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PostgreSQL/src/backend/utils/cache/typcache.c
Nathan Bossart 3b42bdb471 Use new overflow-safe integer comparison functions. 
Commit 6b80394781 introduced integer comparison functions designed
to be as efficient as possible while avoiding overflow.  This
commit makes use of these functions in many of the in-tree qsort()
comparators to help ensure transitivity.  Many of these comparator
functions should also see a small performance boost.

Author: Mats Kindahl
Reviewed-by: Andres Freund, Fabrízio de Royes Mello
Discussion: https://postgr.es/m/CA%2B14426g2Wa9QuUpmakwPxXFWG_1FaY0AsApkvcTBy-YfS6uaw%40mail.gmail.com
2024-02-16 14:05:36 -06:00

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/*-------------------------------------------------------------------------
*
* typcache.c
* POSTGRES type cache code
*
* The type cache exists to speed lookup of certain information about data
* types that is not directly available from a type's pg_type row. For
* example, we use a type's default btree opclass, or the default hash
* opclass if no btree opclass exists, to determine which operators should
* be used for grouping and sorting the type (GROUP BY, ORDER BY ASC/DESC).
*
* Several seemingly-odd choices have been made to support use of the type
* cache by generic array and record handling routines, such as array_eq(),
* record_cmp(), and hash_array(). Because those routines are used as index
* support operations, they cannot leak memory. To allow them to execute
* efficiently, all information that they would like to re-use across calls
* is kept in the type cache.
*
* Once created, a type cache entry lives as long as the backend does, so
* there is no need for a call to release a cache entry. If the type is
* dropped, the cache entry simply becomes wasted storage. This is not
* expected to happen often, and assuming that typcache entries are good
* permanently allows caching pointers to them in long-lived places.
*
* We have some provisions for updating cache entries if the stored data
* becomes obsolete. Core data extracted from the pg_type row is updated
* when we detect updates to pg_type. Information dependent on opclasses is
* cleared if we detect updates to pg_opclass. We also support clearing the
* tuple descriptor and operator/function parts of a rowtype's cache entry,
* since those may need to change as a consequence of ALTER TABLE. Domain
* constraint changes are also tracked properly.
*
*
* Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* src/backend/utils/cache/typcache.c
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include <limits.h>
#include "access/hash.h"
#include "access/htup_details.h"
#include "access/nbtree.h"
#include "access/parallel.h"
#include "access/relation.h"
#include "access/session.h"
#include "access/table.h"
#include "catalog/pg_am.h"
#include "catalog/pg_constraint.h"
#include "catalog/pg_enum.h"
#include "catalog/pg_operator.h"
#include "catalog/pg_range.h"
#include "catalog/pg_type.h"
#include "commands/defrem.h"
#include "common/int.h"
#include "executor/executor.h"
#include "lib/dshash.h"
#include "optimizer/optimizer.h"
#include "port/pg_bitutils.h"
#include "storage/lwlock.h"
#include "utils/builtins.h"
#include "utils/catcache.h"
#include "utils/fmgroids.h"
#include "utils/inval.h"
#include "utils/lsyscache.h"
#include "utils/memutils.h"
#include "utils/rel.h"
#include "utils/snapmgr.h"
#include "utils/syscache.h"
#include "utils/typcache.h"
/* The main type cache hashtable searched by lookup_type_cache */
static HTAB *TypeCacheHash = NULL;
/* List of type cache entries for domain types */
static TypeCacheEntry *firstDomainTypeEntry = NULL;
/* Private flag bits in the TypeCacheEntry.flags field */
#define TCFLAGS_HAVE_PG_TYPE_DATA 0x000001
#define TCFLAGS_CHECKED_BTREE_OPCLASS 0x000002
#define TCFLAGS_CHECKED_HASH_OPCLASS 0x000004
#define TCFLAGS_CHECKED_EQ_OPR 0x000008
#define TCFLAGS_CHECKED_LT_OPR 0x000010
#define TCFLAGS_CHECKED_GT_OPR 0x000020
#define TCFLAGS_CHECKED_CMP_PROC 0x000040
#define TCFLAGS_CHECKED_HASH_PROC 0x000080
#define TCFLAGS_CHECKED_HASH_EXTENDED_PROC 0x000100
#define TCFLAGS_CHECKED_ELEM_PROPERTIES 0x000200
#define TCFLAGS_HAVE_ELEM_EQUALITY 0x000400
#define TCFLAGS_HAVE_ELEM_COMPARE 0x000800
#define TCFLAGS_HAVE_ELEM_HASHING 0x001000
#define TCFLAGS_HAVE_ELEM_EXTENDED_HASHING 0x002000
#define TCFLAGS_CHECKED_FIELD_PROPERTIES 0x004000
#define TCFLAGS_HAVE_FIELD_EQUALITY 0x008000
#define TCFLAGS_HAVE_FIELD_COMPARE 0x010000
#define TCFLAGS_HAVE_FIELD_HASHING 0x020000
#define TCFLAGS_HAVE_FIELD_EXTENDED_HASHING 0x040000
#define TCFLAGS_CHECKED_DOMAIN_CONSTRAINTS 0x080000
#define TCFLAGS_DOMAIN_BASE_IS_COMPOSITE 0x100000
/* The flags associated with equality/comparison/hashing are all but these: */
#define TCFLAGS_OPERATOR_FLAGS \
(~(TCFLAGS_HAVE_PG_TYPE_DATA | \
TCFLAGS_CHECKED_DOMAIN_CONSTRAINTS | \
TCFLAGS_DOMAIN_BASE_IS_COMPOSITE))
/*
* Data stored about a domain type's constraints. Note that we do not create
* this struct for the common case of a constraint-less domain; we just set
* domainData to NULL to indicate that.
*
* Within a DomainConstraintCache, we store expression plan trees, but the
* check_exprstate fields of the DomainConstraintState nodes are just NULL.
* When needed, expression evaluation nodes are built by flat-copying the
* DomainConstraintState nodes and applying ExecInitExpr to check_expr.
* Such a node tree is not part of the DomainConstraintCache, but is
* considered to belong to a DomainConstraintRef.
*/
struct DomainConstraintCache
{
List *constraints; /* list of DomainConstraintState nodes */
MemoryContext dccContext; /* memory context holding all associated data */
long dccRefCount; /* number of references to this struct */
};
/* Private information to support comparisons of enum values */
typedef struct
{
Oid enum_oid; /* OID of one enum value */
float4 sort_order; /* its sort position */
} EnumItem;
typedef struct TypeCacheEnumData
{
Oid bitmap_base; /* OID corresponding to bit 0 of bitmapset */
Bitmapset *sorted_values; /* Set of OIDs known to be in order */
int num_values; /* total number of values in enum */
EnumItem enum_values[FLEXIBLE_ARRAY_MEMBER];
} TypeCacheEnumData;
/*
* We use a separate table for storing the definitions of non-anonymous
* record types. Once defined, a record type will be remembered for the
* life of the backend. Subsequent uses of the "same" record type (where
* sameness means equalTupleDescs) will refer to the existing table entry.
*
* Stored record types are remembered in a linear array of TupleDescs,
* which can be indexed quickly with the assigned typmod. There is also
* a hash table to speed searches for matching TupleDescs.
*/
typedef struct RecordCacheEntry
{
TupleDesc tupdesc;
} RecordCacheEntry;
/*
* To deal with non-anonymous record types that are exchanged by backends
* involved in a parallel query, we also need a shared version of the above.
*/
struct SharedRecordTypmodRegistry
{
/* A hash table for finding a matching TupleDesc. */
dshash_table_handle record_table_handle;
/* A hash table for finding a TupleDesc by typmod. */
dshash_table_handle typmod_table_handle;
/* A source of new record typmod numbers. */
pg_atomic_uint32 next_typmod;
};
/*
* When using shared tuple descriptors as hash table keys we need a way to be
* able to search for an equal shared TupleDesc using a backend-local
* TupleDesc. So we use this type which can hold either, and hash and compare
* functions that know how to handle both.
*/
typedef struct SharedRecordTableKey
{
union
{
TupleDesc local_tupdesc;
dsa_pointer shared_tupdesc;
} u;
bool shared;
} SharedRecordTableKey;
/*
* The shared version of RecordCacheEntry. This lets us look up a typmod
* using a TupleDesc which may be in local or shared memory.
*/
typedef struct SharedRecordTableEntry
{
SharedRecordTableKey key;
} SharedRecordTableEntry;
/*
* An entry in SharedRecordTypmodRegistry's typmod table. This lets us look
* up a TupleDesc in shared memory using a typmod.
*/
typedef struct SharedTypmodTableEntry
{
uint32 typmod;
dsa_pointer shared_tupdesc;
} SharedTypmodTableEntry;
/*
* A comparator function for SharedRecordTableKey.
*/
static int
shared_record_table_compare(const void *a, const void *b, size_t size,
void *arg)
{
dsa_area *area = (dsa_area *) arg;
SharedRecordTableKey *k1 = (SharedRecordTableKey *) a;
SharedRecordTableKey *k2 = (SharedRecordTableKey *) b;
TupleDesc t1;
TupleDesc t2;
if (k1->shared)
t1 = (TupleDesc) dsa_get_address(area, k1->u.shared_tupdesc);
else
t1 = k1->u.local_tupdesc;
if (k2->shared)
t2 = (TupleDesc) dsa_get_address(area, k2->u.shared_tupdesc);
else
t2 = k2->u.local_tupdesc;
return equalTupleDescs(t1, t2) ? 0 : 1;
}
/*
* A hash function for SharedRecordTableKey.
*/
static uint32
shared_record_table_hash(const void *a, size_t size, void *arg)
{
dsa_area *area = (dsa_area *) arg;
SharedRecordTableKey *k = (SharedRecordTableKey *) a;
TupleDesc t;
if (k->shared)
t = (TupleDesc) dsa_get_address(area, k->u.shared_tupdesc);
else
t = k->u.local_tupdesc;
return hashTupleDesc(t);
}
/* Parameters for SharedRecordTypmodRegistry's TupleDesc table. */
static const dshash_parameters srtr_record_table_params = {
sizeof(SharedRecordTableKey), /* unused */
sizeof(SharedRecordTableEntry),
shared_record_table_compare,
shared_record_table_hash,
LWTRANCHE_PER_SESSION_RECORD_TYPE
};
/* Parameters for SharedRecordTypmodRegistry's typmod hash table. */
static const dshash_parameters srtr_typmod_table_params = {
sizeof(uint32),
sizeof(SharedTypmodTableEntry),
dshash_memcmp,
dshash_memhash,
LWTRANCHE_PER_SESSION_RECORD_TYPMOD
};
/* hashtable for recognizing registered record types */
static HTAB *RecordCacheHash = NULL;
typedef struct RecordCacheArrayEntry
{
uint64 id;
TupleDesc tupdesc;
} RecordCacheArrayEntry;
/* array of info about registered record types, indexed by assigned typmod */
static RecordCacheArrayEntry *RecordCacheArray = NULL;
static int32 RecordCacheArrayLen = 0; /* allocated length of above array */
static int32 NextRecordTypmod = 0; /* number of entries used */
/*
* Process-wide counter for generating unique tupledesc identifiers.
* Zero and one (INVALID_TUPLEDESC_IDENTIFIER) aren't allowed to be chosen
* as identifiers, so we start the counter at INVALID_TUPLEDESC_IDENTIFIER.
*/
static uint64 tupledesc_id_counter = INVALID_TUPLEDESC_IDENTIFIER;
static void load_typcache_tupdesc(TypeCacheEntry *typentry);
static void load_rangetype_info(TypeCacheEntry *typentry);
static void load_multirangetype_info(TypeCacheEntry *typentry);
static void load_domaintype_info(TypeCacheEntry *typentry);
static int dcs_cmp(const void *a, const void *b);
static void decr_dcc_refcount(DomainConstraintCache *dcc);
static void dccref_deletion_callback(void *arg);
static List *prep_domain_constraints(List *constraints, MemoryContext execctx);
static bool array_element_has_equality(TypeCacheEntry *typentry);
static bool array_element_has_compare(TypeCacheEntry *typentry);
static bool array_element_has_hashing(TypeCacheEntry *typentry);
static bool array_element_has_extended_hashing(TypeCacheEntry *typentry);
static void cache_array_element_properties(TypeCacheEntry *typentry);
static bool record_fields_have_equality(TypeCacheEntry *typentry);
static bool record_fields_have_compare(TypeCacheEntry *typentry);
static bool record_fields_have_hashing(TypeCacheEntry *typentry);
static bool record_fields_have_extended_hashing(TypeCacheEntry *typentry);
static void cache_record_field_properties(TypeCacheEntry *typentry);
static bool range_element_has_hashing(TypeCacheEntry *typentry);
static bool range_element_has_extended_hashing(TypeCacheEntry *typentry);
static void cache_range_element_properties(TypeCacheEntry *typentry);
static bool multirange_element_has_hashing(TypeCacheEntry *typentry);
static bool multirange_element_has_extended_hashing(TypeCacheEntry *typentry);
static void cache_multirange_element_properties(TypeCacheEntry *typentry);
static void TypeCacheRelCallback(Datum arg, Oid relid);
static void TypeCacheTypCallback(Datum arg, int cacheid, uint32 hashvalue);
static void TypeCacheOpcCallback(Datum arg, int cacheid, uint32 hashvalue);
static void TypeCacheConstrCallback(Datum arg, int cacheid, uint32 hashvalue);
static void load_enum_cache_data(TypeCacheEntry *tcache);
static EnumItem *find_enumitem(TypeCacheEnumData *enumdata, Oid arg);
static int enum_oid_cmp(const void *left, const void *right);
static void shared_record_typmod_registry_detach(dsm_segment *segment,
Datum datum);
static TupleDesc find_or_make_matching_shared_tupledesc(TupleDesc tupdesc);
static dsa_pointer share_tupledesc(dsa_area *area, TupleDesc tupdesc,
uint32 typmod);
/*
* lookup_type_cache
*
* Fetch the type cache entry for the specified datatype, and make sure that
* all the fields requested by bits in 'flags' are valid.
*
* The result is never NULL --- we will ereport() if the passed type OID is
* invalid. Note however that we may fail to find one or more of the
* values requested by 'flags'; the caller needs to check whether the fields
* are InvalidOid or not.
*/
TypeCacheEntry *
lookup_type_cache(Oid type_id, int flags)
{
TypeCacheEntry *typentry;
bool found;
if (TypeCacheHash == NULL)
{
/* First time through: initialize the hash table */
HASHCTL ctl;
ctl.keysize = sizeof(Oid);
ctl.entrysize = sizeof(TypeCacheEntry);
TypeCacheHash = hash_create("Type information cache", 64,
&ctl, HASH_ELEM | HASH_BLOBS);
/* Also set up callbacks for SI invalidations */
CacheRegisterRelcacheCallback(TypeCacheRelCallback, (Datum) 0);
CacheRegisterSyscacheCallback(TYPEOID, TypeCacheTypCallback, (Datum) 0);
CacheRegisterSyscacheCallback(CLAOID, TypeCacheOpcCallback, (Datum) 0);
CacheRegisterSyscacheCallback(CONSTROID, TypeCacheConstrCallback, (Datum) 0);
/* Also make sure CacheMemoryContext exists */
if (!CacheMemoryContext)
CreateCacheMemoryContext();
}
/* Try to look up an existing entry */
typentry = (TypeCacheEntry *) hash_search(TypeCacheHash,
&type_id,
HASH_FIND, NULL);
if (typentry == NULL)
{
/*
* If we didn't find one, we want to make one. But first look up the
* pg_type row, just to make sure we don't make a cache entry for an
* invalid type OID. If the type OID is not valid, present a
* user-facing error, since some code paths such as domain_in() allow
* this function to be reached with a user-supplied OID.
*/
HeapTuple tp;
Form_pg_type typtup;
tp = SearchSysCache1(TYPEOID, ObjectIdGetDatum(type_id));
if (!HeapTupleIsValid(tp))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("type with OID %u does not exist", type_id)));
typtup = (Form_pg_type) GETSTRUCT(tp);
if (!typtup->typisdefined)
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("type \"%s\" is only a shell",
NameStr(typtup->typname))));
/* Now make the typcache entry */
typentry = (TypeCacheEntry *) hash_search(TypeCacheHash,
&type_id,
HASH_ENTER, &found);
Assert(!found); /* it wasn't there a moment ago */
MemSet(typentry, 0, sizeof(TypeCacheEntry));
/* These fields can never change, by definition */
typentry->type_id = type_id;
typentry->type_id_hash = GetSysCacheHashValue1(TYPEOID,
ObjectIdGetDatum(type_id));
/* Keep this part in sync with the code below */
typentry->typlen = typtup->typlen;
typentry->typbyval = typtup->typbyval;
typentry->typalign = typtup->typalign;
typentry->typstorage = typtup->typstorage;
typentry->typtype = typtup->typtype;
typentry->typrelid = typtup->typrelid;
typentry->typsubscript = typtup->typsubscript;
typentry->typelem = typtup->typelem;
typentry->typcollation = typtup->typcollation;
typentry->flags |= TCFLAGS_HAVE_PG_TYPE_DATA;
/* If it's a domain, immediately thread it into the domain cache list */
if (typentry->typtype == TYPTYPE_DOMAIN)
{
typentry->nextDomain = firstDomainTypeEntry;
firstDomainTypeEntry = typentry;
}
ReleaseSysCache(tp);
}
else if (!(typentry->flags & TCFLAGS_HAVE_PG_TYPE_DATA))
{
/*
* We have an entry, but its pg_type row got changed, so reload the
* data obtained directly from pg_type.
*/
HeapTuple tp;
Form_pg_type typtup;
tp = SearchSysCache1(TYPEOID, ObjectIdGetDatum(type_id));
if (!HeapTupleIsValid(tp))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("type with OID %u does not exist", type_id)));
typtup = (Form_pg_type) GETSTRUCT(tp);
if (!typtup->typisdefined)
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("type \"%s\" is only a shell",
NameStr(typtup->typname))));
/*
* Keep this part in sync with the code above. Many of these fields
* shouldn't ever change, particularly typtype, but copy 'em anyway.
*/
typentry->typlen = typtup->typlen;
typentry->typbyval = typtup->typbyval;
typentry->typalign = typtup->typalign;
typentry->typstorage = typtup->typstorage;
typentry->typtype = typtup->typtype;
typentry->typrelid = typtup->typrelid;
typentry->typsubscript = typtup->typsubscript;
typentry->typelem = typtup->typelem;
typentry->typcollation = typtup->typcollation;
typentry->flags |= TCFLAGS_HAVE_PG_TYPE_DATA;
ReleaseSysCache(tp);
}
/*
* Look up opclasses if we haven't already and any dependent info is
* requested.
*/
if ((flags & (TYPECACHE_EQ_OPR | TYPECACHE_LT_OPR | TYPECACHE_GT_OPR |
TYPECACHE_CMP_PROC |
TYPECACHE_EQ_OPR_FINFO | TYPECACHE_CMP_PROC_FINFO |
TYPECACHE_BTREE_OPFAMILY)) &&
!(typentry->flags & TCFLAGS_CHECKED_BTREE_OPCLASS))
{
Oid opclass;
opclass = GetDefaultOpClass(type_id, BTREE_AM_OID);
if (OidIsValid(opclass))
{
typentry->btree_opf = get_opclass_family(opclass);
typentry->btree_opintype = get_opclass_input_type(opclass);
}
else
{
typentry->btree_opf = typentry->btree_opintype = InvalidOid;
}
/*
* Reset information derived from btree opclass. Note in particular
* that we'll redetermine the eq_opr even if we previously found one;
* this matters in case a btree opclass has been added to a type that
* previously had only a hash opclass.
*/
typentry->flags &= ~(TCFLAGS_CHECKED_EQ_OPR |
TCFLAGS_CHECKED_LT_OPR |
TCFLAGS_CHECKED_GT_OPR |
TCFLAGS_CHECKED_CMP_PROC);
typentry->flags |= TCFLAGS_CHECKED_BTREE_OPCLASS;
}
/*
* If we need to look up equality operator, and there's no btree opclass,
* force lookup of hash opclass.
*/
if ((flags & (TYPECACHE_EQ_OPR | TYPECACHE_EQ_OPR_FINFO)) &&
!(typentry->flags & TCFLAGS_CHECKED_EQ_OPR) &&
typentry->btree_opf == InvalidOid)
flags |= TYPECACHE_HASH_OPFAMILY;
if ((flags & (TYPECACHE_HASH_PROC | TYPECACHE_HASH_PROC_FINFO |
TYPECACHE_HASH_EXTENDED_PROC |
TYPECACHE_HASH_EXTENDED_PROC_FINFO |
TYPECACHE_HASH_OPFAMILY)) &&
!(typentry->flags & TCFLAGS_CHECKED_HASH_OPCLASS))
{
Oid opclass;
opclass = GetDefaultOpClass(type_id, HASH_AM_OID);
if (OidIsValid(opclass))
{
typentry->hash_opf = get_opclass_family(opclass);
typentry->hash_opintype = get_opclass_input_type(opclass);
}
else
{
typentry->hash_opf = typentry->hash_opintype = InvalidOid;
}
/*
* Reset information derived from hash opclass. We do *not* reset the
* eq_opr; if we already found one from the btree opclass, that
* decision is still good.
*/
typentry->flags &= ~(TCFLAGS_CHECKED_HASH_PROC |
TCFLAGS_CHECKED_HASH_EXTENDED_PROC);
typentry->flags |= TCFLAGS_CHECKED_HASH_OPCLASS;
}
/*
* Look for requested operators and functions, if we haven't already.
*/
if ((flags & (TYPECACHE_EQ_OPR | TYPECACHE_EQ_OPR_FINFO)) &&
!(typentry->flags & TCFLAGS_CHECKED_EQ_OPR))
{
Oid eq_opr = InvalidOid;
if (typentry->btree_opf != InvalidOid)
eq_opr = get_opfamily_member(typentry->btree_opf,
typentry->btree_opintype,
typentry->btree_opintype,
BTEqualStrategyNumber);
if (eq_opr == InvalidOid &&
typentry->hash_opf != InvalidOid)
eq_opr = get_opfamily_member(typentry->hash_opf,
typentry->hash_opintype,
typentry->hash_opintype,
HTEqualStrategyNumber);
/*
* If the proposed equality operator is array_eq or record_eq, check
* to see if the element type or column types support equality. If
* not, array_eq or record_eq would fail at runtime, so we don't want
* to report that the type has equality. (We can omit similar
* checking for ranges and multiranges because ranges can't be created
* in the first place unless their subtypes support equality.)
*/
if (eq_opr == ARRAY_EQ_OP &&
!array_element_has_equality(typentry))
eq_opr = InvalidOid;
else if (eq_opr == RECORD_EQ_OP &&
!record_fields_have_equality(typentry))
eq_opr = InvalidOid;
/* Force update of eq_opr_finfo only if we're changing state */
if (typentry->eq_opr != eq_opr)
typentry->eq_opr_finfo.fn_oid = InvalidOid;
typentry->eq_opr = eq_opr;
/*
* Reset info about hash functions whenever we pick up new info about
* equality operator. This is so we can ensure that the hash
* functions match the operator.
*/
typentry->flags &= ~(TCFLAGS_CHECKED_HASH_PROC |
TCFLAGS_CHECKED_HASH_EXTENDED_PROC);
typentry->flags |= TCFLAGS_CHECKED_EQ_OPR;
}
if ((flags & TYPECACHE_LT_OPR) &&
!(typentry->flags & TCFLAGS_CHECKED_LT_OPR))
{
Oid lt_opr = InvalidOid;
if (typentry->btree_opf != InvalidOid)
lt_opr = get_opfamily_member(typentry->btree_opf,
typentry->btree_opintype,
typentry->btree_opintype,
BTLessStrategyNumber);
/*
* As above, make sure array_cmp or record_cmp will succeed; but again
* we need no special check for ranges or multiranges.
*/
if (lt_opr == ARRAY_LT_OP &&
!array_element_has_compare(typentry))
lt_opr = InvalidOid;
else if (lt_opr == RECORD_LT_OP &&
!record_fields_have_compare(typentry))
lt_opr = InvalidOid;
typentry->lt_opr = lt_opr;
typentry->flags |= TCFLAGS_CHECKED_LT_OPR;
}
if ((flags & TYPECACHE_GT_OPR) &&
!(typentry->flags & TCFLAGS_CHECKED_GT_OPR))
{
Oid gt_opr = InvalidOid;
if (typentry->btree_opf != InvalidOid)
gt_opr = get_opfamily_member(typentry->btree_opf,
typentry->btree_opintype,
typentry->btree_opintype,
BTGreaterStrategyNumber);
/*
* As above, make sure array_cmp or record_cmp will succeed; but again
* we need no special check for ranges or multiranges.
*/
if (gt_opr == ARRAY_GT_OP &&
!array_element_has_compare(typentry))
gt_opr = InvalidOid;
else if (gt_opr == RECORD_GT_OP &&
!record_fields_have_compare(typentry))
gt_opr = InvalidOid;
typentry->gt_opr = gt_opr;
typentry->flags |= TCFLAGS_CHECKED_GT_OPR;
}
if ((flags & (TYPECACHE_CMP_PROC | TYPECACHE_CMP_PROC_FINFO)) &&
!(typentry->flags & TCFLAGS_CHECKED_CMP_PROC))
{
Oid cmp_proc = InvalidOid;
if (typentry->btree_opf != InvalidOid)
cmp_proc = get_opfamily_proc(typentry->btree_opf,
typentry->btree_opintype,
typentry->btree_opintype,
BTORDER_PROC);
/*
* As above, make sure array_cmp or record_cmp will succeed; but again
* we need no special check for ranges or multiranges.
*/
if (cmp_proc == F_BTARRAYCMP &&
!array_element_has_compare(typentry))
cmp_proc = InvalidOid;
else if (cmp_proc == F_BTRECORDCMP &&
!record_fields_have_compare(typentry))
cmp_proc = InvalidOid;
/* Force update of cmp_proc_finfo only if we're changing state */
if (typentry->cmp_proc != cmp_proc)
typentry->cmp_proc_finfo.fn_oid = InvalidOid;
typentry->cmp_proc = cmp_proc;
typentry->flags |= TCFLAGS_CHECKED_CMP_PROC;
}
if ((flags & (TYPECACHE_HASH_PROC | TYPECACHE_HASH_PROC_FINFO)) &&
!(typentry->flags & TCFLAGS_CHECKED_HASH_PROC))
{
Oid hash_proc = InvalidOid;
/*
* We insist that the eq_opr, if one has been determined, match the
* hash opclass; else report there is no hash function.
*/
if (typentry->hash_opf != InvalidOid &&
(!OidIsValid(typentry->eq_opr) ||
typentry->eq_opr == get_opfamily_member(typentry->hash_opf,
typentry->hash_opintype,
typentry->hash_opintype,
HTEqualStrategyNumber)))
hash_proc = get_opfamily_proc(typentry->hash_opf,
typentry->hash_opintype,
typentry->hash_opintype,
HASHSTANDARD_PROC);
/*
* As above, make sure hash_array, hash_record, or hash_range will
* succeed.
*/
if (hash_proc == F_HASH_ARRAY &&
!array_element_has_hashing(typentry))
hash_proc = InvalidOid;
else if (hash_proc == F_HASH_RECORD &&
!record_fields_have_hashing(typentry))
hash_proc = InvalidOid;
else if (hash_proc == F_HASH_RANGE &&
!range_element_has_hashing(typentry))
hash_proc = InvalidOid;
/*
* Likewise for hash_multirange.
*/
if (hash_proc == F_HASH_MULTIRANGE &&
!multirange_element_has_hashing(typentry))
hash_proc = InvalidOid;
/* Force update of hash_proc_finfo only if we're changing state */
if (typentry->hash_proc != hash_proc)
typentry->hash_proc_finfo.fn_oid = InvalidOid;
typentry->hash_proc = hash_proc;
typentry->flags |= TCFLAGS_CHECKED_HASH_PROC;
}
if ((flags & (TYPECACHE_HASH_EXTENDED_PROC |
TYPECACHE_HASH_EXTENDED_PROC_FINFO)) &&
!(typentry->flags & TCFLAGS_CHECKED_HASH_EXTENDED_PROC))
{
Oid hash_extended_proc = InvalidOid;
/*
* We insist that the eq_opr, if one has been determined, match the
* hash opclass; else report there is no hash function.
*/
if (typentry->hash_opf != InvalidOid &&
(!OidIsValid(typentry->eq_opr) ||
typentry->eq_opr == get_opfamily_member(typentry->hash_opf,
typentry->hash_opintype,
typentry->hash_opintype,
HTEqualStrategyNumber)))
hash_extended_proc = get_opfamily_proc(typentry->hash_opf,
typentry->hash_opintype,
typentry->hash_opintype,
HASHEXTENDED_PROC);
/*
* As above, make sure hash_array_extended, hash_record_extended, or
* hash_range_extended will succeed.
*/
if (hash_extended_proc == F_HASH_ARRAY_EXTENDED &&
!array_element_has_extended_hashing(typentry))
hash_extended_proc = InvalidOid;
else if (hash_extended_proc == F_HASH_RECORD_EXTENDED &&
!record_fields_have_extended_hashing(typentry))
hash_extended_proc = InvalidOid;
else if (hash_extended_proc == F_HASH_RANGE_EXTENDED &&
!range_element_has_extended_hashing(typentry))
hash_extended_proc = InvalidOid;
/*
* Likewise for hash_multirange_extended.
*/
if (hash_extended_proc == F_HASH_MULTIRANGE_EXTENDED &&
!multirange_element_has_extended_hashing(typentry))
hash_extended_proc = InvalidOid;
/* Force update of proc finfo only if we're changing state */
if (typentry->hash_extended_proc != hash_extended_proc)
typentry->hash_extended_proc_finfo.fn_oid = InvalidOid;
typentry->hash_extended_proc = hash_extended_proc;
typentry->flags |= TCFLAGS_CHECKED_HASH_EXTENDED_PROC;
}
/*
* Set up fmgr lookup info as requested
*
* Note: we tell fmgr the finfo structures live in CacheMemoryContext,
* which is not quite right (they're really in the hash table's private
* memory context) but this will do for our purposes.
*
* Note: the code above avoids invalidating the finfo structs unless the
* referenced operator/function OID actually changes. This is to prevent
* unnecessary leakage of any subsidiary data attached to an finfo, since
* that would cause session-lifespan memory leaks.
*/
if ((flags & TYPECACHE_EQ_OPR_FINFO) &&
typentry->eq_opr_finfo.fn_oid == InvalidOid &&
typentry->eq_opr != InvalidOid)
{
Oid eq_opr_func;
eq_opr_func = get_opcode(typentry->eq_opr);
if (eq_opr_func != InvalidOid)
fmgr_info_cxt(eq_opr_func, &typentry->eq_opr_finfo,
CacheMemoryContext);
}
if ((flags & TYPECACHE_CMP_PROC_FINFO) &&
typentry->cmp_proc_finfo.fn_oid == InvalidOid &&
typentry->cmp_proc != InvalidOid)
{
fmgr_info_cxt(typentry->cmp_proc, &typentry->cmp_proc_finfo,
CacheMemoryContext);
}
if ((flags & TYPECACHE_HASH_PROC_FINFO) &&
typentry->hash_proc_finfo.fn_oid == InvalidOid &&
typentry->hash_proc != InvalidOid)
{
fmgr_info_cxt(typentry->hash_proc, &typentry->hash_proc_finfo,
CacheMemoryContext);
}
if ((flags & TYPECACHE_HASH_EXTENDED_PROC_FINFO) &&
typentry->hash_extended_proc_finfo.fn_oid == InvalidOid &&
typentry->hash_extended_proc != InvalidOid)
{
fmgr_info_cxt(typentry->hash_extended_proc,
&typentry->hash_extended_proc_finfo,
CacheMemoryContext);
}
/*
* If it's a composite type (row type), get tupdesc if requested
*/
if ((flags & TYPECACHE_TUPDESC) &&
typentry->tupDesc == NULL &&
typentry->typtype == TYPTYPE_COMPOSITE)
{
load_typcache_tupdesc(typentry);
}
/*
* If requested, get information about a range type
*
* This includes making sure that the basic info about the range element
* type is up-to-date.
*/
if ((flags & TYPECACHE_RANGE_INFO) &&
typentry->typtype == TYPTYPE_RANGE)
{
if (typentry->rngelemtype == NULL)
load_rangetype_info(typentry);
else if (!(typentry->rngelemtype->flags & TCFLAGS_HAVE_PG_TYPE_DATA))
(void) lookup_type_cache(typentry->rngelemtype->type_id, 0);
}
/*
* If requested, get information about a multirange type
*/
if ((flags & TYPECACHE_MULTIRANGE_INFO) &&
typentry->rngtype == NULL &&
typentry->typtype == TYPTYPE_MULTIRANGE)
{
load_multirangetype_info(typentry);
}
/*
* If requested, get information about a domain type
*/
if ((flags & TYPECACHE_DOMAIN_BASE_INFO) &&
typentry->domainBaseType == InvalidOid &&
typentry->typtype == TYPTYPE_DOMAIN)
{
typentry->domainBaseTypmod = -1;
typentry->domainBaseType =
getBaseTypeAndTypmod(type_id, &typentry->domainBaseTypmod);
}
if ((flags & TYPECACHE_DOMAIN_CONSTR_INFO) &&
(typentry->flags & TCFLAGS_CHECKED_DOMAIN_CONSTRAINTS) == 0 &&
typentry->typtype == TYPTYPE_DOMAIN)
{
load_domaintype_info(typentry);
}
return typentry;
}
/*
* load_typcache_tupdesc --- helper routine to set up composite type's tupDesc
*/
static void
load_typcache_tupdesc(TypeCacheEntry *typentry)
{
Relation rel;
if (!OidIsValid(typentry->typrelid)) /* should not happen */
elog(ERROR, "invalid typrelid for composite type %u",
typentry->type_id);
rel = relation_open(typentry->typrelid, AccessShareLock);
Assert(rel->rd_rel->reltype == typentry->type_id);
/*
* Link to the tupdesc and increment its refcount (we assert it's a
* refcounted descriptor). We don't use IncrTupleDescRefCount() for this,
* because the reference mustn't be entered in the current resource owner;
* it can outlive the current query.
*/
typentry->tupDesc = RelationGetDescr(rel);
Assert(typentry->tupDesc->tdrefcount > 0);
typentry->tupDesc->tdrefcount++;
/*
* In future, we could take some pains to not change tupDesc_identifier if
* the tupdesc didn't really change; but for now it's not worth it.
*/
typentry->tupDesc_identifier = ++tupledesc_id_counter;
relation_close(rel, AccessShareLock);
}
/*
* load_rangetype_info --- helper routine to set up range type information
*/
static void
load_rangetype_info(TypeCacheEntry *typentry)
{
Form_pg_range pg_range;
HeapTuple tup;
Oid subtypeOid;
Oid opclassOid;
Oid canonicalOid;
Oid subdiffOid;
Oid opfamilyOid;
Oid opcintype;
Oid cmpFnOid;
/* get information from pg_range */
tup = SearchSysCache1(RANGETYPE, ObjectIdGetDatum(typentry->type_id));
/* should not fail, since we already checked typtype ... */
if (!HeapTupleIsValid(tup))
elog(ERROR, "cache lookup failed for range type %u",
typentry->type_id);
pg_range = (Form_pg_range) GETSTRUCT(tup);
subtypeOid = pg_range->rngsubtype;
typentry->rng_collation = pg_range->rngcollation;
opclassOid = pg_range->rngsubopc;
canonicalOid = pg_range->rngcanonical;
subdiffOid = pg_range->rngsubdiff;
ReleaseSysCache(tup);
/* get opclass properties and look up the comparison function */
opfamilyOid = get_opclass_family(opclassOid);
opcintype = get_opclass_input_type(opclassOid);
typentry->rng_opfamily = opfamilyOid;
cmpFnOid = get_opfamily_proc(opfamilyOid, opcintype, opcintype,
BTORDER_PROC);
if (!RegProcedureIsValid(cmpFnOid))
elog(ERROR, "missing support function %d(%u,%u) in opfamily %u",
BTORDER_PROC, opcintype, opcintype, opfamilyOid);
/* set up cached fmgrinfo structs */
fmgr_info_cxt(cmpFnOid, &typentry->rng_cmp_proc_finfo,
CacheMemoryContext);
if (OidIsValid(canonicalOid))
fmgr_info_cxt(canonicalOid, &typentry->rng_canonical_finfo,
CacheMemoryContext);
if (OidIsValid(subdiffOid))
fmgr_info_cxt(subdiffOid, &typentry->rng_subdiff_finfo,
CacheMemoryContext);
/* Lastly, set up link to the element type --- this marks data valid */
typentry->rngelemtype = lookup_type_cache(subtypeOid, 0);
}
/*
* load_multirangetype_info --- helper routine to set up multirange type
* information
*/
static void
load_multirangetype_info(TypeCacheEntry *typentry)
{
Oid rangetypeOid;
rangetypeOid = get_multirange_range(typentry->type_id);
if (!OidIsValid(rangetypeOid))
elog(ERROR, "cache lookup failed for multirange type %u",
typentry->type_id);
typentry->rngtype = lookup_type_cache(rangetypeOid, TYPECACHE_RANGE_INFO);
}
/*
* load_domaintype_info --- helper routine to set up domain constraint info
*
* Note: we assume we're called in a relatively short-lived context, so it's
* okay to leak data into the current context while scanning pg_constraint.
* We build the new DomainConstraintCache data in a context underneath
* CurrentMemoryContext, and reparent it under CacheMemoryContext when
* complete.
*/
static void
load_domaintype_info(TypeCacheEntry *typentry)
{
Oid typeOid = typentry->type_id;
DomainConstraintCache *dcc;
bool notNull = false;
DomainConstraintState **ccons;
int cconslen;
Relation conRel;
MemoryContext oldcxt;
/*
* If we're here, any existing constraint info is stale, so release it.
* For safety, be sure to null the link before trying to delete the data.
*/
if (typentry->domainData)
{
dcc = typentry->domainData;
typentry->domainData = NULL;
decr_dcc_refcount(dcc);
}
/*
* We try to optimize the common case of no domain constraints, so don't
* create the dcc object and context until we find a constraint. Likewise
* for the temp sorting array.
*/
dcc = NULL;
ccons = NULL;
cconslen = 0;
/*
* Scan pg_constraint for relevant constraints. We want to find
* constraints for not just this domain, but any ancestor domains, so the
* outer loop crawls up the domain stack.
*/
conRel = table_open(ConstraintRelationId, AccessShareLock);
for (;;)
{
HeapTuple tup;
HeapTuple conTup;
Form_pg_type typTup;
int nccons = 0;
ScanKeyData key[1];
SysScanDesc scan;
tup = SearchSysCache1(TYPEOID, ObjectIdGetDatum(typeOid));
if (!HeapTupleIsValid(tup))
elog(ERROR, "cache lookup failed for type %u", typeOid);
typTup = (Form_pg_type) GETSTRUCT(tup);
if (typTup->typtype != TYPTYPE_DOMAIN)
{
/* Not a domain, so done */
ReleaseSysCache(tup);
break;
}
/* Test for NOT NULL Constraint */
if (typTup->typnotnull)
notNull = true;
/* Look for CHECK Constraints on this domain */
ScanKeyInit(&key[0],
Anum_pg_constraint_contypid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(typeOid));
scan = systable_beginscan(conRel, ConstraintTypidIndexId, true,
NULL, 1, key);
while (HeapTupleIsValid(conTup = systable_getnext(scan)))
{
Form_pg_constraint c = (Form_pg_constraint) GETSTRUCT(conTup);
Datum val;
bool isNull;
char *constring;
Expr *check_expr;
DomainConstraintState *r;
/* Ignore non-CHECK constraints (presently, shouldn't be any) */
if (c->contype != CONSTRAINT_CHECK)
continue;
/* Not expecting conbin to be NULL, but we'll test for it anyway */
val = fastgetattr(conTup, Anum_pg_constraint_conbin,
conRel->rd_att, &isNull);
if (isNull)
elog(ERROR, "domain \"%s\" constraint \"%s\" has NULL conbin",
NameStr(typTup->typname), NameStr(c->conname));
/* Convert conbin to C string in caller context */
constring = TextDatumGetCString(val);
/* Create the DomainConstraintCache object and context if needed */
if (dcc == NULL)
{
MemoryContext cxt;
cxt = AllocSetContextCreate(CurrentMemoryContext,
"Domain constraints",
ALLOCSET_SMALL_SIZES);
dcc = (DomainConstraintCache *)
MemoryContextAlloc(cxt, sizeof(DomainConstraintCache));
dcc->constraints = NIL;
dcc->dccContext = cxt;
dcc->dccRefCount = 0;
}
/* Create node trees in DomainConstraintCache's context */
oldcxt = MemoryContextSwitchTo(dcc->dccContext);
check_expr = (Expr *) stringToNode(constring);
/*
* Plan the expression, since ExecInitExpr will expect that.
*
* Note: caching the result of expression_planner() is not very
* good practice. Ideally we'd use a CachedExpression here so
* that we would react promptly to, eg, changes in inlined
* functions. However, because we don't support mutable domain
* CHECK constraints, it's not really clear that it's worth the
* extra overhead to do that.
*/
check_expr = expression_planner(check_expr);
r = makeNode(DomainConstraintState);
r->constrainttype = DOM_CONSTRAINT_CHECK;
r->name = pstrdup(NameStr(c->conname));
r->check_expr = check_expr;
r->check_exprstate = NULL;
MemoryContextSwitchTo(oldcxt);
/* Accumulate constraints in an array, for sorting below */
if (ccons == NULL)
{
cconslen = 8;
ccons = (DomainConstraintState **)
palloc(cconslen * sizeof(DomainConstraintState *));
}
else if (nccons >= cconslen)
{
cconslen *= 2;
ccons = (DomainConstraintState **)
repalloc(ccons, cconslen * sizeof(DomainConstraintState *));
}
ccons[nccons++] = r;
}
systable_endscan(scan);
if (nccons > 0)
{
/*
* Sort the items for this domain, so that CHECKs are applied in a
* deterministic order.
*/
if (nccons > 1)
qsort(ccons, nccons, sizeof(DomainConstraintState *), dcs_cmp);
/*
* Now attach them to the overall list. Use lcons() here because
* constraints of parent domains should be applied earlier.
*/
oldcxt = MemoryContextSwitchTo(dcc->dccContext);
while (nccons > 0)
dcc->constraints = lcons(ccons[--nccons], dcc->constraints);
MemoryContextSwitchTo(oldcxt);
}
/* loop to next domain in stack */
typeOid = typTup->typbasetype;
ReleaseSysCache(tup);
}
table_close(conRel, AccessShareLock);
/*
* Only need to add one NOT NULL check regardless of how many domains in
* the stack request it.
*/
if (notNull)
{
DomainConstraintState *r;
/* Create the DomainConstraintCache object and context if needed */
if (dcc == NULL)
{
MemoryContext cxt;
cxt = AllocSetContextCreate(CurrentMemoryContext,
"Domain constraints",
ALLOCSET_SMALL_SIZES);
dcc = (DomainConstraintCache *)
MemoryContextAlloc(cxt, sizeof(DomainConstraintCache));
dcc->constraints = NIL;
dcc->dccContext = cxt;
dcc->dccRefCount = 0;
}
/* Create node trees in DomainConstraintCache's context */
oldcxt = MemoryContextSwitchTo(dcc->dccContext);
r = makeNode(DomainConstraintState);
r->constrainttype = DOM_CONSTRAINT_NOTNULL;
r->name = pstrdup("NOT NULL");
r->check_expr = NULL;
r->check_exprstate = NULL;
/* lcons to apply the nullness check FIRST */
dcc->constraints = lcons(r, dcc->constraints);
MemoryContextSwitchTo(oldcxt);
}
/*
* If we made a constraint object, move it into CacheMemoryContext and
* attach it to the typcache entry.
*/
if (dcc)
{
MemoryContextSetParent(dcc->dccContext, CacheMemoryContext);
typentry->domainData = dcc;
dcc->dccRefCount++; /* count the typcache's reference */
}
/* Either way, the typcache entry's domain data is now valid. */
typentry->flags |= TCFLAGS_CHECKED_DOMAIN_CONSTRAINTS;
}
/*
* qsort comparator to sort DomainConstraintState pointers by name
*/
static int
dcs_cmp(const void *a, const void *b)
{
const DomainConstraintState *const *ca = (const DomainConstraintState *const *) a;
const DomainConstraintState *const *cb = (const DomainConstraintState *const *) b;
return strcmp((*ca)->name, (*cb)->name);
}
/*
* decr_dcc_refcount --- decrement a DomainConstraintCache's refcount,
* and free it if no references remain
*/
static void
decr_dcc_refcount(DomainConstraintCache *dcc)
{
Assert(dcc->dccRefCount > 0);
if (--(dcc->dccRefCount) <= 0)
MemoryContextDelete(dcc->dccContext);
}
/*
* Context reset/delete callback for a DomainConstraintRef
*/
static void
dccref_deletion_callback(void *arg)
{
DomainConstraintRef *ref = (DomainConstraintRef *) arg;
DomainConstraintCache *dcc = ref->dcc;
/* Paranoia --- be sure link is nulled before trying to release */
if (dcc)
{
ref->constraints = NIL;
ref->dcc = NULL;
decr_dcc_refcount(dcc);
}
}
/*
* prep_domain_constraints --- prepare domain constraints for execution
*
* The expression trees stored in the DomainConstraintCache's list are
* converted to executable expression state trees stored in execctx.
*/
static List *
prep_domain_constraints(List *constraints, MemoryContext execctx)
{
List *result = NIL;
MemoryContext oldcxt;
ListCell *lc;
oldcxt = MemoryContextSwitchTo(execctx);
foreach(lc, constraints)
{
DomainConstraintState *r = (DomainConstraintState *) lfirst(lc);
DomainConstraintState *newr;
newr = makeNode(DomainConstraintState);
newr->constrainttype = r->constrainttype;
newr->name = r->name;
newr->check_expr = r->check_expr;
newr->check_exprstate = ExecInitExpr(r->check_expr, NULL);
result = lappend(result, newr);
}
MemoryContextSwitchTo(oldcxt);
return result;
}
/*
* InitDomainConstraintRef --- initialize a DomainConstraintRef struct
*
* Caller must tell us the MemoryContext in which the DomainConstraintRef
* lives. The ref will be cleaned up when that context is reset/deleted.
*
* Caller must also tell us whether it wants check_exprstate fields to be
* computed in the DomainConstraintState nodes attached to this ref.
* If it doesn't, we need not make a copy of the DomainConstraintState list.
*/
void
InitDomainConstraintRef(Oid type_id, DomainConstraintRef *ref,
MemoryContext refctx, bool need_exprstate)
{
/* Look up the typcache entry --- we assume it survives indefinitely */
ref->tcache = lookup_type_cache(type_id, TYPECACHE_DOMAIN_CONSTR_INFO);
ref->need_exprstate = need_exprstate;
/* For safety, establish the callback before acquiring a refcount */
ref->refctx = refctx;
ref->dcc = NULL;
ref->callback.func = dccref_deletion_callback;
ref->callback.arg = (void *) ref;
MemoryContextRegisterResetCallback(refctx, &ref->callback);
/* Acquire refcount if there are constraints, and set up exported list */
if (ref->tcache->domainData)
{
ref->dcc = ref->tcache->domainData;
ref->dcc->dccRefCount++;
if (ref->need_exprstate)
ref->constraints = prep_domain_constraints(ref->dcc->constraints,
ref->refctx);
else
ref->constraints = ref->dcc->constraints;
}
else
ref->constraints = NIL;
}
/*
* UpdateDomainConstraintRef --- recheck validity of domain constraint info
*
* If the domain's constraint set changed, ref->constraints is updated to
* point at a new list of cached constraints.
*
* In the normal case where nothing happened to the domain, this is cheap
* enough that it's reasonable (and expected) to check before *each* use
* of the constraint info.
*/
void
UpdateDomainConstraintRef(DomainConstraintRef *ref)
{
TypeCacheEntry *typentry = ref->tcache;
/* Make sure typcache entry's data is up to date */
if ((typentry->flags & TCFLAGS_CHECKED_DOMAIN_CONSTRAINTS) == 0 &&
typentry->typtype == TYPTYPE_DOMAIN)
load_domaintype_info(typentry);
/* Transfer to ref object if there's new info, adjusting refcounts */
if (ref->dcc != typentry->domainData)
{
/* Paranoia --- be sure link is nulled before trying to release */
DomainConstraintCache *dcc = ref->dcc;
if (dcc)
{
/*
* Note: we just leak the previous list of executable domain
* constraints. Alternatively, we could keep those in a child
* context of ref->refctx and free that context at this point.
* However, in practice this code path will be taken so seldom
* that the extra bookkeeping for a child context doesn't seem
* worthwhile; we'll just allow a leak for the lifespan of refctx.
*/
ref->constraints = NIL;
ref->dcc = NULL;
decr_dcc_refcount(dcc);
}
dcc = typentry->domainData;
if (dcc)
{
ref->dcc = dcc;
dcc->dccRefCount++;
if (ref->need_exprstate)
ref->constraints = prep_domain_constraints(dcc->constraints,
ref->refctx);
else
ref->constraints = dcc->constraints;
}
}
}
/*
* DomainHasConstraints --- utility routine to check if a domain has constraints
*
* This is defined to return false, not fail, if type is not a domain.
*/
bool
DomainHasConstraints(Oid type_id)
{
TypeCacheEntry *typentry;
/*
* Note: a side effect is to cause the typcache's domain data to become
* valid. This is fine since we'll likely need it soon if there is any.
*/
typentry = lookup_type_cache(type_id, TYPECACHE_DOMAIN_CONSTR_INFO);
return (typentry->domainData != NULL);
}
/*
* array_element_has_equality and friends are helper routines to check
* whether we should believe that array_eq and related functions will work
* on the given array type or composite type.
*
* The logic above may call these repeatedly on the same type entry, so we
* make use of the typentry->flags field to cache the results once known.
* Also, we assume that we'll probably want all these facts about the type
* if we want any, so we cache them all using only one lookup of the
* component datatype(s).
*/
static bool
array_element_has_equality(TypeCacheEntry *typentry)
{
if (!(typentry->flags & TCFLAGS_CHECKED_ELEM_PROPERTIES))
cache_array_element_properties(typentry);
return (typentry->flags & TCFLAGS_HAVE_ELEM_EQUALITY) != 0;
}
static bool
array_element_has_compare(TypeCacheEntry *typentry)
{
if (!(typentry->flags & TCFLAGS_CHECKED_ELEM_PROPERTIES))
cache_array_element_properties(typentry);
return (typentry->flags & TCFLAGS_HAVE_ELEM_COMPARE) != 0;
}
static bool
array_element_has_hashing(TypeCacheEntry *typentry)
{
if (!(typentry->flags & TCFLAGS_CHECKED_ELEM_PROPERTIES))
cache_array_element_properties(typentry);
return (typentry->flags & TCFLAGS_HAVE_ELEM_HASHING) != 0;
}
static bool
array_element_has_extended_hashing(TypeCacheEntry *typentry)
{
if (!(typentry->flags & TCFLAGS_CHECKED_ELEM_PROPERTIES))
cache_array_element_properties(typentry);
return (typentry->flags & TCFLAGS_HAVE_ELEM_EXTENDED_HASHING) != 0;
}
static void
cache_array_element_properties(TypeCacheEntry *typentry)
{
Oid elem_type = get_base_element_type(typentry->type_id);
if (OidIsValid(elem_type))
{
TypeCacheEntry *elementry;
elementry = lookup_type_cache(elem_type,
TYPECACHE_EQ_OPR |
TYPECACHE_CMP_PROC |
TYPECACHE_HASH_PROC |
TYPECACHE_HASH_EXTENDED_PROC);
if (OidIsValid(elementry->eq_opr))
typentry->flags |= TCFLAGS_HAVE_ELEM_EQUALITY;
if (OidIsValid(elementry->cmp_proc))
typentry->flags |= TCFLAGS_HAVE_ELEM_COMPARE;
if (OidIsValid(elementry->hash_proc))
typentry->flags |= TCFLAGS_HAVE_ELEM_HASHING;
if (OidIsValid(elementry->hash_extended_proc))
typentry->flags |= TCFLAGS_HAVE_ELEM_EXTENDED_HASHING;
}
typentry->flags |= TCFLAGS_CHECKED_ELEM_PROPERTIES;
}
/*
* Likewise, some helper functions for composite types.
*/
static bool
record_fields_have_equality(TypeCacheEntry *typentry)
{
if (!(typentry->flags & TCFLAGS_CHECKED_FIELD_PROPERTIES))
cache_record_field_properties(typentry);
return (typentry->flags & TCFLAGS_HAVE_FIELD_EQUALITY) != 0;
}
static bool
record_fields_have_compare(TypeCacheEntry *typentry)
{
if (!(typentry->flags & TCFLAGS_CHECKED_FIELD_PROPERTIES))
cache_record_field_properties(typentry);
return (typentry->flags & TCFLAGS_HAVE_FIELD_COMPARE) != 0;
}
static bool
record_fields_have_hashing(TypeCacheEntry *typentry)
{
if (!(typentry->flags & TCFLAGS_CHECKED_FIELD_PROPERTIES))
cache_record_field_properties(typentry);
return (typentry->flags & TCFLAGS_HAVE_FIELD_HASHING) != 0;
}
static bool
record_fields_have_extended_hashing(TypeCacheEntry *typentry)
{
if (!(typentry->flags & TCFLAGS_CHECKED_FIELD_PROPERTIES))
cache_record_field_properties(typentry);
return (typentry->flags & TCFLAGS_HAVE_FIELD_EXTENDED_HASHING) != 0;
}
static void
cache_record_field_properties(TypeCacheEntry *typentry)
{
/*
* For type RECORD, we can't really tell what will work, since we don't
* have access here to the specific anonymous type. Just assume that
* equality and comparison will (we may get a failure at runtime). We
* could also claim that hashing works, but then if code that has the
* option between a comparison-based (sort-based) and a hash-based plan
* chooses hashing, stuff could fail that would otherwise work if it chose
* a comparison-based plan. In practice more types support comparison
* than hashing.
*/
if (typentry->type_id == RECORDOID)
{
typentry->flags |= (TCFLAGS_HAVE_FIELD_EQUALITY |
TCFLAGS_HAVE_FIELD_COMPARE);
}
else if (typentry->typtype == TYPTYPE_COMPOSITE)
{
TupleDesc tupdesc;
int newflags;
int i;
/* Fetch composite type's tupdesc if we don't have it already */
if (typentry->tupDesc == NULL)
load_typcache_tupdesc(typentry);
tupdesc = typentry->tupDesc;
/* Must bump the refcount while we do additional catalog lookups */
IncrTupleDescRefCount(tupdesc);
/* Have each property if all non-dropped fields have the property */
newflags = (TCFLAGS_HAVE_FIELD_EQUALITY |
TCFLAGS_HAVE_FIELD_COMPARE |
TCFLAGS_HAVE_FIELD_HASHING |
TCFLAGS_HAVE_FIELD_EXTENDED_HASHING);
for (i = 0; i < tupdesc->natts; i++)
{
TypeCacheEntry *fieldentry;
Form_pg_attribute attr = TupleDescAttr(tupdesc, i);
if (attr->attisdropped)
continue;
fieldentry = lookup_type_cache(attr->atttypid,
TYPECACHE_EQ_OPR |
TYPECACHE_CMP_PROC |
TYPECACHE_HASH_PROC |
TYPECACHE_HASH_EXTENDED_PROC);
if (!OidIsValid(fieldentry->eq_opr))
newflags &= ~TCFLAGS_HAVE_FIELD_EQUALITY;
if (!OidIsValid(fieldentry->cmp_proc))
newflags &= ~TCFLAGS_HAVE_FIELD_COMPARE;
if (!OidIsValid(fieldentry->hash_proc))
newflags &= ~TCFLAGS_HAVE_FIELD_HASHING;
if (!OidIsValid(fieldentry->hash_extended_proc))
newflags &= ~TCFLAGS_HAVE_FIELD_EXTENDED_HASHING;
/* We can drop out of the loop once we disprove all bits */
if (newflags == 0)
break;
}
typentry->flags |= newflags;
DecrTupleDescRefCount(tupdesc);
}
else if (typentry->typtype == TYPTYPE_DOMAIN)
{
/* If it's domain over composite, copy base type's properties */
TypeCacheEntry *baseentry;
/* load up basetype info if we didn't already */
if (typentry->domainBaseType == InvalidOid)
{
typentry->domainBaseTypmod = -1;
typentry->domainBaseType =
getBaseTypeAndTypmod(typentry->type_id,
&typentry->domainBaseTypmod);
}
baseentry = lookup_type_cache(typentry->domainBaseType,
TYPECACHE_EQ_OPR |
TYPECACHE_CMP_PROC |
TYPECACHE_HASH_PROC |
TYPECACHE_HASH_EXTENDED_PROC);
if (baseentry->typtype == TYPTYPE_COMPOSITE)
{
typentry->flags |= TCFLAGS_DOMAIN_BASE_IS_COMPOSITE;
typentry->flags |= baseentry->flags & (TCFLAGS_HAVE_FIELD_EQUALITY |
TCFLAGS_HAVE_FIELD_COMPARE |
TCFLAGS_HAVE_FIELD_HASHING |
TCFLAGS_HAVE_FIELD_EXTENDED_HASHING);
}
}
typentry->flags |= TCFLAGS_CHECKED_FIELD_PROPERTIES;
}
/*
* Likewise, some helper functions for range and multirange types.
*
* We can borrow the flag bits for array element properties to use for range
* element properties, since those flag bits otherwise have no use in a
* range or multirange type's typcache entry.
*/
static bool
range_element_has_hashing(TypeCacheEntry *typentry)
{
if (!(typentry->flags & TCFLAGS_CHECKED_ELEM_PROPERTIES))
cache_range_element_properties(typentry);
return (typentry->flags & TCFLAGS_HAVE_ELEM_HASHING) != 0;
}
static bool
range_element_has_extended_hashing(TypeCacheEntry *typentry)
{
if (!(typentry->flags & TCFLAGS_CHECKED_ELEM_PROPERTIES))
cache_range_element_properties(typentry);
return (typentry->flags & TCFLAGS_HAVE_ELEM_EXTENDED_HASHING) != 0;
}
static void
cache_range_element_properties(TypeCacheEntry *typentry)
{
/* load up subtype link if we didn't already */
if (typentry->rngelemtype == NULL &&
typentry->typtype == TYPTYPE_RANGE)
load_rangetype_info(typentry);
if (typentry->rngelemtype != NULL)
{
TypeCacheEntry *elementry;
/* might need to calculate subtype's hash function properties */
elementry = lookup_type_cache(typentry->rngelemtype->type_id,
TYPECACHE_HASH_PROC |
TYPECACHE_HASH_EXTENDED_PROC);
if (OidIsValid(elementry->hash_proc))
typentry->flags |= TCFLAGS_HAVE_ELEM_HASHING;
if (OidIsValid(elementry->hash_extended_proc))
typentry->flags |= TCFLAGS_HAVE_ELEM_EXTENDED_HASHING;
}
typentry->flags |= TCFLAGS_CHECKED_ELEM_PROPERTIES;
}
static bool
multirange_element_has_hashing(TypeCacheEntry *typentry)
{
if (!(typentry->flags & TCFLAGS_CHECKED_ELEM_PROPERTIES))
cache_multirange_element_properties(typentry);
return (typentry->flags & TCFLAGS_HAVE_ELEM_HASHING) != 0;
}
static bool
multirange_element_has_extended_hashing(TypeCacheEntry *typentry)
{
if (!(typentry->flags & TCFLAGS_CHECKED_ELEM_PROPERTIES))
cache_multirange_element_properties(typentry);
return (typentry->flags & TCFLAGS_HAVE_ELEM_EXTENDED_HASHING) != 0;
}
static void
cache_multirange_element_properties(TypeCacheEntry *typentry)
{
/* load up range link if we didn't already */
if (typentry->rngtype == NULL &&
typentry->typtype == TYPTYPE_MULTIRANGE)
load_multirangetype_info(typentry);
if (typentry->rngtype != NULL && typentry->rngtype->rngelemtype != NULL)
{
TypeCacheEntry *elementry;
/* might need to calculate subtype's hash function properties */
elementry = lookup_type_cache(typentry->rngtype->rngelemtype->type_id,
TYPECACHE_HASH_PROC |
TYPECACHE_HASH_EXTENDED_PROC);
if (OidIsValid(elementry->hash_proc))
typentry->flags |= TCFLAGS_HAVE_ELEM_HASHING;
if (OidIsValid(elementry->hash_extended_proc))
typentry->flags |= TCFLAGS_HAVE_ELEM_EXTENDED_HASHING;
}
typentry->flags |= TCFLAGS_CHECKED_ELEM_PROPERTIES;
}
/*
* Make sure that RecordCacheArray and RecordIdentifierArray are large enough
* to store 'typmod'.
*/
static void
ensure_record_cache_typmod_slot_exists(int32 typmod)
{
if (RecordCacheArray == NULL)
{
RecordCacheArray = (RecordCacheArrayEntry *)
MemoryContextAllocZero(CacheMemoryContext,
64 * sizeof(RecordCacheArrayEntry));
RecordCacheArrayLen = 64;
}
if (typmod >= RecordCacheArrayLen)
{
int32 newlen = pg_nextpower2_32(typmod + 1);
RecordCacheArray = repalloc0_array(RecordCacheArray,
RecordCacheArrayEntry,
RecordCacheArrayLen,
newlen);
RecordCacheArrayLen = newlen;
}
}
/*
* lookup_rowtype_tupdesc_internal --- internal routine to lookup a rowtype
*
* Same API as lookup_rowtype_tupdesc_noerror, but the returned tupdesc
* hasn't had its refcount bumped.
*/
static TupleDesc
lookup_rowtype_tupdesc_internal(Oid type_id, int32 typmod, bool noError)
{
if (type_id != RECORDOID)
{
/*
* It's a named composite type, so use the regular typcache.
*/
TypeCacheEntry *typentry;
typentry = lookup_type_cache(type_id, TYPECACHE_TUPDESC);
if (typentry->tupDesc == NULL && !noError)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("type %s is not composite",
format_type_be(type_id))));
return typentry->tupDesc;
}
else
{
/*
* It's a transient record type, so look in our record-type table.
*/
if (typmod >= 0)
{
/* It is already in our local cache? */
if (typmod < RecordCacheArrayLen &&
RecordCacheArray[typmod].tupdesc != NULL)
return RecordCacheArray[typmod].tupdesc;
/* Are we attached to a shared record typmod registry? */
if (CurrentSession->shared_typmod_registry != NULL)
{
SharedTypmodTableEntry *entry;
/* Try to find it in the shared typmod index. */
entry = dshash_find(CurrentSession->shared_typmod_table,
&typmod, false);
if (entry != NULL)
{
TupleDesc tupdesc;
tupdesc = (TupleDesc)
dsa_get_address(CurrentSession->area,
entry->shared_tupdesc);
Assert(typmod == tupdesc->tdtypmod);
/* We may need to extend the local RecordCacheArray. */
ensure_record_cache_typmod_slot_exists(typmod);
/*
* Our local array can now point directly to the TupleDesc
* in shared memory, which is non-reference-counted.
*/
RecordCacheArray[typmod].tupdesc = tupdesc;
Assert(tupdesc->tdrefcount == -1);
/*
* We don't share tupdesc identifiers across processes, so
* assign one locally.
*/
RecordCacheArray[typmod].id = ++tupledesc_id_counter;
dshash_release_lock(CurrentSession->shared_typmod_table,
entry);
return RecordCacheArray[typmod].tupdesc;
}
}
}
if (!noError)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("record type has not been registered")));
return NULL;
}
}
/*
* lookup_rowtype_tupdesc
*
* Given a typeid/typmod that should describe a known composite type,
* return the tuple descriptor for the type. Will ereport on failure.
* (Use ereport because this is reachable with user-specified OIDs,
* for example from record_in().)
*
* Note: on success, we increment the refcount of the returned TupleDesc,
* and log the reference in CurrentResourceOwner. Caller must call
* ReleaseTupleDesc when done using the tupdesc. (There are some
* cases in which the returned tupdesc is not refcounted, in which
* case PinTupleDesc/ReleaseTupleDesc are no-ops; but in these cases
* the tupdesc is guaranteed to live till process exit.)
*/
TupleDesc
lookup_rowtype_tupdesc(Oid type_id, int32 typmod)
{
TupleDesc tupDesc;
tupDesc = lookup_rowtype_tupdesc_internal(type_id, typmod, false);
PinTupleDesc(tupDesc);
return tupDesc;
}
/*
* lookup_rowtype_tupdesc_noerror
*
* As above, but if the type is not a known composite type and noError
* is true, returns NULL instead of ereport'ing. (Note that if a bogus
* type_id is passed, you'll get an ereport anyway.)
*/
TupleDesc
lookup_rowtype_tupdesc_noerror(Oid type_id, int32 typmod, bool noError)
{
TupleDesc tupDesc;
tupDesc = lookup_rowtype_tupdesc_internal(type_id, typmod, noError);
if (tupDesc != NULL)
PinTupleDesc(tupDesc);
return tupDesc;
}
/*
* lookup_rowtype_tupdesc_copy
*
* Like lookup_rowtype_tupdesc(), but the returned TupleDesc has been
* copied into the CurrentMemoryContext and is not reference-counted.
*/
TupleDesc
lookup_rowtype_tupdesc_copy(Oid type_id, int32 typmod)
{
TupleDesc tmp;
tmp = lookup_rowtype_tupdesc_internal(type_id, typmod, false);
return CreateTupleDescCopyConstr(tmp);
}
/*
* lookup_rowtype_tupdesc_domain
*
* Same as lookup_rowtype_tupdesc_noerror(), except that the type can also be
* a domain over a named composite type; so this is effectively equivalent to
* lookup_rowtype_tupdesc_noerror(getBaseType(type_id), typmod, noError)
* except for being a tad faster.
*
* Note: the reason we don't fold the look-through-domain behavior into plain
* lookup_rowtype_tupdesc() is that we want callers to know they might be
* dealing with a domain. Otherwise they might construct a tuple that should
* be of the domain type, but not apply domain constraints.
*/
TupleDesc
lookup_rowtype_tupdesc_domain(Oid type_id, int32 typmod, bool noError)
{
TupleDesc tupDesc;
if (type_id != RECORDOID)
{
/*
* Check for domain or named composite type. We might as well load
* whichever data is needed.
*/
TypeCacheEntry *typentry;
typentry = lookup_type_cache(type_id,
TYPECACHE_TUPDESC |
TYPECACHE_DOMAIN_BASE_INFO);
if (typentry->typtype == TYPTYPE_DOMAIN)
return lookup_rowtype_tupdesc_noerror(typentry->domainBaseType,
typentry->domainBaseTypmod,
noError);
if (typentry->tupDesc == NULL && !noError)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("type %s is not composite",
format_type_be(type_id))));
tupDesc = typentry->tupDesc;
}
else
tupDesc = lookup_rowtype_tupdesc_internal(type_id, typmod, noError);
if (tupDesc != NULL)
PinTupleDesc(tupDesc);
return tupDesc;
}
/*
* Hash function for the hash table of RecordCacheEntry.
*/
static uint32
record_type_typmod_hash(const void *data, size_t size)
{
RecordCacheEntry *entry = (RecordCacheEntry *) data;
return hashTupleDesc(entry->tupdesc);
}
/*
* Match function for the hash table of RecordCacheEntry.
*/
static int
record_type_typmod_compare(const void *a, const void *b, size_t size)
{
RecordCacheEntry *left = (RecordCacheEntry *) a;
RecordCacheEntry *right = (RecordCacheEntry *) b;
return equalTupleDescs(left->tupdesc, right->tupdesc) ? 0 : 1;
}
/*
* assign_record_type_typmod
*
* Given a tuple descriptor for a RECORD type, find or create a cache entry
* for the type, and set the tupdesc's tdtypmod field to a value that will
* identify this cache entry to lookup_rowtype_tupdesc.
*/
void
assign_record_type_typmod(TupleDesc tupDesc)
{
RecordCacheEntry *recentry;
TupleDesc entDesc;
bool found;
MemoryContext oldcxt;
Assert(tupDesc->tdtypeid == RECORDOID);
if (RecordCacheHash == NULL)
{
/* First time through: initialize the hash table */
HASHCTL ctl;
ctl.keysize = sizeof(TupleDesc); /* just the pointer */
ctl.entrysize = sizeof(RecordCacheEntry);
ctl.hash = record_type_typmod_hash;
ctl.match = record_type_typmod_compare;
RecordCacheHash = hash_create("Record information cache", 64,
&ctl,
HASH_ELEM | HASH_FUNCTION | HASH_COMPARE);
/* Also make sure CacheMemoryContext exists */
if (!CacheMemoryContext)
CreateCacheMemoryContext();
}
/*
* Find a hashtable entry for this tuple descriptor. We don't use
* HASH_ENTER yet, because if it's missing, we need to make sure that all
* the allocations succeed before we create the new entry.
*/
recentry = (RecordCacheEntry *) hash_search(RecordCacheHash,
&tupDesc,
HASH_FIND, &found);
if (found && recentry->tupdesc != NULL)
{
tupDesc->tdtypmod = recentry->tupdesc->tdtypmod;
return;
}
/* Not present, so need to manufacture an entry */
oldcxt = MemoryContextSwitchTo(CacheMemoryContext);
/* Look in the SharedRecordTypmodRegistry, if attached */
entDesc = find_or_make_matching_shared_tupledesc(tupDesc);
if (entDesc == NULL)
{
/*
* Make sure we have room before we CreateTupleDescCopy() or advance
* NextRecordTypmod.
*/
ensure_record_cache_typmod_slot_exists(NextRecordTypmod);
/* Reference-counted local cache only. */
entDesc = CreateTupleDescCopy(tupDesc);
entDesc->tdrefcount = 1;
entDesc->tdtypmod = NextRecordTypmod++;
}
else
{
ensure_record_cache_typmod_slot_exists(entDesc->tdtypmod);
}
RecordCacheArray[entDesc->tdtypmod].tupdesc = entDesc;
/* Assign a unique tupdesc identifier, too. */
RecordCacheArray[entDesc->tdtypmod].id = ++tupledesc_id_counter;
/* Fully initialized; create the hash table entry */
recentry = (RecordCacheEntry *) hash_search(RecordCacheHash,
&tupDesc,
HASH_ENTER, NULL);
recentry->tupdesc = entDesc;
/* Update the caller's tuple descriptor. */
tupDesc->tdtypmod = entDesc->tdtypmod;
MemoryContextSwitchTo(oldcxt);
}
/*
* assign_record_type_identifier
*
* Get an identifier, which will be unique over the lifespan of this backend
* process, for the current tuple descriptor of the specified composite type.
* For named composite types, the value is guaranteed to change if the type's
* definition does. For registered RECORD types, the value will not change
* once assigned, since the registered type won't either. If an anonymous
* RECORD type is specified, we return a new identifier on each call.
*/
uint64
assign_record_type_identifier(Oid type_id, int32 typmod)
{
if (type_id != RECORDOID)
{
/*
* It's a named composite type, so use the regular typcache.
*/
TypeCacheEntry *typentry;
typentry = lookup_type_cache(type_id, TYPECACHE_TUPDESC);
if (typentry->tupDesc == NULL)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("type %s is not composite",
format_type_be(type_id))));
Assert(typentry->tupDesc_identifier != 0);
return typentry->tupDesc_identifier;
}
else
{
/*
* It's a transient record type, so look in our record-type table.
*/
if (typmod >= 0 && typmod < RecordCacheArrayLen &&
RecordCacheArray[typmod].tupdesc != NULL)
{
Assert(RecordCacheArray[typmod].id != 0);
return RecordCacheArray[typmod].id;
}
/* For anonymous or unrecognized record type, generate a new ID */
return ++tupledesc_id_counter;
}
}
/*
* Return the amount of shmem required to hold a SharedRecordTypmodRegistry.
* This exists only to avoid exposing private innards of
* SharedRecordTypmodRegistry in a header.
*/
size_t
SharedRecordTypmodRegistryEstimate(void)
{
return sizeof(SharedRecordTypmodRegistry);
}
/*
* Initialize 'registry' in a pre-existing shared memory region, which must be
* maximally aligned and have space for SharedRecordTypmodRegistryEstimate()
* bytes.
*
* 'area' will be used to allocate shared memory space as required for the
* typemod registration. The current process, expected to be a leader process
* in a parallel query, will be attached automatically and its current record
* types will be loaded into *registry. While attached, all calls to
* assign_record_type_typmod will use the shared registry. Worker backends
* will need to attach explicitly.
*
* Note that this function takes 'area' and 'segment' as arguments rather than
* accessing them via CurrentSession, because they aren't installed there
* until after this function runs.
*/
void
SharedRecordTypmodRegistryInit(SharedRecordTypmodRegistry *registry,
dsm_segment *segment,
dsa_area *area)
{
MemoryContext old_context;
dshash_table *record_table;
dshash_table *typmod_table;
int32 typmod;
Assert(!IsParallelWorker());
/* We can't already be attached to a shared registry. */
Assert(CurrentSession->shared_typmod_registry == NULL);
Assert(CurrentSession->shared_record_table == NULL);
Assert(CurrentSession->shared_typmod_table == NULL);
old_context = MemoryContextSwitchTo(TopMemoryContext);
/* Create the hash table of tuple descriptors indexed by themselves. */
record_table = dshash_create(area, &srtr_record_table_params, area);
/* Create the hash table of tuple descriptors indexed by typmod. */
typmod_table = dshash_create(area, &srtr_typmod_table_params, NULL);
MemoryContextSwitchTo(old_context);
/* Initialize the SharedRecordTypmodRegistry. */
registry->record_table_handle = dshash_get_hash_table_handle(record_table);
registry->typmod_table_handle = dshash_get_hash_table_handle(typmod_table);
pg_atomic_init_u32(&registry->next_typmod, NextRecordTypmod);
/*
* Copy all entries from this backend's private registry into the shared
* registry.
*/
for (typmod = 0; typmod < NextRecordTypmod; ++typmod)
{
SharedTypmodTableEntry *typmod_table_entry;
SharedRecordTableEntry *record_table_entry;
SharedRecordTableKey record_table_key;
dsa_pointer shared_dp;
TupleDesc tupdesc;
bool found;
tupdesc = RecordCacheArray[typmod].tupdesc;
if (tupdesc == NULL)
continue;
/* Copy the TupleDesc into shared memory. */
shared_dp = share_tupledesc(area, tupdesc, typmod);
/* Insert into the typmod table. */
typmod_table_entry = dshash_find_or_insert(typmod_table,
&tupdesc->tdtypmod,
&found);
if (found)
elog(ERROR, "cannot create duplicate shared record typmod");
typmod_table_entry->typmod = tupdesc->tdtypmod;
typmod_table_entry->shared_tupdesc = shared_dp;
dshash_release_lock(typmod_table, typmod_table_entry);
/* Insert into the record table. */
record_table_key.shared = false;
record_table_key.u.local_tupdesc = tupdesc;
record_table_entry = dshash_find_or_insert(record_table,
&record_table_key,
&found);
if (!found)
{
record_table_entry->key.shared = true;
record_table_entry->key.u.shared_tupdesc = shared_dp;
}
dshash_release_lock(record_table, record_table_entry);
}
/*
* Set up the global state that will tell assign_record_type_typmod and
* lookup_rowtype_tupdesc_internal about the shared registry.
*/
CurrentSession->shared_record_table = record_table;
CurrentSession->shared_typmod_table = typmod_table;
CurrentSession->shared_typmod_registry = registry;
/*
* We install a detach hook in the leader, but only to handle cleanup on
* failure during GetSessionDsmHandle(). Once GetSessionDsmHandle() pins
* the memory, the leader process will use a shared registry until it
* exits.
*/
on_dsm_detach(segment, shared_record_typmod_registry_detach, (Datum) 0);
}
/*
* Attach to 'registry', which must have been initialized already by another
* backend. Future calls to assign_record_type_typmod and
* lookup_rowtype_tupdesc_internal will use the shared registry until the
* current session is detached.
*/
void
SharedRecordTypmodRegistryAttach(SharedRecordTypmodRegistry *registry)
{
MemoryContext old_context;
dshash_table *record_table;
dshash_table *typmod_table;
Assert(IsParallelWorker());
/* We can't already be attached to a shared registry. */
Assert(CurrentSession != NULL);
Assert(CurrentSession->segment != NULL);
Assert(CurrentSession->area != NULL);
Assert(CurrentSession->shared_typmod_registry == NULL);
Assert(CurrentSession->shared_record_table == NULL);
Assert(CurrentSession->shared_typmod_table == NULL);
/*
* We can't already have typmods in our local cache, because they'd clash
* with those imported by SharedRecordTypmodRegistryInit. This should be
* a freshly started parallel worker. If we ever support worker
* recycling, a worker would need to zap its local cache in between
* servicing different queries, in order to be able to call this and
* synchronize typmods with a new leader; but that's problematic because
* we can't be very sure that record-typmod-related state hasn't escaped
* to anywhere else in the process.
*/
Assert(NextRecordTypmod == 0);
old_context = MemoryContextSwitchTo(TopMemoryContext);
/* Attach to the two hash tables. */
record_table = dshash_attach(CurrentSession->area,
&srtr_record_table_params,
registry->record_table_handle,
CurrentSession->area);
typmod_table = dshash_attach(CurrentSession->area,
&srtr_typmod_table_params,
registry->typmod_table_handle,
NULL);
MemoryContextSwitchTo(old_context);
/*
* Set up detach hook to run at worker exit. Currently this is the same
* as the leader's detach hook, but in future they might need to be
* different.
*/
on_dsm_detach(CurrentSession->segment,
shared_record_typmod_registry_detach,
PointerGetDatum(registry));
/*
* Set up the session state that will tell assign_record_type_typmod and
* lookup_rowtype_tupdesc_internal about the shared registry.
*/
CurrentSession->shared_typmod_registry = registry;
CurrentSession->shared_record_table = record_table;
CurrentSession->shared_typmod_table = typmod_table;
}
/*
* TypeCacheRelCallback
* Relcache inval callback function
*
* Delete the cached tuple descriptor (if any) for the given rel's composite
* type, or for all composite types if relid == InvalidOid. Also reset
* whatever info we have cached about the composite type's comparability.
*
* This is called when a relcache invalidation event occurs for the given
* relid. We must scan the whole typcache hash since we don't know the
* type OID corresponding to the relid. We could do a direct search if this
* were a syscache-flush callback on pg_type, but then we would need all
* ALTER-TABLE-like commands that could modify a rowtype to issue syscache
* invals against the rel's pg_type OID. The extra SI signaling could very
* well cost more than we'd save, since in most usages there are not very
* many entries in a backend's typcache. The risk of bugs-of-omission seems
* high, too.
*
* Another possibility, with only localized impact, is to maintain a second
* hashtable that indexes composite-type typcache entries by their typrelid.
* But it's still not clear it's worth the trouble.
*/
static void
TypeCacheRelCallback(Datum arg, Oid relid)
{
HASH_SEQ_STATUS status;
TypeCacheEntry *typentry;
/* TypeCacheHash must exist, else this callback wouldn't be registered */
hash_seq_init(&status, TypeCacheHash);
while ((typentry = (TypeCacheEntry *) hash_seq_search(&status)) != NULL)
{
if (typentry->typtype == TYPTYPE_COMPOSITE)
{
/* Skip if no match, unless we're zapping all composite types */
if (relid != typentry->typrelid && relid != InvalidOid)
continue;
/* Delete tupdesc if we have it */
if (typentry->tupDesc != NULL)
{
/*
* Release our refcount, and free the tupdesc if none remain.
* (Can't use DecrTupleDescRefCount because this reference is
* not logged in current resource owner.)
*/
Assert(typentry->tupDesc->tdrefcount > 0);
if (--typentry->tupDesc->tdrefcount == 0)
FreeTupleDesc(typentry->tupDesc);
typentry->tupDesc = NULL;
/*
* Also clear tupDesc_identifier, so that anything watching
* that will realize that the tupdesc has possibly changed.
* (Alternatively, we could specify that to detect possible
* tupdesc change, one must check for tupDesc != NULL as well
* as tupDesc_identifier being the same as what was previously
* seen. That seems error-prone.)
*/
typentry->tupDesc_identifier = 0;
}
/* Reset equality/comparison/hashing validity information */
typentry->flags &= ~TCFLAGS_OPERATOR_FLAGS;
}
else if (typentry->typtype == TYPTYPE_DOMAIN)
{
/*
* If it's domain over composite, reset flags. (We don't bother
* trying to determine whether the specific base type needs a
* reset.) Note that if we haven't determined whether the base
* type is composite, we don't need to reset anything.
*/
if (typentry->flags & TCFLAGS_DOMAIN_BASE_IS_COMPOSITE)
typentry->flags &= ~TCFLAGS_OPERATOR_FLAGS;
}
}
}
/*
* TypeCacheTypCallback
* Syscache inval callback function
*
* This is called when a syscache invalidation event occurs for any
* pg_type row. If we have information cached about that type, mark
* it as needing to be reloaded.
*/
static void
TypeCacheTypCallback(Datum arg, int cacheid, uint32 hashvalue)
{
HASH_SEQ_STATUS status;
TypeCacheEntry *typentry;
/* TypeCacheHash must exist, else this callback wouldn't be registered */
hash_seq_init(&status, TypeCacheHash);
while ((typentry = (TypeCacheEntry *) hash_seq_search(&status)) != NULL)
{
/* Is this the targeted type row (or it's a total cache flush)? */
if (hashvalue == 0 || typentry->type_id_hash == hashvalue)
{
/*
* Mark the data obtained directly from pg_type as invalid. Also,
* if it's a domain, typnotnull might've changed, so we'll need to
* recalculate its constraints.
*/
typentry->flags &= ~(TCFLAGS_HAVE_PG_TYPE_DATA |
TCFLAGS_CHECKED_DOMAIN_CONSTRAINTS);
}
}
}
/*
* TypeCacheOpcCallback
* Syscache inval callback function
*
* This is called when a syscache invalidation event occurs for any pg_opclass
* row. In principle we could probably just invalidate data dependent on the
* particular opclass, but since updates on pg_opclass are rare in production
* it doesn't seem worth a lot of complication: we just mark all cached data
* invalid.
*
* Note that we don't bother watching for updates on pg_amop or pg_amproc.
* This should be safe because ALTER OPERATOR FAMILY ADD/DROP OPERATOR/FUNCTION
* is not allowed to be used to add/drop the primary operators and functions
* of an opclass, only cross-type members of a family; and the latter sorts
* of members are not going to get cached here.
*/
static void
TypeCacheOpcCallback(Datum arg, int cacheid, uint32 hashvalue)
{
HASH_SEQ_STATUS status;
TypeCacheEntry *typentry;
/* TypeCacheHash must exist, else this callback wouldn't be registered */
hash_seq_init(&status, TypeCacheHash);
while ((typentry = (TypeCacheEntry *) hash_seq_search(&status)) != NULL)
{
/* Reset equality/comparison/hashing validity information */
typentry->flags &= ~TCFLAGS_OPERATOR_FLAGS;
}
}
/*
* TypeCacheConstrCallback
* Syscache inval callback function
*
* This is called when a syscache invalidation event occurs for any
* pg_constraint row. We flush information about domain constraints
* when this happens.
*
* It's slightly annoying that we can't tell whether the inval event was for
* a domain constraint record or not; there's usually more update traffic
* for table constraints than domain constraints, so we'll do a lot of
* useless flushes. Still, this is better than the old no-caching-at-all
* approach to domain constraints.
*/
static void
TypeCacheConstrCallback(Datum arg, int cacheid, uint32 hashvalue)
{
TypeCacheEntry *typentry;
/*
* Because this is called very frequently, and typically very few of the
* typcache entries are for domains, we don't use hash_seq_search here.
* Instead we thread all the domain-type entries together so that we can
* visit them cheaply.
*/
for (typentry = firstDomainTypeEntry;
typentry != NULL;
typentry = typentry->nextDomain)
{
/* Reset domain constraint validity information */
typentry->flags &= ~TCFLAGS_CHECKED_DOMAIN_CONSTRAINTS;
}
}
/*
* Check if given OID is part of the subset that's sortable by comparisons
*/
static inline bool
enum_known_sorted(TypeCacheEnumData *enumdata, Oid arg)
{
Oid offset;
if (arg < enumdata->bitmap_base)
return false;
offset = arg - enumdata->bitmap_base;
if (offset > (Oid) INT_MAX)
return false;
return bms_is_member((int) offset, enumdata->sorted_values);
}
/*
* compare_values_of_enum
* Compare two members of an enum type.
* Return <0, 0, or >0 according as arg1 <, =, or > arg2.
*
* Note: currently, the enumData cache is refreshed only if we are asked
* to compare an enum value that is not already in the cache. This is okay
* because there is no support for re-ordering existing values, so comparisons
* of previously cached values will return the right answer even if other
* values have been added since we last loaded the cache.
*
* Note: the enum logic has a special-case rule about even-numbered versus
* odd-numbered OIDs, but we take no account of that rule here; this
* routine shouldn't even get called when that rule applies.
*/
int
compare_values_of_enum(TypeCacheEntry *tcache, Oid arg1, Oid arg2)
{
TypeCacheEnumData *enumdata;
EnumItem *item1;
EnumItem *item2;
/*
* Equal OIDs are certainly equal --- this case was probably handled by
* our caller, but we may as well check.
*/
if (arg1 == arg2)
return 0;
/* Load up the cache if first time through */
if (tcache->enumData == NULL)
load_enum_cache_data(tcache);
enumdata = tcache->enumData;
/*
* If both OIDs are known-sorted, we can just compare them directly.
*/
if (enum_known_sorted(enumdata, arg1) &&
enum_known_sorted(enumdata, arg2))
{
if (arg1 < arg2)
return -1;
else
return 1;
}
/*
* Slow path: we have to identify their actual sort-order positions.
*/
item1 = find_enumitem(enumdata, arg1);
item2 = find_enumitem(enumdata, arg2);
if (item1 == NULL || item2 == NULL)
{
/*
* We couldn't find one or both values. That means the enum has
* changed under us, so re-initialize the cache and try again. We
* don't bother retrying the known-sorted case in this path.
*/
load_enum_cache_data(tcache);
enumdata = tcache->enumData;
item1 = find_enumitem(enumdata, arg1);
item2 = find_enumitem(enumdata, arg2);
/*
* If we still can't find the values, complain: we must have corrupt
* data.
*/
if (item1 == NULL)
elog(ERROR, "enum value %u not found in cache for enum %s",
arg1, format_type_be(tcache->type_id));
if (item2 == NULL)
elog(ERROR, "enum value %u not found in cache for enum %s",
arg2, format_type_be(tcache->type_id));
}
if (item1->sort_order < item2->sort_order)
return -1;
else if (item1->sort_order > item2->sort_order)
return 1;
else
return 0;
}
/*
* Load (or re-load) the enumData member of the typcache entry.
*/
static void
load_enum_cache_data(TypeCacheEntry *tcache)
{
TypeCacheEnumData *enumdata;
Relation enum_rel;
SysScanDesc enum_scan;
HeapTuple enum_tuple;
ScanKeyData skey;
EnumItem *items;
int numitems;
int maxitems;
Oid bitmap_base;
Bitmapset *bitmap;
MemoryContext oldcxt;
int bm_size,
start_pos;
/* Check that this is actually an enum */
if (tcache->typtype != TYPTYPE_ENUM)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("%s is not an enum",
format_type_be(tcache->type_id))));
/*
* Read all the information for members of the enum type. We collect the
* info in working memory in the caller's context, and then transfer it to
* permanent memory in CacheMemoryContext. This minimizes the risk of
* leaking memory from CacheMemoryContext in the event of an error partway
* through.
*/
maxitems = 64;
items = (EnumItem *) palloc(sizeof(EnumItem) * maxitems);
numitems = 0;
/* Scan pg_enum for the members of the target enum type. */
ScanKeyInit(&skey,
Anum_pg_enum_enumtypid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(tcache->type_id));
enum_rel = table_open(EnumRelationId, AccessShareLock);
enum_scan = systable_beginscan(enum_rel,
EnumTypIdLabelIndexId,
true, NULL,
1, &skey);
while (HeapTupleIsValid(enum_tuple = systable_getnext(enum_scan)))
{
Form_pg_enum en = (Form_pg_enum) GETSTRUCT(enum_tuple);
if (numitems >= maxitems)
{
maxitems *= 2;
items = (EnumItem *) repalloc(items, sizeof(EnumItem) * maxitems);
}
items[numitems].enum_oid = en->oid;
items[numitems].sort_order = en->enumsortorder;
numitems++;
}
systable_endscan(enum_scan);
table_close(enum_rel, AccessShareLock);
/* Sort the items into OID order */
qsort(items, numitems, sizeof(EnumItem), enum_oid_cmp);
/*
* Here, we create a bitmap listing a subset of the enum's OIDs that are
* known to be in order and can thus be compared with just OID comparison.
*
* The point of this is that the enum's initial OIDs were certainly in
* order, so there is some subset that can be compared via OID comparison;
* and we'd rather not do binary searches unnecessarily.
*
* This is somewhat heuristic, and might identify a subset of OIDs that
* isn't exactly what the type started with. That's okay as long as the
* subset is correctly sorted.
*/
bitmap_base = InvalidOid;
bitmap = NULL;
bm_size = 1; /* only save sets of at least 2 OIDs */
for (start_pos = 0; start_pos < numitems - 1; start_pos++)
{
/*
* Identify longest sorted subsequence starting at start_pos
*/
Bitmapset *this_bitmap = bms_make_singleton(0);
int this_bm_size = 1;
Oid start_oid = items[start_pos].enum_oid;
float4 prev_order = items[start_pos].sort_order;
int i;
for (i = start_pos + 1; i < numitems; i++)
{
Oid offset;
offset = items[i].enum_oid - start_oid;
/* quit if bitmap would be too large; cutoff is arbitrary */
if (offset >= 8192)
break;
/* include the item if it's in-order */
if (items[i].sort_order > prev_order)
{
prev_order = items[i].sort_order;
this_bitmap = bms_add_member(this_bitmap, (int) offset);
this_bm_size++;
}
}
/* Remember it if larger than previous best */
if (this_bm_size > bm_size)
{
bms_free(bitmap);
bitmap_base = start_oid;
bitmap = this_bitmap;
bm_size = this_bm_size;
}
else
bms_free(this_bitmap);
/*
* Done if it's not possible to find a longer sequence in the rest of
* the list. In typical cases this will happen on the first
* iteration, which is why we create the bitmaps on the fly instead of
* doing a second pass over the list.
*/
if (bm_size >= (numitems - start_pos - 1))
break;
}
/* OK, copy the data into CacheMemoryContext */
oldcxt = MemoryContextSwitchTo(CacheMemoryContext);
enumdata = (TypeCacheEnumData *)
palloc(offsetof(TypeCacheEnumData, enum_values) +
numitems * sizeof(EnumItem));
enumdata->bitmap_base = bitmap_base;
enumdata->sorted_values = bms_copy(bitmap);
enumdata->num_values = numitems;
memcpy(enumdata->enum_values, items, numitems * sizeof(EnumItem));
MemoryContextSwitchTo(oldcxt);
pfree(items);
bms_free(bitmap);
/* And link the finished cache struct into the typcache */
if (tcache->enumData != NULL)
pfree(tcache->enumData);
tcache->enumData = enumdata;
}
/*
* Locate the EnumItem with the given OID, if present
*/
static EnumItem *
find_enumitem(TypeCacheEnumData *enumdata, Oid arg)
{
EnumItem srch;
/* On some versions of Solaris, bsearch of zero items dumps core */
if (enumdata->num_values <= 0)
return NULL;
srch.enum_oid = arg;
return bsearch(&srch, enumdata->enum_values, enumdata->num_values,
sizeof(EnumItem), enum_oid_cmp);
}
/*
* qsort comparison function for OID-ordered EnumItems
*/
static int
enum_oid_cmp(const void *left, const void *right)
{
const EnumItem *l = (const EnumItem *) left;
const EnumItem *r = (const EnumItem *) right;
return pg_cmp_u32(l->enum_oid, r->enum_oid);
}
/*
* Copy 'tupdesc' into newly allocated shared memory in 'area', set its typmod
* to the given value and return a dsa_pointer.
*/
static dsa_pointer
share_tupledesc(dsa_area *area, TupleDesc tupdesc, uint32 typmod)
{
dsa_pointer shared_dp;
TupleDesc shared;
shared_dp = dsa_allocate(area, TupleDescSize(tupdesc));
shared = (TupleDesc) dsa_get_address(area, shared_dp);
TupleDescCopy(shared, tupdesc);
shared->tdtypmod = typmod;
return shared_dp;
}
/*
* If we are attached to a SharedRecordTypmodRegistry, use it to find or
* create a shared TupleDesc that matches 'tupdesc'. Otherwise return NULL.
* Tuple descriptors returned by this function are not reference counted, and
* will exist at least as long as the current backend remained attached to the
* current session.
*/
static TupleDesc
find_or_make_matching_shared_tupledesc(TupleDesc tupdesc)
{
TupleDesc result;
SharedRecordTableKey key;
SharedRecordTableEntry *record_table_entry;
SharedTypmodTableEntry *typmod_table_entry;
dsa_pointer shared_dp;
bool found;
uint32 typmod;
/* If not even attached, nothing to do. */
if (CurrentSession->shared_typmod_registry == NULL)
return NULL;
/* Try to find a matching tuple descriptor in the record table. */
key.shared = false;
key.u.local_tupdesc = tupdesc;
record_table_entry = (SharedRecordTableEntry *)
dshash_find(CurrentSession->shared_record_table, &key, false);
if (record_table_entry)
{
Assert(record_table_entry->key.shared);
dshash_release_lock(CurrentSession->shared_record_table,
record_table_entry);
result = (TupleDesc)
dsa_get_address(CurrentSession->area,
record_table_entry->key.u.shared_tupdesc);
Assert(result->tdrefcount == -1);
return result;
}
/* Allocate a new typmod number. This will be wasted if we error out. */
typmod = (int)
pg_atomic_fetch_add_u32(&CurrentSession->shared_typmod_registry->next_typmod,
1);
/* Copy the TupleDesc into shared memory. */
shared_dp = share_tupledesc(CurrentSession->area, tupdesc, typmod);
/*
* Create an entry in the typmod table so that others will understand this
* typmod number.
*/
PG_TRY();
{
typmod_table_entry = (SharedTypmodTableEntry *)
dshash_find_or_insert(CurrentSession->shared_typmod_table,
&typmod, &found);
if (found)
elog(ERROR, "cannot create duplicate shared record typmod");
}
PG_CATCH();
{
dsa_free(CurrentSession->area, shared_dp);
PG_RE_THROW();
}
PG_END_TRY();
typmod_table_entry->typmod = typmod;
typmod_table_entry->shared_tupdesc = shared_dp;
dshash_release_lock(CurrentSession->shared_typmod_table,
typmod_table_entry);
/*
* Finally create an entry in the record table so others with matching
* tuple descriptors can reuse the typmod.
*/
record_table_entry = (SharedRecordTableEntry *)
dshash_find_or_insert(CurrentSession->shared_record_table, &key,
&found);
if (found)
{
/*
* Someone concurrently inserted a matching tuple descriptor since the
* first time we checked. Use that one instead.
*/
dshash_release_lock(CurrentSession->shared_record_table,
record_table_entry);
/* Might as well free up the space used by the one we created. */
found = dshash_delete_key(CurrentSession->shared_typmod_table,
&typmod);
Assert(found);
dsa_free(CurrentSession->area, shared_dp);
/* Return the one we found. */
Assert(record_table_entry->key.shared);
result = (TupleDesc)
dsa_get_address(CurrentSession->area,
record_table_entry->key.u.shared_tupdesc);
Assert(result->tdrefcount == -1);
return result;
}
/* Store it and return it. */
record_table_entry->key.shared = true;
record_table_entry->key.u.shared_tupdesc = shared_dp;
dshash_release_lock(CurrentSession->shared_record_table,
record_table_entry);
result = (TupleDesc)
dsa_get_address(CurrentSession->area, shared_dp);
Assert(result->tdrefcount == -1);
return result;
}
/*
* On-DSM-detach hook to forget about the current shared record typmod
* infrastructure. This is currently used by both leader and workers.
*/
static void
shared_record_typmod_registry_detach(dsm_segment *segment, Datum datum)
{
/* Be cautious here: maybe we didn't finish initializing. */
if (CurrentSession->shared_record_table != NULL)
{
dshash_detach(CurrentSession->shared_record_table);
CurrentSession->shared_record_table = NULL;
}
if (CurrentSession->shared_typmod_table != NULL)
{
dshash_detach(CurrentSession->shared_typmod_table);
CurrentSession->shared_typmod_table = NULL;
}
CurrentSession->shared_typmod_registry = NULL;
}
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