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dynahash.c File Reference
#include "postgres.h"
#include <limits.h>
#include "access/xact.h"
#include "storage/shmem.h"
#include "storage/spin.h"
#include "utils/dynahash.h"
#include "utils/memutils.h"
Include dependency graph for dynahash.c:

Go to the source code of this file.

Data Structures

struct  FreeListData
 
struct  HASHHDR
 
struct  HTAB
 

Macros

#define DEF_SEGSIZE   256
 
#define DEF_SEGSIZE_SHIFT   8 /* must be log2(DEF_SEGSIZE) */
 
#define DEF_DIRSIZE   256
 
#define DEF_FFACTOR   1 /* default fill factor */
 
#define NUM_FREELISTS   32
 
#define IS_PARTITIONED(hctl)   ((hctl)->num_partitions != 0)
 
#define FREELIST_IDX(hctl, hashcode)   (IS_PARTITIONED(hctl) ? (hashcode) % NUM_FREELISTS : 0)
 
#define ELEMENTKEY(helem)   (((char *)(helem)) + MAXALIGN(sizeof(HASHELEMENT)))
 
#define ELEMENT_FROM_KEY(key)   ((HASHELEMENT *) (((char *) (key)) - MAXALIGN(sizeof(HASHELEMENT))))
 
#define MOD(x, y)   ((x) & ((y)-1))
 
#define MAX_SEQ_SCANS   100
 

Typedefs

typedef HASHELEMENTHASHBUCKET
 
typedef HASHBUCKETHASHSEGMENT
 

Functions

static void * DynaHashAlloc (Size size)
 
static HASHSEGMENT seg_alloc (HTAB *hashp)
 
static bool element_alloc (HTAB *hashp, int nelem, int freelist_idx)
 
static bool dir_realloc (HTAB *hashp)
 
static bool expand_table (HTAB *hashp)
 
static HASHBUCKET get_hash_entry (HTAB *hashp, int freelist_idx)
 
static void hdefault (HTAB *hashp)
 
static int choose_nelem_alloc (Size entrysize)
 
static bool init_htab (HTAB *hashp, long nelem)
 
static void hash_corrupted (HTAB *hashp)
 
static long next_pow2_long (long num)
 
static int next_pow2_int (long num)
 
static void register_seq_scan (HTAB *hashp)
 
static void deregister_seq_scan (HTAB *hashp)
 
static bool has_seq_scans (HTAB *hashp)
 
static int string_compare (const char *key1, const char *key2, Size keysize)
 
HTABhash_create (const char *tabname, long nelem, HASHCTL *info, int flags)
 
Size hash_estimate_size (long num_entries, Size entrysize)
 
long hash_select_dirsize (long num_entries)
 
Size hash_get_shared_size (HASHCTL *info, int flags)
 
void hash_destroy (HTAB *hashp)
 
void hash_stats (const char *where, HTAB *hashp)
 
uint32 get_hash_value (HTAB *hashp, const void *keyPtr)
 
static uint32 calc_bucket (HASHHDR *hctl, uint32 hash_val)
 
void * hash_search (HTAB *hashp, const void *keyPtr, HASHACTION action, bool *foundPtr)
 
void * hash_search_with_hash_value (HTAB *hashp, const void *keyPtr, uint32 hashvalue, HASHACTION action, bool *foundPtr)
 
bool hash_update_hash_key (HTAB *hashp, void *existingEntry, const void *newKeyPtr)
 
long hash_get_num_entries (HTAB *hashp)
 
void hash_seq_init (HASH_SEQ_STATUS *status, HTAB *hashp)
 
void * hash_seq_search (HASH_SEQ_STATUS *status)
 
void hash_seq_term (HASH_SEQ_STATUS *status)
 
void hash_freeze (HTAB *hashp)
 
int my_log2 (long num)
 
void AtEOXact_HashTables (bool isCommit)
 
void AtEOSubXact_HashTables (bool isCommit, int nestDepth)
 

Variables

static MemoryContext CurrentDynaHashCxt = NULL
 
static HTABseq_scan_tables [MAX_SEQ_SCANS]
 
static int seq_scan_level [MAX_SEQ_SCANS]
 
static int num_seq_scans = 0
 

Macro Definition Documentation

#define DEF_DIRSIZE   256

Definition at line 112 of file dynahash.c.

Referenced by hash_estimate_size(), hash_select_dirsize(), and hdefault().

#define DEF_FFACTOR   1 /* default fill factor */

Definition at line 113 of file dynahash.c.

Referenced by hash_estimate_size(), hash_select_dirsize(), and hdefault().

#define DEF_SEGSIZE   256

Definition at line 110 of file dynahash.c.

Referenced by hash_estimate_size(), hash_select_dirsize(), and hdefault().

#define DEF_SEGSIZE_SHIFT   8 /* must be log2(DEF_SEGSIZE) */

Definition at line 111 of file dynahash.c.

Referenced by hdefault().

#define ELEMENT_FROM_KEY (   key)    ((HASHELEMENT *) (((char *) (key)) - MAXALIGN(sizeof(HASHELEMENT))))

Definition at line 238 of file dynahash.c.

Referenced by hash_update_hash_key().

#define ELEMENTKEY (   helem)    (((char *)(helem)) + MAXALIGN(sizeof(HASHELEMENT)))

Definition at line 233 of file dynahash.c.

Referenced by hash_search_with_hash_value(), hash_seq_search(), and hash_update_hash_key().

#define FREELIST_IDX (   hctl,
  hashcode 
)    (IS_PARTITIONED(hctl) ? (hashcode) % NUM_FREELISTS : 0)

Definition at line 201 of file dynahash.c.

Referenced by hash_search_with_hash_value().

#define IS_PARTITIONED (   hctl)    ((hctl)->num_partitions != 0)
#define MAX_SEQ_SCANS   100

Definition at line 1775 of file dynahash.c.

Referenced by register_seq_scan().

#define MOD (   x,
 
)    ((x) & ((y)-1))
#define NUM_FREELISTS   32

Definition at line 116 of file dynahash.c.

Referenced by get_hash_entry(), hash_create(), hash_get_num_entries(), and init_htab().

Typedef Documentation

Definition at line 119 of file dynahash.c.

Definition at line 122 of file dynahash.c.

Function Documentation

void AtEOSubXact_HashTables ( bool  isCommit,
int  nestDepth 
)

Definition at line 1857 of file dynahash.c.

References elog, i, num_seq_scans, seq_scan_level, and WARNING.

Referenced by AbortSubTransaction(), and CommitSubTransaction().

1858 {
1859  int i;
1860 
1861  /*
1862  * Search backward to make cleanup easy. Note we must check all entries,
1863  * not only those at the end of the array, because deletion technique
1864  * doesn't keep them in order.
1865  */
1866  for (i = num_seq_scans - 1; i >= 0; i--)
1867  {
1868  if (seq_scan_level[i] >= nestDepth)
1869  {
1870  if (isCommit)
1871  elog(WARNING, "leaked hash_seq_search scan for hash table %p",
1872  seq_scan_tables[i]);
1875  num_seq_scans--;
1876  }
1877  }
1878 }
static int seq_scan_level[MAX_SEQ_SCANS]
Definition: dynahash.c:1778
#define WARNING
Definition: elog.h:40
static int num_seq_scans
Definition: dynahash.c:1779
static HTAB * seq_scan_tables[MAX_SEQ_SCANS]
Definition: dynahash.c:1777
int i
#define elog
Definition: elog.h:219
void AtEOXact_HashTables ( bool  isCommit)

Definition at line 1831 of file dynahash.c.

References elog, i, num_seq_scans, and WARNING.

Referenced by AbortTransaction(), BackgroundWriterMain(), CheckpointerMain(), CommitTransaction(), PrepareTransaction(), and WalWriterMain().

1832 {
1833  /*
1834  * During abort cleanup, open scans are expected; just silently clean 'em
1835  * out. An open scan at commit means someone forgot a hash_seq_term()
1836  * call, so complain.
1837  *
1838  * Note: it's tempting to try to print the tabname here, but refrain for
1839  * fear of touching deallocated memory. This isn't a user-facing message
1840  * anyway, so it needn't be pretty.
1841  */
1842  if (isCommit)
1843  {
1844  int i;
1845 
1846  for (i = 0; i < num_seq_scans; i++)
1847  {
1848  elog(WARNING, "leaked hash_seq_search scan for hash table %p",
1849  seq_scan_tables[i]);
1850  }
1851  }
1852  num_seq_scans = 0;
1853 }
#define WARNING
Definition: elog.h:40
static int num_seq_scans
Definition: dynahash.c:1779
static HTAB * seq_scan_tables[MAX_SEQ_SCANS]
Definition: dynahash.c:1777
int i
#define elog
Definition: elog.h:219
static uint32 calc_bucket ( HASHHDR hctl,
uint32  hash_val 
)
inlinestatic

Definition at line 864 of file dynahash.c.

References HASHHDR::high_mask, HASHHDR::low_mask, and HASHHDR::max_bucket.

Referenced by expand_table(), hash_search_with_hash_value(), and hash_update_hash_key().

865 {
866  uint32 bucket;
867 
868  bucket = hash_val & hctl->high_mask;
869  if (bucket > hctl->max_bucket)
870  bucket = bucket & hctl->low_mask;
871 
872  return bucket;
873 }
uint32 max_bucket
Definition: dynahash.c:174
uint32 low_mask
Definition: dynahash.c:176
unsigned int uint32
Definition: c.h:268
uint32 high_mask
Definition: dynahash.c:175
static int choose_nelem_alloc ( Size  entrysize)
static

Definition at line 599 of file dynahash.c.

References MAXALIGN.

Referenced by hash_estimate_size(), and init_htab().

600 {
601  int nelem_alloc;
602  Size elementSize;
603  Size allocSize;
604 
605  /* Each element has a HASHELEMENT header plus user data. */
606  /* NB: this had better match element_alloc() */
607  elementSize = MAXALIGN(sizeof(HASHELEMENT)) + MAXALIGN(entrysize);
608 
609  /*
610  * The idea here is to choose nelem_alloc at least 32, but round up so
611  * that the allocation request will be a power of 2 or just less. This
612  * makes little difference for hash tables in shared memory, but for hash
613  * tables managed by palloc, the allocation request will be rounded up to
614  * a power of 2 anyway. If we fail to take this into account, we'll waste
615  * as much as half the allocated space.
616  */
617  allocSize = 32 * 4; /* assume elementSize at least 8 */
618  do
619  {
620  allocSize <<= 1;
621  nelem_alloc = allocSize / elementSize;
622  } while (nelem_alloc < 32);
623 
624  return nelem_alloc;
625 }
size_t Size
Definition: c.h:356
#define MAXALIGN(LEN)
Definition: c.h:588
static void deregister_seq_scan ( HTAB hashp)
static

Definition at line 1796 of file dynahash.c.

References elog, ERROR, i, num_seq_scans, seq_scan_level, and HTAB::tabname.

Referenced by hash_seq_term().

1797 {
1798  int i;
1799 
1800  /* Search backward since it's most likely at the stack top */
1801  for (i = num_seq_scans - 1; i >= 0; i--)
1802  {
1803  if (seq_scan_tables[i] == hashp)
1804  {
1807  num_seq_scans--;
1808  return;
1809  }
1810  }
1811  elog(ERROR, "no hash_seq_search scan for hash table \"%s\"",
1812  hashp->tabname);
1813 }
static int seq_scan_level[MAX_SEQ_SCANS]
Definition: dynahash.c:1778
#define ERROR
Definition: elog.h:43
static int num_seq_scans
Definition: dynahash.c:1779
static HTAB * seq_scan_tables[MAX_SEQ_SCANS]
Definition: dynahash.c:1777
char * tabname
Definition: dynahash.c:217
int i
#define elog
Definition: elog.h:219
static bool dir_realloc ( HTAB hashp)
static

Definition at line 1596 of file dynahash.c.

References HTAB::alloc, Assert, HTAB::dir, HASHHDR::dsize, DynaHashAlloc(), HTAB::hctl, HTAB::hcxt, HASHHDR::max_dsize, MemSet, NO_MAX_DSIZE, NULL, and pfree().

Referenced by expand_table().

1597 {
1598  HASHSEGMENT *p;
1599  HASHSEGMENT *old_p;
1600  long new_dsize;
1601  long old_dirsize;
1602  long new_dirsize;
1603 
1604  if (hashp->hctl->max_dsize != NO_MAX_DSIZE)
1605  return false;
1606 
1607  /* Reallocate directory */
1608  new_dsize = hashp->hctl->dsize << 1;
1609  old_dirsize = hashp->hctl->dsize * sizeof(HASHSEGMENT);
1610  new_dirsize = new_dsize * sizeof(HASHSEGMENT);
1611 
1612  old_p = hashp->dir;
1613  CurrentDynaHashCxt = hashp->hcxt;
1614  p = (HASHSEGMENT *) hashp->alloc((Size) new_dirsize);
1615 
1616  if (p != NULL)
1617  {
1618  memcpy(p, old_p, old_dirsize);
1619  MemSet(((char *) p) + old_dirsize, 0, new_dirsize - old_dirsize);
1620  hashp->dir = p;
1621  hashp->hctl->dsize = new_dsize;
1622 
1623  /* XXX assume the allocator is palloc, so we know how to free */
1624  Assert(hashp->alloc == DynaHashAlloc);
1625  pfree(old_p);
1626 
1627  return true;
1628  }
1629 
1630  return false;
1631 }
long dsize
Definition: dynahash.c:172
#define NO_MAX_DSIZE
Definition: hsearch.h:100
HashAllocFunc alloc
Definition: dynahash.c:215
#define MemSet(start, val, len)
Definition: c.h:857
void pfree(void *pointer)
Definition: mcxt.c:950
HASHBUCKET * HASHSEGMENT
Definition: dynahash.c:122
long max_dsize
Definition: dynahash.c:183
HASHHDR * hctl
Definition: dynahash.c:210
MemoryContext hcxt
Definition: dynahash.c:216
#define NULL
Definition: c.h:229
#define Assert(condition)
Definition: c.h:675
size_t Size
Definition: c.h:356
static void * DynaHashAlloc(Size size)
Definition: dynahash.c:278
static MemoryContext CurrentDynaHashCxt
Definition: dynahash.c:275
HASHSEGMENT * dir
Definition: dynahash.c:211
static void * DynaHashAlloc ( Size  size)
static

Definition at line 278 of file dynahash.c.

References Assert, MemoryContextAlloc(), and MemoryContextIsValid.

Referenced by dir_realloc(), hash_create(), hash_destroy(), and hash_search_with_hash_value().

279 {
282 }
#define MemoryContextIsValid(context)
Definition: memnodes.h:97
#define Assert(condition)
Definition: c.h:675
void * MemoryContextAlloc(MemoryContext context, Size size)
Definition: mcxt.c:707
static MemoryContext CurrentDynaHashCxt
Definition: dynahash.c:275
static bool element_alloc ( HTAB hashp,
int  nelem,
int  freelist_idx 
)
static

Definition at line 1654 of file dynahash.c.

References HTAB::alloc, HASHHDR::entrysize, FreeListData::freeList, HASHHDR::freeList, HTAB::hctl, HTAB::hcxt, i, IS_PARTITIONED, HTAB::isfixed, HASHELEMENT::link, MAXALIGN, FreeListData::mutex, NULL, SpinLockAcquire, and SpinLockRelease.

Referenced by get_hash_entry(), and hash_create().

1655 {
1656  HASHHDR *hctl = hashp->hctl;
1657  Size elementSize;
1658  HASHELEMENT *firstElement;
1659  HASHELEMENT *tmpElement;
1660  HASHELEMENT *prevElement;
1661  int i;
1662 
1663  if (hashp->isfixed)
1664  return false;
1665 
1666  /* Each element has a HASHELEMENT header plus user data. */
1667  elementSize = MAXALIGN(sizeof(HASHELEMENT)) + MAXALIGN(hctl->entrysize);
1668 
1669  CurrentDynaHashCxt = hashp->hcxt;
1670  firstElement = (HASHELEMENT *) hashp->alloc(nelem * elementSize);
1671 
1672  if (!firstElement)
1673  return false;
1674 
1675  /* prepare to link all the new entries into the freelist */
1676  prevElement = NULL;
1677  tmpElement = firstElement;
1678  for (i = 0; i < nelem; i++)
1679  {
1680  tmpElement->link = prevElement;
1681  prevElement = tmpElement;
1682  tmpElement = (HASHELEMENT *) (((char *) tmpElement) + elementSize);
1683  }
1684 
1685  /* if partitioned, must lock to touch freeList */
1686  if (IS_PARTITIONED(hctl))
1687  SpinLockAcquire(&hctl->freeList[freelist_idx].mutex);
1688 
1689  /* freelist could be nonempty if two backends did this concurrently */
1690  firstElement->link = hctl->freeList[freelist_idx].freeList;
1691  hctl->freeList[freelist_idx].freeList = prevElement;
1692 
1693  if (IS_PARTITIONED(hctl))
1694  SpinLockRelease(&hctl->freeList[freelist_idx].mutex);
1695 
1696  return true;
1697 }
Size entrysize
Definition: dynahash.c:180
#define IS_PARTITIONED(hctl)
Definition: dynahash.c:199
HashAllocFunc alloc
Definition: dynahash.c:215
slock_t mutex
Definition: dynahash.c:143
#define SpinLockAcquire(lock)
Definition: spin.h:62
HASHHDR * hctl
Definition: dynahash.c:210
#define SpinLockRelease(lock)
Definition: spin.h:64
FreeListData freeList[NUM_FREELISTS]
Definition: dynahash.c:168
MemoryContext hcxt
Definition: dynahash.c:216
#define NULL
Definition: c.h:229
size_t Size
Definition: c.h:356
#define MAXALIGN(LEN)
Definition: c.h:588
bool isfixed
Definition: dynahash.c:219
struct HASHELEMENT * link
Definition: hsearch.h:53
static MemoryContext CurrentDynaHashCxt
Definition: dynahash.c:275
int i
HASHELEMENT * freeList
Definition: dynahash.c:145
static bool expand_table ( HTAB hashp)
static

Definition at line 1499 of file dynahash.c.

References Assert, calc_bucket(), HTAB::dir, dir_realloc(), HASHHDR::dsize, HASHELEMENT::hashvalue, HTAB::hctl, HASHHDR::high_mask, IS_PARTITIONED, HASHELEMENT::link, HASHHDR::low_mask, HASHHDR::max_bucket, MOD, HASHHDR::nsegs, NULL, seg_alloc(), HTAB::sshift, and HTAB::ssize.

Referenced by hash_search_with_hash_value().

1500 {
1501  HASHHDR *hctl = hashp->hctl;
1502  HASHSEGMENT old_seg,
1503  new_seg;
1504  long old_bucket,
1505  new_bucket;
1506  long new_segnum,
1507  new_segndx;
1508  long old_segnum,
1509  old_segndx;
1510  HASHBUCKET *oldlink,
1511  *newlink;
1512  HASHBUCKET currElement,
1513  nextElement;
1514 
1515  Assert(!IS_PARTITIONED(hctl));
1516 
1517 #ifdef HASH_STATISTICS
1518  hash_expansions++;
1519 #endif
1520 
1521  new_bucket = hctl->max_bucket + 1;
1522  new_segnum = new_bucket >> hashp->sshift;
1523  new_segndx = MOD(new_bucket, hashp->ssize);
1524 
1525  if (new_segnum >= hctl->nsegs)
1526  {
1527  /* Allocate new segment if necessary -- could fail if dir full */
1528  if (new_segnum >= hctl->dsize)
1529  if (!dir_realloc(hashp))
1530  return false;
1531  if (!(hashp->dir[new_segnum] = seg_alloc(hashp)))
1532  return false;
1533  hctl->nsegs++;
1534  }
1535 
1536  /* OK, we created a new bucket */
1537  hctl->max_bucket++;
1538 
1539  /*
1540  * *Before* changing masks, find old bucket corresponding to same hash
1541  * values; values in that bucket may need to be relocated to new bucket.
1542  * Note that new_bucket is certainly larger than low_mask at this point,
1543  * so we can skip the first step of the regular hash mask calc.
1544  */
1545  old_bucket = (new_bucket & hctl->low_mask);
1546 
1547  /*
1548  * If we crossed a power of 2, readjust masks.
1549  */
1550  if ((uint32) new_bucket > hctl->high_mask)
1551  {
1552  hctl->low_mask = hctl->high_mask;
1553  hctl->high_mask = (uint32) new_bucket | hctl->low_mask;
1554  }
1555 
1556  /*
1557  * Relocate records to the new bucket. NOTE: because of the way the hash
1558  * masking is done in calc_bucket, only one old bucket can need to be
1559  * split at this point. With a different way of reducing the hash value,
1560  * that might not be true!
1561  */
1562  old_segnum = old_bucket >> hashp->sshift;
1563  old_segndx = MOD(old_bucket, hashp->ssize);
1564 
1565  old_seg = hashp->dir[old_segnum];
1566  new_seg = hashp->dir[new_segnum];
1567 
1568  oldlink = &old_seg[old_segndx];
1569  newlink = &new_seg[new_segndx];
1570 
1571  for (currElement = *oldlink;
1572  currElement != NULL;
1573  currElement = nextElement)
1574  {
1575  nextElement = currElement->link;
1576  if ((long) calc_bucket(hctl, currElement->hashvalue) == old_bucket)
1577  {
1578  *oldlink = currElement;
1579  oldlink = &currElement->link;
1580  }
1581  else
1582  {
1583  *newlink = currElement;
1584  newlink = &currElement->link;
1585  }
1586  }
1587  /* don't forget to terminate the rebuilt hash chains... */
1588  *oldlink = NULL;
1589  *newlink = NULL;
1590 
1591  return true;
1592 }
long dsize
Definition: dynahash.c:172
uint32 max_bucket
Definition: dynahash.c:174
static uint32 calc_bucket(HASHHDR *hctl, uint32 hash_val)
Definition: dynahash.c:864
#define IS_PARTITIONED(hctl)
Definition: dynahash.c:199
uint32 low_mask
Definition: dynahash.c:176
long ssize
Definition: dynahash.c:226
int sshift
Definition: dynahash.c:227
#define MOD(x, y)
Definition: dynahash.c:244
HASHHDR * hctl
Definition: dynahash.c:210
unsigned int uint32
Definition: c.h:268
uint32 high_mask
Definition: dynahash.c:175
#define NULL
Definition: c.h:229
#define Assert(condition)
Definition: c.h:675
static HASHSEGMENT seg_alloc(HTAB *hashp)
Definition: dynahash.c:1635
struct HASHELEMENT * link
Definition: hsearch.h:53
HASHSEGMENT * dir
Definition: dynahash.c:211
static bool dir_realloc(HTAB *hashp)
Definition: dynahash.c:1596
uint32 hashvalue
Definition: hsearch.h:54
long nsegs
Definition: dynahash.c:173
static HASHBUCKET get_hash_entry ( HTAB hashp,
int  freelist_idx 
)
static

Definition at line 1247 of file dynahash.c.

References element_alloc(), FreeListData::freeList, HASHHDR::freeList, HTAB::hctl, IS_PARTITIONED, HASHELEMENT::link, FreeListData::mutex, HASHHDR::nelem_alloc, FreeListData::nentries, NULL, NUM_FREELISTS, SpinLockAcquire, and SpinLockRelease.

Referenced by hash_search_with_hash_value().

1248 {
1249  HASHHDR *hctl = hashp->hctl;
1250  HASHBUCKET newElement;
1251 
1252  for (;;)
1253  {
1254  /* if partitioned, must lock to touch nentries and freeList */
1255  if (IS_PARTITIONED(hctl))
1256  SpinLockAcquire(&hctl->freeList[freelist_idx].mutex);
1257 
1258  /* try to get an entry from the freelist */
1259  newElement = hctl->freeList[freelist_idx].freeList;
1260 
1261  if (newElement != NULL)
1262  break;
1263 
1264  if (IS_PARTITIONED(hctl))
1265  SpinLockRelease(&hctl->freeList[freelist_idx].mutex);
1266 
1267  /*
1268  * No free elements in this freelist. In a partitioned table, there
1269  * might be entries in other freelists, but to reduce contention we
1270  * prefer to first try to get another chunk of buckets from the main
1271  * shmem allocator. If that fails, though, we *MUST* root through all
1272  * the other freelists before giving up. There are multiple callers
1273  * that assume that they can allocate every element in the initially
1274  * requested table size, or that deleting an element guarantees they
1275  * can insert a new element, even if shared memory is entirely full.
1276  * Failing because the needed element is in a different freelist is
1277  * not acceptable.
1278  */
1279  if (!element_alloc(hashp, hctl->nelem_alloc, freelist_idx))
1280  {
1281  int borrow_from_idx;
1282 
1283  if (!IS_PARTITIONED(hctl))
1284  return NULL; /* out of memory */
1285 
1286  /* try to borrow element from another freelist */
1287  borrow_from_idx = freelist_idx;
1288  for (;;)
1289  {
1290  borrow_from_idx = (borrow_from_idx + 1) % NUM_FREELISTS;
1291  if (borrow_from_idx == freelist_idx)
1292  break; /* examined all freelists, fail */
1293 
1294  SpinLockAcquire(&(hctl->freeList[borrow_from_idx].mutex));
1295  newElement = hctl->freeList[borrow_from_idx].freeList;
1296 
1297  if (newElement != NULL)
1298  {
1299  hctl->freeList[borrow_from_idx].freeList = newElement->link;
1300  SpinLockRelease(&(hctl->freeList[borrow_from_idx].mutex));
1301 
1302  /* careful: count the new element in its proper freelist */
1303  SpinLockAcquire(&hctl->freeList[freelist_idx].mutex);
1304  hctl->freeList[freelist_idx].nentries++;
1305  SpinLockRelease(&hctl->freeList[freelist_idx].mutex);
1306 
1307  return newElement;
1308  }
1309 
1310  SpinLockRelease(&(hctl->freeList[borrow_from_idx].mutex));
1311  }
1312 
1313  /* no elements available to borrow either, so out of memory */
1314  return NULL;
1315  }
1316  }
1317 
1318  /* remove entry from freelist, bump nentries */
1319  hctl->freeList[freelist_idx].freeList = newElement->link;
1320  hctl->freeList[freelist_idx].nentries++;
1321 
1322  if (IS_PARTITIONED(hctl))
1323  SpinLockRelease(&hctl->freeList[freelist_idx].mutex);
1324 
1325  return newElement;
1326 }
#define IS_PARTITIONED(hctl)
Definition: dynahash.c:199
#define NUM_FREELISTS
Definition: dynahash.c:116
slock_t mutex
Definition: dynahash.c:143
#define SpinLockAcquire(lock)
Definition: spin.h:62
HASHHDR * hctl
Definition: dynahash.c:210
long nentries
Definition: dynahash.c:144
#define SpinLockRelease(lock)
Definition: spin.h:64
FreeListData freeList[NUM_FREELISTS]
Definition: dynahash.c:168
#define NULL
Definition: c.h:229
int nelem_alloc
Definition: dynahash.c:186
struct HASHELEMENT * link
Definition: hsearch.h:53
HASHELEMENT * freeList
Definition: dynahash.c:145
static bool element_alloc(HTAB *hashp, int nelem, int freelist_idx)
Definition: dynahash.c:1654
uint32 get_hash_value ( HTAB hashp,
const void *  keyPtr 
)

Definition at line 857 of file dynahash.c.

References HTAB::hash, and HTAB::keysize.

Referenced by BufTableHashCode(), and LockTagHashCode().

858 {
859  return hashp->hash(keyPtr, hashp->keysize);
860 }
Size keysize
Definition: dynahash.c:225
HashValueFunc hash
Definition: dynahash.c:212
static bool has_seq_scans ( HTAB hashp)
static

Definition at line 1817 of file dynahash.c.

References i, and num_seq_scans.

Referenced by hash_freeze(), and hash_search_with_hash_value().

1818 {
1819  int i;
1820 
1821  for (i = 0; i < num_seq_scans; i++)
1822  {
1823  if (seq_scan_tables[i] == hashp)
1824  return true;
1825  }
1826  return false;
1827 }
static int num_seq_scans
Definition: dynahash.c:1779
static HTAB * seq_scan_tables[MAX_SEQ_SCANS]
Definition: dynahash.c:1777
int i
static void hash_corrupted ( HTAB hashp)
static

Definition at line 1701 of file dynahash.c.

References elog, FATAL, HTAB::isshared, PANIC, and HTAB::tabname.

Referenced by hash_search_with_hash_value(), and hash_update_hash_key().

1702 {
1703  /*
1704  * If the corruption is in a shared hashtable, we'd better force a
1705  * systemwide restart. Otherwise, just shut down this one backend.
1706  */
1707  if (hashp->isshared)
1708  elog(PANIC, "hash table \"%s\" corrupted", hashp->tabname);
1709  else
1710  elog(FATAL, "hash table \"%s\" corrupted", hashp->tabname);
1711 }
#define PANIC
Definition: elog.h:53
#define FATAL
Definition: elog.h:52
bool isshared
Definition: dynahash.c:218
char * tabname
Definition: dynahash.c:217
#define elog
Definition: elog.h:219
HTAB* hash_create ( const char *  tabname,
long  nelem,
HASHCTL info,
int  flags 
)

Definition at line 316 of file dynahash.c.

References HASHCTL::alloc, HTAB::alloc, ALLOCSET_DEFAULT_SIZES, AllocSetContextCreate(), Assert, CurrentDynaHashCxt, HTAB::dir, HASHCTL::dsize, HASHHDR::dsize, DynaHashAlloc(), element_alloc(), elog, HASHCTL::entrysize, HASHHDR::entrysize, ereport, errcode(), errmsg(), ERROR, HASHCTL::ffactor, HASHHDR::ffactor, HTAB::frozen, HASHCTL::hash, HTAB::hash, HASH_ALLOC, HASH_ATTACH, HASH_BLOBS, HASH_COMPARE, HASH_CONTEXT, HASH_DIRSIZE, HASH_ELEM, HASH_FFACTOR, HASH_FIXED_SIZE, HASH_FUNCTION, HASH_KEYCOPY, HASH_PARTITION, HASH_SEGMENT, HASH_SHARED_MEM, HASHCTL::hctl, HTAB::hctl, HASHCTL::hcxt, HTAB::hcxt, hdefault(), i, init_htab(), IS_PARTITIONED, HTAB::isfixed, HTAB::isshared, HASHCTL::keycopy, HTAB::keycopy, HASHCTL::keysize, HASHHDR::keysize, HTAB::keysize, HASHCTL::match, HTAB::match, HASHCTL::max_dsize, HASHHDR::max_dsize, MemSet, my_log2(), next_pow2_int(), NULL, NUM_FREELISTS, HASHCTL::num_partitions, HASHHDR::num_partitions, HASHHDR::sshift, HTAB::sshift, HASHCTL::ssize, HASHHDR::ssize, HTAB::ssize, string_compare(), string_hash(), strlcpy(), HTAB::tabname, tag_hash(), TopMemoryContext, and uint32_hash().

Referenced by _hash_finish_split(), _PG_init(), assign_record_type_typmod(), begin_heap_rewrite(), build_join_rel_hash(), BuildEventTriggerCache(), CompactCheckpointerRequestQueue(), compute_array_stats(), compute_tsvector_stats(), create_seq_hashtable(), createConnHash(), do_autovacuum(), EnablePortalManager(), find_all_inheritors(), find_oper_cache_entry(), find_rendezvous_variable(), get_json_object_as_hash(), get_tabstat_entry(), GetComboCommandId(), GetConnection(), GetSerializableTransactionSnapshotInt(), gistInitBuildBuffers(), gistInitParentMap(), init_procedure_caches(), init_rel_sync_cache(), init_timezone_hashtable(), init_ts_config_cache(), InitBufferPoolAccess(), InitializeAttoptCache(), InitializeRelfilenodeMap(), InitializeShippableCache(), InitializeTableSpaceCache(), InitLocalBuffers(), InitLocks(), InitQueryHashTable(), load_categories_hash(), log_invalid_page(), logical_begin_heap_rewrite(), logicalrep_relmap_init(), lookup_collation_cache(), lookup_proof_cache(), lookup_ts_dictionary_cache(), lookup_ts_parser_cache(), lookup_type_cache(), LookupOpclassInfo(), mdinit(), pgstat_collect_oids(), pgstat_init_function_usage(), pgstat_read_statsfiles(), plpgsql_estate_setup(), plpgsql_HashTableInit(), PLy_add_exceptions(), populate_recordset_object_start(), process_syncing_tables_for_apply(), rebuild_database_list(), record_C_func(), RegisterExtensibleNodeEntry(), RelationCacheInitialize(), ReorderBufferAllocate(), ReorderBufferBuildTupleCidHash(), ReorderBufferToastInitHash(), reset_dbentry_counters(), ResetUnloggedRelationsInDbspaceDir(), ri_InitHashTables(), select_perl_context(), set_rtable_names(), ShmemInitHash(), smgropen(), TQSendRecordInfo(), transformGraph(), and TupleQueueHandleControlMessage().

317 {
318  HTAB *hashp;
319  HASHHDR *hctl;
320 
321  /*
322  * For shared hash tables, we have a local hash header (HTAB struct) that
323  * we allocate in TopMemoryContext; all else is in shared memory.
324  *
325  * For non-shared hash tables, everything including the hash header is in
326  * a memory context created specially for the hash table --- this makes
327  * hash_destroy very simple. The memory context is made a child of either
328  * a context specified by the caller, or TopMemoryContext if nothing is
329  * specified.
330  */
331  if (flags & HASH_SHARED_MEM)
332  {
333  /* Set up to allocate the hash header */
335  }
336  else
337  {
338  /* Create the hash table's private memory context */
339  if (flags & HASH_CONTEXT)
340  CurrentDynaHashCxt = info->hcxt;
341  else
344  tabname,
346  }
347 
348  /* Initialize the hash header, plus a copy of the table name */
349  hashp = (HTAB *) DynaHashAlloc(sizeof(HTAB) + strlen(tabname) + 1);
350  MemSet(hashp, 0, sizeof(HTAB));
351 
352  hashp->tabname = (char *) (hashp + 1);
353  strcpy(hashp->tabname, tabname);
354 
355  /*
356  * Select the appropriate hash function (see comments at head of file).
357  */
358  if (flags & HASH_FUNCTION)
359  hashp->hash = info->hash;
360  else if (flags & HASH_BLOBS)
361  {
362  /* We can optimize hashing for common key sizes */
363  Assert(flags & HASH_ELEM);
364  if (info->keysize == sizeof(uint32))
365  hashp->hash = uint32_hash;
366  else
367  hashp->hash = tag_hash;
368  }
369  else
370  hashp->hash = string_hash; /* default hash function */
371 
372  /*
373  * If you don't specify a match function, it defaults to string_compare if
374  * you used string_hash (either explicitly or by default) and to memcmp
375  * otherwise.
376  *
377  * Note: explicitly specifying string_hash is deprecated, because this
378  * might not work for callers in loadable modules on some platforms due to
379  * referencing a trampoline instead of the string_hash function proper.
380  * Just let it default, eh?
381  */
382  if (flags & HASH_COMPARE)
383  hashp->match = info->match;
384  else if (hashp->hash == string_hash)
386  else
387  hashp->match = memcmp;
388 
389  /*
390  * Similarly, the key-copying function defaults to strlcpy or memcpy.
391  */
392  if (flags & HASH_KEYCOPY)
393  hashp->keycopy = info->keycopy;
394  else if (hashp->hash == string_hash)
395  hashp->keycopy = (HashCopyFunc) strlcpy;
396  else
397  hashp->keycopy = memcpy;
398 
399  /* And select the entry allocation function, too. */
400  if (flags & HASH_ALLOC)
401  hashp->alloc = info->alloc;
402  else
403  hashp->alloc = DynaHashAlloc;
404 
405  if (flags & HASH_SHARED_MEM)
406  {
407  /*
408  * ctl structure and directory are preallocated for shared memory
409  * tables. Note that HASH_DIRSIZE and HASH_ALLOC had better be set as
410  * well.
411  */
412  hashp->hctl = info->hctl;
413  hashp->dir = (HASHSEGMENT *) (((char *) info->hctl) + sizeof(HASHHDR));
414  hashp->hcxt = NULL;
415  hashp->isshared = true;
416 
417  /* hash table already exists, we're just attaching to it */
418  if (flags & HASH_ATTACH)
419  {
420  /* make local copies of some heavily-used values */
421  hctl = hashp->hctl;
422  hashp->keysize = hctl->keysize;
423  hashp->ssize = hctl->ssize;
424  hashp->sshift = hctl->sshift;
425 
426  return hashp;
427  }
428  }
429  else
430  {
431  /* setup hash table defaults */
432  hashp->hctl = NULL;
433  hashp->dir = NULL;
434  hashp->hcxt = CurrentDynaHashCxt;
435  hashp->isshared = false;
436  }
437 
438  if (!hashp->hctl)
439  {
440  hashp->hctl = (HASHHDR *) hashp->alloc(sizeof(HASHHDR));
441  if (!hashp->hctl)
442  ereport(ERROR,
443  (errcode(ERRCODE_OUT_OF_MEMORY),
444  errmsg("out of memory")));
445  }
446 
447  hashp->frozen = false;
448 
449  hdefault(hashp);
450 
451  hctl = hashp->hctl;
452 
453  if (flags & HASH_PARTITION)
454  {
455  /* Doesn't make sense to partition a local hash table */
456  Assert(flags & HASH_SHARED_MEM);
457 
458  /*
459  * The number of partitions had better be a power of 2. Also, it must
460  * be less than INT_MAX (see init_htab()), so call the int version of
461  * next_pow2.
462  */
464 
465  hctl->num_partitions = info->num_partitions;
466  }
467 
468  if (flags & HASH_SEGMENT)
469  {
470  hctl->ssize = info->ssize;
471  hctl->sshift = my_log2(info->ssize);
472  /* ssize had better be a power of 2 */
473  Assert(hctl->ssize == (1L << hctl->sshift));
474  }
475  if (flags & HASH_FFACTOR)
476  hctl->ffactor = info->ffactor;
477 
478  /*
479  * SHM hash tables have fixed directory size passed by the caller.
480  */
481  if (flags & HASH_DIRSIZE)
482  {
483  hctl->max_dsize = info->max_dsize;
484  hctl->dsize = info->dsize;
485  }
486 
487  /*
488  * hash table now allocates space for key and data but you have to say how
489  * much space to allocate
490  */
491  if (flags & HASH_ELEM)
492  {
493  Assert(info->entrysize >= info->keysize);
494  hctl->keysize = info->keysize;
495  hctl->entrysize = info->entrysize;
496  }
497 
498  /* make local copies of heavily-used constant fields */
499  hashp->keysize = hctl->keysize;
500  hashp->ssize = hctl->ssize;
501  hashp->sshift = hctl->sshift;
502 
503  /* Build the hash directory structure */
504  if (!init_htab(hashp, nelem))
505  elog(ERROR, "failed to initialize hash table \"%s\"", hashp->tabname);
506 
507  /*
508  * For a shared hash table, preallocate the requested number of elements.
509  * This reduces problems with run-time out-of-shared-memory conditions.
510  *
511  * For a non-shared hash table, preallocate the requested number of
512  * elements if it's less than our chosen nelem_alloc. This avoids wasting
513  * space if the caller correctly estimates a small table size.
514  */
515  if ((flags & HASH_SHARED_MEM) ||
516  nelem < hctl->nelem_alloc)
517  {
518  int i,
519  freelist_partitions,
520  nelem_alloc,
521  nelem_alloc_first;
522 
523  /*
524  * If hash table is partitioned, give each freelist an equal share of
525  * the initial allocation. Otherwise only freeList[0] is used.
526  */
527  if (IS_PARTITIONED(hashp->hctl))
528  freelist_partitions = NUM_FREELISTS;
529  else
530  freelist_partitions = 1;
531 
532  nelem_alloc = nelem / freelist_partitions;
533  if (nelem_alloc <= 0)
534  nelem_alloc = 1;
535 
536  /*
537  * Make sure we'll allocate all the requested elements; freeList[0]
538  * gets the excess if the request isn't divisible by NUM_FREELISTS.
539  */
540  if (nelem_alloc * freelist_partitions < nelem)
541  nelem_alloc_first =
542  nelem - nelem_alloc * (freelist_partitions - 1);
543  else
544  nelem_alloc_first = nelem_alloc;
545 
546  for (i = 0; i < freelist_partitions; i++)
547  {
548  int temp = (i == 0) ? nelem_alloc_first : nelem_alloc;
549 
550  if (!element_alloc(hashp, temp, i))
551  ereport(ERROR,
552  (errcode(ERRCODE_OUT_OF_MEMORY),
553  errmsg("out of memory")));
554  }
555  }
556 
557  if (flags & HASH_FIXED_SIZE)
558  hashp->isfixed = true;
559  return hashp;
560 }
Size keysize
Definition: dynahash.c:179
Size keysize
Definition: dynahash.c:225
long dsize
Definition: dynahash.c:172
#define HASH_CONTEXT
Definition: hsearch.h:93
#define HASH_ELEM
Definition: hsearch.h:87
MemoryContext hcxt
Definition: hsearch.h:78
long ssize
Definition: hsearch.h:68
HashCopyFunc keycopy
Definition: hsearch.h:76
Size entrysize
Definition: dynahash.c:180
#define IS_PARTITIONED(hctl)
Definition: dynahash.c:199
uint32 string_hash(const void *key, Size keysize)
Definition: hashfn.c:34
long num_partitions
Definition: dynahash.c:181
Size entrysize
Definition: hsearch.h:73
#define NUM_FREELISTS
Definition: dynahash.c:116
int errcode(int sqlerrcode)
Definition: elog.c:575
HashAllocFunc alloc
Definition: dynahash.c:215
#define MemSet(start, val, len)
Definition: c.h:857
#define HASH_SHARED_MEM
Definition: hsearch.h:94
static int string_compare(const char *key1, const char *key2, Size keysize)
Definition: dynahash.c:293
long dsize
Definition: hsearch.h:69
uint32 uint32_hash(const void *key, Size keysize)
Definition: hashfn.c:64
#define HASH_PARTITION
Definition: hsearch.h:83
#define HASH_ATTACH
Definition: hsearch.h:95
long ffactor
Definition: dynahash.c:182
HashValueFunc hash
Definition: dynahash.c:212
Definition: dynahash.c:208
long max_dsize
Definition: hsearch.h:70
long ssize
Definition: dynahash.c:226
#define ERROR
Definition: elog.h:43
long num_partitions
Definition: hsearch.h:67
int sshift
Definition: dynahash.c:227
#define ALLOCSET_DEFAULT_SIZES
Definition: memutils.h:165
HashAllocFunc alloc
Definition: hsearch.h:77
#define HASH_KEYCOPY
Definition: hsearch.h:91
long max_dsize
Definition: dynahash.c:183
static void hdefault(HTAB *hashp)
Definition: dynahash.c:566
HASHHDR * hctl
Definition: dynahash.c:210
unsigned int uint32
Definition: c.h:268
static bool init_htab(HTAB *hashp, long nelem)
Definition: dynahash.c:632
#define ereport(elevel, rest)
Definition: elog.h:122
MemoryContext TopMemoryContext
Definition: mcxt.c:43
int my_log2(long num)
Definition: dynahash.c:1715
HashCompareFunc match
Definition: dynahash.c:213
static int next_pow2_int(long num)
Definition: dynahash.c:1739
bool isshared
Definition: dynahash.c:218
#define HASH_BLOBS
Definition: hsearch.h:88
bool frozen
Definition: dynahash.c:222
MemoryContext AllocSetContextCreate(MemoryContext parent, const char *name, Size minContextSize, Size initBlockSize, Size maxBlockSize)
Definition: aset.c:322
uint32 tag_hash(const void *key, Size keysize)
Definition: hashfn.c:52
long ssize
Definition: dynahash.c:184
Size keysize
Definition: hsearch.h:72
HashCompareFunc match
Definition: hsearch.h:75
MemoryContext hcxt
Definition: dynahash.c:216
HashCopyFunc keycopy
Definition: dynahash.c:214
#define HASH_SEGMENT
Definition: hsearch.h:84
size_t strlcpy(char *dst, const char *src, size_t siz)
Definition: strlcpy.c:45
#define NULL
Definition: c.h:229
#define Assert(condition)
Definition: c.h:675
#define HASH_COMPARE
Definition: hsearch.h:90
HASHHDR * hctl
Definition: hsearch.h:79
long ffactor
Definition: hsearch.h:71
char * tabname
Definition: dynahash.c:217
#define HASH_FIXED_SIZE
Definition: hsearch.h:96
bool isfixed
Definition: dynahash.c:219
#define HASH_FFACTOR
Definition: hsearch.h:86
static void * DynaHashAlloc(Size size)
Definition: dynahash.c:278
int(* HashCompareFunc)(const void *key1, const void *key2, Size keysize)
Definition: hsearch.h:29
#define HASH_DIRSIZE
Definition: hsearch.h:85
int errmsg(const char *fmt,...)
Definition: elog.c:797
static MemoryContext CurrentDynaHashCxt
Definition: dynahash.c:275
int i
#define HASH_ALLOC
Definition: hsearch.h:92
HASHSEGMENT * dir
Definition: dynahash.c:211
#define elog
Definition: elog.h:219
static bool element_alloc(HTAB *hashp, int nelem, int freelist_idx)
Definition: dynahash.c:1654
int sshift
Definition: dynahash.c:185
void *(* HashCopyFunc)(void *dest, const void *src, Size keysize)
Definition: hsearch.h:37
HashValueFunc hash
Definition: hsearch.h:74
#define HASH_FUNCTION
Definition: hsearch.h:89
void hash_destroy ( HTAB hashp)

Definition at line 811 of file dynahash.c.

References HTAB::alloc, Assert, DynaHashAlloc(), hash_stats(), HTAB::hcxt, MemoryContextDelete(), and NULL.

Referenced by _hash_finish_split(), clear_external_function_hash(), CompactCheckpointerRequestQueue(), DestroyTupleQueueReader(), find_all_inheritors(), InitLocks(), pgoutput_shutdown(), pgstat_recv_dropdb(), pgstat_recv_resetcounter(), pgstat_report_stat(), pgstat_vacuum_stat(), populate_recordset_object_end(), PostPrepare_PredicateLocks(), process_syncing_tables_for_apply(), ReleasePredicateLocks(), ReorderBufferReturnTXN(), ReorderBufferToastReset(), ResetSequenceCaches(), ResetUnloggedRelationsInDbspaceDir(), set_rtable_names(), SetForwardFsyncRequests(), tqueueDestroyReceiver(), and XLogCheckInvalidPages().

812 {
813  if (hashp != NULL)
814  {
815  /* allocation method must be one we know how to free, too */
816  Assert(hashp->alloc == DynaHashAlloc);
817  /* so this hashtable must have it's own context */
818  Assert(hashp->hcxt != NULL);
819 
820  hash_stats("destroy", hashp);
821 
822  /*
823  * Free everything by destroying the hash table's memory context.
824  */
825  MemoryContextDelete(hashp->hcxt);
826  }
827 }
void MemoryContextDelete(MemoryContext context)
Definition: mcxt.c:200
void hash_stats(const char *where, HTAB *hashp)
Definition: dynahash.c:830
HashAllocFunc alloc
Definition: dynahash.c:215
MemoryContext hcxt
Definition: dynahash.c:216
#define NULL
Definition: c.h:229
#define Assert(condition)
Definition: c.h:675
static void * DynaHashAlloc(Size size)
Definition: dynahash.c:278
Size hash_estimate_size ( long  num_entries,
Size  entrysize 
)

Definition at line 729 of file dynahash.c.

References add_size(), choose_nelem_alloc(), DEF_DIRSIZE, DEF_FFACTOR, DEF_SEGSIZE, MAXALIGN, mul_size(), and next_pow2_long().

Referenced by BufTableShmemSize(), CreateSharedMemoryAndSemaphores(), LockShmemSize(), pgss_memsize(), and PredicateLockShmemSize().

730 {
731  Size size;
732  long nBuckets,
733  nSegments,
734  nDirEntries,
735  nElementAllocs,
736  elementSize,
737  elementAllocCnt;
738 
739  /* estimate number of buckets wanted */
740  nBuckets = next_pow2_long((num_entries - 1) / DEF_FFACTOR + 1);
741  /* # of segments needed for nBuckets */
742  nSegments = next_pow2_long((nBuckets - 1) / DEF_SEGSIZE + 1);
743  /* directory entries */
744  nDirEntries = DEF_DIRSIZE;
745  while (nDirEntries < nSegments)
746  nDirEntries <<= 1; /* dir_alloc doubles dsize at each call */
747 
748  /* fixed control info */
749  size = MAXALIGN(sizeof(HASHHDR)); /* but not HTAB, per above */
750  /* directory */
751  size = add_size(size, mul_size(nDirEntries, sizeof(HASHSEGMENT)));
752  /* segments */
753  size = add_size(size, mul_size(nSegments,
754  MAXALIGN(DEF_SEGSIZE * sizeof(HASHBUCKET))));
755  /* elements --- allocated in groups of choose_nelem_alloc() entries */
756  elementAllocCnt = choose_nelem_alloc(entrysize);
757  nElementAllocs = (num_entries - 1) / elementAllocCnt + 1;
758  elementSize = MAXALIGN(sizeof(HASHELEMENT)) + MAXALIGN(entrysize);
759  size = add_size(size,
760  mul_size(nElementAllocs,
761  mul_size(elementAllocCnt, elementSize)));
762 
763  return size;
764 }
static long next_pow2_long(long num)
Definition: dynahash.c:1731
Size mul_size(Size s1, Size s2)
Definition: shmem.c:492
Size add_size(Size s1, Size s2)
Definition: shmem.c:475
size_t Size
Definition: c.h:356
#define MAXALIGN(LEN)
Definition: c.h:588
static int choose_nelem_alloc(Size entrysize)
Definition: dynahash.c:599
#define DEF_FFACTOR
Definition: dynahash.c:113
#define DEF_SEGSIZE
Definition: dynahash.c:110
#define DEF_DIRSIZE
Definition: dynahash.c:112
void hash_freeze ( HTAB hashp)

Definition at line 1482 of file dynahash.c.

References elog, ERROR, HTAB::frozen, has_seq_scans(), HTAB::isshared, and HTAB::tabname.

1483 {
1484  if (hashp->isshared)
1485  elog(ERROR, "cannot freeze shared hashtable \"%s\"", hashp->tabname);
1486  if (!hashp->frozen && has_seq_scans(hashp))
1487  elog(ERROR, "cannot freeze hashtable \"%s\" because it has active scans",
1488  hashp->tabname);
1489  hashp->frozen = true;
1490 }
#define ERROR
Definition: elog.h:43
static bool has_seq_scans(HTAB *hashp)
Definition: dynahash.c:1817
bool isshared
Definition: dynahash.c:218
bool frozen
Definition: dynahash.c:222
char * tabname
Definition: dynahash.c:217
#define elog
Definition: elog.h:219
long hash_get_num_entries ( HTAB hashp)

Definition at line 1332 of file dynahash.c.

References HASHHDR::freeList, HTAB::hctl, i, IS_PARTITIONED, FreeListData::nentries, and NUM_FREELISTS.

Referenced by compute_array_stats(), compute_tsvector_stats(), entry_alloc(), entry_dealloc(), get_crosstab_tuplestore(), GetLockStatusData(), GetPredicateLockStatusData(), GetRunningTransactionLocks(), hash_stats(), init_htab(), pgss_shmem_shutdown(), pgstat_vacuum_stat(), ResetUnloggedRelationsInDbspaceDir(), transformGraph(), and XLogHaveInvalidPages().

1333 {
1334  int i;
1335  long sum = hashp->hctl->freeList[0].nentries;
1336 
1337  /*
1338  * We currently don't bother with acquiring the mutexes; it's only
1339  * sensible to call this function if you've got lock on all partitions of
1340  * the table.
1341  */
1342  if (IS_PARTITIONED(hashp->hctl))
1343  {
1344  for (i = 1; i < NUM_FREELISTS; i++)
1345  sum += hashp->hctl->freeList[i].nentries;
1346  }
1347 
1348  return sum;
1349 }
#define IS_PARTITIONED(hctl)
Definition: dynahash.c:199
#define NUM_FREELISTS
Definition: dynahash.c:116
HASHHDR * hctl
Definition: dynahash.c:210
long nentries
Definition: dynahash.c:144
FreeListData freeList[NUM_FREELISTS]
Definition: dynahash.c:168
int i
Size hash_get_shared_size ( HASHCTL info,
int  flags 
)

Definition at line 800 of file dynahash.c.

References Assert, HASHCTL::dsize, HASH_DIRSIZE, and HASHCTL::max_dsize.

Referenced by ShmemInitHash().

801 {
802  Assert(flags & HASH_DIRSIZE);
803  Assert(info->dsize == info->max_dsize);
804  return sizeof(HASHHDR) + info->dsize * sizeof(HASHSEGMENT);
805 }
long dsize
Definition: hsearch.h:69
long max_dsize
Definition: hsearch.h:70
struct HASHHDR HASHHDR
Definition: hsearch.h:58
#define Assert(condition)
Definition: c.h:675
#define HASH_DIRSIZE
Definition: hsearch.h:85
void* hash_search ( HTAB hashp,
const void *  keyPtr,
HASHACTION  action,
bool foundPtr 
)

Definition at line 903 of file dynahash.c.

References HTAB::hash, hash_search_with_hash_value(), and HTAB::keysize.

Referenced by _hash_finish_split(), _hash_splitbucket(), add_join_rel(), ApplyLogicalMappingFile(), assign_record_type_typmod(), AtEOSubXact_RelationCache(), AtEOXact_RelationCache(), build_join_rel_hash(), BuildEventTriggerCache(), CheckAndPromotePredicateLockRequest(), CheckForSerializableConflictOut(), CompactCheckpointerRequestQueue(), compile_plperl_function(), compile_pltcl_function(), compute_array_stats(), compute_tsvector_stats(), createNewConnection(), deleteConnection(), do_autovacuum(), DropAllPredicateLocksFromTable(), DropAllPreparedStatements(), DropPreparedStatement(), DropRelFileNodeAllLocalBuffers(), DropRelFileNodeLocalBuffers(), entry_alloc(), entry_dealloc(), entry_reset(), EventCacheLookup(), FetchPreparedStatement(), find_all_inheritors(), find_funcstat_entry(), find_join_rel(), find_oper_cache_entry(), find_rendezvous_variable(), find_tabstat_entry(), forget_invalid_pages(), forget_invalid_pages_db(), ForgetPrivateRefCountEntry(), get_attribute_options(), get_cast_hashentry(), get_pgstat_tabentry_relid(), get_rel_sync_entry(), get_tablespace(), get_tabstat_entry(), GetComboCommandId(), GetConnection(), getConnectionByName(), GetExtensibleNodeEntry(), GetPrivateRefCountEntry(), getState(), gistGetNodeBuffer(), gistGetParent(), gistMemorizeParent(), gistRelocateBuildBuffersOnSplit(), hash_object_field_end(), init_sequence(), InitPredicateLocks(), InvalidateAttoptCacheCallback(), InvalidateOprCacheCallBack(), InvalidateShippableCacheCallback(), InvalidateTableSpaceCacheCallback(), is_shippable(), JsObjectGetField(), LocalBufferAlloc(), LocalPrefetchBuffer(), LockAcquireExtended(), LockHasWaiters(), LockRelease(), log_invalid_page(), logical_rewrite_log_mapping(), logicalrep_rel_open(), logicalrep_relmap_update(), logicalrep_typmap_getid(), logicalrep_typmap_update(), lookup_C_func(), lookup_collation_cache(), lookup_proof_cache(), lookup_ts_config_cache(), lookup_ts_dictionary_cache(), lookup_ts_parser_cache(), lookup_type_cache(), LookupOpclassInfo(), make_oper_cache_entry(), mdsync(), pg_tzset(), pgss_store(), pgstat_collect_oids(), pgstat_fetch_stat_dbentry(), pgstat_fetch_stat_funcentry(), pgstat_fetch_stat_tabentry(), pgstat_get_db_entry(), pgstat_get_tab_entry(), pgstat_init_function_usage(), pgstat_read_db_statsfile(), pgstat_read_statsfiles(), pgstat_recv_dropdb(), pgstat_recv_funcpurge(), pgstat_recv_funcstat(), pgstat_recv_resetsinglecounter(), pgstat_recv_tabpurge(), pgstat_recv_tabstat(), pgstat_vacuum_stat(), plperl_spi_exec_prepared(), plperl_spi_freeplan(), plperl_spi_prepare(), plperl_spi_query_prepared(), plpgsql_HashTableDelete(), plpgsql_HashTableInsert(), plpgsql_HashTableLookup(), pltcl_fetch_interp(), PLy_generate_spi_exceptions(), PLy_procedure_get(), PLy_spi_subtransaction_abort(), populate_recordset_object_field_end(), predicatelock_twophase_recover(), PredicateLockExists(), PredicateLockTwoPhaseFinish(), process_syncing_tables_for_apply(), prune_element_hashtable(), prune_lexemes_hashtable(), rebuild_database_list(), record_C_func(), RegisterExtensibleNodeEntry(), RegisterPredicateLockingXid(), rel_sync_cache_relation_cb(), ReleaseOneSerializableXact(), RelfilenodeMapInvalidateCallback(), RelidByRelfilenode(), RememberFsyncRequest(), RemoveLocalLock(), ReorderBufferBuildTupleCidHash(), ReorderBufferCleanupTXN(), ReorderBufferToastAppendChunk(), ReorderBufferToastReplace(), ReorderBufferTXNByXid(), ReservePrivateRefCountEntry(), ResetUnloggedRelationsInDbspaceDir(), ResolveCminCmaxDuringDecoding(), rewrite_heap_dead_tuple(), rewrite_heap_tuple(), ri_FetchPreparedPlan(), ri_HashCompareOp(), ri_HashPreparedPlan(), ri_LoadConstraintInfo(), select_perl_context(), set_rtable_names(), ShmemInitStruct(), smgrclose(), smgrclosenode(), smgropen(), StorePreparedStatement(), table_recheck_autovac(), TQRemapRecord(), TQSendRecordInfo(), and TupleQueueHandleControlMessage().

907 {
908  return hash_search_with_hash_value(hashp,
909  keyPtr,
910  hashp->hash(keyPtr, hashp->keysize),
911  action,
912  foundPtr);
913 }
void * hash_search_with_hash_value(HTAB *hashp, const void *keyPtr, uint32 hashvalue, HASHACTION action, bool *foundPtr)
Definition: dynahash.c:916
Size keysize
Definition: dynahash.c:225
HashValueFunc hash
Definition: dynahash.c:212
void* hash_search_with_hash_value ( HTAB hashp,
const void *  keyPtr,
uint32  hashvalue,
HASHACTION  action,
bool foundPtr 
)

Definition at line 916 of file dynahash.c.

References HTAB::alloc, Assert, calc_bucket(), HTAB::dir, DynaHashAlloc(), ELEMENTKEY, elog, ereport, errcode(), errmsg(), ERROR, expand_table(), HASHHDR::ffactor, FreeListData::freeList, HASHHDR::freeList, FREELIST_IDX, HTAB::frozen, get_hash_entry(), has_seq_scans(), hash_corrupted(), HASH_ENTER, HASH_ENTER_NULL, HASH_FIND, HASH_REMOVE, HASHELEMENT::hashvalue, HTAB::hctl, IS_PARTITIONED, HTAB::isshared, HTAB::keycopy, HTAB::keysize, HASHELEMENT::link, HTAB::match, HASHHDR::max_bucket, MOD, FreeListData::mutex, FreeListData::nentries, NULL, SpinLockAcquire, SpinLockRelease, HTAB::sshift, HTAB::ssize, and HTAB::tabname.

Referenced by BufTableDelete(), BufTableInsert(), BufTableLookup(), CheckTargetForConflictsIn(), CleanUpLock(), ClearOldPredicateLocks(), CreatePredicateLock(), DecrementParentLocks(), DeleteChildTargetLocks(), DeleteLockTarget(), DropAllPredicateLocksFromTable(), FastPathGetRelationLockEntry(), GetLockConflicts(), hash_search(), lock_twophase_recover(), LockAcquireExtended(), LockRefindAndRelease(), LockRelease(), LockWaiterCount(), PageIsPredicateLocked(), PredicateLockAcquire(), ReleaseOneSerializableXact(), RemoveScratchTarget(), RemoveTargetIfNoLongerUsed(), RestoreScratchTarget(), SetupLockInTable(), and TransferPredicateLocksToNewTarget().

921 {
922  HASHHDR *hctl = hashp->hctl;
923  int freelist_idx = FREELIST_IDX(hctl, hashvalue);
924  Size keysize;
925  uint32 bucket;
926  long segment_num;
927  long segment_ndx;
928  HASHSEGMENT segp;
929  HASHBUCKET currBucket;
930  HASHBUCKET *prevBucketPtr;
931  HashCompareFunc match;
932 
933 #if HASH_STATISTICS
934  hash_accesses++;
935  hctl->accesses++;
936 #endif
937 
938  /*
939  * If inserting, check if it is time to split a bucket.
940  *
941  * NOTE: failure to expand table is not a fatal error, it just means we
942  * have to run at higher fill factor than we wanted. However, if we're
943  * using the palloc allocator then it will throw error anyway on
944  * out-of-memory, so we must do this before modifying the table.
945  */
946  if (action == HASH_ENTER || action == HASH_ENTER_NULL)
947  {
948  /*
949  * Can't split if running in partitioned mode, nor if frozen, nor if
950  * table is the subject of any active hash_seq_search scans. Strange
951  * order of these tests is to try to check cheaper conditions first.
952  */
953  if (!IS_PARTITIONED(hctl) && !hashp->frozen &&
954  hctl->freeList[0].nentries / (long) (hctl->max_bucket + 1) >= hctl->ffactor &&
955  !has_seq_scans(hashp))
956  (void) expand_table(hashp);
957  }
958 
959  /*
960  * Do the initial lookup
961  */
962  bucket = calc_bucket(hctl, hashvalue);
963 
964  segment_num = bucket >> hashp->sshift;
965  segment_ndx = MOD(bucket, hashp->ssize);
966 
967  segp = hashp->dir[segment_num];
968 
969  if (segp == NULL)
970  hash_corrupted(hashp);
971 
972  prevBucketPtr = &segp[segment_ndx];
973  currBucket = *prevBucketPtr;
974 
975  /*
976  * Follow collision chain looking for matching key
977  */
978  match = hashp->match; /* save one fetch in inner loop */
979  keysize = hashp->keysize; /* ditto */
980 
981  while (currBucket != NULL)
982  {
983  if (currBucket->hashvalue == hashvalue &&
984  match(ELEMENTKEY(currBucket), keyPtr, keysize) == 0)
985  break;
986  prevBucketPtr = &(currBucket->link);
987  currBucket = *prevBucketPtr;
988 #if HASH_STATISTICS
989  hash_collisions++;
990  hctl->collisions++;
991 #endif
992  }
993 
994  if (foundPtr)
995  *foundPtr = (bool) (currBucket != NULL);
996 
997  /*
998  * OK, now what?
999  */
1000  switch (action)
1001  {
1002  case HASH_FIND:
1003  if (currBucket != NULL)
1004  return (void *) ELEMENTKEY(currBucket);
1005  return NULL;
1006 
1007  case HASH_REMOVE:
1008  if (currBucket != NULL)
1009  {
1010  /* if partitioned, must lock to touch nentries and freeList */
1011  if (IS_PARTITIONED(hctl))
1012  SpinLockAcquire(&(hctl->freeList[freelist_idx].mutex));
1013 
1014  /* delete the record from the appropriate nentries counter. */
1015  Assert(hctl->freeList[freelist_idx].nentries > 0);
1016  hctl->freeList[freelist_idx].nentries--;
1017 
1018  /* remove record from hash bucket's chain. */
1019  *prevBucketPtr = currBucket->link;
1020 
1021  /* add the record to the appropriate freelist. */
1022  currBucket->link = hctl->freeList[freelist_idx].freeList;
1023  hctl->freeList[freelist_idx].freeList = currBucket;
1024 
1025  if (IS_PARTITIONED(hctl))
1026  SpinLockRelease(&hctl->freeList[freelist_idx].mutex);
1027 
1028  /*
1029  * better hope the caller is synchronizing access to this
1030  * element, because someone else is going to reuse it the next
1031  * time something is added to the table
1032  */
1033  return (void *) ELEMENTKEY(currBucket);
1034  }
1035  return NULL;
1036 
1037  case HASH_ENTER_NULL:
1038  /* ENTER_NULL does not work with palloc-based allocator */
1039  Assert(hashp->alloc != DynaHashAlloc);
1040  /* FALL THRU */
1041 
1042  case HASH_ENTER:
1043  /* Return existing element if found, else create one */
1044  if (currBucket != NULL)
1045  return (void *) ELEMENTKEY(currBucket);
1046 
1047  /* disallow inserts if frozen */
1048  if (hashp->frozen)
1049  elog(ERROR, "cannot insert into frozen hashtable \"%s\"",
1050  hashp->tabname);
1051 
1052  currBucket = get_hash_entry(hashp, freelist_idx);
1053  if (currBucket == NULL)
1054  {
1055  /* out of memory */
1056  if (action == HASH_ENTER_NULL)
1057  return NULL;
1058  /* report a generic message */
1059  if (hashp->isshared)
1060  ereport(ERROR,
1061  (errcode(ERRCODE_OUT_OF_MEMORY),
1062  errmsg("out of shared memory")));
1063  else
1064  ereport(ERROR,
1065  (errcode(ERRCODE_OUT_OF_MEMORY),
1066  errmsg("out of memory")));
1067  }
1068 
1069  /* link into hashbucket chain */
1070  *prevBucketPtr = currBucket;
1071  currBucket->link = NULL;
1072 
1073  /* copy key into record */
1074  currBucket->hashvalue = hashvalue;
1075  hashp->keycopy(ELEMENTKEY(currBucket), keyPtr, keysize);
1076 
1077  /*
1078  * Caller is expected to fill the data field on return. DO NOT
1079  * insert any code that could possibly throw error here, as doing
1080  * so would leave the table entry incomplete and hence corrupt the
1081  * caller's data structure.
1082  */
1083 
1084  return (void *) ELEMENTKEY(currBucket);
1085  }
1086 
1087  elog(ERROR, "unrecognized hash action code: %d", (int) action);
1088 
1089  return NULL; /* keep compiler quiet */
1090 }
Size keysize
Definition: dynahash.c:225
uint32 max_bucket
Definition: dynahash.c:174
static uint32 calc_bucket(HASHHDR *hctl, uint32 hash_val)
Definition: dynahash.c:864
#define IS_PARTITIONED(hctl)
Definition: dynahash.c:199
#define ELEMENTKEY(helem)
Definition: dynahash.c:233
int errcode(int sqlerrcode)
Definition: elog.c:575
HashAllocFunc alloc
Definition: dynahash.c:215
slock_t mutex
Definition: dynahash.c:143
static HASHBUCKET get_hash_entry(HTAB *hashp, int freelist_idx)
Definition: dynahash.c:1247
char bool
Definition: c.h:202
long ffactor
Definition: dynahash.c:182
#define SpinLockAcquire(lock)
Definition: spin.h:62
long ssize
Definition: dynahash.c:226
#define ERROR
Definition: elog.h:43
int sshift
Definition: dynahash.c:227
#define MOD(x, y)
Definition: dynahash.c:244
HASHHDR * hctl
Definition: dynahash.c:210
static void hash_corrupted(HTAB *hashp)
Definition: dynahash.c:1701
static bool has_seq_scans(HTAB *hashp)
Definition: dynahash.c:1817
unsigned int uint32
Definition: c.h:268
long nentries
Definition: dynahash.c:144
#define ereport(elevel, rest)
Definition: elog.h:122
HashCompareFunc match
Definition: dynahash.c:213
bool isshared
Definition: dynahash.c:218
#define SpinLockRelease(lock)
Definition: spin.h:64
bool frozen
Definition: dynahash.c:222
FreeListData freeList[NUM_FREELISTS]
Definition: dynahash.c:168
HashCopyFunc keycopy
Definition: dynahash.c:214
#define NULL
Definition: c.h:229
#define Assert(condition)
Definition: c.h:675
size_t Size
Definition: c.h:356
static bool expand_table(HTAB *hashp)
Definition: dynahash.c:1499
char * tabname
Definition: dynahash.c:217
static void * DynaHashAlloc(Size size)
Definition: dynahash.c:278
int(* HashCompareFunc)(const void *key1, const void *key2, Size keysize)
Definition: hsearch.h:29
int errmsg(const char *fmt,...)
Definition: elog.c:797
struct HASHELEMENT * link
Definition: hsearch.h:53
HASHELEMENT * freeList
Definition: dynahash.c:145
HASHSEGMENT * dir
Definition: dynahash.c:211
#define elog
Definition: elog.h:219
#define FREELIST_IDX(hctl, hashcode)
Definition: dynahash.c:201
uint32 hashvalue
Definition: hsearch.h:54
long hash_select_dirsize ( long  num_entries)

Definition at line 776 of file dynahash.c.

References DEF_DIRSIZE, DEF_FFACTOR, DEF_SEGSIZE, and next_pow2_long().

Referenced by ShmemInitHash().

777 {
778  long nBuckets,
779  nSegments,
780  nDirEntries;
781 
782  /* estimate number of buckets wanted */
783  nBuckets = next_pow2_long((num_entries - 1) / DEF_FFACTOR + 1);
784  /* # of segments needed for nBuckets */
785  nSegments = next_pow2_long((nBuckets - 1) / DEF_SEGSIZE + 1);
786  /* directory entries */
787  nDirEntries = DEF_DIRSIZE;
788  while (nDirEntries < nSegments)
789  nDirEntries <<= 1; /* dir_alloc doubles dsize at each call */
790 
791  return nDirEntries;
792 }
static long next_pow2_long(long num)
Definition: dynahash.c:1731
#define DEF_FFACTOR
Definition: dynahash.c:113
#define DEF_SEGSIZE
Definition: dynahash.c:110
#define DEF_DIRSIZE
Definition: dynahash.c:112
void hash_seq_init ( HASH_SEQ_STATUS status,
HTAB hashp 
)

Definition at line 1376 of file dynahash.c.

References HASH_SEQ_STATUS::curBucket, HASH_SEQ_STATUS::curEntry, HTAB::frozen, HASH_SEQ_STATUS::hashp, NULL, and register_seq_scan().

Referenced by AtAbort_Portals(), AtCleanup_Portals(), AtEOSubXact_RelationCache(), AtEOXact_RelationCache(), AtPrepare_Locks(), AtSubAbort_Portals(), AtSubCleanup_Portals(), AtSubCommit_Portals(), CheckForBufferLeaks(), CheckTableForSerializableConflictIn(), compute_array_stats(), compute_tsvector_stats(), dblink_get_connections(), DropAllPredicateLocksFromTable(), DropAllPreparedStatements(), end_heap_rewrite(), entry_dealloc(), entry_reset(), forget_invalid_pages(), forget_invalid_pages_db(), gc_qtexts(), GetLockStatusData(), GetPredicateLockStatusData(), GetRunningTransactionLocks(), InvalidateAttoptCacheCallback(), InvalidateOprCacheCallBack(), InvalidateOprProofCacheCallBack(), InvalidateShippableCacheCallback(), InvalidateTableSpaceCacheCallback(), InvalidateTSCacheCallBack(), LockReassignCurrentOwner(), LockReleaseAll(), LockReleaseCurrentOwner(), LockReleaseSession(), logical_end_heap_rewrite(), logical_heap_rewrite_flush_mappings(), logicalrep_relmap_invalidate_cb(), logicalrep_typmap_invalidate_cb(), mdsync(), packGraph(), pg_cursor(), pg_prepared_statement(), pg_stat_statements_internal(), pgfdw_inval_callback(), pgfdw_subxact_callback(), pgfdw_xact_callback(), pgss_shmem_shutdown(), pgstat_send_funcstats(), pgstat_vacuum_stat(), pgstat_write_db_statsfile(), pgstat_write_statsfiles(), plperl_fini(), PortalHashTableDeleteAll(), PostPrepare_Locks(), PreCommit_Portals(), prune_element_hashtable(), prune_lexemes_hashtable(), rebuild_database_list(), rel_sync_cache_publication_cb(), RelationCacheInitializePhase3(), RelationCacheInvalidate(), RelfilenodeMapInvalidateCallback(), RememberFsyncRequest(), ReorderBufferToastReset(), selectColorTrigrams(), smgrcloseall(), ThereAreNoReadyPortals(), TypeCacheOpcCallback(), TypeCacheRelCallback(), write_relcache_init_file(), and XLogCheckInvalidPages().

1377 {
1378  status->hashp = hashp;
1379  status->curBucket = 0;
1380  status->curEntry = NULL;
1381  if (!hashp->frozen)
1382  register_seq_scan(hashp);
1383 }
uint32 curBucket
Definition: hsearch.h:115
HASHELEMENT * curEntry
Definition: hsearch.h:116
HTAB * hashp
Definition: hsearch.h:114
bool frozen
Definition: dynahash.c:222
#define NULL
Definition: c.h:229
static void register_seq_scan(HTAB *hashp)
Definition: dynahash.c:1784
void* hash_seq_search ( HASH_SEQ_STATUS status)

Definition at line 1386 of file dynahash.c.

References HASH_SEQ_STATUS::curBucket, HASH_SEQ_STATUS::curEntry, HTAB::dir, ELEMENTKEY, hash_seq_term(), HASH_SEQ_STATUS::hashp, HTAB::hctl, HASHELEMENT::link, HASHHDR::max_bucket, MOD, NULL, HTAB::sshift, and HTAB::ssize.

Referenced by AtAbort_Portals(), AtCleanup_Portals(), AtEOSubXact_RelationCache(), AtEOXact_RelationCache(), AtPrepare_Locks(), AtSubAbort_Portals(), AtSubCleanup_Portals(), AtSubCommit_Portals(), CheckForBufferLeaks(), CheckTableForSerializableConflictIn(), compute_array_stats(), compute_tsvector_stats(), dblink_get_connections(), DropAllPredicateLocksFromTable(), DropAllPreparedStatements(), end_heap_rewrite(), entry_dealloc(), entry_reset(), forget_invalid_pages(), forget_invalid_pages_db(), gc_qtexts(), GetLockStatusData(), GetPredicateLockStatusData(), GetRunningTransactionLocks(), InvalidateAttoptCacheCallback(), InvalidateOprCacheCallBack(), InvalidateOprProofCacheCallBack(), InvalidateShippableCacheCallback(), InvalidateTableSpaceCacheCallback(), InvalidateTSCacheCallBack(), LockReassignCurrentOwner(), LockReleaseAll(), LockReleaseCurrentOwner(), LockReleaseSession(), logical_end_heap_rewrite(), logical_heap_rewrite_flush_mappings(), logicalrep_relmap_invalidate_cb(), logicalrep_typmap_invalidate_cb(), mdsync(), packGraph(), pg_cursor(), pg_prepared_statement(), pg_stat_statements_internal(), pgfdw_inval_callback(), pgfdw_subxact_callback(), pgfdw_xact_callback(), pgss_shmem_shutdown(), pgstat_send_funcstats(), pgstat_vacuum_stat(), pgstat_write_db_statsfile(), pgstat_write_statsfiles(), plperl_fini(), PortalHashTableDeleteAll(), PostPrepare_Locks(), PreCommit_Portals(), prune_element_hashtable(), prune_lexemes_hashtable(), rebuild_database_list(), rel_sync_cache_publication_cb(), RelationCacheInitializePhase3(), RelationCacheInvalidate(), RelfilenodeMapInvalidateCallback(), RememberFsyncRequest(), ReorderBufferToastReset(), selectColorTrigrams(), smgrcloseall(), ThereAreNoReadyPortals(), TypeCacheOpcCallback(), TypeCacheRelCallback(), write_relcache_init_file(), and XLogCheckInvalidPages().

1387 {
1388  HTAB *hashp;
1389  HASHHDR *hctl;
1390  uint32 max_bucket;
1391  long ssize;
1392  long segment_num;
1393  long segment_ndx;
1394  HASHSEGMENT segp;
1395  uint32 curBucket;
1396  HASHELEMENT *curElem;
1397 
1398  if ((curElem = status->curEntry) != NULL)
1399  {
1400  /* Continuing scan of curBucket... */
1401  status->curEntry = curElem->link;
1402  if (status->curEntry == NULL) /* end of this bucket */
1403  ++status->curBucket;
1404  return (void *) ELEMENTKEY(curElem);
1405  }
1406 
1407  /*
1408  * Search for next nonempty bucket starting at curBucket.
1409  */
1410  curBucket = status->curBucket;
1411  hashp = status->hashp;
1412  hctl = hashp->hctl;
1413  ssize = hashp->ssize;
1414  max_bucket = hctl->max_bucket;
1415 
1416  if (curBucket > max_bucket)
1417  {
1418  hash_seq_term(status);
1419  return NULL; /* search is done */
1420  }
1421 
1422  /*
1423  * first find the right segment in the table directory.
1424  */
1425  segment_num = curBucket >> hashp->sshift;
1426  segment_ndx = MOD(curBucket, ssize);
1427 
1428  segp = hashp->dir[segment_num];
1429 
1430  /*
1431  * Pick up the first item in this bucket's chain. If chain is not empty
1432  * we can begin searching it. Otherwise we have to advance to find the
1433  * next nonempty bucket. We try to optimize that case since searching a
1434  * near-empty hashtable has to iterate this loop a lot.
1435  */
1436  while ((curElem = segp[segment_ndx]) == NULL)
1437  {
1438  /* empty bucket, advance to next */
1439  if (++curBucket > max_bucket)
1440  {
1441  status->curBucket = curBucket;
1442  hash_seq_term(status);
1443  return NULL; /* search is done */
1444  }
1445  if (++segment_ndx >= ssize)
1446  {
1447  segment_num++;
1448  segment_ndx = 0;
1449  segp = hashp->dir[segment_num];
1450  }
1451  }
1452 
1453  /* Begin scan of curBucket... */
1454  status->curEntry = curElem->link;
1455  if (status->curEntry == NULL) /* end of this bucket */
1456  ++curBucket;
1457  status->curBucket = curBucket;
1458  return (void *) ELEMENTKEY(curElem);
1459 }
uint32 curBucket
Definition: hsearch.h:115
uint32 max_bucket
Definition: dynahash.c:174
#define ELEMENTKEY(helem)
Definition: dynahash.c:233
HASHELEMENT * curEntry
Definition: hsearch.h:116
Definition: dynahash.c:208
long ssize
Definition: dynahash.c:226
int sshift
Definition: dynahash.c:227
#define MOD(x, y)
Definition: dynahash.c:244
HASHHDR * hctl
Definition: dynahash.c:210
unsigned int uint32
Definition: c.h:268
HTAB * hashp
Definition: hsearch.h:114
#define NULL
Definition: c.h:229
struct HASHELEMENT * link
Definition: hsearch.h:53
HASHSEGMENT * dir
Definition: dynahash.c:211
void hash_seq_term(HASH_SEQ_STATUS *status)
Definition: dynahash.c:1462
void hash_seq_term ( HASH_SEQ_STATUS status)

Definition at line 1462 of file dynahash.c.

References deregister_seq_scan(), HTAB::frozen, and HASH_SEQ_STATUS::hashp.

Referenced by gc_qtexts(), hash_seq_search(), logicalrep_relmap_invalidate_cb(), pgss_shmem_shutdown(), PortalHashTableDeleteAll(), PreCommit_Portals(), and RelationCacheInitializePhase3().

1463 {
1464  if (!status->hashp->frozen)
1465  deregister_seq_scan(status->hashp);
1466 }
HTAB * hashp
Definition: hsearch.h:114
bool frozen
Definition: dynahash.c:222
static void deregister_seq_scan(HTAB *hashp)
Definition: dynahash.c:1796
void hash_stats ( const char *  where,
HTAB hashp 
)

Definition at line 830 of file dynahash.c.

References hash_get_num_entries(), HTAB::hctl, HASHHDR::keysize, HASHHDR::max_bucket, and HASHHDR::nsegs.

Referenced by hash_destroy().

831 {
832 #if HASH_STATISTICS
833  fprintf(stderr, "%s: this HTAB -- accesses %ld collisions %ld\n",
834  where, hashp->hctl->accesses, hashp->hctl->collisions);
835 
836  fprintf(stderr, "hash_stats: entries %ld keysize %ld maxp %u segmentcount %ld\n",
837  hash_get_num_entries(hashp), (long) hashp->hctl->keysize,
838  hashp->hctl->max_bucket, hashp->hctl->nsegs);
839  fprintf(stderr, "%s: total accesses %ld total collisions %ld\n",
840  where, hash_accesses, hash_collisions);
841  fprintf(stderr, "hash_stats: total expansions %ld\n",
842  hash_expansions);
843 #endif
844 }
Size keysize
Definition: dynahash.c:179
uint32 max_bucket
Definition: dynahash.c:174
long hash_get_num_entries(HTAB *hashp)
Definition: dynahash.c:1332
HASHHDR * hctl
Definition: dynahash.c:210
long nsegs
Definition: dynahash.c:173
bool hash_update_hash_key ( HTAB hashp,
void *  existingEntry,
const void *  newKeyPtr 
)

Definition at line 1112 of file dynahash.c.

References calc_bucket(), HTAB::dir, ELEMENT_FROM_KEY, ELEMENTKEY, elog, ERROR, HTAB::frozen, HTAB::hash, hash_corrupted(), HASHELEMENT::hashvalue, HTAB::hctl, HTAB::keycopy, HTAB::keysize, HASHELEMENT::link, HTAB::match, MOD, NULL, HTAB::sshift, HTAB::ssize, and HTAB::tabname.

Referenced by PostPrepare_Locks().

1115 {
1116  HASHELEMENT *existingElement = ELEMENT_FROM_KEY(existingEntry);
1117  HASHHDR *hctl = hashp->hctl;
1118  uint32 newhashvalue;
1119  Size keysize;
1120  uint32 bucket;
1121  uint32 newbucket;
1122  long segment_num;
1123  long segment_ndx;
1124  HASHSEGMENT segp;
1125  HASHBUCKET currBucket;
1126  HASHBUCKET *prevBucketPtr;
1127  HASHBUCKET *oldPrevPtr;
1128  HashCompareFunc match;
1129 
1130 #if HASH_STATISTICS
1131  hash_accesses++;
1132  hctl->accesses++;
1133 #endif
1134 
1135  /* disallow updates if frozen */
1136  if (hashp->frozen)
1137  elog(ERROR, "cannot update in frozen hashtable \"%s\"",
1138  hashp->tabname);
1139 
1140  /*
1141  * Lookup the existing element using its saved hash value. We need to do
1142  * this to be able to unlink it from its hash chain, but as a side benefit
1143  * we can verify the validity of the passed existingEntry pointer.
1144  */
1145  bucket = calc_bucket(hctl, existingElement->hashvalue);
1146 
1147  segment_num = bucket >> hashp->sshift;
1148  segment_ndx = MOD(bucket, hashp->ssize);
1149 
1150  segp = hashp->dir[segment_num];
1151 
1152  if (segp == NULL)
1153  hash_corrupted(hashp);
1154 
1155  prevBucketPtr = &segp[segment_ndx];
1156  currBucket = *prevBucketPtr;
1157 
1158  while (currBucket != NULL)
1159  {
1160  if (currBucket == existingElement)
1161  break;
1162  prevBucketPtr = &(currBucket->link);
1163  currBucket = *prevBucketPtr;
1164  }
1165 
1166  if (currBucket == NULL)
1167  elog(ERROR, "hash_update_hash_key argument is not in hashtable \"%s\"",
1168  hashp->tabname);
1169 
1170  oldPrevPtr = prevBucketPtr;
1171 
1172  /*
1173  * Now perform the equivalent of a HASH_ENTER operation to locate the hash
1174  * chain we want to put the entry into.
1175  */
1176  newhashvalue = hashp->hash(newKeyPtr, hashp->keysize);
1177 
1178  newbucket = calc_bucket(hctl, newhashvalue);
1179 
1180  segment_num = newbucket >> hashp->sshift;
1181  segment_ndx = MOD(newbucket, hashp->ssize);
1182 
1183  segp = hashp->dir[segment_num];
1184 
1185  if (segp == NULL)
1186  hash_corrupted(hashp);
1187 
1188  prevBucketPtr = &segp[segment_ndx];
1189  currBucket = *prevBucketPtr;
1190 
1191  /*
1192  * Follow collision chain looking for matching key
1193  */
1194  match = hashp->match; /* save one fetch in inner loop */
1195  keysize = hashp->keysize; /* ditto */
1196 
1197  while (currBucket != NULL)
1198  {
1199  if (currBucket->hashvalue == newhashvalue &&
1200  match(ELEMENTKEY(currBucket), newKeyPtr, keysize) == 0)
1201  break;
1202  prevBucketPtr = &(currBucket->link);
1203  currBucket = *prevBucketPtr;
1204 #if HASH_STATISTICS
1205  hash_collisions++;
1206  hctl->collisions++;
1207 #endif
1208  }
1209 
1210  if (currBucket != NULL)
1211  return false; /* collision with an existing entry */
1212 
1213  currBucket = existingElement;
1214 
1215  /*
1216  * If old and new hash values belong to the same bucket, we need not
1217  * change any chain links, and indeed should not since this simplistic
1218  * update will corrupt the list if currBucket is the last element. (We
1219  * cannot fall out earlier, however, since we need to scan the bucket to
1220  * check for duplicate keys.)
1221  */
1222  if (bucket != newbucket)
1223  {
1224  /* OK to remove record from old hash bucket's chain. */
1225  *oldPrevPtr = currBucket->link;
1226 
1227  /* link into new hashbucket chain */
1228  *prevBucketPtr = currBucket;
1229  currBucket->link = NULL;
1230  }
1231 
1232  /* copy new key into record */
1233  currBucket->hashvalue = newhashvalue;
1234  hashp->keycopy(ELEMENTKEY(currBucket), newKeyPtr, keysize);
1235 
1236  /* rest of record is untouched */
1237 
1238  return true;
1239 }
Size keysize
Definition: dynahash.c:225
static uint32 calc_bucket(HASHHDR *hctl, uint32 hash_val)
Definition: dynahash.c:864
#define ELEMENTKEY(helem)
Definition: dynahash.c:233
#define ELEMENT_FROM_KEY(key)
Definition: dynahash.c:238
HashValueFunc hash
Definition: dynahash.c:212
long ssize
Definition: dynahash.c:226
#define ERROR
Definition: elog.h:43
int sshift
Definition: dynahash.c:227
#define MOD(x, y)
Definition: dynahash.c:244
HASHHDR * hctl
Definition: dynahash.c:210
static void hash_corrupted(HTAB *hashp)
Definition: dynahash.c:1701
unsigned int uint32
Definition: c.h:268
HashCompareFunc match
Definition: dynahash.c:213
bool frozen
Definition: dynahash.c:222
HashCopyFunc keycopy
Definition: dynahash.c:214
#define NULL
Definition: c.h:229
size_t Size
Definition: c.h:356
char * tabname
Definition: dynahash.c:217
int(* HashCompareFunc)(const void *key1, const void *key2, Size keysize)
Definition: hsearch.h:29
struct HASHELEMENT * link
Definition: hsearch.h:53
HASHSEGMENT * dir
Definition: dynahash.c:211
#define elog
Definition: elog.h:219
uint32 hashvalue
Definition: hsearch.h:54
static void hdefault ( HTAB hashp)
static

Definition at line 566 of file dynahash.c.

References DEF_DIRSIZE, DEF_FFACTOR, DEF_SEGSIZE, DEF_SEGSIZE_SHIFT, HASHHDR::dsize, HASHHDR::entrysize, HASHHDR::ffactor, HTAB::hctl, HASHHDR::keysize, HASHHDR::max_dsize, MemSet, NO_MAX_DSIZE, HASHHDR::nsegs, HASHHDR::num_partitions, HASHHDR::sshift, and HASHHDR::ssize.

Referenced by hash_create().

567 {
568  HASHHDR *hctl = hashp->hctl;
569 
570  MemSet(hctl, 0, sizeof(HASHHDR));
571 
572  hctl->dsize = DEF_DIRSIZE;
573  hctl->nsegs = 0;
574 
575  /* rather pointless defaults for key & entry size */
576  hctl->keysize = sizeof(char *);
577  hctl->entrysize = 2 * sizeof(char *);
578 
579  hctl->num_partitions = 0; /* not partitioned */
580 
581  hctl->ffactor = DEF_FFACTOR;
582 
583  /* table has no fixed maximum size */
584  hctl->max_dsize = NO_MAX_DSIZE;
585 
586  hctl->ssize = DEF_SEGSIZE;
587  hctl->sshift = DEF_SEGSIZE_SHIFT;
588 
589 #ifdef HASH_STATISTICS
590  hctl->accesses = hctl->collisions = 0;
591 #endif
592 }
Size keysize
Definition: dynahash.c:179
long dsize
Definition: dynahash.c:172
Size entrysize
Definition: dynahash.c:180
#define NO_MAX_DSIZE
Definition: hsearch.h:100
long num_partitions
Definition: dynahash.c:181
#define MemSet(start, val, len)
Definition: c.h:857
long ffactor
Definition: dynahash.c:182
#define DEF_SEGSIZE_SHIFT
Definition: dynahash.c:111
long max_dsize
Definition: dynahash.c:183
HASHHDR * hctl
Definition: dynahash.c:210
long ssize
Definition: dynahash.c:184
int sshift
Definition: dynahash.c:185
#define DEF_FFACTOR
Definition: dynahash.c:113
#define DEF_SEGSIZE
Definition: dynahash.c:110
#define DEF_DIRSIZE
Definition: dynahash.c:112
long nsegs
Definition: dynahash.c:173
static bool init_htab ( HTAB hashp,
long  nelem 
)
static

Definition at line 632 of file dynahash.c.

References HTAB::alloc, choose_nelem_alloc(), HTAB::dir, HASHHDR::dsize, HASHHDR::entrysize, HASHHDR::ffactor, HASHHDR::freeList, hash_get_num_entries(), HTAB::hctl, HTAB::hcxt, HASHHDR::high_mask, i, IS_PARTITIONED, HASHHDR::low_mask, HASHHDR::max_bucket, FreeListData::mutex, HASHHDR::nelem_alloc, next_pow2_int(), HASHHDR::nsegs, NULL, NUM_FREELISTS, seg_alloc(), SpinLockInit, HASHHDR::sshift, and HASHHDR::ssize.

Referenced by hash_create().

633 {
634  HASHHDR *hctl = hashp->hctl;
635  HASHSEGMENT *segp;
636  int nbuckets;
637  int nsegs;
638  int i;
639 
640  /*
641  * initialize mutexes if it's a partitioned table
642  */
643  if (IS_PARTITIONED(hctl))
644  for (i = 0; i < NUM_FREELISTS; i++)
645  SpinLockInit(&(hctl->freeList[i].mutex));
646 
647  /*
648  * Divide number of elements by the fill factor to determine a desired
649  * number of buckets. Allocate space for the next greater power of two
650  * number of buckets
651  */
652  nbuckets = next_pow2_int((nelem - 1) / hctl->ffactor + 1);
653 
654  /*
655  * In a partitioned table, nbuckets must be at least equal to
656  * num_partitions; were it less, keys with apparently different partition
657  * numbers would map to the same bucket, breaking partition independence.
658  * (Normally nbuckets will be much bigger; this is just a safety check.)
659  */
660  while (nbuckets < hctl->num_partitions)
661  nbuckets <<= 1;
662 
663  hctl->max_bucket = hctl->low_mask = nbuckets - 1;
664  hctl->high_mask = (nbuckets << 1) - 1;
665 
666  /*
667  * Figure number of directory segments needed, round up to a power of 2
668  */
669  nsegs = (nbuckets - 1) / hctl->ssize + 1;
670  nsegs = next_pow2_int(nsegs);
671 
672  /*
673  * Make sure directory is big enough. If pre-allocated directory is too
674  * small, choke (caller screwed up).
675  */
676  if (nsegs > hctl->dsize)
677  {
678  if (!(hashp->dir))
679  hctl->dsize = nsegs;
680  else
681  return false;
682  }
683 
684  /* Allocate a directory */
685  if (!(hashp->dir))
686  {
687  CurrentDynaHashCxt = hashp->hcxt;
688  hashp->dir = (HASHSEGMENT *)
689  hashp->alloc(hctl->dsize * sizeof(HASHSEGMENT));
690  if (!hashp->dir)
691  return false;
692  }
693 
694  /* Allocate initial segments */
695  for (segp = hashp->dir; hctl->nsegs < nsegs; hctl->nsegs++, segp++)
696  {
697  *segp = seg_alloc(hashp);
698  if (*segp == NULL)
699  return false;
700  }
701 
702  /* Choose number of entries to allocate at a time */
704 
705 #if HASH_DEBUG
706  fprintf(stderr, "init_htab:\n%s%p\n%s%ld\n%s%ld\n%s%d\n%s%ld\n%s%u\n%s%x\n%s%x\n%s%ld\n%s%ld\n",
707  "TABLE POINTER ", hashp,
708  "DIRECTORY SIZE ", hctl->dsize,
709  "SEGMENT SIZE ", hctl->ssize,
710  "SEGMENT SHIFT ", hctl->sshift,
711  "FILL FACTOR ", hctl->ffactor,
712  "MAX BUCKET ", hctl->max_bucket,
713  "HIGH MASK ", hctl->high_mask,
714  "LOW MASK ", hctl->low_mask,
715  "NSEGS ", hctl->nsegs,
716  "NENTRIES ", hash_get_num_entries(hctl));
717 #endif
718  return true;
719 }
long dsize
Definition: dynahash.c:172
uint32 max_bucket
Definition: dynahash.c:174
Size entrysize
Definition: dynahash.c:180
#define IS_PARTITIONED(hctl)
Definition: dynahash.c:199
#define SpinLockInit(lock)
Definition: spin.h:60
#define NUM_FREELISTS
Definition: dynahash.c:116
HashAllocFunc alloc
Definition: dynahash.c:215
long hash_get_num_entries(HTAB *hashp)
Definition: dynahash.c:1332
slock_t mutex
Definition: dynahash.c:143
uint32 low_mask
Definition: dynahash.c:176
long ffactor
Definition: dynahash.c:182
HASHHDR * hctl
Definition: dynahash.c:210
uint32 high_mask
Definition: dynahash.c:175
static int next_pow2_int(long num)
Definition: dynahash.c:1739
long ssize
Definition: dynahash.c:184
FreeListData freeList[NUM_FREELISTS]
Definition: dynahash.c:168
MemoryContext hcxt
Definition: dynahash.c:216
#define NULL
Definition: c.h:229
int nelem_alloc
Definition: dynahash.c:186
static HASHSEGMENT seg_alloc(HTAB *hashp)
Definition: dynahash.c:1635
static int choose_nelem_alloc(Size entrysize)
Definition: dynahash.c:599
static MemoryContext CurrentDynaHashCxt
Definition: dynahash.c:275
int i
HASHSEGMENT * dir
Definition: dynahash.c:211
int sshift
Definition: dynahash.c:185
long nsegs
Definition: dynahash.c:173
int my_log2 ( long  num)

Definition at line 1715 of file dynahash.c.

References i.

Referenced by ExecChooseHashTableSize(), ExecHashTableCreate(), hash_create(), next_pow2_int(), and next_pow2_long().

1716 {
1717  int i;
1718  long limit;
1719 
1720  /* guard against too-large input, which would put us into infinite loop */
1721  if (num > LONG_MAX / 2)
1722  num = LONG_MAX / 2;
1723 
1724  for (i = 0, limit = 1; limit < num; i++, limit <<= 1)
1725  ;
1726  return i;
1727 }
int i
static int next_pow2_int ( long  num)
static

Definition at line 1739 of file dynahash.c.

References my_log2().

Referenced by hash_create(), and init_htab().

1740 {
1741  if (num > INT_MAX / 2)
1742  num = INT_MAX / 2;
1743  return 1 << my_log2(num);
1744 }
int my_log2(long num)
Definition: dynahash.c:1715
static long next_pow2_long ( long  num)
static

Definition at line 1731 of file dynahash.c.

References my_log2().

Referenced by hash_estimate_size(), and hash_select_dirsize().

1732 {
1733  /* my_log2's internal range check is sufficient */
1734  return 1L << my_log2(num);
1735 }
int my_log2(long num)
Definition: dynahash.c:1715
static void register_seq_scan ( HTAB hashp)
static

Definition at line 1784 of file dynahash.c.

References elog, ERROR, GetCurrentTransactionNestLevel(), MAX_SEQ_SCANS, num_seq_scans, seq_scan_level, and HTAB::tabname.

Referenced by hash_seq_init().

1785 {
1787  elog(ERROR, "too many active hash_seq_search scans, cannot start one on \"%s\"",
1788  hashp->tabname);
1789  seq_scan_tables[num_seq_scans] = hashp;
1791  num_seq_scans++;
1792 }
static int seq_scan_level[MAX_SEQ_SCANS]
Definition: dynahash.c:1778
#define ERROR
Definition: elog.h:43
#define MAX_SEQ_SCANS
Definition: dynahash.c:1775
static int num_seq_scans
Definition: dynahash.c:1779
static HTAB * seq_scan_tables[MAX_SEQ_SCANS]
Definition: dynahash.c:1777
int GetCurrentTransactionNestLevel(void)
Definition: xact.c:761
char * tabname
Definition: dynahash.c:217
#define elog
Definition: elog.h:219
static HASHSEGMENT seg_alloc ( HTAB hashp)
static

Definition at line 1635 of file dynahash.c.

References HTAB::alloc, HTAB::hcxt, MemSet, NULL, and HTAB::ssize.

Referenced by expand_table(), and init_htab().

1636 {
1637  HASHSEGMENT segp;
1638 
1639  CurrentDynaHashCxt = hashp->hcxt;
1640  segp = (HASHSEGMENT) hashp->alloc(sizeof(HASHBUCKET) * hashp->ssize);
1641 
1642  if (!segp)
1643  return NULL;
1644 
1645  MemSet(segp, 0, sizeof(HASHBUCKET) * hashp->ssize);
1646 
1647  return segp;
1648 }
HashAllocFunc alloc
Definition: dynahash.c:215
#define MemSet(start, val, len)
Definition: c.h:857
HASHBUCKET * HASHSEGMENT
Definition: dynahash.c:122
long ssize
Definition: dynahash.c:226
MemoryContext hcxt
Definition: dynahash.c:216
#define NULL
Definition: c.h:229
static MemoryContext CurrentDynaHashCxt
Definition: dynahash.c:275
static int string_compare ( const char *  key1,
const char *  key2,
Size  keysize 
)
static

Definition at line 293 of file dynahash.c.

Referenced by hash_create().

294 {
295  return strncmp(key1, key2, keysize - 1);
296 }

Variable Documentation

MemoryContext CurrentDynaHashCxt = NULL
static

Definition at line 275 of file dynahash.c.

Referenced by hash_create().

int num_seq_scans = 0
static
int seq_scan_level[MAX_SEQ_SCANS]
static

Definition at line 1778 of file dynahash.c.

Referenced by AtEOSubXact_HashTables(), deregister_seq_scan(), and register_seq_scan().

HTAB* seq_scan_tables[MAX_SEQ_SCANS]
static

Definition at line 1777 of file dynahash.c.