| /*------------------------------------------------------------------------- |
| * |
| * catcache.h |
| * Low-level catalog cache definitions. |
| * |
| * NOTE: every catalog cache must have a corresponding unique index on |
| * the system table that it caches --- ie, the index must match the keys |
| * used to do lookups in this cache. All cache fetches are done with |
| * indexscans (under normal conditions). The index should be unique to |
| * guarantee that there can only be one matching row for a key combination. |
| * |
| * |
| * Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group |
| * Portions Copyright (c) 1994, Regents of the University of California |
| * |
| * $PostgreSQL: pgsql/src/include/utils/catcache.h,v 1.73 2010/02/26 02:01:29 momjian Exp $ |
| * |
| *------------------------------------------------------------------------- |
| */ |
| #ifndef CATCACHE_H |
| #define CATCACHE_H |
| |
| #include "access/htup.h" |
| #include "access/skey.h" |
| #include "lib/dllist.h" |
| #include "utils/relcache.h" |
| |
| /* |
| * struct catctup: individual tuple in the cache. |
| * struct catclist: list of tuples matching a partial key. |
| * struct catcache: information for managing a cache. |
| * struct catcacheheader: information for managing all the caches. |
| */ |
| |
| #define CATCACHE_MAXKEYS 4 |
| |
| typedef struct catcache |
| { |
| int id; /* cache identifier --- see syscache.h */ |
| struct catcache *cc_next; /* link to next catcache */ |
| const char *cc_relname; /* name of relation the tuples come from */ |
| Oid cc_reloid; /* OID of relation the tuples come from */ |
| Oid cc_indexoid; /* OID of index matching cache keys */ |
| bool cc_relisshared; /* is relation shared across databases? */ |
| TupleDesc cc_tupdesc; /* tuple descriptor (copied from reldesc) */ |
| int cc_ntup; /* # of tuples currently in this cache */ |
| int cc_nbuckets; /* # of hash buckets in this cache */ |
| int cc_nkeys; /* # of keys (1..CATCACHE_MAXKEYS) */ |
| int cc_key[CATCACHE_MAXKEYS]; /* AttrNumber of each key */ |
| PGFunction cc_hashfunc[CATCACHE_MAXKEYS]; /* hash function for each key */ |
| ScanKeyData cc_skey[CATCACHE_MAXKEYS]; /* precomputed key info for |
| * heap scans */ |
| bool cc_isname[CATCACHE_MAXKEYS]; /* flag "name" key columns */ |
| Dllist cc_lists; /* list of CatCList structs */ |
| #ifdef CATCACHE_STATS |
| long cc_searches; /* total # searches against this cache */ |
| long cc_hits; /* # of matches against existing entry */ |
| long cc_neg_hits; /* # of matches against negative entry */ |
| long cc_newloads; /* # of successful loads of new entry */ |
| |
| /* |
| * cc_searches - (cc_hits + cc_neg_hits + cc_newloads) is number of failed |
| * searches, each of which will result in loading a negative entry |
| */ |
| long cc_invals; /* # of entries invalidated from cache */ |
| long cc_lsearches; /* total # list-searches */ |
| long cc_lhits; /* # of matches against existing lists */ |
| #endif |
| Dllist cc_bucket[1]; /* hash buckets --- VARIABLE LENGTH ARRAY */ |
| } CatCache; /* VARIABLE LENGTH STRUCT */ |
| |
| |
| typedef struct catctup |
| { |
| int ct_magic; /* for identifying CatCTup entries */ |
| #define CT_MAGIC 0x57261502 |
| CatCache *my_cache; /* link to owning catcache */ |
| |
| /* |
| * Each tuple in a cache is a member of a Dllist that stores the elements |
| * of its hash bucket. We keep each Dllist in LRU order to speed repeated |
| * lookups. |
| */ |
| Dlelem cache_elem; /* list member of per-bucket list */ |
| |
| /* |
| * The tuple may also be a member of at most one CatCList. (If a single |
| * catcache is list-searched with varying numbers of keys, we may have to |
| * make multiple entries for the same tuple because of this restriction. |
| * Currently, that's not expected to be common, so we accept the potential |
| * inefficiency.) |
| */ |
| struct catclist *c_list; /* containing CatCList, or NULL if none */ |
| |
| /* |
| * A tuple marked "dead" must not be returned by subsequent searches. |
| * However, it won't be physically deleted from the cache until its |
| * refcount goes to zero. (If it's a member of a CatCList, the list's |
| * refcount must go to zero, too; also, remember to mark the list dead at |
| * the same time the tuple is marked.) |
| * |
| * A negative cache entry is an assertion that there is no tuple matching |
| * a particular key. This is just as useful as a normal entry so far as |
| * avoiding catalog searches is concerned. Management of positive and |
| * negative entries is identical. |
| */ |
| int refcount; /* number of active references */ |
| bool dead; /* dead but not yet removed? */ |
| bool negative; /* negative cache entry? */ |
| uint32 hash_value; /* hash value for this tuple's keys */ |
| HeapTupleData tuple; /* tuple management header */ |
| } CatCTup; |
| |
| |
| typedef struct catclist |
| { |
| int cl_magic; /* for identifying CatCList entries */ |
| #define CL_MAGIC 0x52765103 |
| CatCache *my_cache; /* link to owning catcache */ |
| |
| /* |
| * A CatCList describes the result of a partial search, ie, a search using |
| * only the first K key columns of an N-key cache. We form the keys used |
| * into a tuple (with other attributes NULL) to represent the stored key |
| * set. The CatCList object contains links to cache entries for all the |
| * table rows satisfying the partial key. (Note: none of these will be |
| * negative cache entries.) |
| * |
| * A CatCList is only a member of a per-cache list; we do not currently |
| * divide them into hash buckets. |
| * |
| * A list marked "dead" must not be returned by subsequent searches. |
| * However, it won't be physically deleted from the cache until its |
| * refcount goes to zero. (A list should be marked dead if any of its |
| * member entries are dead.) |
| * |
| * If "ordered" is true then the member tuples appear in the order of the |
| * cache's underlying index. This will be true in normal operation, but |
| * might not be true during bootstrap or recovery operations. (namespace.c |
| * is able to save some cycles when it is true.) |
| */ |
| Dlelem cache_elem; /* list member of per-catcache list */ |
| int refcount; /* number of active references */ |
| bool dead; /* dead but not yet removed? */ |
| bool ordered; /* members listed in index order? */ |
| short nkeys; /* number of lookup keys specified */ |
| uint32 hash_value; /* hash value for lookup keys */ |
| HeapTupleData tuple; /* header for tuple holding keys */ |
| int n_members; /* number of member tuples */ |
| CatCTup *members[1]; /* members --- VARIABLE LENGTH ARRAY */ |
| } CatCList; /* VARIABLE LENGTH STRUCT */ |
| |
| |
| typedef struct catcacheheader |
| { |
| CatCache *ch_caches; /* head of list of CatCache structs */ |
| int ch_ntup; /* # of tuples in all caches */ |
| } CatCacheHeader; |
| |
| |
| /* this extern duplicates utils/memutils.h... */ |
| extern PGDLLIMPORT MemoryContext CacheMemoryContext; |
| |
| extern void CreateCacheMemoryContext(void); |
| extern void AtEOXact_CatCache(bool isCommit); |
| |
| extern CatCache *InitCatCache(int id, Oid reloid, Oid indexoid, |
| int nkeys, const int *key, |
| int nbuckets); |
| extern void InitCatCachePhase2(CatCache *cache, bool touch_index); |
| |
| extern HeapTuple SearchCatCache(CatCache *cache, |
| Datum v1, Datum v2, |
| Datum v3, Datum v4); |
| extern void ReleaseCatCache(HeapTuple tuple); |
| |
| extern CatCList *SearchCatCacheList(CatCache *cache, int nkeys, |
| Datum v1, Datum v2, |
| Datum v3, Datum v4); |
| extern void ReleaseCatCacheList(CatCList *list); |
| |
| extern void ResetCatalogCaches(void); |
| extern void CatalogCacheFlushCatalog(Oid catId); |
| extern void CatalogCacheIdInvalidate(int cacheId, uint32 hashValue, |
| ItemPointer pointer); |
| extern void PrepareToInvalidateCacheTuple(Relation relation, |
| HeapTuple tuple, |
| SysCacheInvalidateAction action, |
| void (*function) (int, uint32, ItemPointer, Oid, SysCacheInvalidateAction)); |
| |
| extern void PrintCatCacheLeakWarning(HeapTuple tuple, const char *resOwnerName); |
| extern void PrintCatCacheListLeakWarning(CatCList *list, const char *resOwnerName); |
| |
| #endif /* CATCACHE_H */ |