Form_pg_amproc amprocform = (Form_pg_amproc) GETSTRUCT(htup);
if (amprocform->amprocnum <= 0 ||
(StrategyNumber) amprocform->amprocnum > numSupport)
elog(ERROR, "Bogus amproc number %d for opclass %u",
amprocform->amprocnum, operatorClassOid);
opcentry->supportProcs[amprocform->amprocnum - 1] =
amprocform->amproc;
}
systable_endscan(pg_amproc_scan);
heap_close(pg_amproc_desc, AccessShareLock);
}
opcentry->valid = true;
return opcentry;
}
/*
* formrdesc
*
* This is a special cut-down version of RelationBuildDesc()
* used by RelationCacheInitialize() in initializing the relcache.
* The relation descriptor is built just from the supplied parameters,
* without actually looking at any system table entries. We cheat
* quite a lot since we only need to work for a few basic system
* catalogs.
*
* formrdesc is currently used for: pg_class, pg_attribute, pg_proc,
* and pg_type (see RelationCacheInitialize).
*
* Note that these catalogs can't have constraints, default values,
* rules, or triggers, since we don't cope with any of that.
*
* NOTE: we assume we are already switched into CacheMemoryContext.
*/
static void
formrdesc(const char *relationName,
int natts,
FormData_pg_attribute *att)
{
Relation relation;
int i;
/*
* allocate new relation desc
*/
relation = (Relation) palloc(sizeof(RelationData));
/*
* clear all fields of reldesc
*/
MemSet((char *) relation, 0, sizeof(RelationData));
relation->rd_targblock = InvalidBlockNumber;
/* make sure relation is marked as having no open file yet */
relation->rd_fd = -1;
/*
* initialize reference count
*/
RelationSetReferenceCount(relation, 1);
/*
* all entries built with this routine are nailed-in-cache; none are
* for new or temp relations.
*/
relation->rd_isnailed = true;
relation->rd_isnew = false;
relation->rd_istemp = false;
/*
* initialize relation tuple form
*
* The data we insert here is pretty incomplete/bogus, but it'll serve to
* get us launched. RelationCacheInitializePhase2() will read the
* real data from pg_class and replace what we've done here.
*/
relation->rd_rel = (Form_pg_class) palloc(CLASS_TUPLE_SIZE);
MemSet(relation->rd_rel, 0, CLASS_TUPLE_SIZE);
namestrcpy(&relation->rd_rel->relname, relationName);
relation->rd_rel->relnamespace = PG_CATALOG_NAMESPACE;
/*
* It's important to distinguish between shared and non-shared
* relations, even at bootstrap time, to make sure we know where they
* are stored. At present, all relations that formrdesc is used for
* are not shared.
*/
relation->rd_rel->relisshared = false;
relation->rd_rel->relpages = 1;
relation->rd_rel->reltuples = 1;
relation->rd_rel->relkind = RELKIND_RELATION;
relation->rd_rel->relhasoids = true;
relation->rd_rel->relnatts = (int16) natts;
/*
* initialize attribute tuple form
*
* Unlike the case with the relation tuple, this data had better be
* right because it will never be replaced. The input values must be
* correctly defined by macros in src/include/catalog/ headers.
*/
relation->rd_att = CreateTemplateTupleDesc(natts,
relation->rd_rel->relhasoids);
/*
* initialize tuple desc info
*/
for (i = 0; i < natts; i++)
{
relation->rd_att->attrs[i] = (Form_pg_attribute) palloc(ATTRIBUTE_TUPLE_SIZE);
memcpy((char *) relation->rd_att->attrs[i],
(char *) &att[i],
ATTRIBUTE_TUPLE_SIZE);
/* make sure attcacheoff is valid */
relation->rd_att->attrs[i]->attcacheoff = -1;
}
/* initialize first attribute's attcacheoff, cf RelationBuildTupleDesc */
relation->rd_att->attrs[0]->attcacheoff = 0;
/*
* initialize relation id from info in att array (my, this is ugly)
*/
RelationGetRelid(relation) = relation->rd_att->attrs[0]->attrelid;
/*
* initialize the relation's lock manager and RelFileNode information
*/
RelationInitLockInfo(relation); /* see lmgr.c */
if (relation->rd_rel->relisshared)
relation->rd_node.tblNode = InvalidOid;
else
relation->rd_node.tblNode = MyDatabaseId;
relation->rd_node.relNode =
relation->rd_rel->relfilenode = RelationGetRelid(relation);
/*
* initialize the rel-has-index flag, using hardwired knowledge
*/
relation->rd_rel->relhasindex = false;
/* In bootstrap mode, we have no indexes */
if (!IsBootstrapProcessingMode())
{
/* Otherwise, all the rels formrdesc is used for have indexes */
relation->rd_rel->relhasindex = true;
}
/*
* add new reldesc to relcache
*/
RelationCacheInsert(relation);
}
/* ----------------------------------------------------------------
* Relation Descriptor Lookup Interface
* ----------------------------------------------------------------
*/
/*
* RelationIdCacheGetRelation
*
* Lookup an existing reldesc by OID.
*
* Only try to get the reldesc by looking in the cache,
* do not go to the disk.
*
* NB: relation ref count is incremented if successful.
* Caller should eventually decrement count. (Usually,
* that happens by calling RelationClose().)
*/
Relation
RelationIdCacheGetRelation(Oid relationId)
{
Relation rd;
RelationIdCacheLookup(relationId, rd);
if (RelationIsValid(rd))
RelationIncrementReferenceCount(rd);
return rd;
}
/*
* RelationSysNameCacheGetRelation
*
* As above, but lookup by name; only works for system catalogs.
*/
static Relation
RelationSysNameCacheGetRelation(const char *relationName)
{
Relation rd;
NameData name;
/*
* make sure that the name key used for hash lookup is properly
* null-padded
*/
namestrcpy(&name, relationName);
RelationSysNameCacheLookup(NameStr(name), rd);
if (RelationIsValid(rd))
RelationIncrementReferenceCount(rd);
return rd;
}
Relation
RelationNodeCacheGetRelation(RelFileNode rnode)
{
Relation rd;
RelationNodeCacheLookup(rnode, rd);
if (RelationIsValid(rd))
RelationIncrementReferenceCount(rd);
return rd;
}
/*
* RelationIdGetRelation
*
* Lookup a reldesc by OID; make one if not already in cache.
*
* NB: relation ref count is incremented, or set to 1 if new entry.
* Caller should eventually decrement count. (Usually,
* that happens by calling RelationClose().)
*/
Relation
RelationIdGetRelation(Oid relationId)
{
Relation rd;
RelationBuildDescInfo buildinfo;
/*
* first try and get a reldesc from the cache
*/
rd = RelationIdCacheGetRelation(relationId);
if (RelationIsValid(rd))
return rd;
/*
* no reldesc in the cache, so have RelationBuildDesc() build one and
* add it.
*/
buildinfo.infotype = INFO_RELID;
buildinfo.i.info_id = relationId;
rd = RelationBuildDesc(buildinfo, NULL);
return rd;
}
/*
* RelationSysNameGetRelation
*
* As above, but lookup by name; only works for system catalogs.
*/
Relation
RelationSysNameGetRelation(const char *relationName)
{
Relation rd;
RelationBuildDescInfo buildinfo;
/*
* first try and get a reldesc from the cache
*/
rd = RelationSysNameCacheGetRelation(relationName);
if (RelationIsValid(rd))
return rd;
/*
* no reldesc in the cache, so have RelationBuildDesc() build one and
* add it.
*/
buildinfo.infotype = INFO_RELNAME;
buildinfo.i.info_name = (char *) relationName;
rd = RelationBuildDesc(buildinfo, NULL);
return rd;
}
/* ----------------------------------------------------------------
* cache invalidation support routines
* ----------------------------------------------------------------
*/
/*
* RelationClose - close an open relation
*
* Actually, we just decrement the refcount.
*
* NOTE: if compiled with -DRELCACHE_FORCE_RELEASE then relcache entries
* will be freed as soon as their refcount goes to zero. In combination
* with aset.c's CLOBBER_FREED_MEMORY option, this provides a good test
* to catch references to already-released relcache entries. It slows
* things down quite a bit, however.
*/
void
RelationClose(Relation relation)
{
/* Note: no locking manipulations needed */
RelationDecrementReferenceCount(relation);
#ifdef RELCACHE_FORCE_RELEASE
if (RelationHasReferenceCountZero(relation) &&
!relation->rd_isnew)
RelationClearRelation(relation, false);
#endif
}
#ifdef ENABLE_REINDEX_NAILED_RELATIONS
/*
* RelationReloadClassinfo
*
* This function is especially for nailed relations.
* relhasindex/relfilenode could be changed even for
* nailed relations.
*/
static void
RelationReloadClassinfo(Relation relation)
{
RelationBuildDescInfo buildinfo;
HeapTuple pg_class_tuple;
Form_pg_class relp;
if (!relation->rd_rel)
return;
buildinfo.infotype = INFO_RELID;
buildinfo.i.info_id = relation->rd_id;
pg_class_tuple = ScanPgRelation(buildinfo);
if (!HeapTupleIsValid(pg_class_tuple))
{
elog(ERROR, "RelationReloadClassinfo system relation id=%d doesn't exist", relation->rd_id);
return;
}
RelationCacheDelete(relation);
relp = (Form_pg_class) GETSTRUCT(pg_class_tuple);
memcpy((char *) relation->rd_rel, (char *) relp, CLASS_TUPLE_SIZE);
relation->rd_node.relNode = relp->relfilenode;
RelationCacheInsert(relation);
heap_freetuple(pg_class_tuple);
return;
}
#endif /* ENABLE_REINDEX_NAILED_RELATIONS */
/*
* RelationClearRelation
*
* Physically blow away a relation cache entry, or reset it and rebuild
* it from scratch (that is, from catalog entries). The latter path is
* usually used when we are notified of a change to an open relation
* (one with refcount > 0). However, this routine just does whichever
* it's told to do; callers must determine which they want.
*/
static void
RelationClearRelation(Relation relation, bool rebuild)
{
MemoryContext oldcxt;
/*
* Make sure smgr and lower levels close the relation's files, if they
* weren't closed already. If the relation is not getting deleted,
* the next smgr access should reopen the files automatically. This
* ensures that the low-level file access state is updated after, say,
* a vacuum truncation.
*/
if (relation->rd_fd >= 0)
{
smgrclose(DEFAULT_SMGR, relation);
relation->rd_fd = -1;
}
/*
* Never, never ever blow away a nailed-in system relation, because
* we'd be unable to recover.
*/
if (relation->rd_isnailed)
{
#ifdef ENABLE_REINDEX_NAILED_RELATIONS
RelationReloadClassinfo(relation);
#endif /* ENABLE_REINDEX_NAILED_RELATIONS */
return;
}
/*
* Remove relation from hash tables
*
* Note: we might be reinserting it momentarily, but we must not have it
* visible in the hash tables until it's valid again, so don't try to
* optimize this away...
*/
oldcxt = MemoryContextSwitchTo(CacheMemoryContext);
RelationCacheDelete(relation);
MemoryContextSwitchTo(oldcxt);
/* Clear out catcache's entries for this relation */
CatalogCacheFlushRelation(RelationGetRelid(relation));
/*
* Free all the subsidiary data structures of the relcache entry. We
* cannot free rd_att if we are trying to rebuild the entry, however,
* because pointers to it may be cached in various places. The trigger
* manager might also have pointers into the trigdesc, and the rule
* manager might have pointers into the rewrite rules. So to begin
* with, we can only get rid of these fields:
*/
if (relation->rd_index)
pfree(relation->rd_index);
if (relation->rd_am)
pfree(relation->rd_am);
if (relation->rd_rel)
pfree(relation->rd_rel);
freeList(relation->rd_indexlist);
if (relation->rd_indexcxt)
MemoryContextDelete(relation->rd_indexcxt);
/*
* If we're really done with the relcache entry, blow it away. But if
* someone is still using it, reconstruct the whole deal without
* moving the physical RelationData record (so that the someone's
* pointer is still valid).
*/
if (!rebuild)
{
/* ok to zap remaining substructure */
FreeTupleDesc(relation->rd_att);
if (relation->rd_rulescxt)
MemoryContextDelete(relation->rd_rulescxt);
FreeTriggerDesc(relation->trigdesc);
pfree(relation);
}
else
{
/*
* When rebuilding an open relcache entry, must preserve ref count
* and rd_isnew flag. Also attempt to preserve the tupledesc,
* rewrite rules, and trigger substructures in place.
*/
int old_refcnt = relation->rd_refcnt;
bool old_isnew = relation->rd_isnew;
TupleDesc old_att = relation->rd_att;
RuleLock *old_rules = relation->rd_rules;
MemoryContext old_rulescxt = relation->rd_rulescxt;
TriggerDesc *old_trigdesc = relation->trigdesc;
RelationBuildDescInfo buildinfo;
buildinfo.infotype = INFO_RELID;
buildinfo.i.info_id = RelationGetRelid(relation);
if (RelationBuildDesc(buildinfo, relation) != relation)
{
/* Should only get here if relation was deleted */
FreeTupleDesc(old_att);
if (old_rulescxt)
MemoryContextDelete(old_rulescxt);
FreeTriggerDesc(old_trigdesc);
pfree(relation);
elog(ERROR, "RelationClearRelation: relation %u deleted while still in use",
buildinfo.i.info_id);
}
RelationSetReferenceCount(relation, old_refcnt);
relation->rd_isnew = old_isnew;
if (equalTupleDescs(old_att, relation->rd_att))
{
FreeTupleDesc(relation->rd_att);
relation->rd_att = old_att;
}
else
FreeTupleDesc(old_att);
if (equalRuleLocks(old_rules, relation->rd_rules))
{
if (relation->rd_rulescxt)
MemoryContextDelete(relation->rd_rulescxt);
relation->rd_rules = old_rules;
relation->rd_rulescxt = old_rulescxt;
}
else
{
if (old_rulescxt)
MemoryContextDelete(old_rulescxt);
}
if (equalTriggerDescs(old_trigdesc, relation->trigdesc))
{
FreeTriggerDesc(relation->trigdesc);
relation->trigdesc = old_trigdesc;
}
else
FreeTriggerDesc(old_trigdesc);
/*
* Update rd_nblocks. This is kind of expensive, but I think we must
* do it in case relation has been truncated... we definitely must
* do it if the rel is new or temp, since RelationGetNumberOfBlocks
* will subsequently assume that the block count is correct.
*/
RelationUpdateNumberOfBlocks(relation);
}
}
/*
* RelationFlushRelation
*
* Rebuild the relation if it is open (refcount > 0), else blow it away.
*/
static void
RelationFlushRelation(Relation relation)
{
bool rebuild;
if (relation->rd_isnew)
{
/*
* New relcache entries are always rebuilt, not flushed; else we'd
* forget the "new" status of the relation, which is a useful
* optimization to have.
*/
rebuild = true;
}
else
{
/*
* Pre-existing rels can be dropped from the relcache if not open.
*/
rebuild = !RelationHasReferenceCountZero(relation);
}
RelationClearRelation(relation, rebuild);
}
/*
* RelationForgetRelation - unconditionally remove a relcache entry
*
* External interface for destroying a relcache entry when we
* drop the relation.
*/
void
RelationForgetRelation(Oid rid)
{
Relation relation;
RelationIdCacheLookup(rid, relation);
if (!PointerIsValid(relation))
return; /* not in cache, nothing to do */
if (!RelationHasReferenceCountZero(relation))
elog(ERROR, "RelationForgetRelation: relation %u is still open", rid);
/* Unconditionally destroy the relcache entry */
RelationClearRelation(relation, false);
}
/*
* RelationIdInvalidateRelationCacheByRelationId
*
* This routine is invoked for SI cache flush messages.
*
* We used to skip local relations, on the grounds that they could
* not be targets of cross-backend SI update messages; but it seems
* safer to process them, so that our *own* SI update messages will
* have the same effects during CommandCounterIncrement for both
* local and nonlocal relations.
*/
void
RelationIdInvalidateRelationCacheByRelationId(Oid relationId)
{
Relation relation;
RelationIdCacheLookup(relationId, relation);
if (PointerIsValid(relation))
{
relcacheInvalsReceived++;
RelationFlushRelation(relation);
}
}
/*
* RelationCacheInvalidate
* Blow away cached relation descriptors that have zero reference counts,
* and rebuild those with positive reference counts.
*
* This is currently used only to recover from SI message buffer overflow,
* so we do not touch new-in-transaction relations; they cannot be targets
* of cross-backend SI updates (and our own updates now go through a
* separate linked list that isn't limited by the SI message buffer size).
*
* We do this in two phases: the first pass deletes deletable items, and
* the second one rebuilds the rebuildable items. This is essential for
* safety, because hash_seq_search only copes with concurrent deletion of
* the element it is currently visiting. If a second SI overflow were to
* occur while we are walking the table, resulting in recursive entry to
* this routine, we could crash because the inner invocation blows away
* the entry next to be visited by the outer scan. But this way is OK,
* because (a) during the first pass we won't process any more SI messages,
* so hash_seq_search will complete safely; (b) during the second pass we
* only hold onto pointers to nondeletable entries.
*/
void
RelationCacheInvalidate(void)
{
HASH_SEQ_STATUS status;
RelIdCacheEnt *idhentry;
Relation relation;
List *rebuildList = NIL;
List *l;
/* Phase 1 */
hash_seq_init(&status, RelationIdCache);
while ((idhentry = (RelIdCacheEnt *) hash_seq_search(&status)) != NULL)
{
relation = idhentry->reldesc;
/* Ignore new relations, since they are never SI targets */
if (relation->rd_isnew)
continue;
relcacheInvalsReceived++;
if (RelationHasReferenceCountZero(relation))
{
/* Delete this entry immediately */
RelationClearRelation(relation, false);
}
else
{
/* Add entry to list of stuff to rebuild in second pass */
rebuildList = lcons(relation, rebuildList);
}
}
/* Phase 2: rebuild the items found to need rebuild in phase 1 */
foreach(l, rebuildList)
{
relation = (Relation) lfirst(l);
RelationClearRelation(relation, true);
}
freeList(rebuildList);
}
/*
* AtEOXact_RelationCache
*
* Clean up the relcache at transaction commit or abort.
*/
void
AtEOXact_RelationCache(bool commit)
{
HASH_SEQ_STATUS status;
RelIdCacheEnt *idhentry;
hash_seq_init(&status, RelationIdCache);
while ((idhentry = (RelIdCacheEnt *) hash_seq_search(&status)) != NULL)
{
Relation relation = idhentry->reldesc;
int expected_refcnt;
/*
* Is it a relation created in the current transaction?
*
* During commit, reset the flag to false, since we are now out of the
* creating transaction. During abort, simply delete the relcache
* entry --- it isn't interesting any longer. (NOTE: if we have
* forgotten the isnew state of a new relation due to a forced cache
* flush, the entry will get deleted anyway by shared-cache-inval
* processing of the aborted pg_class insertion.)
*/
if (relation->rd_isnew)
{
if (commit)
relation->rd_isnew = false;
else
{
RelationClearRelation(relation, false);
continue;
}
}
/*
* During transaction abort, we must also reset relcache entry ref
* counts to their normal not-in-a-transaction state. A ref count may
* be too high because some routine was exited by elog() between
* incrementing and decrementing the count.
*
* During commit, we should not have to do this, but it's still useful
* to check that the counts are correct to catch missed relcache
* closes.
*
* In bootstrap mode, do NOT reset the refcnt nor complain that it's
* nonzero --- the bootstrap code expects relations to stay open
* across start/commit transaction calls. (That seems bogus, but it's
* not worth fixing.)
*/
expected_refcnt = relation->rd_isnailed ? 1 : 0;
if (commit)
{
if (relation->rd_refcnt != expected_refcnt &&
!IsBootstrapProcessingMode())
{
elog(WARNING, "Relcache reference leak: relation \"%s\" has refcnt %d instead of %d",
RelationGetRelationName(relation),
relation->rd_refcnt, expected_refcnt);
RelationSetReferenceCount(relation, expected_refcnt);
}
}
else
{
/* abort case, just reset it quietly */
RelationSetReferenceCount(relation, expected_refcnt);
}
}
}
/*
* RelationBuildLocalRelation
* Build a relcache entry for an about-to-be-created relation,
* and enter it into the relcache.
*/
Relation
RelationBuildLocalRelation(const char *relname,
Oid relnamespace,
TupleDesc tupDesc,
Oid relid, Oid dbid,
RelFileNode rnode,
bool nailit)
{
Relation rel;
MemoryContext oldcxt;
int natts = tupDesc->natts;
int i;
AssertArg(natts > 0);
/*
* switch to the cache context to create the relcache entry.
*/
if (!CacheMemoryContext)
CreateCacheMemoryContext();
oldcxt = MemoryContextSwitchTo(CacheMemoryContext);
/*
* allocate a new relation descriptor and fill in basic state fields.
*/
rel = (Relation) palloc(sizeof(RelationData));
MemSet((char *) rel, 0, sizeof(RelationData));
rel->rd_targblock = InvalidBlockNumber;
/* make sure relation is marked as having no open file yet */
rel->rd_fd = -1;
RelationSetReferenceCount(rel, 1);
/* it's being created in this transaction */
rel->rd_isnew = true;
/* is it a temporary relation? */
rel->rd_istemp = isTempNamespace(relnamespace);
/*
* nail the reldesc if this is a bootstrap create reln and we may need
* it in the cache later on in the bootstrap process so we don't ever
* want it kicked out. e.g. pg_attribute!!!
*/
if (nailit)
rel->rd_isnailed = true;
/*
* create a new tuple descriptor from the one passed in. We do this
* partly to copy it into the cache context, and partly because the
* new relation can't have any defaults or constraints yet; they
* have to be added in later steps, because they require additions
* to multiple system catalogs. We can copy attnotnull constraints
* here, however.
*/
rel->rd_att = CreateTupleDescCopy(tupDesc);
for (i = 0; i < natts; i++)
rel->rd_att->attrs[i]->attnotnull = tupDesc->attrs[i]->attnotnull;
/*
* initialize relation tuple form (caller may add/override data later)
*/
rel->rd_rel = (Form_pg_class) palloc(CLASS_TUPLE_SIZE);
MemSet((char *) rel->rd_rel, 0, CLASS_TUPLE_SIZE);
namestrcpy(&rel->rd_rel->relname, relname);
rel->rd_rel->relnamespace = relnamespace;
rel->rd_rel->relkind = RELKIND_UNCATALOGED;
rel->rd_rel->relhasoids = rel->rd_att->tdhasoid;
rel->rd_rel->relnatts = natts;
rel->rd_rel->reltype = InvalidOid;
/*
* Insert relation physical and logical identifiers (OIDs) into the
* right places.
*/
rel->rd_rel->relisshared = (dbid == InvalidOid);
RelationGetRelid(rel) = relid;
for (i = 0; i < natts; i++)
rel->rd_att->attrs[i]->attrelid = relid;
rel->rd_node = rnode;
rel->rd_rel->relfilenode = rnode.relNode;
RelationInitLockInfo(rel); /* see lmgr.c */
/*
* Okay to insert into the relcache hash tables.
*/
RelationCacheInsert(rel);
/*
* done building relcache entry.
*/
MemoryContextSwitchTo(oldcxt);
return rel;
}
/*
* RelationCacheInitialize
*
* This initializes the relation descriptor cache. At the time
* that this is invoked, we can't do database access yet (mainly
* because the transaction subsystem is not up), so we can't get
* "real" info. However it's okay to read the pg_internal.init
* cache file, if one is available. Otherwise we make phony
* entries for the minimum set of nailed-in-cache relations.
*/
#define INITRELCACHESIZE 400
void
RelationCacheInitialize(void)
{
MemoryContext oldcxt;
HASHCTL ctl;
/*
* switch to cache memory context
*/
if (!CacheMemoryContext)
CreateCacheMemoryContext();
oldcxt = MemoryContextSwitchTo(CacheMemoryContext);
/*
* create hashtables that index the relcache
*/
MemSet(&ctl, 0, sizeof(ctl));
ctl.keysize = sizeof(NameData);
ctl.entrysize = sizeof(RelNameCacheEnt);
RelationSysNameCache = hash_create("Relcache by name", INITRELCACHESIZE,
&ctl, HASH_ELEM);
ctl.keysize = sizeof(Oid);
ctl.entrysize = sizeof(RelIdCacheEnt);
ctl.hash = tag_hash;
RelationIdCache = hash_create("Relcache by OID", INITRELCACHESIZE,
&ctl, HASH_ELEM | HASH_FUNCTION);
ctl.keysize = sizeof(RelFileNode);
ctl.entrysize = sizeof(RelNodeCacheEnt);
ctl.hash = tag_hash;
RelationNodeCache = hash_create("Relcache by rnode", INITRELCACHESIZE,
&ctl, HASH_ELEM | HASH_FUNCTION);
/*
* Try to load the relcache cache file. If successful, we're done
* for now. Otherwise, initialize the cache with pre-made descriptors
* for the critical "nailed-in" system catalogs.
*/
if (IsBootstrapProcessingMode() ||
! load_relcache_init_file())
{
formrdesc(RelationRelationName,
Natts_pg_class, Desc_pg_class);
formrdesc(AttributeRelationName,
Natts_pg_attribute, Desc_pg_attribute);
formrdesc(ProcedureRelationName,
Natts_pg_proc, Desc_pg_proc);
formrdesc(TypeRelationName,
Natts_pg_type, Desc_pg_type);
#define NUM_CRITICAL_RELS 4 /* fix if you change list above */
}
MemoryContextSwitchTo(oldcxt);
}
/*
* RelationCacheInitializePhase2
*
* This is called as soon as the catcache and transaction system
* are functional. At this point we can actually read data from
* the system catalogs. Update the relcache entries made during
* RelationCacheInitialize, and make sure we have entries for the
* critical system indexes.
*/
void
RelationCacheInitializePhase2(void)
{
HASH_SEQ_STATUS status;
RelIdCacheEnt *idhentry;
if (IsBootstrapProcessingMode())
return;
/*
* If we didn't get the critical system indexes loaded into relcache,
* do so now. These are critical because the catcache depends on them
* for catcache fetches that are done during relcache load. Thus, we
* have an infinite-recursion problem. We can break the recursion
* by doing heapscans instead of indexscans at certain key spots.
* To avoid hobbling performance, we only want to do that until we
* have the critical indexes loaded into relcache. Thus, the flag
* criticalRelcachesBuilt is used to decide whether to do heapscan
* or indexscan at the key spots, and we set it true after we've loaded
* the critical indexes.
*
* The critical indexes are marked as "nailed in cache", partly to make
* it easy for load_relcache_init_file to count them, but mainly
* because we cannot flush and rebuild them once we've set
* criticalRelcachesBuilt to true. (NOTE: perhaps it would be possible
* to reload them by temporarily setting criticalRelcachesBuilt to
* false again. For now, though, we just nail 'em in.)
*/
if (! criticalRelcachesBuilt)
{
RelationBuildDescInfo buildinfo;
Relation ird;
#define LOAD_CRIT_INDEX(indname) \
do { \
buildinfo.infotype = INFO_RELNAME; \
buildinfo.i.info_name = (indname); \
ird = RelationBuildDesc(buildinfo, NULL); \
ird->rd_isnailed = true; \
RelationSetReferenceCount(ird, 1); \
} while (0)
LOAD_CRIT_INDEX(ClassNameNspIndex);
LOAD_CRIT_INDEX(ClassOidIndex);
LOAD_CRIT_INDEX(AttributeRelidNumIndex);
LOAD_CRIT_INDEX(IndexRelidIndex);
LOAD_CRIT_INDEX(AccessMethodStrategyIndex);
LOAD_CRIT_INDEX(AccessMethodProcedureIndex);
LOAD_CRIT_INDEX(OperatorOidIndex);
#define NUM_CRITICAL_INDEXES 7 /* fix if you change list above */
criticalRelcachesBuilt = true;
}
/*
* Now, scan all the relcache entries and update anything that might
* be wrong in the results from formrdesc or the relcache cache file.
* If we faked up relcache entries using formrdesc, then read
* the real pg_class rows and replace the fake entries with them.
* Also, if any of the relcache entries have rules or triggers,
* load that info the hard way since it isn't recorded in the cache file.
*/
hash_seq_init(&status, RelationIdCache);
while ((idhentry = (RelIdCacheEnt *) hash_seq_search(&status)) != NULL)
{
Relation relation = idhentry->reldesc;
/*
* If it's a faked-up entry, read the real pg_class tuple.
*/
if (needNewCacheFile && relation->rd_isnailed)
{
HeapTuple htup;
Form_pg_class relp;
htup = SearchSysCache(RELOID,
ObjectIdGetDatum(RelationGetRelid(relation)),
0, 0, 0);
if (!HeapTupleIsValid(htup))
elog(FATAL, "RelationCacheInitializePhase2: no pg_class entry for %s",
RelationGetRelationName(relation));
relp = (Form_pg_class) GETSTRUCT(htup);
/*
* Copy tuple to relation->rd_rel. (See notes in
* AllocateRelationDesc())
*/
Assert(relation->rd_rel != NULL);
memcpy((char *) relation->rd_rel, (char *) relp, CLASS_TUPLE_SIZE);
relation->rd_att->tdhasoid = relp->relhasoids;
ReleaseSysCache(htup);
}
/*
* Fix data that isn't saved in relcache cache file.
*/
if (relation->rd_rel->relhasrules && relation->rd_rules == NULL)
RelationBuildRuleLock(relation);
if (relation->rd_rel->reltriggers > 0 && relation->trigdesc == NULL)
RelationBuildTriggers(relation);
}
}
/*
* RelationCacheInitializePhase3
*
* Final step of relcache initialization: write out a new relcache
* cache file if one is needed.
*/
void
RelationCacheInitializePhase3(void)
{
if (IsBootstrapProcessingMode())
return;
if (needNewCacheFile)
{
/*
* Force all the catcaches to finish initializing and thereby
* open the catalogs and indexes they use. This will preload
* the relcache with entries for all the most important system
* catalogs and indexes, so that the init file will be most
* useful for future backends.
*/
InitCatalogCachePhase2();
/* now write the file */
write_relcache_init_file();
}
}
/* used by XLogInitCache */
void CreateDummyCaches(void);
void DestroyDummyCaches(void);
void
CreateDummyCaches(void)
{
MemoryContext oldcxt;
HASHCTL ctl;
if (!CacheMemoryContext)
CreateCacheMemoryContext();
oldcxt = MemoryContextSwitchTo(CacheMemoryContext);
MemSet(&ctl, 0, sizeof(ctl));
ctl.keysize = sizeof(NameData);
ctl.entrysize = sizeof(RelNameCacheEnt);
RelationSysNameCache = hash_create("Relcache by name", INITRELCACHESIZE,
&ctl, HASH_ELEM);
ctl.keysize = sizeof(Oid);
ctl.entrysize = sizeof(RelIdCacheEnt);
ctl.hash = tag_hash;
RelationIdCache = hash_create("Relcache by OID", INITRELCACHESIZE,
&ctl, HASH_ELEM | HASH_FUNCTION);
ctl.keysize = sizeof(RelFileNode);
ctl.entrysize = sizeof(RelNodeCacheEnt);
ctl.hash = tag_hash;
RelationNodeCache = hash_create("Relcache by rnode", INITRELCACHESIZE,
&ctl, HASH_ELEM | HASH_FUNCTION);
MemoryContextSwitchTo(oldcxt);
}
void
DestroyDummyCaches(void)
{
MemoryContext oldcxt;
if (!CacheMemoryContext)
return;
oldcxt = MemoryContextSwitchTo(CacheMemoryContext);
if (RelationIdCache)
hash_destroy(RelationIdCache);
if (RelationSysNameCache)
hash_destroy(RelationSysNameCache);
if (RelationNodeCache)
hash_destroy(RelationNodeCache);
RelationIdCache = RelationSysNameCache = RelationNodeCache = NULL;
MemoryContextSwitchTo(oldcxt);
}
static void
AttrDefaultFetch(Relation relation)
{
AttrDefault *attrdef = relation->rd_att->constr->defval;
int ndef = relation->rd_att->constr->num_defval;
Relation adrel;
SysScanDesc adscan;
ScanKeyData skey;
HeapTuple htup;
Datum val;
bool isnull;
int found;
int i;
ScanKeyEntryInitialize(&skey,
(bits16) 0x0,
(AttrNumber) Anum_pg_attrdef_adrelid,
(RegProcedure) F_OIDEQ,
ObjectIdGetDatum(RelationGetRelid(relation)));
adrel = heap_openr(AttrDefaultRelationName, AccessShareLock);
adscan = systable_beginscan(adrel, AttrDefaultIndex, true,
SnapshotNow,
1, &skey);
found = 0;
while (HeapTupleIsValid(htup = systable_getnext(adscan)))
{
Form_pg_attrdef adform = (Form_pg_attrdef) GETSTRUCT(htup);
found++;
for (i = 0; i < ndef; i++)
{
if (adform->adnum != attrdef[i].adnum)
continue;
if (attrdef[i].adbin != NULL)
elog(WARNING, "AttrDefaultFetch: second record found for attr %s in rel %s",
NameStr(relation->rd_att->attrs[adform->adnum - 1]->attname),
RelationGetRelationName(relation));
val = fastgetattr(htup,
Anum_pg_attrdef_adbin,
adrel->rd_att, &isnull);
if (isnull)
elog(WARNING, "AttrDefaultFetch: adbin IS NULL for attr %s in rel %s",
NameStr(relation->rd_att->attrs[adform->adnum - 1]->attname),
RelationGetRelationName(relation));
else
attrdef[i].adbin = MemoryContextStrdup(CacheMemoryContext,
DatumGetCString(DirectFunctionCall1(textout,
val)));
break;
}
if (i >= ndef)
elog(WARNING, "AttrDefaultFetch: unexpected record found for attr %d in rel %s",
adform->adnum,
RelationGetRelationName(relation));
}
systable_endscan(adscan);
heap_close(adrel, AccessShareLock);
if (found != ndef)
elog(WARNING, "AttrDefaultFetch: %d record(s) not found for rel %s",
ndef - found, RelationGetRelationName(relation));
}
static void
CheckConstraintFetch(Relation relation)
{
ConstrCheck *check = relation->rd_att->constr->check;
int ncheck = relation->rd_att->constr->num_check;
Relation conrel;
SysScanDesc conscan;
ScanKeyData skey[1];
HeapTuple htup;
Datum val;
bool isnull;
int found = 0;
ScanKeyEntryInitialize(&skey[0], 0x0,
Anum_pg_constraint_conrelid, F_OIDEQ,
ObjectIdGetDatum(RelationGetRelid(relation)));
conrel = heap_openr(ConstraintRelationName, AccessShareLock);
conscan = systable_beginscan(conrel, ConstraintRelidIndex, true,
SnapshotNow, 1, skey);
while (HeapTupleIsValid(htup = systable_getnext(conscan)))
{
Form_pg_constraint conform = (Form_pg_constraint) GETSTRUCT(htup);
/* We want check constraints only */
if (conform->contype != CONSTRAINT_CHECK)
continue;
if (found == ncheck)
elog(ERROR, "CheckConstraintFetch: unexpected record found for rel %s",
RelationGetRelationName(relation));
check[found].ccname = MemoryContextStrdup(CacheMemoryContext,
NameStr(conform->conname));
/* Grab and test conbin is actually set */
val = fastgetattr(htup,
Anum_pg_constraint_conbin,
conrel->rd_att, &isnull);
if (isnull)
elog(ERROR, "CheckConstraintFetch: conbin IS NULL for rel %s",
RelationGetRelationName(relation));
check[found].ccbin = MemoryContextStrdup(CacheMemoryContext,
DatumGetCString(DirectFunctionCall1(textout,
val)));
found++;
}
systable_endscan(conscan);
heap_close(conrel, AccessShareLock);
if (found != ncheck)
elog(ERROR, "CheckConstraintFetch: %d record(s) not found for rel %s",
ncheck - found, RelationGetRelationName(relation));
}
/*
* RelationGetIndexList -- get a list of OIDs of indexes on this relation
*
* The index list is created only if someone requests it. We scan pg_index
* to find relevant indexes, and add the list to the relcache entry so that
* we won't have to compute it again. Note that shared cache inval of a
* relcache entry will delete the old list and set rd_indexfound to false,
* so that we must recompute the index list on next request. This handles
* creation or deletion of an index.
*
* The returned list is guaranteed to be sorted in order by OID. This is
* needed by the executor, since for index types that we obtain exclusive
* locks on when updating the index, all backends must lock the indexes in
* the same order or we will get deadlocks (see ExecOpenIndices()). Any
* consistent ordering would do, but ordering by OID is easy.
*
* Since shared cache inval causes the relcache's copy of the list to go away,
* we return a copy of the list palloc'd in the caller's context. The caller
* may freeList() the returned list after scanning it. This is necessary
* since the caller will typically be doing syscache lookups on the relevant
* indexes, and syscache lookup could cause SI messages to be processed!
*/
List *
RelationGetIndexList(Relation relation)
{
Relation indrel;
SysScanDesc indscan;
ScanKeyData skey;
HeapTuple htup;
List *result;
MemoryContext oldcxt;
/* Quick exit if we already computed the list. */
if (relation->rd_indexfound)
return listCopy(relation->rd_indexlist);
/*
* We build the list we intend to return (in the caller's context)
* while doing the scan. After successfully completing the scan, we
* copy that list into the relcache entry. This avoids cache-context
* memory leakage if we get some sort of error partway through.
*/
result = NIL;
/* Prepare to scan pg_index for entries having indrelid = this rel. */
ScanKeyEntryInitialize(&skey,
(bits16) 0x0,
(AttrNumber) Anum_pg_index_indrelid,
(RegProcedure) F_OIDEQ,
ObjectIdGetDatum(RelationGetRelid(relation)));
indrel = heap_openr(IndexRelationName, AccessShareLock);
indscan = systable_beginscan(indrel, IndexIndrelidIndex, true,
SnapshotNow,
1, &skey);
while (HeapTupleIsValid(htup = systable_getnext(indscan)))
{
Form_pg_index index = (Form_pg_index) GETSTRUCT(htup);
result = insert_ordered_oid(result, index->indexrelid);
}
systable_endscan(indscan);
heap_close(indrel, AccessShareLock);
/* Now save a copy of the completed list in the relcache entry. */
oldcxt = MemoryContextSwitchTo(CacheMemoryContext);
relation->rd_indexlist = listCopy(result);
relation->rd_indexfound = true;
MemoryContextSwitchTo(oldcxt);
return result;
}
/*
* insert_ordered_oid
* Insert a new Oid into a sorted list of Oids, preserving ordering
*
* Building the ordered list this way is O(N^2), but with a pretty small
* constant, so for the number of entries we expect it will probably be
* faster than trying to apply qsort(). Most tables don't have very many
* indexes...
*/
static List *
insert_ordered_oid(List *list, Oid datum)
{
List *l;
/* Does the datum belong at the front? */
if (list == NIL || datum < (Oid) lfirsti(list))
return lconsi(datum, list);
/* No, so find the entry it belongs after */
l = list;
for (;;)
{
List *n = lnext(l);
if (n == NIL || datum < (Oid) lfirsti(n))
break; /* it belongs before n */
l = n;
}
/* Insert datum into list after item l */
lnext(l) = lconsi(datum, lnext(l));
return list;
}
/*
* load_relcache_init_file, write_relcache_init_file
*
* In late 1992, we started regularly having databases with more than
* a thousand classes in them. With this number of classes, it became
* critical to do indexed lookups on the system catalogs.
*
* Bootstrapping these lookups is very hard. We want to be able to
* use an index on pg_attribute, for example, but in order to do so,
* we must have read pg_attribute for the attributes in the index,
* which implies that we need to use the index.
*
* In order to get around the problem, we do the following:
*
* + When the database system is initialized (at initdb time), we
* don't use indexes. We do sequential scans.
*
* + When the backend is started up in normal mode, we load an image
* of the appropriate relation descriptors, in internal format,
* from an initialization file in the data/base/... directory.
*
* + If the initialization file isn't there, then we create the
* relation descriptors using sequential scans and write 'em to
* the initialization file for use by subsequent backends.
*
* We could dispense with the initialization file and just build the
* critical reldescs the hard way on every backend startup, but that
* slows down backend startup noticeably.
*
* We can in fact go further, and save more relcache entries than
* just the ones that are absolutely critical; this allows us to speed
* up backend startup by not having to build such entries the hard way.
* Presently, all the catalog and index entries that are referred to
* by catcaches are stored in the initialization file.
*
* The same mechanism that detects when catcache and relcache entries
* need to be invalidated (due to catalog updates) also arranges to
* unlink the initialization file when its contents may be out of date.
* The file will then be rebuilt during the next backend startup.
*/
/*
* load_relcache_init_file -- attempt to load cache from the init file
*
* If successful, return TRUE and set criticalRelcachesBuilt to true.
* If not successful, return FALSE and set needNewCacheFile to true.
*
* NOTE: we assume we are already switched into CacheMemoryContext.
*/
static bool
load_relcache_init_file(void)
{
FILE *fp;
char initfilename[MAXPGPATH];
Relation *rels;
int relno,
num_rels,
max_rels,
nailed_rels,
nailed_indexes;
int i;
snprintf(initfilename, sizeof(initfilename), "%s/%s",
DatabasePath, RELCACHE_INIT_FILENAME);
fp = AllocateFile(initfilename, PG_BINARY_R);
if (fp == NULL)
{
needNewCacheFile = true;
return false;
}
/*
* Read the index relcache entries from the file. Note we will not
* enter any of them into the cache if the read fails partway through;
* this helps to guard against broken init files.
*/
max_rels = 100;
rels = (Relation *) palloc(max_rels * sizeof(Relation));
num_rels = 0;
nailed_rels = nailed_indexes = 0;
initFileRelationIds = NIL;
for (relno = 0; ; relno++)
{
Size len;
size_t nread;
Relation rel;
Form_pg_class relform;
/* first read the relation descriptor length */
if ((nread = fread(&len, 1, sizeof(len), fp)) != sizeof(len))
{
if (nread == 0)
break; /* end of file */
goto read_failed;
}
/* safety check for incompatible relcache layout */
if (len != sizeof(RelationData))
goto read_failed;
/* allocate another relcache header */
if (num_rels >= max_rels)
{
max_rels *= 2;
rels = (Relation *) repalloc(rels, max_rels * sizeof(Relation));
}
rel = rels[num_rels++] = (Relation) palloc(len);
/* then, read the Relation structure */
if ((nread = fread(rel, 1, len, fp)) != len)
goto read_failed;
/* next read the relation tuple form */
if ((nread = fread(&len, 1, sizeof(len), fp)) != sizeof(len))
goto read_failed;
relform = (Form_pg_class) palloc(len);
if ((nread = fread(relform, 1, len, fp)) != len)
goto read_failed;
rel->rd_rel = relform;
/* initialize attribute tuple forms */
rel->rd_att = CreateTemplateTupleDesc(relform->relnatts,
relform->relhasoids);
/* next read all the attribute tuple form data entries */
for (i = 0; i < relform->relnatts; i++)
{
if ((nread = fread(&len, 1, sizeof(len), fp)) != sizeof(len))
goto read_failed;
rel->rd_att->attrs[i] = (Form_pg_attribute) palloc(len);
if ((nread = fread(rel->rd_att->attrs[i], 1, len, fp)) != len)
goto read_failed;
}
/* If it's an index, there's more to do */
if (rel->rd_rel->relkind == RELKIND_INDEX)
{
Form_pg_am am;
MemoryContext indexcxt;
IndexStrategy strat;
Oid *operator;
RegProcedure *support;
int nstrategies,
nsupport;
/* Count nailed indexes to ensure we have 'em all */
if (rel->rd_isnailed)
nailed_indexes++;
/* next, read the pg_index tuple form */
if ((nread = fread(&len, 1, sizeof(len), fp)) != sizeof(len))
goto read_failed;
rel->rd_index = (Form_pg_index) palloc(len);
if ((nread = fread(rel->rd_index, 1, len, fp)) != len)
goto read_failed;
/* next, read the access method tuple form */
if ((nread = fread(&len, 1, sizeof(len), fp)) != sizeof(len))
goto read_failed;
am = (Form_pg_am) palloc(len);
if ((nread = fread(am, 1, len, fp)) != len)
goto read_failed;
rel->rd_am = am;
/*
* prepare index info context --- parameters should match
* RelationInitIndexAccessInfo
*/
indexcxt = AllocSetContextCreate(CacheMemoryContext,
RelationGetRelationName(rel),
0, /* minsize */
512, /* initsize */
1024); /* maxsize */
rel->rd_indexcxt = indexcxt;
/* next, read the index strategy map */
if ((nread = fread(&len, 1, sizeof(len), fp)) != sizeof(len))
goto read_failed;
strat = (IndexStrategy) MemoryContextAlloc(indexcxt, len);
if ((nread = fread(strat, 1, len, fp)) != len)
goto read_failed;
/* have to invalidate any FmgrInfo data in the strategy maps */
nstrategies = am->amstrategies * relform->relnatts;
for (i = 0; i < nstrategies; i++)
strat->strategyMapData[i].entry[0].sk_func.fn_oid = InvalidOid;
rel->rd_istrat = strat;
/* next, read the vector of operator OIDs */
if ((nread = fread(&len, 1, sizeof(len), fp)) != sizeof(len))
goto read_failed;
operator = (Oid *) MemoryContextAlloc(indexcxt, len);
if ((nread = fread(operator, 1, len, fp)) != len)
goto read_failed;
rel->rd_operator = operator;
/* finally, read the vector of support procedures */
if ((nread = fread(&len, 1, sizeof(len), fp)) != sizeof(len))
goto read_failed;
support = (RegProcedure *) MemoryContextAlloc(indexcxt, len);
if ((nread = fread(support, 1, len, fp)) != len)
goto read_failed;
rel->rd_support = support;
/* add a zeroed support-fmgr-info vector */
nsupport = relform->relnatts * am->amsupport;
rel->rd_supportinfo = (FmgrInfo *)
MemoryContextAlloc(indexcxt, nsupport * sizeof(FmgrInfo));
MemSet(rel->rd_supportinfo, 0, nsupport * sizeof(FmgrInfo));
}
else
{
/* Count nailed rels to ensure we have 'em all */
if (rel->rd_isnailed)
nailed_rels++;
Assert(rel->rd_index == NULL);
Assert(rel->rd_am == NULL);
Assert(rel->rd_indexcxt == NULL);
Assert(rel->rd_istrat == NULL);
Assert(rel->rd_operator == NULL);
Assert(rel->rd_support == NULL);
Assert(rel->rd_supportinfo == NULL);
}
/*
* Rules and triggers are not saved (mainly because the internal
* format is complex and subject to change). They must be rebuilt
* if needed by RelationCacheInitializePhase2. This is not expected
* to be a big performance hit since few system catalogs have such.
*/
rel->rd_rules = NULL;
rel->rd_rulescxt = NULL;
rel->trigdesc = NULL;
/*
* Reset transient-state fields in the relcache entry
*/
rel->rd_fd = -1;
rel->rd_targblock = InvalidBlockNumber;
if (rel->rd_isnailed)
RelationSetReferenceCount(rel, 1);
else
RelationSetReferenceCount(rel, 0);
rel->rd_indexfound = false;
rel->rd_indexlist = NIL;
MemSet(&rel->pgstat_info, 0, sizeof(rel->pgstat_info));
/*
* Make sure database ID is correct. This is needed in case the
* pg_internal.init file was copied from some other database by
* CREATE DATABASE.
*/
if (rel->rd_rel->relisshared)
rel->rd_node.tblNode = InvalidOid;
else
rel->rd_node.tblNode = MyDatabaseId;
RelationInitLockInfo(rel);
}
/*
* We reached the end of the init file without apparent problem.
* Did we get the right number of nailed items? (This is a useful
* crosscheck in case the set of critical rels or indexes changes.)
*/
if (nailed_rels != NUM_CRITICAL_RELS ||
nailed_indexes != NUM_CRITICAL_INDEXES)
goto read_failed;
/*
* OK, all appears well.
*
* Now insert all the new relcache entries into the cache.
*/
for (relno = 0; relno < num_rels; relno++)
{
RelationCacheInsert(rels[relno]);
/* also make a list of their OIDs, for RelationIdIsInInitFile */
initFileRelationIds = lconsi((int) RelationGetRelid(rels[relno]),
initFileRelationIds);
}
pfree(rels);
FreeFile(fp);
criticalRelcachesBuilt = true;
return true;
/*
* init file is broken, so do it the hard way. We don't bother
* trying to free the clutter we just allocated; it's not in the
* relcache so it won't hurt.
*/
read_failed:
pfree(rels);
FreeFile(fp);
needNewCacheFile = true;
return false;
}
/*
* Write out a new initialization file with the current contents
* of the relcache.
*/
static void
write_relcache_init_file(void)
{
FILE *fp;
char tempfilename[MAXPGPATH];
char finalfilename[MAXPGPATH];
HASH_SEQ_STATUS status;
RelIdCacheEnt *idhentry;
MemoryContext oldcxt;
int i;
/*
* We must write a temporary file and rename it into place. Otherwise,
* another backend starting at about the same time might crash trying
* to read the partially-complete file.
*/
snprintf(tempfilename, sizeof(tempfilename), "%s/%s.%d",
DatabasePath, RELCACHE_INIT_FILENAME, MyProcPid);
snprintf(finalfilename, sizeof(finalfilename), "%s/%s",
DatabasePath, RELCACHE_INIT_FILENAME);
unlink(tempfilename); /* in case it exists w/wrong permissions */
fp = AllocateFile(tempfilename, PG_BINARY_W);
if (fp == NULL)
{
/*
* We used to consider this a fatal error, but we might as well
* continue with backend startup ...
*/
elog(WARNING, "Cannot create init file %s: %m\n\tContinuing anyway, but there's something wrong.", tempfilename);
return;
}
/*
* Write all the reldescs (in no particular order).
*/
hash_seq_init(&status, RelationIdCache);
initFileRelationIds = NIL;
while ((idhentry = (RelIdCacheEnt *) hash_seq_search(&status)) != NULL)
{
Relation rel = idhentry->reldesc;
Form_pg_class relform = rel->rd_rel;
Size len;
/*
* first write the relcache entry proper
*/
len = sizeof(RelationData);
/* first, write the relation descriptor length */
if (fwrite(&len, 1, sizeof(len), fp) != sizeof(len))
elog(FATAL, "cannot write init file -- descriptor length");
/* next, write out the Relation structure */
if (fwrite(rel, 1, len, fp) != len)
elog(FATAL, "cannot write init file -- reldesc");
/* next write the relation tuple form */
len = sizeof(FormData_pg_class);
if (fwrite(&len, 1, sizeof(len), fp) != sizeof(len))
elog(FATAL, "cannot write init file -- relation tuple form length");
if (fwrite(relform, 1, len, fp) != len)
elog(FATAL, "cannot write init file -- relation tuple form");
/* next, do all the attribute tuple form data entries */
for (i = 0; i < relform->relnatts; i++)
{
len = ATTRIBUTE_TUPLE_SIZE;
if (fwrite(&len, 1, sizeof(len), fp) != sizeof(len))
elog(FATAL, "cannot write init file -- length of attdesc %d", i);
if (fwrite(rel->rd_att->attrs[i], 1, len, fp) != len)
elog(FATAL, "cannot write init file -- attdesc %d", i);
}
/* If it's an index, there's more to do */
if (rel->rd_rel->relkind == RELKIND_INDEX)
{
Form_pg_am am = rel->rd_am;
HeapTuple tuple;
/*
* We need to write the index tuple form, but this is a bit
* tricky since it's a variable-length struct. Rather than
* hoping to intuit the length, fetch the pg_index tuple
* afresh using the syscache, and write that.
*/
tuple = SearchSysCache(INDEXRELID,
ObjectIdGetDatum(RelationGetRelid(rel)),
0, 0, 0);
if (!HeapTupleIsValid(tuple))
elog(ERROR, "write_relcache_init_file: no pg_index entry for index %u",
RelationGetRelid(rel));
len = tuple->t_len - tuple->t_data->t_hoff;
if (fwrite(&len, 1, sizeof(len), fp) != sizeof(len))
elog(FATAL, "cannot write init file -- index tuple form length");
if (fwrite(GETSTRUCT(tuple), 1, len, fp) != len)
elog(FATAL, "cannot write init file -- index tuple form");
ReleaseSysCache(tuple);
/* next, write the access method tuple form */
len = sizeof(FormData_pg_am);
if (fwrite(&len, 1, sizeof(len), fp) != sizeof(len))
elog(FATAL, "cannot write init file -- am tuple form length");
if (fwrite(am, 1, len, fp) != len)
elog(FATAL, "cannot write init file -- am tuple form");
/* next, write the index strategy map */
len = AttributeNumberGetIndexStrategySize(relform->relnatts,
am->amstrategies);
if (fwrite(&len, 1, sizeof(len), fp) != sizeof(len))
elog(FATAL, "cannot write init file -- strategy map length");
if (fwrite(rel->rd_istrat, 1, len, fp) != len)
elog(FATAL, "cannot write init file -- strategy map");
/* next, write the vector of operator OIDs */
len = relform->relnatts * (am->amstrategies * sizeof(Oid));
if (fwrite(&len, 1, sizeof(len), fp) != sizeof(len))
elog(FATAL, "cannot write init file -- operator vector length");
if (fwrite(rel->rd_operator, 1, len, fp) != len)
elog(FATAL, "cannot write init file -- operator vector");
/* finally, write the vector of support procedures */
len = relform->relnatts * (am->amsupport * sizeof(RegProcedure));
if (fwrite(&len, 1, sizeof(len), fp) != sizeof(len))
elog(FATAL, "cannot write init file -- support vector length");
if (fwrite(rel->rd_support, 1, len, fp) != len)
elog(FATAL, "cannot write init file -- support vector");
}
/* also make a list of their OIDs, for RelationIdIsInInitFile */
oldcxt = MemoryContextSwitchTo(CacheMemoryContext);
initFileRelationIds = lconsi((int) RelationGetRelid(rel),
initFileRelationIds);
MemoryContextSwitchTo(oldcxt);
}
FreeFile(fp);
/*
* Now we have to check whether the data we've so painstakingly
* accumulated is already obsolete due to someone else's just-committed
* catalog changes. If so, we just delete the temp file and leave it
* to the next backend to try again. (Our own relcache entries will be
* updated by SI message processing, but we can't be sure whether what
* we wrote out was up-to-date.)
*
* This mustn't run concurrently with RelationCacheInitFileInvalidate,
* so grab a serialization lock for the duration.
*/
LWLockAcquire(RelCacheInitLock, LW_EXCLUSIVE);
/* Make sure we have seen all incoming SI messages */
AcceptInvalidationMessages();
/*
* If we have received any SI relcache invals since backend start,
* assume we may have written out-of-date data.
*/
if (relcacheInvalsReceived == 0L)
{
/*
* OK, rename the temp file to its final name, deleting any
* previously-existing init file.
*
* Note: a failure here is possible under Cygwin, if some other
* backend is holding open an unlinked-but-not-yet-gone init file.
* So treat this as a noncritical failure.
*/
if (rename(tempfilename, finalfilename) < 0)
{
elog(WARNING, "Cannot rename init file %s to %s: %m\n\tContinuing anyway, but there's something wrong.", tempfilename, finalfilename);
/*
* If we fail, try to clean up the useless temp file; don't bother
* to complain if this fails too.
*/
unlink(tempfilename);
}
}
else
{
/* Delete the already-obsolete temp file */
unlink(tempfilename);
}
LWLockRelease(RelCacheInitLock);
}
/*
* Detect whether a given relation (identified by OID) is one of the ones
* we store in the init file.
*
* Note that we effectively assume that all backends running in a database
* would choose to store the same set of relations in the init file;
* otherwise there are cases where we'd fail to detect the need for an init
* file invalidation. This does not seem likely to be a problem in practice.
*/
bool
RelationIdIsInInitFile(Oid relationId)
{
return intMember((int) relationId, initFileRelationIds);
}
/*
* Invalidate (remove) the init file during commit of a transaction that
* changed one or more of the relation cache entries that are kept in the
* init file.
*
* We actually need to remove the init file twice: once just before sending
* the SI messages that include relcache inval for such relations, and once
* just after sending them. The unlink before ensures that a backend that's
* currently starting cannot read the now-obsolete init file and then miss
* the SI messages that will force it to update its relcache entries. (This
* works because the backend startup sequence gets into the PROC array before
* trying to load the init file.) The unlink after is to synchronize with a
* backend that may currently be trying to write an init file based on data
* that we've just rendered invalid. Such a backend will see the SI messages,
* but we can't leave the init file sitting around to fool later backends.
*
* Ignore any failure to unlink the file, since it might not be there if
* no backend has been started since the last removal.
*/
void
RelationCacheInitFileInvalidate(bool beforeSend)
{
char initfilename[MAXPGPATH];
snprintf(initfilename, sizeof(initfilename), "%s/%s",
DatabasePath, RELCACHE_INIT_FILENAME);
if (beforeSend)
{
/* no interlock needed here */
unlink(initfilename);
}
else
{
/*
* We need to interlock this against write_relcache_init_file,
* to guard against possibility that someone renames a new-but-
* already-obsolete init file into place just after we unlink.
* With the interlock, it's certain that write_relcache_init_file
* will notice our SI inval message before renaming into place,
* or else that we will execute second and successfully unlink
* the file.
*/
LWLockAcquire(RelCacheInitLock, LW_EXCLUSIVE);
unlink(initfilename);
LWLockRelease(RelCacheInitLock);
}
}