codekingpro/portable-devtools

1/*-------------------------------------------------------------------------2 *3 * catcache.h4 *	  Low-level catalog cache definitions.5 *6 * NOTE: every catalog cache must have a corresponding unique index on7 * the system table that it caches --- ie, the index must match the keys8 * used to do lookups in this cache.  All cache fetches are done with9 * indexscans (under normal conditions).  The index should be unique to10 * guarantee that there can only be one matching row for a key combination.11 *12 *13 * Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group14 * Portions Copyright (c) 1994, Regents of the University of California15 *16 * src/include/utils/catcache.h17 *18 *-------------------------------------------------------------------------19 */20#ifndef CATCACHE_H21#define CATCACHE_H22 23#include "access/htup.h"24#include "access/skey.h"25#include "lib/ilist.h"26#include "utils/relcache.h"27 28/*29 *		struct catctup:			individual tuple in the cache.30 *		struct catclist:		list of tuples matching a partial key.31 *		struct catcache:		information for managing a cache.32 *		struct catcacheheader:	information for managing all the caches.33 */34 35#define CATCACHE_MAXKEYS		436 37 38/* function computing a datum's hash */39typedef uint32 (*CCHashFN) (Datum datum);40 41/* function computing equality of two datums */42typedef bool (*CCFastEqualFN) (Datum a, Datum b);43 44typedef struct catcache45{46	int			id;				/* cache identifier --- see syscache.h */47	int			cc_nbuckets;	/* # of hash buckets in this cache */48	TupleDesc	cc_tupdesc;		/* tuple descriptor (copied from reldesc) */49	dlist_head *cc_bucket;		/* hash buckets */50	CCHashFN	cc_hashfunc[CATCACHE_MAXKEYS];	/* hash function for each key */51	CCFastEqualFN cc_fastequal[CATCACHE_MAXKEYS];	/* fast equal function for52													 * each key */53	int			cc_keyno[CATCACHE_MAXKEYS]; /* AttrNumber of each key */54	dlist_head	cc_lists;		/* list of CatCList structs */55	int			cc_ntup;		/* # of tuples currently in this cache */56	int			cc_nkeys;		/* # of keys (1..CATCACHE_MAXKEYS) */57	const char *cc_relname;		/* name of relation the tuples come from */58	Oid			cc_reloid;		/* OID of relation the tuples come from */59	Oid			cc_indexoid;	/* OID of index matching cache keys */60	bool		cc_relisshared; /* is relation shared across databases? */61	slist_node	cc_next;		/* list link */62	ScanKeyData cc_skey[CATCACHE_MAXKEYS];	/* precomputed key info for heap63											 * scans */64 65	/* These fields are placed here to avoid ABI breakage in v16 */66	int			cc_nlist;		/* # of CatCLists currently in this cache */67	int			cc_nlbuckets;	/* # of CatCList hash buckets in this cache */68	dlist_head *cc_lbucket;		/* hash buckets for CatCLists */69 70	/*71	 * Keep these at the end, so that compiling catcache.c with CATCACHE_STATS72	 * doesn't break ABI for other modules73	 */74#ifdef CATCACHE_STATS75	long		cc_searches;	/* total # searches against this cache */76	long		cc_hits;		/* # of matches against existing entry */77	long		cc_neg_hits;	/* # of matches against negative entry */78	long		cc_newloads;	/* # of successful loads of new entry */79 80	/*81	 * cc_searches - (cc_hits + cc_neg_hits + cc_newloads) is number of failed82	 * searches, each of which will result in loading a negative entry83	 */84	long		cc_invals;		/* # of entries invalidated from cache */85	long		cc_lsearches;	/* total # list-searches */86	long		cc_lhits;		/* # of matches against existing lists */87#endif88} CatCache;89 90 91typedef struct catctup92{93	int			ct_magic;		/* for identifying CatCTup entries */94#define CT_MAGIC   0x5726150295 96	uint32		hash_value;		/* hash value for this tuple's keys */97 98	/*99	 * Lookup keys for the entry. By-reference datums point into the tuple for100	 * positive cache entries, and are separately allocated for negative ones.101	 */102	Datum		keys[CATCACHE_MAXKEYS];103 104	/*105	 * Each tuple in a cache is a member of a dlist that stores the elements106	 * of its hash bucket.  We keep each dlist in LRU order to speed repeated107	 * lookups.108	 */109	dlist_node	cache_elem;		/* list member of per-bucket list */110 111	/*112	 * A tuple marked "dead" must not be returned by subsequent searches.113	 * However, it won't be physically deleted from the cache until its114	 * refcount goes to zero.  (If it's a member of a CatCList, the list's115	 * refcount must go to zero, too; also, remember to mark the list dead at116	 * the same time the tuple is marked.)117	 *118	 * A negative cache entry is an assertion that there is no tuple matching119	 * a particular key.  This is just as useful as a normal entry so far as120	 * avoiding catalog searches is concerned.  Management of positive and121	 * negative entries is identical.122	 */123	int			refcount;		/* number of active references */124	bool		dead;			/* dead but not yet removed? */125	bool		negative;		/* negative cache entry? */126	HeapTupleData tuple;		/* tuple management header */127 128	/*129	 * The tuple may also be a member of at most one CatCList.  (If a single130	 * catcache is list-searched with varying numbers of keys, we may have to131	 * make multiple entries for the same tuple because of this restriction.132	 * Currently, that's not expected to be common, so we accept the potential133	 * inefficiency.)134	 */135	struct catclist *c_list;	/* containing CatCList, or NULL if none */136 137	CatCache   *my_cache;		/* link to owning catcache */138	/* properly aligned tuple data follows, unless a negative entry */139} CatCTup;140 141 142/*143 * A CatCList describes the result of a partial search, ie, a search using144 * only the first K key columns of an N-key cache.  We store the keys used145 * into the keys attribute to represent the stored key set.  The CatCList146 * object contains links to cache entries for all the table rows satisfying147 * the partial key.  (Note: none of these will be negative cache entries.)148 *149 * A CatCList is only a member of a per-cache list; we do not currently150 * divide them into hash buckets.151 *152 * A list marked "dead" must not be returned by subsequent searches.153 * However, it won't be physically deleted from the cache until its154 * refcount goes to zero.  (A list should be marked dead if any of its155 * member entries are dead.)156 *157 * If "ordered" is true then the member tuples appear in the order of the158 * cache's underlying index.  This will be true in normal operation, but159 * might not be true during bootstrap or recovery operations. (namespace.c160 * is able to save some cycles when it is true.)161 */162typedef struct catclist163{164	int			cl_magic;		/* for identifying CatCList entries */165#define CL_MAGIC   0x52765103166 167	uint32		hash_value;		/* hash value for lookup keys */168 169	dlist_node	cache_elem;		/* list member of per-catcache list */170 171	/*172	 * Lookup keys for the entry, with the first nkeys elements being valid.173	 * All by-reference are separately allocated.174	 */175	Datum		keys[CATCACHE_MAXKEYS];176 177	int			refcount;		/* number of active references */178	bool		dead;			/* dead but not yet removed? */179	bool		ordered;		/* members listed in index order? */180	short		nkeys;			/* number of lookup keys specified */181	int			n_members;		/* number of member tuples */182	CatCache   *my_cache;		/* link to owning catcache */183	CatCTup    *members[FLEXIBLE_ARRAY_MEMBER]; /* members */184} CatCList;185 186 187typedef struct catcacheheader188{189	slist_head	ch_caches;		/* head of list of CatCache structs */190	int			ch_ntup;		/* # of tuples in all caches */191} CatCacheHeader;192 193 194/* this extern duplicates utils/memutils.h... */195extern PGDLLIMPORT MemoryContext CacheMemoryContext;196 197extern void CreateCacheMemoryContext(void);198 199extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid,200							  int nkeys, const int *key,201							  int nbuckets);202extern void InitCatCachePhase2(CatCache *cache, bool touch_index);203 204extern HeapTuple SearchCatCache(CatCache *cache,205								Datum v1, Datum v2, Datum v3, Datum v4);206extern HeapTuple SearchCatCache1(CatCache *cache,207								 Datum v1);208extern HeapTuple SearchCatCache2(CatCache *cache,209								 Datum v1, Datum v2);210extern HeapTuple SearchCatCache3(CatCache *cache,211								 Datum v1, Datum v2, Datum v3);212extern HeapTuple SearchCatCache4(CatCache *cache,213								 Datum v1, Datum v2, Datum v3, Datum v4);214extern void ReleaseCatCache(HeapTuple tuple);215 216extern uint32 GetCatCacheHashValue(CatCache *cache,217								   Datum v1, Datum v2,218								   Datum v3, Datum v4);219 220extern CatCList *SearchCatCacheList(CatCache *cache, int nkeys,221									Datum v1, Datum v2,222									Datum v3);223extern void ReleaseCatCacheList(CatCList *list);224 225extern void ResetCatalogCaches(void);226extern void CatalogCacheFlushCatalog(Oid catId);227extern void CatCacheInvalidate(CatCache *cache, uint32 hashValue);228extern void PrepareToInvalidateCacheTuple(Relation relation,229										  HeapTuple tuple,230										  HeapTuple newtuple,231										  void (*function) (int, uint32, Oid));232 233extern void PrintCatCacheLeakWarning(HeapTuple tuple);234extern void PrintCatCacheListLeakWarning(CatCList *list);235 236#endif							/* CATCACHE_H */237