PostgreSQL Source Code  git master
evtcache.c File Reference
#include "postgres.h"
#include "access/genam.h"
#include "access/htup_details.h"
#include "access/relation.h"
#include "catalog/pg_event_trigger.h"
#include "catalog/pg_type.h"
#include "commands/trigger.h"
#include "tcop/cmdtag.h"
#include "utils/array.h"
#include "utils/builtins.h"
#include "utils/catcache.h"
#include "utils/evtcache.h"
#include "utils/hsearch.h"
#include "utils/inval.h"
#include "utils/memutils.h"
#include "utils/rel.h"
#include "utils/snapmgr.h"
#include "utils/syscache.h"
Include dependency graph for evtcache.c:

Go to the source code of this file.

Data Structures

struct  EventTriggerCacheEntry
 

Enumerations

enum  EventTriggerCacheStateType { ETCS_NEEDS_REBUILD, ETCS_REBUILD_STARTED, ETCS_VALID }
 

Functions

static void BuildEventTriggerCache (void)
 
static void InvalidateEventCacheCallback (Datum arg, int cacheid, uint32 hashvalue)
 
static BitmapsetDecodeTextArrayToBitmapset (Datum array)
 
ListEventCacheLookup (EventTriggerEvent event)
 

Variables

static HTABEventTriggerCache
 
static MemoryContext EventTriggerCacheContext
 
static EventTriggerCacheStateType EventTriggerCacheState = ETCS_NEEDS_REBUILD
 

Enumeration Type Documentation

◆ EventTriggerCacheStateType

Enumerator
ETCS_NEEDS_REBUILD 
ETCS_REBUILD_STARTED 
ETCS_VALID 

Definition at line 34 of file evtcache.c.

Function Documentation

◆ BuildEventTriggerCache()

static void BuildEventTriggerCache ( void  )
static

Definition at line 78 of file evtcache.c.

References AccessShareLock, ALLOCSET_DEFAULT_SIZES, AllocSetContextCreate, CacheMemoryContext, CacheRegisterSyscacheCallback(), CreateCacheMemoryContext(), DecodeTextArrayToBitmapset(), EventTriggerCacheItem::enabled, HASHCTL::entrysize, ETCS_REBUILD_STARTED, ETCS_VALID, EventTriggerCacheContext, EventTriggerCacheState, EventTriggerNameIndexId, EVENTTRIGGEROID, EVT_DDLCommandEnd, EVT_DDLCommandStart, EVT_SQLDrop, EVT_TableRewrite, EventTriggerCacheItem::fnoid, ForwardScanDirection, GETSTRUCT, HASH_BLOBS, HASH_CONTEXT, hash_create(), HASH_ELEM, HASH_ENTER, hash_search(), HASHCTL::hcxt, heap_getattr, HeapTupleIsValid, index_close(), index_open(), InvalidateEventCacheCallback(), HASHCTL::keysize, lappend(), list_make1, MemoryContextResetAndDeleteChildren, MemoryContextSwitchTo(), NameStr, palloc0(), relation_close(), relation_open(), RelationGetDescr, systable_beginscan_ordered(), systable_endscan_ordered(), systable_getnext_ordered(), EventTriggerCacheItem::tagset, TRIGGER_DISABLED, and EventTriggerCacheEntry::triggerlist.

Referenced by EventCacheLookup().

79 {
80  HASHCTL ctl;
81  HTAB *cache;
82  MemoryContext oldcontext;
83  Relation rel;
84  Relation irel;
85  SysScanDesc scan;
86 
87  if (EventTriggerCacheContext != NULL)
88  {
89  /*
90  * Free up any memory already allocated in EventTriggerCacheContext.
91  * This can happen either because a previous rebuild failed, or
92  * because an invalidation happened before the rebuild was complete.
93  */
95  }
96  else
97  {
98  /*
99  * This is our first time attempting to build the cache, so we need to
100  * set up the memory context and register a syscache callback to
101  * capture future invalidation events.
102  */
103  if (CacheMemoryContext == NULL)
107  "EventTriggerCache",
111  (Datum) 0);
112  }
113 
114  /* Switch to correct memory context. */
116 
117  /* Prevent the memory context from being nuked while we're rebuilding. */
119 
120  /* Create new hash table. */
121  ctl.keysize = sizeof(EventTriggerEvent);
122  ctl.entrysize = sizeof(EventTriggerCacheEntry);
124  cache = hash_create("Event Trigger Cache", 32, &ctl,
126 
127  /*
128  * Prepare to scan pg_event_trigger in name order.
129  */
130  rel = relation_open(EventTriggerRelationId, AccessShareLock);
132  scan = systable_beginscan_ordered(rel, irel, NULL, 0, NULL);
133 
134  /*
135  * Build a cache item for each pg_event_trigger tuple, and append each one
136  * to the appropriate cache entry.
137  */
138  for (;;)
139  {
140  HeapTuple tup;
142  char *evtevent;
143  EventTriggerEvent event;
144  EventTriggerCacheItem *item;
145  Datum evttags;
146  bool evttags_isnull;
147  EventTriggerCacheEntry *entry;
148  bool found;
149 
150  /* Get next tuple. */
152  if (!HeapTupleIsValid(tup))
153  break;
154 
155  /* Skip trigger if disabled. */
156  form = (Form_pg_event_trigger) GETSTRUCT(tup);
157  if (form->evtenabled == TRIGGER_DISABLED)
158  continue;
159 
160  /* Decode event name. */
161  evtevent = NameStr(form->evtevent);
162  if (strcmp(evtevent, "ddl_command_start") == 0)
163  event = EVT_DDLCommandStart;
164  else if (strcmp(evtevent, "ddl_command_end") == 0)
165  event = EVT_DDLCommandEnd;
166  else if (strcmp(evtevent, "sql_drop") == 0)
167  event = EVT_SQLDrop;
168  else if (strcmp(evtevent, "table_rewrite") == 0)
169  event = EVT_TableRewrite;
170  else
171  continue;
172 
173  /* Allocate new cache item. */
174  item = palloc0(sizeof(EventTriggerCacheItem));
175  item->fnoid = form->evtfoid;
176  item->enabled = form->evtenabled;
177 
178  /* Decode and sort tags array. */
179  evttags = heap_getattr(tup, Anum_pg_event_trigger_evttags,
180  RelationGetDescr(rel), &evttags_isnull);
181  if (!evttags_isnull)
182  item->tagset = DecodeTextArrayToBitmapset(evttags);
183 
184  /* Add to cache entry. */
185  entry = hash_search(cache, &event, HASH_ENTER, &found);
186  if (found)
187  entry->triggerlist = lappend(entry->triggerlist, item);
188  else
189  entry->triggerlist = list_make1(item);
190  }
191 
192  /* Done with pg_event_trigger scan. */
196 
197  /* Restore previous memory context. */
198  MemoryContextSwitchTo(oldcontext);
199 
200  /* Install new cache. */
201  EventTriggerCache = cache;
202 
203  /*
204  * If the cache has been invalidated since we entered this routine, we
205  * still use and return the cache we just finished constructing, to avoid
206  * infinite loops, but we leave the cache marked stale so that we'll
207  * rebuild it again on next access. Otherwise, we mark the cache valid.
208  */
211 }
static void InvalidateEventCacheCallback(Datum arg, int cacheid, uint32 hashvalue)
Definition: evtcache.c:255
#define AllocSetContextCreate
Definition: memutils.h:173
static HTAB * EventTriggerCache
Definition: evtcache.c:47
#define GETSTRUCT(TUP)
Definition: htup_details.h:654
#define HASH_CONTEXT
Definition: hsearch.h:102
#define HASH_ELEM
Definition: hsearch.h:95
MemoryContext hcxt
Definition: hsearch.h:86
#define RelationGetDescr(relation)
Definition: rel.h:495
static MemoryContext MemoryContextSwitchTo(MemoryContext context)
Definition: palloc.h:109
#define AccessShareLock
Definition: lockdefs.h:36
Size entrysize
Definition: hsearch.h:76
static MemoryContext EventTriggerCacheContext
Definition: evtcache.c:48
void * hash_search(HTAB *hashp, const void *keyPtr, HASHACTION action, bool *foundPtr)
Definition: dynahash.c:954
HeapTuple systable_getnext_ordered(SysScanDesc sysscan, ScanDirection direction)
Definition: genam.c:707
EventTriggerEvent
Definition: evtcache.h:20
#define list_make1(x1)
Definition: pg_list.h:206
Definition: dynahash.c:219
Relation relation_open(Oid relationId, LOCKMODE lockmode)
Definition: relation.c:48
static Bitmapset * DecodeTextArrayToBitmapset(Datum array)
Definition: evtcache.c:221
#define ALLOCSET_DEFAULT_SIZES
Definition: memutils.h:195
HTAB * hash_create(const char *tabname, long nelem, const HASHCTL *info, int flags)
Definition: dynahash.c:349
static EventTriggerCacheStateType EventTriggerCacheState
Definition: evtcache.c:49
List * lappend(List *list, void *datum)
Definition: list.c:336
#define heap_getattr(tup, attnum, tupleDesc, isnull)
Definition: htup_details.h:761
#define MemoryContextResetAndDeleteChildren(ctx)
Definition: memutils.h:67
#define HASH_BLOBS
Definition: hsearch.h:97
void CacheRegisterSyscacheCallback(int cacheid, SyscacheCallbackFunction func, Datum arg)
Definition: inval.c:1435
void * palloc0(Size size)
Definition: mcxt.c:1093
#define TRIGGER_DISABLED
Definition: trigger.h:151
uintptr_t Datum
Definition: postgres.h:411
void systable_endscan_ordered(SysScanDesc sysscan)
Definition: genam.c:732
Size keysize
Definition: hsearch.h:75
#define EventTriggerNameIndexId
FormData_pg_event_trigger * Form_pg_event_trigger
#define HeapTupleIsValid(tuple)
Definition: htup.h:78
void relation_close(Relation relation, LOCKMODE lockmode)
Definition: relation.c:206
void CreateCacheMemoryContext(void)
Definition: catcache.c:620
void index_close(Relation relation, LOCKMODE lockmode)
Definition: indexam.c:158
Bitmapset * tagset
Definition: evtcache.h:32
SysScanDesc systable_beginscan_ordered(Relation heapRelation, Relation indexRelation, Snapshot snapshot, int nkeys, ScanKey key)
Definition: genam.c:642
#define NameStr(name)
Definition: c.h:681
Relation index_open(Oid relationId, LOCKMODE lockmode)
Definition: indexam.c:132
MemoryContext CacheMemoryContext
Definition: mcxt.c:51

◆ DecodeTextArrayToBitmapset()

static Bitmapset * DecodeTextArrayToBitmapset ( Datum  array)
static

Definition at line 221 of file evtcache.c.

References ARR_ELEMTYPE, ARR_HASNULL, ARR_NDIM, bms_add_member(), DatumGetArrayTypeP, deconstruct_array(), elog, ERROR, GetCommandTagEnum(), i, pfree(), generate_unaccent_rules::str, and TextDatumGetCString.

Referenced by BuildEventTriggerCache().

222 {
223  ArrayType *arr = DatumGetArrayTypeP(array);
224  Datum *elems;
225  Bitmapset *bms;
226  int i;
227  int nelems;
228 
229  if (ARR_NDIM(arr) != 1 || ARR_HASNULL(arr) || ARR_ELEMTYPE(arr) != TEXTOID)
230  elog(ERROR, "expected 1-D text array");
231  deconstruct_array(arr, TEXTOID, -1, false, TYPALIGN_INT,
232  &elems, NULL, &nelems);
233 
234  for (bms = NULL, i = 0; i < nelems; ++i)
235  {
236  char *str = TextDatumGetCString(elems[i]);
237 
238  bms = bms_add_member(bms, GetCommandTagEnum(str));
239  pfree(str);
240  }
241 
242  pfree(elems);
243 
244  return bms;
245 }
void pfree(void *pointer)
Definition: mcxt.c:1169
#define ERROR
Definition: elog.h:46
#define ARR_HASNULL(a)
Definition: array.h:284
#define TextDatumGetCString(d)
Definition: builtins.h:83
uintptr_t Datum
Definition: postgres.h:411
Bitmapset * bms_add_member(Bitmapset *a, int x)
Definition: bitmapset.c:736
#define ARR_NDIM(a)
Definition: array.h:283
CommandTag GetCommandTagEnum(const char *commandname)
Definition: cmdtag.c:74
void deconstruct_array(ArrayType *array, Oid elmtype, int elmlen, bool elmbyval, char elmalign, Datum **elemsp, bool **nullsp, int *nelemsp)
Definition: arrayfuncs.c:3490
#define elog(elevel,...)
Definition: elog.h:232
int i
#define ARR_ELEMTYPE(a)
Definition: array.h:285
#define DatumGetArrayTypeP(X)
Definition: array.h:254

◆ EventCacheLookup()

List* EventCacheLookup ( EventTriggerEvent  event)

Definition at line 64 of file evtcache.c.

References BuildEventTriggerCache(), ETCS_VALID, EventTriggerCacheState, HASH_FIND, hash_search(), NIL, and EventTriggerCacheEntry::triggerlist.

Referenced by EventTriggerCommonSetup(), and trackDroppedObjectsNeeded().

65 {
67 
70  entry = hash_search(EventTriggerCache, &event, HASH_FIND, NULL);
71  return entry != NULL ? entry->triggerlist : NIL;
72 }
#define NIL
Definition: pg_list.h:65
static HTAB * EventTriggerCache
Definition: evtcache.c:47
void * hash_search(HTAB *hashp, const void *keyPtr, HASHACTION action, bool *foundPtr)
Definition: dynahash.c:954
static void BuildEventTriggerCache(void)
Definition: evtcache.c:78
static EventTriggerCacheStateType EventTriggerCacheState
Definition: evtcache.c:49

◆ InvalidateEventCacheCallback()

static void InvalidateEventCacheCallback ( Datum  arg,
int  cacheid,
uint32  hashvalue 
)
static

Definition at line 255 of file evtcache.c.

References ETCS_NEEDS_REBUILD, ETCS_VALID, EventTriggerCacheState, and MemoryContextResetAndDeleteChildren.

Referenced by BuildEventTriggerCache().

256 {
257  /*
258  * If the cache isn't valid, then there might be a rebuild in progress, so
259  * we can't immediately blow it away. But it's advantageous to do this
260  * when possible, so as to immediately free memory.
261  */
263  {
265  EventTriggerCache = NULL;
266  }
267 
268  /* Mark cache for rebuild. */
270 }
static HTAB * EventTriggerCache
Definition: evtcache.c:47
static MemoryContext EventTriggerCacheContext
Definition: evtcache.c:48
static EventTriggerCacheStateType EventTriggerCacheState
Definition: evtcache.c:49
#define MemoryContextResetAndDeleteChildren(ctx)
Definition: memutils.h:67

Variable Documentation

◆ EventTriggerCache

HTAB* EventTriggerCache
static

Definition at line 47 of file evtcache.c.

◆ EventTriggerCacheContext

MemoryContext EventTriggerCacheContext
static

Definition at line 48 of file evtcache.c.

Referenced by BuildEventTriggerCache().

◆ EventTriggerCacheState

EventTriggerCacheStateType EventTriggerCacheState = ETCS_NEEDS_REBUILD
static