PostgreSQL Source Code  git master
dynahash.c File Reference
#include "postgres.h"
#include <limits.h>
#include "access/xact.h"
#include "common/hashfn.h"
#include "port/pg_bitutils.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

◆ DEF_DIRSIZE

#define DEF_DIRSIZE   256

Definition at line 114 of file dynahash.c.

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

◆ DEF_FFACTOR

#define DEF_FFACTOR   1 /* default fill factor */

Definition at line 115 of file dynahash.c.

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

◆ DEF_SEGSIZE

#define DEF_SEGSIZE   256

Definition at line 112 of file dynahash.c.

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

◆ DEF_SEGSIZE_SHIFT

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

Definition at line 113 of file dynahash.c.

Referenced by hdefault().

◆ ELEMENT_FROM_KEY

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

Definition at line 240 of file dynahash.c.

Referenced by hash_update_hash_key().

◆ ELEMENTKEY

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

Definition at line 235 of file dynahash.c.

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

◆ FREELIST_IDX

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

Definition at line 203 of file dynahash.c.

Referenced by hash_search_with_hash_value().

◆ IS_PARTITIONED

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

◆ MAX_SEQ_SCANS

#define MAX_SEQ_SCANS   100

Definition at line 1782 of file dynahash.c.

Referenced by register_seq_scan().

◆ MOD

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

◆ NUM_FREELISTS

#define NUM_FREELISTS   32

Definition at line 118 of file dynahash.c.

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

Typedef Documentation

◆ HASHBUCKET

Definition at line 121 of file dynahash.c.

◆ HASHSEGMENT

Definition at line 124 of file dynahash.c.

Function Documentation

◆ AtEOSubXact_HashTables()

void AtEOSubXact_HashTables ( bool  isCommit,
int  nestDepth 
)

Definition at line 1864 of file dynahash.c.

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

Referenced by AbortSubTransaction(), and CommitSubTransaction().

1865 {
1866  int i;
1867 
1868  /*
1869  * Search backward to make cleanup easy. Note we must check all entries,
1870  * not only those at the end of the array, because deletion technique
1871  * doesn't keep them in order.
1872  */
1873  for (i = num_seq_scans - 1; i >= 0; i--)
1874  {
1875  if (seq_scan_level[i] >= nestDepth)
1876  {
1877  if (isCommit)
1878  elog(WARNING, "leaked hash_seq_search scan for hash table %p",
1879  seq_scan_tables[i]);
1882  num_seq_scans--;
1883  }
1884  }
1885 }
static int seq_scan_level[MAX_SEQ_SCANS]
Definition: dynahash.c:1785
#define WARNING
Definition: elog.h:40
static int num_seq_scans
Definition: dynahash.c:1786
static HTAB * seq_scan_tables[MAX_SEQ_SCANS]
Definition: dynahash.c:1784
#define elog(elevel,...)
Definition: elog.h:214
int i

◆ AtEOXact_HashTables()

void AtEOXact_HashTables ( bool  isCommit)

Definition at line 1838 of file dynahash.c.

References elog, i, num_seq_scans, and WARNING.

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

1839 {
1840  /*
1841  * During abort cleanup, open scans are expected; just silently clean 'em
1842  * out. An open scan at commit means someone forgot a hash_seq_term()
1843  * call, so complain.
1844  *
1845  * Note: it's tempting to try to print the tabname here, but refrain for
1846  * fear of touching deallocated memory. This isn't a user-facing message
1847  * anyway, so it needn't be pretty.
1848  */
1849  if (isCommit)
1850  {
1851  int i;
1852 
1853  for (i = 0; i < num_seq_scans; i++)
1854  {
1855  elog(WARNING, "leaked hash_seq_search scan for hash table %p",
1856  seq_scan_tables[i]);
1857  }
1858  }
1859  num_seq_scans = 0;
1860 }
#define WARNING
Definition: elog.h:40
static int num_seq_scans
Definition: dynahash.c:1786
static HTAB * seq_scan_tables[MAX_SEQ_SCANS]
Definition: dynahash.c:1784
#define elog(elevel,...)
Definition: elog.h:214
int i

◆ calc_bucket()

static uint32 calc_bucket ( HASHHDR hctl,
uint32  hash_val 
)
inlinestatic

Definition at line 869 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().

870 {
871  uint32 bucket;
872 
873  bucket = hash_val & hctl->high_mask;
874  if (bucket > hctl->max_bucket)
875  bucket = bucket & hctl->low_mask;
876 
877  return bucket;
878 }
uint32 max_bucket
Definition: dynahash.c:176
uint32 low_mask
Definition: dynahash.c:178
unsigned int uint32
Definition: c.h:367
uint32 high_mask
Definition: dynahash.c:177

◆ choose_nelem_alloc()

static int choose_nelem_alloc ( Size  entrysize)
static

Definition at line 605 of file dynahash.c.

References MAXALIGN, and HASHHDR::nelem_alloc.

Referenced by hash_estimate_size(), and init_htab().

606 {
607  int nelem_alloc;
608  Size elementSize;
609  Size allocSize;
610 
611  /* Each element has a HASHELEMENT header plus user data. */
612  /* NB: this had better match element_alloc() */
613  elementSize = MAXALIGN(sizeof(HASHELEMENT)) + MAXALIGN(entrysize);
614 
615  /*
616  * The idea here is to choose nelem_alloc at least 32, but round up so
617  * that the allocation request will be a power of 2 or just less. This
618  * makes little difference for hash tables in shared memory, but for hash
619  * tables managed by palloc, the allocation request will be rounded up to
620  * a power of 2 anyway. If we fail to take this into account, we'll waste
621  * as much as half the allocated space.
622  */
623  allocSize = 32 * 4; /* assume elementSize at least 8 */
624  do
625  {
626  allocSize <<= 1;
627  nelem_alloc = allocSize / elementSize;
628  } while (nelem_alloc < 32);
629 
630  return nelem_alloc;
631 }
size_t Size
Definition: c.h:466
#define MAXALIGN(LEN)
Definition: c.h:691

◆ deregister_seq_scan()

static void deregister_seq_scan ( HTAB hashp)
static

Definition at line 1803 of file dynahash.c.

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

Referenced by hash_seq_term().

1804 {
1805  int i;
1806 
1807  /* Search backward since it's most likely at the stack top */
1808  for (i = num_seq_scans - 1; i >= 0; i--)
1809  {
1810  if (seq_scan_tables[i] == hashp)
1811  {
1814  num_seq_scans--;
1815  return;
1816  }
1817  }
1818  elog(ERROR, "no hash_seq_search scan for hash table \"%s\"",
1819  hashp->tabname);
1820 }
static int seq_scan_level[MAX_SEQ_SCANS]
Definition: dynahash.c:1785
#define ERROR
Definition: elog.h:43
static int num_seq_scans
Definition: dynahash.c:1786
static HTAB * seq_scan_tables[MAX_SEQ_SCANS]
Definition: dynahash.c:1784
char * tabname
Definition: dynahash.c:219
#define elog(elevel,...)
Definition: elog.h:214
int i

◆ dir_realloc()

static bool dir_realloc ( HTAB hashp)
static

Definition at line 1601 of file dynahash.c.

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

Referenced by expand_table().

1602 {
1603  HASHSEGMENT *p;
1604  HASHSEGMENT *old_p;
1605  long new_dsize;
1606  long old_dirsize;
1607  long new_dirsize;
1608 
1609  if (hashp->hctl->max_dsize != NO_MAX_DSIZE)
1610  return false;
1611 
1612  /* Reallocate directory */
1613  new_dsize = hashp->hctl->dsize << 1;
1614  old_dirsize = hashp->hctl->dsize * sizeof(HASHSEGMENT);
1615  new_dirsize = new_dsize * sizeof(HASHSEGMENT);
1616 
1617  old_p = hashp->dir;
1618  CurrentDynaHashCxt = hashp->hcxt;
1619  p = (HASHSEGMENT *) hashp->alloc((Size) new_dirsize);
1620 
1621  if (p != NULL)
1622  {
1623  memcpy(p, old_p, old_dirsize);
1624  MemSet(((char *) p) + old_dirsize, 0, new_dirsize - old_dirsize);
1625  hashp->dir = p;
1626  hashp->hctl->dsize = new_dsize;
1627 
1628  /* XXX assume the allocator is palloc, so we know how to free */
1629  Assert(hashp->alloc == DynaHashAlloc);
1630  pfree(old_p);
1631 
1632  return true;
1633  }
1634 
1635  return false;
1636 }
long dsize
Definition: dynahash.c:174
#define NO_MAX_DSIZE
Definition: hsearch.h:100
HashAllocFunc alloc
Definition: dynahash.c:217
#define MemSet(start, val, len)
Definition: c.h:971
void pfree(void *pointer)
Definition: mcxt.c:1056
HASHBUCKET * HASHSEGMENT
Definition: dynahash.c:124
long max_dsize
Definition: dynahash.c:185
HASHHDR * hctl
Definition: dynahash.c:212
MemoryContext hcxt
Definition: dynahash.c:218
#define Assert(condition)
Definition: c.h:738
size_t Size
Definition: c.h:466
static void * DynaHashAlloc(Size size)
Definition: dynahash.c:280
static MemoryContext CurrentDynaHashCxt
Definition: dynahash.c:277
HASHSEGMENT * dir
Definition: dynahash.c:213

◆ DynaHashAlloc()

static void * DynaHashAlloc ( Size  size)
static

Definition at line 280 of file dynahash.c.

References Assert, MemoryContextAlloc(), and MemoryContextIsValid.

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

281 {
284 }
#define MemoryContextIsValid(context)
Definition: memnodes.h:102
#define Assert(condition)
Definition: c.h:738
void * MemoryContextAlloc(MemoryContext context, Size size)
Definition: mcxt.c:796
static MemoryContext CurrentDynaHashCxt
Definition: dynahash.c:277

◆ element_alloc()

static bool element_alloc ( HTAB hashp,
int  nelem,
int  freelist_idx 
)
static

Definition at line 1659 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, SpinLockAcquire, and SpinLockRelease.

Referenced by get_hash_entry(), and hash_create().

1660 {
1661  HASHHDR *hctl = hashp->hctl;
1662  Size elementSize;
1663  HASHELEMENT *firstElement;
1664  HASHELEMENT *tmpElement;
1665  HASHELEMENT *prevElement;
1666  int i;
1667 
1668  if (hashp->isfixed)
1669  return false;
1670 
1671  /* Each element has a HASHELEMENT header plus user data. */
1672  elementSize = MAXALIGN(sizeof(HASHELEMENT)) + MAXALIGN(hctl->entrysize);
1673 
1674  CurrentDynaHashCxt = hashp->hcxt;
1675  firstElement = (HASHELEMENT *) hashp->alloc(nelem * elementSize);
1676 
1677  if (!firstElement)
1678  return false;
1679 
1680  /* prepare to link all the new entries into the freelist */
1681  prevElement = NULL;
1682  tmpElement = firstElement;
1683  for (i = 0; i < nelem; i++)
1684  {
1685  tmpElement->link = prevElement;
1686  prevElement = tmpElement;
1687  tmpElement = (HASHELEMENT *) (((char *) tmpElement) + elementSize);
1688  }
1689 
1690  /* if partitioned, must lock to touch freeList */
1691  if (IS_PARTITIONED(hctl))
1692  SpinLockAcquire(&hctl->freeList[freelist_idx].mutex);
1693 
1694  /* freelist could be nonempty if two backends did this concurrently */
1695  firstElement->link = hctl->freeList[freelist_idx].freeList;
1696  hctl->freeList[freelist_idx].freeList = prevElement;
1697 
1698  if (IS_PARTITIONED(hctl))
1699  SpinLockRelease(&hctl->freeList[freelist_idx].mutex);
1700 
1701  return true;
1702 }
Size entrysize
Definition: dynahash.c:182
#define IS_PARTITIONED(hctl)
Definition: dynahash.c:201
HashAllocFunc alloc
Definition: dynahash.c:217
slock_t mutex
Definition: dynahash.c:145
#define SpinLockAcquire(lock)
Definition: spin.h:62
HASHHDR * hctl
Definition: dynahash.c:212
#define SpinLockRelease(lock)
Definition: spin.h:64
FreeListData freeList[NUM_FREELISTS]
Definition: dynahash.c:170
MemoryContext hcxt
Definition: dynahash.c:218
size_t Size
Definition: c.h:466
#define MAXALIGN(LEN)
Definition: c.h:691
bool isfixed
Definition: dynahash.c:221
struct HASHELEMENT * link
Definition: hsearch.h:53
static MemoryContext CurrentDynaHashCxt
Definition: dynahash.c:277
int i
HASHELEMENT * freeList
Definition: dynahash.c:147

◆ expand_table()

static bool expand_table ( HTAB hashp)
static

Definition at line 1504 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, seg_alloc(), HTAB::sshift, and HTAB::ssize.

Referenced by hash_search_with_hash_value().

1505 {
1506  HASHHDR *hctl = hashp->hctl;
1507  HASHSEGMENT old_seg,
1508  new_seg;
1509  long old_bucket,
1510  new_bucket;
1511  long new_segnum,
1512  new_segndx;
1513  long old_segnum,
1514  old_segndx;
1515  HASHBUCKET *oldlink,
1516  *newlink;
1517  HASHBUCKET currElement,
1518  nextElement;
1519 
1520  Assert(!IS_PARTITIONED(hctl));
1521 
1522 #ifdef HASH_STATISTICS
1523  hash_expansions++;
1524 #endif
1525 
1526  new_bucket = hctl->max_bucket + 1;
1527  new_segnum = new_bucket >> hashp->sshift;
1528  new_segndx = MOD(new_bucket, hashp->ssize);
1529 
1530  if (new_segnum >= hctl->nsegs)
1531  {
1532  /* Allocate new segment if necessary -- could fail if dir full */
1533  if (new_segnum >= hctl->dsize)
1534  if (!dir_realloc(hashp))
1535  return false;
1536  if (!(hashp->dir[new_segnum] = seg_alloc(hashp)))
1537  return false;
1538  hctl->nsegs++;
1539  }
1540 
1541  /* OK, we created a new bucket */
1542  hctl->max_bucket++;
1543 
1544  /*
1545  * *Before* changing masks, find old bucket corresponding to same hash
1546  * values; values in that bucket may need to be relocated to new bucket.
1547  * Note that new_bucket is certainly larger than low_mask at this point,
1548  * so we can skip the first step of the regular hash mask calc.
1549  */
1550  old_bucket = (new_bucket & hctl->low_mask);
1551 
1552  /*
1553  * If we crossed a power of 2, readjust masks.
1554  */
1555  if ((uint32) new_bucket > hctl->high_mask)
1556  {
1557  hctl->low_mask = hctl->high_mask;
1558  hctl->high_mask = (uint32) new_bucket | hctl->low_mask;
1559  }
1560 
1561  /*
1562  * Relocate records to the new bucket. NOTE: because of the way the hash
1563  * masking is done in calc_bucket, only one old bucket can need to be
1564  * split at this point. With a different way of reducing the hash value,
1565  * that might not be true!
1566  */
1567  old_segnum = old_bucket >> hashp->sshift;
1568  old_segndx = MOD(old_bucket, hashp->ssize);
1569 
1570  old_seg = hashp->dir[old_segnum];
1571  new_seg = hashp->dir[new_segnum];
1572 
1573  oldlink = &old_seg[old_segndx];
1574  newlink = &new_seg[new_segndx];
1575 
1576  for (currElement = *oldlink;
1577  currElement != NULL;
1578  currElement = nextElement)
1579  {
1580  nextElement = currElement->link;
1581  if ((long) calc_bucket(hctl, currElement->hashvalue) == old_bucket)
1582  {
1583  *oldlink = currElement;
1584  oldlink = &currElement->link;
1585  }
1586  else
1587  {
1588  *newlink = currElement;
1589  newlink = &currElement->link;
1590  }
1591  }
1592  /* don't forget to terminate the rebuilt hash chains... */
1593  *oldlink = NULL;
1594  *newlink = NULL;
1595 
1596  return true;
1597 }
long dsize
Definition: dynahash.c:174
uint32 max_bucket
Definition: dynahash.c:176
static uint32 calc_bucket(HASHHDR *hctl, uint32 hash_val)
Definition: dynahash.c:869
#define IS_PARTITIONED(hctl)
Definition: dynahash.c:201
uint32 low_mask
Definition: dynahash.c:178
long ssize
Definition: dynahash.c:228
int sshift
Definition: dynahash.c:229
#define MOD(x, y)
Definition: dynahash.c:246
HASHHDR * hctl
Definition: dynahash.c:212
unsigned int uint32
Definition: c.h:367
uint32 high_mask
Definition: dynahash.c:177
#define Assert(condition)
Definition: c.h:738
static HASHSEGMENT seg_alloc(HTAB *hashp)
Definition: dynahash.c:1640
struct HASHELEMENT * link
Definition: hsearch.h:53
HASHSEGMENT * dir
Definition: dynahash.c:213
static bool dir_realloc(HTAB *hashp)
Definition: dynahash.c:1601
uint32 hashvalue
Definition: hsearch.h:54
long nsegs
Definition: dynahash.c:175

◆ get_hash_entry()

static HASHBUCKET get_hash_entry ( HTAB hashp,
int  freelist_idx 
)
static

Definition at line 1252 of file dynahash.c.

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

Referenced by hash_search_with_hash_value().

1253 {
1254  HASHHDR *hctl = hashp->hctl;
1255  HASHBUCKET newElement;
1256 
1257  for (;;)
1258  {
1259  /* if partitioned, must lock to touch nentries and freeList */
1260  if (IS_PARTITIONED(hctl))
1261  SpinLockAcquire(&hctl->freeList[freelist_idx].mutex);
1262 
1263  /* try to get an entry from the freelist */
1264  newElement = hctl->freeList[freelist_idx].freeList;
1265 
1266  if (newElement != NULL)
1267  break;
1268 
1269  if (IS_PARTITIONED(hctl))
1270  SpinLockRelease(&hctl->freeList[freelist_idx].mutex);
1271 
1272  /*
1273  * No free elements in this freelist. In a partitioned table, there
1274  * might be entries in other freelists, but to reduce contention we
1275  * prefer to first try to get another chunk of buckets from the main
1276  * shmem allocator. If that fails, though, we *MUST* root through all
1277  * the other freelists before giving up. There are multiple callers
1278  * that assume that they can allocate every element in the initially
1279  * requested table size, or that deleting an element guarantees they
1280  * can insert a new element, even if shared memory is entirely full.
1281  * Failing because the needed element is in a different freelist is
1282  * not acceptable.
1283  */
1284  if (!element_alloc(hashp, hctl->nelem_alloc, freelist_idx))
1285  {
1286  int borrow_from_idx;
1287 
1288  if (!IS_PARTITIONED(hctl))
1289  return NULL; /* out of memory */
1290 
1291  /* try to borrow element from another freelist */
1292  borrow_from_idx = freelist_idx;
1293  for (;;)
1294  {
1295  borrow_from_idx = (borrow_from_idx + 1) % NUM_FREELISTS;
1296  if (borrow_from_idx == freelist_idx)
1297  break; /* examined all freelists, fail */
1298 
1299  SpinLockAcquire(&(hctl->freeList[borrow_from_idx].mutex));
1300  newElement = hctl->freeList[borrow_from_idx].freeList;
1301 
1302  if (newElement != NULL)
1303  {
1304  hctl->freeList[borrow_from_idx].freeList = newElement->link;
1305  SpinLockRelease(&(hctl->freeList[borrow_from_idx].mutex));
1306 
1307  /* careful: count the new element in its proper freelist */
1308  SpinLockAcquire(&hctl->freeList[freelist_idx].mutex);
1309  hctl->freeList[freelist_idx].nentries++;
1310  SpinLockRelease(&hctl->freeList[freelist_idx].mutex);
1311 
1312  return newElement;
1313  }
1314 
1315  SpinLockRelease(&(hctl->freeList[borrow_from_idx].mutex));
1316  }
1317 
1318  /* no elements available to borrow either, so out of memory */
1319  return NULL;
1320  }
1321  }
1322 
1323  /* remove entry from freelist, bump nentries */
1324  hctl->freeList[freelist_idx].freeList = newElement->link;
1325  hctl->freeList[freelist_idx].nentries++;
1326 
1327  if (IS_PARTITIONED(hctl))
1328  SpinLockRelease(&hctl->freeList[freelist_idx].mutex);
1329 
1330  return newElement;
1331 }
#define IS_PARTITIONED(hctl)
Definition: dynahash.c:201
#define NUM_FREELISTS
Definition: dynahash.c:118
slock_t mutex
Definition: dynahash.c:145
#define SpinLockAcquire(lock)
Definition: spin.h:62
HASHHDR * hctl
Definition: dynahash.c:212
long nentries
Definition: dynahash.c:146
#define SpinLockRelease(lock)
Definition: spin.h:64
FreeListData freeList[NUM_FREELISTS]
Definition: dynahash.c:170
int nelem_alloc
Definition: dynahash.c:188
struct HASHELEMENT * link
Definition: hsearch.h:53
HASHELEMENT * freeList
Definition: dynahash.c:147
static bool element_alloc(HTAB *hashp, int nelem, int freelist_idx)
Definition: dynahash.c:1659

◆ get_hash_value()

uint32 get_hash_value ( HTAB hashp,
const void *  keyPtr 
)

Definition at line 862 of file dynahash.c.

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

Referenced by BufTableHashCode(), and LockTagHashCode().

863 {
864  return hashp->hash(keyPtr, hashp->keysize);
865 }
Size keysize
Definition: dynahash.c:227
HashValueFunc hash
Definition: dynahash.c:214

◆ has_seq_scans()

static bool has_seq_scans ( HTAB hashp)
static

Definition at line 1824 of file dynahash.c.

References i, and num_seq_scans.

Referenced by hash_freeze(), and hash_search_with_hash_value().

1825 {
1826  int i;
1827 
1828  for (i = 0; i < num_seq_scans; i++)
1829  {
1830  if (seq_scan_tables[i] == hashp)
1831  return true;
1832  }
1833  return false;
1834 }
static int num_seq_scans
Definition: dynahash.c:1786
static HTAB * seq_scan_tables[MAX_SEQ_SCANS]
Definition: dynahash.c:1784
int i

◆ hash_corrupted()

static void hash_corrupted ( HTAB hashp)
static

Definition at line 1706 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().

1707 {
1708  /*
1709  * If the corruption is in a shared hashtable, we'd better force a
1710  * systemwide restart. Otherwise, just shut down this one backend.
1711  */
1712  if (hashp->isshared)
1713  elog(PANIC, "hash table \"%s\" corrupted", hashp->tabname);
1714  else
1715  elog(FATAL, "hash table \"%s\" corrupted", hashp->tabname);
1716 }
#define PANIC
Definition: elog.h:53
#define FATAL
Definition: elog.h:52
bool isshared
Definition: dynahash.c:220
char * tabname
Definition: dynahash.c:219
#define elog(elevel,...)
Definition: elog.h:214

◆ hash_create()

HTAB* hash_create ( const char *  tabname,
long  nelem,
HASHCTL info,
int  flags 
)

Definition at line 318 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, MemoryContextSetIdentifier(), MemSet, my_log2(), HASHHDR::nelem_alloc, next_pow2_int(), 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(), AddEventToPendingNotifies(), AddPendingSync(), assign_record_type_typmod(), begin_heap_rewrite(), build_join_rel_hash(), BuildEventTriggerCache(), CompactCheckpointerRequestQueue(), compute_array_stats(), compute_tsvector_stats(), create_seq_hashtable(), createConnHash(), CreateLocalPredicateLockHash(), CreatePartitionDirectory(), do_autovacuum(), EnablePortalManager(), ExecHashSubPlanResultRelsByOid(), find_all_inheritors(), find_oper_cache_entry(), find_rendezvous_variable(), get_json_object_as_hash(), get_tabstat_entry(), GetComboCommandId(), GetConnection(), gistInitBuildBuffers(), gistInitParentMap(), init_enum_blacklist(), init_procedure_caches(), init_rel_sync_cache(), init_timezone_hashtable(), init_ts_config_cache(), InitBufferPoolAccess(), InitializeAttoptCache(), InitializeRelfilenodeMap(), InitializeShippableCache(), InitializeTableSpaceCache(), InitLocalBuffers(), InitLocks(), InitQueryHashTable(), InitRecoveryTransactionEnvironment(), InitSync(), load_categories_hash(), log_invalid_page(), logical_begin_heap_rewrite(), logicalrep_partmap_init(), logicalrep_relmap_init(), lookup_collation_cache(), lookup_proof_cache(), lookup_ts_dictionary_cache(), lookup_ts_parser_cache(), lookup_type_cache(), LookupOpclassInfo(), 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(), SerializePendingSyncs(), set_rtable_names(), ShmemInitHash(), smgropen(), and transformGraph().

319 {
320  HTAB *hashp;
321  HASHHDR *hctl;
322 
323  /*
324  * For shared hash tables, we have a local hash header (HTAB struct) that
325  * we allocate in TopMemoryContext; all else is in shared memory.
326  *
327  * For non-shared hash tables, everything including the hash header is in
328  * a memory context created specially for the hash table --- this makes
329  * hash_destroy very simple. The memory context is made a child of either
330  * a context specified by the caller, or TopMemoryContext if nothing is
331  * specified.
332  */
333  if (flags & HASH_SHARED_MEM)
334  {
335  /* Set up to allocate the hash header */
337  }
338  else
339  {
340  /* Create the hash table's private memory context */
341  if (flags & HASH_CONTEXT)
342  CurrentDynaHashCxt = info->hcxt;
343  else
346  "dynahash",
348  }
349 
350  /* Initialize the hash header, plus a copy of the table name */
351  hashp = (HTAB *) DynaHashAlloc(sizeof(HTAB) + strlen(tabname) + 1);
352  MemSet(hashp, 0, sizeof(HTAB));
353 
354  hashp->tabname = (char *) (hashp + 1);
355  strcpy(hashp->tabname, tabname);
356 
357  /* If we have a private context, label it with hashtable's name */
358  if (!(flags & HASH_SHARED_MEM))
360 
361  /*
362  * Select the appropriate hash function (see comments at head of file).
363  */
364  if (flags & HASH_FUNCTION)
365  hashp->hash = info->hash;
366  else if (flags & HASH_BLOBS)
367  {
368  /* We can optimize hashing for common key sizes */
369  Assert(flags & HASH_ELEM);
370  if (info->keysize == sizeof(uint32))
371  hashp->hash = uint32_hash;
372  else
373  hashp->hash = tag_hash;
374  }
375  else
376  hashp->hash = string_hash; /* default hash function */
377 
378  /*
379  * If you don't specify a match function, it defaults to string_compare if
380  * you used string_hash (either explicitly or by default) and to memcmp
381  * otherwise.
382  *
383  * Note: explicitly specifying string_hash is deprecated, because this
384  * might not work for callers in loadable modules on some platforms due to
385  * referencing a trampoline instead of the string_hash function proper.
386  * Just let it default, eh?
387  */
388  if (flags & HASH_COMPARE)
389  hashp->match = info->match;
390  else if (hashp->hash == string_hash)
392  else
393  hashp->match = memcmp;
394 
395  /*
396  * Similarly, the key-copying function defaults to strlcpy or memcpy.
397  */
398  if (flags & HASH_KEYCOPY)
399  hashp->keycopy = info->keycopy;
400  else if (hashp->hash == string_hash)
401  hashp->keycopy = (HashCopyFunc) strlcpy;
402  else
403  hashp->keycopy = memcpy;
404 
405  /* And select the entry allocation function, too. */
406  if (flags & HASH_ALLOC)
407  hashp->alloc = info->alloc;
408  else
409  hashp->alloc = DynaHashAlloc;
410 
411  if (flags & HASH_SHARED_MEM)
412  {
413  /*
414  * ctl structure and directory are preallocated for shared memory
415  * tables. Note that HASH_DIRSIZE and HASH_ALLOC had better be set as
416  * well.
417  */
418  hashp->hctl = info->hctl;
419  hashp->dir = (HASHSEGMENT *) (((char *) info->hctl) + sizeof(HASHHDR));
420  hashp->hcxt = NULL;
421  hashp->isshared = true;
422 
423  /* hash table already exists, we're just attaching to it */
424  if (flags & HASH_ATTACH)
425  {
426  /* make local copies of some heavily-used values */
427  hctl = hashp->hctl;
428  hashp->keysize = hctl->keysize;
429  hashp->ssize = hctl->ssize;
430  hashp->sshift = hctl->sshift;
431 
432  return hashp;
433  }
434  }
435  else
436  {
437  /* setup hash table defaults */
438  hashp->hctl = NULL;
439  hashp->dir = NULL;
440  hashp->hcxt = CurrentDynaHashCxt;
441  hashp->isshared = false;
442  }
443 
444  if (!hashp->hctl)
445  {
446  hashp->hctl = (HASHHDR *) hashp->alloc(sizeof(HASHHDR));
447  if (!hashp->hctl)
448  ereport(ERROR,
449  (errcode(ERRCODE_OUT_OF_MEMORY),
450  errmsg("out of memory")));
451  }
452 
453  hashp->frozen = false;
454 
455  hdefault(hashp);
456 
457  hctl = hashp->hctl;
458 
459  if (flags & HASH_PARTITION)
460  {
461  /* Doesn't make sense to partition a local hash table */
462  Assert(flags & HASH_SHARED_MEM);
463 
464  /*
465  * The number of partitions had better be a power of 2. Also, it must
466  * be less than INT_MAX (see init_htab()), so call the int version of
467  * next_pow2.
468  */
470 
471  hctl->num_partitions = info->num_partitions;
472  }
473 
474  if (flags & HASH_SEGMENT)
475  {
476  hctl->ssize = info->ssize;
477  hctl->sshift = my_log2(info->ssize);
478  /* ssize had better be a power of 2 */
479  Assert(hctl->ssize == (1L << hctl->sshift));
480  }
481  if (flags & HASH_FFACTOR)
482  hctl->ffactor = info->ffactor;
483 
484  /*
485  * SHM hash tables have fixed directory size passed by the caller.
486  */
487  if (flags & HASH_DIRSIZE)
488  {
489  hctl->max_dsize = info->max_dsize;
490  hctl->dsize = info->dsize;
491  }
492 
493  /*
494  * hash table now allocates space for key and data but you have to say how
495  * much space to allocate
496  */
497  if (flags & HASH_ELEM)
498  {
499  Assert(info->entrysize >= info->keysize);
500  hctl->keysize = info->keysize;
501  hctl->entrysize = info->entrysize;
502  }
503 
504  /* make local copies of heavily-used constant fields */
505  hashp->keysize = hctl->keysize;
506  hashp->ssize = hctl->ssize;
507  hashp->sshift = hctl->sshift;
508 
509  /* Build the hash directory structure */
510  if (!init_htab(hashp, nelem))
511  elog(ERROR, "failed to initialize hash table \"%s\"", hashp->tabname);
512 
513  /*
514  * For a shared hash table, preallocate the requested number of elements.
515  * This reduces problems with run-time out-of-shared-memory conditions.
516  *
517  * For a non-shared hash table, preallocate the requested number of
518  * elements if it's less than our chosen nelem_alloc. This avoids wasting
519  * space if the caller correctly estimates a small table size.
520  */
521  if ((flags & HASH_SHARED_MEM) ||
522  nelem < hctl->nelem_alloc)
523  {
524  int i,
525  freelist_partitions,
526  nelem_alloc,
527  nelem_alloc_first;
528 
529  /*
530  * If hash table is partitioned, give each freelist an equal share of
531  * the initial allocation. Otherwise only freeList[0] is used.
532  */
533  if (IS_PARTITIONED(hashp->hctl))
534  freelist_partitions = NUM_FREELISTS;
535  else
536  freelist_partitions = 1;
537 
538  nelem_alloc = nelem / freelist_partitions;
539  if (nelem_alloc <= 0)
540  nelem_alloc = 1;
541 
542  /*
543  * Make sure we'll allocate all the requested elements; freeList[0]
544  * gets the excess if the request isn't divisible by NUM_FREELISTS.
545  */
546  if (nelem_alloc * freelist_partitions < nelem)
547  nelem_alloc_first =
548  nelem - nelem_alloc * (freelist_partitions - 1);
549  else
550  nelem_alloc_first = nelem_alloc;
551 
552  for (i = 0; i < freelist_partitions; i++)
553  {
554  int temp = (i == 0) ? nelem_alloc_first : nelem_alloc;
555 
556  if (!element_alloc(hashp, temp, i))
557  ereport(ERROR,
558  (errcode(ERRCODE_OUT_OF_MEMORY),
559  errmsg("out of memory")));
560  }
561  }
562 
563  if (flags & HASH_FIXED_SIZE)
564  hashp->isfixed = true;
565  return hashp;
566 }
int(* HashCompareFunc)(const void *key1, const void *key2, Size keysize)
Definition: hsearch.h:29
Size keysize
Definition: dynahash.c:181
Size keysize
Definition: dynahash.c:227
long dsize
Definition: dynahash.c:174
#define AllocSetContextCreate
Definition: memutils.h:170
#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:182
#define IS_PARTITIONED(hctl)
Definition: dynahash.c:201
uint32 string_hash(const void *key, Size keysize)
Definition: hashfn.c:660
long num_partitions
Definition: dynahash.c:183
Size entrysize
Definition: hsearch.h:73
#define NUM_FREELISTS
Definition: dynahash.c:118
int errcode(int sqlerrcode)
Definition: elog.c:610
HashAllocFunc alloc
Definition: dynahash.c:217
#define MemSet(start, val, len)
Definition: c.h:971
#define HASH_SHARED_MEM
Definition: hsearch.h:94
static int string_compare(const char *key1, const char *key2, Size keysize)
Definition: dynahash.c:295
long dsize
Definition: hsearch.h:69
uint32 uint32_hash(const void *key, Size keysize)
Definition: hashfn.c:688
#define HASH_PARTITION
Definition: hsearch.h:83
#define HASH_ATTACH
Definition: hsearch.h:95
long ffactor
Definition: dynahash.c:184
HashValueFunc hash
Definition: dynahash.c:214
Definition: dynahash.c:210
long max_dsize
Definition: hsearch.h:70
long ssize
Definition: dynahash.c:228
#define ERROR
Definition: elog.h:43
long num_partitions
Definition: hsearch.h:67
int sshift
Definition: dynahash.c:229
#define ALLOCSET_DEFAULT_SIZES
Definition: memutils.h:192
HashAllocFunc alloc
Definition: hsearch.h:77
#define HASH_KEYCOPY
Definition: hsearch.h:91
long max_dsize
Definition: dynahash.c:185
static void hdefault(HTAB *hashp)
Definition: dynahash.c:572
HASHHDR * hctl
Definition: dynahash.c:212
unsigned int uint32
Definition: c.h:367
static bool init_htab(HTAB *hashp, long nelem)
Definition: dynahash.c:638
MemoryContext TopMemoryContext
Definition: mcxt.c:44
int my_log2(long num)
Definition: dynahash.c:1720
HashCompareFunc match
Definition: dynahash.c:215
static int next_pow2_int(long num)
Definition: dynahash.c:1746
bool isshared
Definition: dynahash.c:220
#define HASH_BLOBS
Definition: hsearch.h:88
bool frozen
Definition: dynahash.c:224
uint32 tag_hash(const void *key, Size keysize)
Definition: hashfn.c:677
long ssize
Definition: dynahash.c:186
Size keysize
Definition: hsearch.h:72
void *(* HashCopyFunc)(void *dest, const void *src, Size keysize)
Definition: hsearch.h:37
HashCompareFunc match
Definition: hsearch.h:75
MemoryContext hcxt
Definition: dynahash.c:218
#define ereport(elevel,...)
Definition: elog.h:144
HashCopyFunc keycopy
Definition: dynahash.c:216
#define HASH_SEGMENT
Definition: hsearch.h:84
size_t strlcpy(char *dst, const char *src, size_t siz)
Definition: strlcpy.c:45
#define Assert(condition)
Definition: c.h:738
#define HASH_COMPARE
Definition: hsearch.h:90
void MemoryContextSetIdentifier(MemoryContext context, const char *id)
Definition: mcxt.c:329
HASHHDR * hctl
Definition: hsearch.h:79
long ffactor
Definition: hsearch.h:71
char * tabname
Definition: dynahash.c:219
#define HASH_FIXED_SIZE
Definition: hsearch.h:96
bool isfixed
Definition: dynahash.c:221
#define HASH_FFACTOR
Definition: hsearch.h:86
static void * DynaHashAlloc(Size size)
Definition: dynahash.c:280
#define HASH_DIRSIZE
Definition: hsearch.h:85
int errmsg(const char *fmt,...)
Definition: elog.c:824
#define elog(elevel,...)
Definition: elog.h:214
static MemoryContext CurrentDynaHashCxt
Definition: dynahash.c:277
int i
#define HASH_ALLOC
Definition: hsearch.h:92
HASHSEGMENT * dir
Definition: dynahash.c:213
static bool element_alloc(HTAB *hashp, int nelem, int freelist_idx)
Definition: dynahash.c:1659
int sshift
Definition: dynahash.c:187
HashValueFunc hash
Definition: hsearch.h:74
#define HASH_FUNCTION
Definition: hsearch.h:89

◆ hash_destroy()

void hash_destroy ( HTAB hashp)

Definition at line 816 of file dynahash.c.

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

Referenced by _hash_finish_split(), clear_external_function_hash(), CompactCheckpointerRequestQueue(), EnableSyncRequestForwarding(), 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(), ReleasePredicateLocksLocal(), ReorderBufferReturnTXN(), ReorderBufferToastReset(), ResetSequenceCaches(), ResetUnloggedRelationsInDbspaceDir(), SerializePendingSyncs(), set_rtable_names(), ShutdownRecoveryTransactionEnvironment(), and XLogCheckInvalidPages().

817 {
818  if (hashp != NULL)
819  {
820  /* allocation method must be one we know how to free, too */
821  Assert(hashp->alloc == DynaHashAlloc);
822  /* so this hashtable must have its own context */
823  Assert(hashp->hcxt != NULL);
824 
825  hash_stats("destroy", hashp);
826 
827  /*
828  * Free everything by destroying the hash table's memory context.
829  */
830  MemoryContextDelete(hashp->hcxt);
831  }
832 }
void MemoryContextDelete(MemoryContext context)
Definition: mcxt.c:211
void hash_stats(const char *where, HTAB *hashp)
Definition: dynahash.c:835
HashAllocFunc alloc
Definition: dynahash.c:217
MemoryContext hcxt
Definition: dynahash.c:218
#define Assert(condition)
Definition: c.h:738
static void * DynaHashAlloc(Size size)
Definition: dynahash.c:280

◆ hash_estimate_size()

Size hash_estimate_size ( long  num_entries,
Size  entrysize 
)

Definition at line 734 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().

735 {
736  Size size;
737  long nBuckets,
738  nSegments,
739  nDirEntries,
740  nElementAllocs,
741  elementSize,
742  elementAllocCnt;
743 
744  /* estimate number of buckets wanted */
745  nBuckets = next_pow2_long((num_entries - 1) / DEF_FFACTOR + 1);
746  /* # of segments needed for nBuckets */
747  nSegments = next_pow2_long((nBuckets - 1) / DEF_SEGSIZE + 1);
748  /* directory entries */
749  nDirEntries = DEF_DIRSIZE;
750  while (nDirEntries < nSegments)
751  nDirEntries <<= 1; /* dir_alloc doubles dsize at each call */
752 
753  /* fixed control info */
754  size = MAXALIGN(sizeof(HASHHDR)); /* but not HTAB, per above */
755  /* directory */
756  size = add_size(size, mul_size(nDirEntries, sizeof(HASHSEGMENT)));
757  /* segments */
758  size = add_size(size, mul_size(nSegments,
759  MAXALIGN(DEF_SEGSIZE * sizeof(HASHBUCKET))));
760  /* elements --- allocated in groups of choose_nelem_alloc() entries */
761  elementAllocCnt = choose_nelem_alloc(entrysize);
762  nElementAllocs = (num_entries - 1) / elementAllocCnt + 1;
763  elementSize = MAXALIGN(sizeof(HASHELEMENT)) + MAXALIGN(entrysize);
764  size = add_size(size,
765  mul_size(nElementAllocs,
766  mul_size(elementAllocCnt, elementSize)));
767 
768  return size;
769 }
static long next_pow2_long(long num)
Definition: dynahash.c:1738
Size mul_size(Size s1, Size s2)
Definition: shmem.c:515
Size add_size(Size s1, Size s2)
Definition: shmem.c:498
size_t Size
Definition: c.h:466
#define MAXALIGN(LEN)
Definition: c.h:691
static int choose_nelem_alloc(Size entrysize)
Definition: dynahash.c:605
#define DEF_FFACTOR
Definition: dynahash.c:115
#define DEF_SEGSIZE
Definition: dynahash.c:112
#define DEF_DIRSIZE
Definition: dynahash.c:114

◆ hash_freeze()

void hash_freeze ( HTAB hashp)

Definition at line 1487 of file dynahash.c.

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

1488 {
1489  if (hashp->isshared)
1490  elog(ERROR, "cannot freeze shared hashtable \"%s\"", hashp->tabname);
1491  if (!hashp->frozen && has_seq_scans(hashp))
1492  elog(ERROR, "cannot freeze hashtable \"%s\" because it has active scans",
1493  hashp->tabname);
1494  hashp->frozen = true;
1495 }
#define ERROR
Definition: elog.h:43
static bool has_seq_scans(HTAB *hashp)
Definition: dynahash.c:1824
bool isshared
Definition: dynahash.c:220
bool frozen
Definition: dynahash.c:224
char * tabname
Definition: dynahash.c:219
#define elog(elevel,...)
Definition: elog.h:214

◆ hash_get_num_entries()

long hash_get_num_entries ( HTAB hashp)

Definition at line 1337 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(), entry_reset(), EstimateEnumBlacklistSpace(), EstimatePendingSyncsSpace(), get_crosstab_tuplestore(), GetLockStatusData(), GetPredicateLockStatusData(), GetRunningTransactionLocks(), hash_stats(), pgss_shmem_shutdown(), pgstat_vacuum_stat(), ResetUnloggedRelationsInDbspaceDir(), SerializePendingSyncs(), transformGraph(), and XLogHaveInvalidPages().

1338 {
1339  int i;
1340  long sum = hashp->hctl->freeList[0].nentries;
1341 
1342  /*
1343  * We currently don't bother with acquiring the mutexes; it's only
1344  * sensible to call this function if you've got lock on all partitions of
1345  * the table.
1346  */
1347  if (IS_PARTITIONED(hashp->hctl))
1348  {
1349  for (i = 1; i < NUM_FREELISTS; i++)
1350  sum += hashp->hctl->freeList[i].nentries;
1351  }
1352 
1353  return sum;
1354 }
#define IS_PARTITIONED(hctl)
Definition: dynahash.c:201
#define NUM_FREELISTS
Definition: dynahash.c:118
HASHHDR * hctl
Definition: dynahash.c:212
long nentries
Definition: dynahash.c:146
FreeListData freeList[NUM_FREELISTS]
Definition: dynahash.c:170
int i

◆ hash_get_shared_size()

Size hash_get_shared_size ( HASHCTL info,
int  flags 
)

Definition at line 805 of file dynahash.c.

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

Referenced by ShmemInitHash().

806 {
807  Assert(flags & HASH_DIRSIZE);
808  Assert(info->dsize == info->max_dsize);
809  return sizeof(HASHHDR) + info->dsize * sizeof(HASHSEGMENT);
810 }
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:738
#define HASH_DIRSIZE
Definition: hsearch.h:85

◆ hash_search()

void* hash_search ( HTAB hashp,
const void *  keyPtr,
HASHACTION  action,
bool foundPtr 
)

Definition at line 908 of file dynahash.c.

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

Referenced by _hash_finish_split(), _hash_splitbucket(), add_join_rel(), AddEnumLabel(), AddEventToPendingNotifies(), AddPendingSync(), ApplyLogicalMappingFile(), assign_record_type_typmod(), AsyncExistsPendingNotify(), 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(), EnumBlacklisted(), EventCacheLookup(), ExecCleanupTupleRouting(), ExecFindPartition(), ExecHashSubPlanResultRelsByOid(), 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(), LockAcquireExtended(), LockHasWaiters(), LockHeldByMe(), LockRelease(), log_invalid_page(), logical_rewrite_log_mapping(), logicalrep_partition_open(), logicalrep_rel_open(), logicalrep_relmap_update(), logicalrep_typmap_gettypname(), 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(), PartitionDirectoryLookup(), 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(), PrefetchLocalBuffer(), process_syncing_tables_for_apply(), ProcessSyncRequests(), prune_element_hashtable(), prune_lexemes_hashtable(), rebuild_database_list(), record_C_func(), RegisterExtensibleNodeEntry(), RegisterPredicateLockingXid(), rel_sync_cache_relation_cb(), RelationPreTruncate(), ReleaseOneSerializableXact(), RelfilenodeMapInvalidateCallback(), RelFileNodeSkippingWAL(), RelidByRelfilenode(), RememberSyncRequest(), RemoveLocalLock(), ReorderBufferBuildTupleCidHash(), ReorderBufferCleanupTXN(), ReorderBufferToastAppendChunk(), ReorderBufferToastReplace(), ReorderBufferTXNByXid(), ReservePrivateRefCountEntry(), ResetUnloggedRelationsInDbspaceDir(), ResolveCminCmaxDuringDecoding(), RestoreEnumBlacklist(), rewrite_heap_dead_tuple(), rewrite_heap_tuple(), ri_FetchPreparedPlan(), ri_HashCompareOp(), ri_HashPreparedPlan(), ri_LoadConstraintInfo(), select_perl_context(), SerializePendingSyncs(), set_rtable_names(), ShmemInitStruct(), smgrclose(), smgrclosenode(), smgrDoPendingSyncs(), smgropen(), StandbyAcquireAccessExclusiveLock(), StandbyReleaseAllLocks(), StandbyReleaseLocks(), StandbyReleaseOldLocks(), StorePreparedStatement(), and table_recheck_autovac().

912 {
913  return hash_search_with_hash_value(hashp,
914  keyPtr,
915  hashp->hash(keyPtr, hashp->keysize),
916  action,
917  foundPtr);
918 }
void * hash_search_with_hash_value(HTAB *hashp, const void *keyPtr, uint32 hashvalue, HASHACTION action, bool *foundPtr)
Definition: dynahash.c:921
Size keysize
Definition: dynahash.c:227
HashValueFunc hash
Definition: dynahash.c:214

◆ hash_search_with_hash_value()

void* hash_search_with_hash_value ( HTAB hashp,
const void *  keyPtr,
uint32  hashvalue,
HASHACTION  action,
bool foundPtr 
)

Definition at line 921 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, HASHHDR::keysize, HTAB::keysize, HASHELEMENT::link, HTAB::match, HASHHDR::max_bucket, MOD, FreeListData::mutex, FreeListData::nentries, 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().

926 {
927  HASHHDR *hctl = hashp->hctl;
928  int freelist_idx = FREELIST_IDX(hctl, hashvalue);
929  Size keysize;
930  uint32 bucket;
931  long segment_num;
932  long segment_ndx;
933  HASHSEGMENT segp;
934  HASHBUCKET currBucket;
935  HASHBUCKET *prevBucketPtr;
936  HashCompareFunc match;
937 
938 #ifdef HASH_STATISTICS
939  hash_accesses++;
940  hctl->accesses++;
941 #endif
942 
943  /*
944  * If inserting, check if it is time to split a bucket.
945  *
946  * NOTE: failure to expand table is not a fatal error, it just means we
947  * have to run at higher fill factor than we wanted. However, if we're
948  * using the palloc allocator then it will throw error anyway on
949  * out-of-memory, so we must do this before modifying the table.
950  */
952  {
953  /*
954  * Can't split if running in partitioned mode, nor if frozen, nor if
955  * table is the subject of any active hash_seq_search scans. Strange
956  * order of these tests is to try to check cheaper conditions first.
957  */
958  if (!IS_PARTITIONED(hctl) && !hashp->frozen &&
959  hctl->freeList[0].nentries / (long) (hctl->max_bucket + 1) >= hctl->ffactor &&
960  !has_seq_scans(hashp))
961  (void) expand_table(hashp);
962  }
963 
964  /*
965  * Do the initial lookup
966  */
967  bucket = calc_bucket(hctl, hashvalue);
968 
969  segment_num = bucket >> hashp->sshift;
970  segment_ndx = MOD(bucket, hashp->ssize);
971 
972  segp = hashp->dir[segment_num];
973 
974  if (segp == NULL)
975  hash_corrupted(hashp);
976 
977  prevBucketPtr = &segp[segment_ndx];
978  currBucket = *prevBucketPtr;
979 
980  /*
981  * Follow collision chain looking for matching key
982  */
983  match = hashp->match; /* save one fetch in inner loop */
984  keysize = hashp->keysize; /* ditto */
985 
986  while (currBucket != NULL)
987  {
988  if (currBucket->hashvalue == hashvalue &&
989  match(ELEMENTKEY(currBucket), keyPtr, keysize) == 0)
990  break;
991  prevBucketPtr = &(currBucket->link);
992  currBucket = *prevBucketPtr;
993 #ifdef HASH_STATISTICS
994  hash_collisions++;
995  hctl->collisions++;
996 #endif
997  }
998 
999  if (foundPtr)
1000  *foundPtr = (bool) (currBucket != NULL);
1001 
1002  /*
1003  * OK, now what?
1004  */
1005  switch (action)
1006  {
1007  case HASH_FIND:
1008  if (currBucket != NULL)
1009  return (void *) ELEMENTKEY(currBucket);
1010  return NULL;
1011 
1012  case HASH_REMOVE:
1013  if (currBucket != NULL)
1014  {
1015  /* if partitioned, must lock to touch nentries and freeList */
1016  if (IS_PARTITIONED(hctl))
1017  SpinLockAcquire(&(hctl->freeList[freelist_idx].mutex));
1018 
1019  /* delete the record from the appropriate nentries counter. */
1020  Assert(hctl->freeList[freelist_idx].nentries > 0);
1021  hctl->freeList[freelist_idx].nentries--;
1022 
1023  /* remove record from hash bucket's chain. */
1024  *prevBucketPtr = currBucket->link;
1025 
1026  /* add the record to the appropriate freelist. */
1027  currBucket->link = hctl->freeList[freelist_idx].freeList;
1028  hctl->freeList[freelist_idx].freeList = currBucket;
1029 
1030  if (IS_PARTITIONED(hctl))
1031  SpinLockRelease(&hctl->freeList[freelist_idx].mutex);
1032 
1033  /*
1034  * better hope the caller is synchronizing access to this
1035  * element, because someone else is going to reuse it the next
1036  * time something is added to the table
1037  */
1038  return (void *) ELEMENTKEY(currBucket);
1039  }
1040  return NULL;
1041 
1042  case HASH_ENTER_NULL:
1043  /* ENTER_NULL does not work with palloc-based allocator */
1044  Assert(hashp->alloc != DynaHashAlloc);
1045  /* FALL THRU */
1046 
1047  case HASH_ENTER:
1048  /* Return existing element if found, else create one */
1049  if (currBucket != NULL)
1050  return (void *) ELEMENTKEY(currBucket);
1051 
1052  /* disallow inserts if frozen */
1053  if (hashp->frozen)
1054  elog(ERROR, "cannot insert into frozen hashtable \"%s\"",
1055  hashp->tabname);
1056 
1057  currBucket = get_hash_entry(hashp, freelist_idx);
1058  if (currBucket == NULL)
1059  {
1060  /* out of memory */
1061  if (action == HASH_ENTER_NULL)
1062  return NULL;
1063  /* report a generic message */
1064  if (hashp->isshared)
1065  ereport(ERROR,
1066  (errcode(ERRCODE_OUT_OF_MEMORY),
1067  errmsg("out of shared memory")));
1068  else
1069  ereport(ERROR,
1070  (errcode(ERRCODE_OUT_OF_MEMORY),
1071  errmsg("out of memory")));
1072  }
1073 
1074  /* link into hashbucket chain */
1075  *prevBucketPtr = currBucket;
1076  currBucket->link = NULL;
1077 
1078  /* copy key into record */
1079  currBucket->hashvalue = hashvalue;
1080  hashp->keycopy(ELEMENTKEY(currBucket), keyPtr, keysize);
1081 
1082  /*
1083  * Caller is expected to fill the data field on return. DO NOT
1084  * insert any code that could possibly throw error here, as doing
1085  * so would leave the table entry incomplete and hence corrupt the
1086  * caller's data structure.
1087  */
1088 
1089  return (void *) ELEMENTKEY(currBucket);
1090  }
1091 
1092  elog(ERROR, "unrecognized hash action code: %d", (int) action);
1093 
1094  return NULL; /* keep compiler quiet */
1095 }
int(* HashCompareFunc)(const void *key1, const void *key2, Size keysize)
Definition: hsearch.h:29
Size keysize
Definition: dynahash.c:227
uint32 max_bucket
Definition: dynahash.c:176
static uint32 calc_bucket(HASHHDR *hctl, uint32 hash_val)
Definition: dynahash.c:869
#define IS_PARTITIONED(hctl)
Definition: dynahash.c:201
#define ELEMENTKEY(helem)
Definition: dynahash.c:235
int errcode(int sqlerrcode)
Definition: elog.c:610
HashAllocFunc alloc
Definition: dynahash.c:217
slock_t mutex
Definition: dynahash.c:145
static HASHBUCKET get_hash_entry(HTAB *hashp, int freelist_idx)
Definition: dynahash.c:1252
long ffactor
Definition: dynahash.c:184
#define SpinLockAcquire(lock)
Definition: spin.h:62
long ssize
Definition: dynahash.c:228
#define ERROR
Definition: elog.h:43
int sshift
Definition: dynahash.c:229
#define MOD(x, y)
Definition: dynahash.c:246
HASHHDR * hctl
Definition: dynahash.c:212
static void hash_corrupted(HTAB *hashp)
Definition: dynahash.c:1706
static bool has_seq_scans(HTAB *hashp)
Definition: dynahash.c:1824
unsigned int uint32
Definition: c.h:367
long nentries
Definition: dynahash.c:146
HashCompareFunc match
Definition: dynahash.c:215
bool isshared
Definition: dynahash.c:220
#define SpinLockRelease(lock)
Definition: spin.h:64
bool frozen
Definition: dynahash.c:224
FreeListData freeList[NUM_FREELISTS]
Definition: dynahash.c:170
#define ereport(elevel,...)
Definition: elog.h:144
HashCopyFunc keycopy
Definition: dynahash.c:216
#define Assert(condition)
Definition: c.h:738
size_t Size
Definition: c.h:466
static bool expand_table(HTAB *hashp)
Definition: dynahash.c:1504
char * tabname
Definition: dynahash.c:219
static void * DynaHashAlloc(Size size)
Definition: dynahash.c:280
int errmsg(const char *fmt,...)
Definition: elog.c:824
struct HASHELEMENT * link
Definition: hsearch.h:53
#define elog(elevel,...)
Definition: elog.h:214
HASHELEMENT * freeList
Definition: dynahash.c:147
HASHSEGMENT * dir
Definition: dynahash.c:213
#define FREELIST_IDX(hctl, hashcode)
Definition: dynahash.c:203
uint32 hashvalue
Definition: hsearch.h:54
unsigned char bool
Definition: c.h:317

◆ hash_select_dirsize()

long hash_select_dirsize ( long  num_entries)

Definition at line 781 of file dynahash.c.

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

Referenced by ShmemInitHash().

782 {
783  long nBuckets,
784  nSegments,
785  nDirEntries;
786 
787  /* estimate number of buckets wanted */
788  nBuckets = next_pow2_long((num_entries - 1) / DEF_FFACTOR + 1);
789  /* # of segments needed for nBuckets */
790  nSegments = next_pow2_long((nBuckets - 1) / DEF_SEGSIZE + 1);
791  /* directory entries */
792  nDirEntries = DEF_DIRSIZE;
793  while (nDirEntries < nSegments)
794  nDirEntries <<= 1; /* dir_alloc doubles dsize at each call */
795 
796  return nDirEntries;
797 }
static long next_pow2_long(long num)
Definition: dynahash.c:1738
#define DEF_FFACTOR
Definition: dynahash.c:115
#define DEF_SEGSIZE
Definition: dynahash.c:112
#define DEF_DIRSIZE
Definition: dynahash.c:114

◆ hash_seq_init()

void hash_seq_init ( HASH_SEQ_STATUS status,
HTAB hashp 
)

Definition at line 1381 of file dynahash.c.

References HASH_SEQ_STATUS::curBucket, HASH_SEQ_STATUS::curEntry, HTAB::frozen, HASH_SEQ_STATUS::hashp, 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(), DestroyPartitionDirectory(), DropAllPredicateLocksFromTable(), DropAllPreparedStatements(), end_heap_rewrite(), entry_dealloc(), entry_reset(), forget_invalid_pages(), forget_invalid_pages_db(), gc_qtexts(), GetLockmodeName(), GetLockStatusData(), GetPredicateLockStatusData(), GetRunningTransactionLocks(), HoldPinnedPortals(), InvalidateAttoptCacheCallback(), InvalidateOprCacheCallBack(), InvalidateOprProofCacheCallBack(), InvalidateShippableCacheCallback(), InvalidateTableSpaceCacheCallback(), InvalidateTSCacheCallBack(), LockReassignCurrentOwner(), LockReleaseAll(), LockReleaseCurrentOwner(), LockReleaseSession(), logical_end_heap_rewrite(), logical_heap_rewrite_flush_mappings(), logicalrep_partmap_invalidate_cb(), logicalrep_relmap_invalidate_cb(), packArcInfoCmp(), packGraph(), pg_cursor(), pg_get_shmem_allocations(), 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(), PortalErrorCleanup(), PortalHashTableDeleteAll(), PostPrepare_Locks(), PreCommit_Portals(), ProcessSyncRequests(), prune_element_hashtable(), prune_lexemes_hashtable(), rebuild_database_list(), rel_sync_cache_publication_cb(), RelationCacheInitializePhase3(), RelationCacheInvalidate(), RelfilenodeMapInvalidateCallback(), RememberSyncRequest(), RememberToFreeTupleDescAtEOX(), ReorderBufferLargestTXN(), ReorderBufferToastReset(), selectColorTrigrams(), SerializeEnumBlacklist(), SerializePendingSyncs(), smgrcloseall(), smgrDoPendingSyncs(), StandbyReleaseAllLocks(), StandbyReleaseOldLocks(), ThereAreNoReadyPortals(), TypeCacheOpcCallback(), TypeCacheRelCallback(), TypeCacheTypCallback(), write_relcache_init_file(), and XLogCheckInvalidPages().

1382 {
1383  status->hashp = hashp;
1384  status->curBucket = 0;
1385  status->curEntry = NULL;
1386  if (!hashp->frozen)
1387  register_seq_scan(hashp);
1388 }
uint32 curBucket
Definition: hsearch.h:115
HASHELEMENT * curEntry
Definition: hsearch.h:116
HTAB * hashp
Definition: hsearch.h:114
bool frozen
Definition: dynahash.c:224
static void register_seq_scan(HTAB *hashp)
Definition: dynahash.c:1791

◆ hash_seq_search()

void* hash_seq_search ( HASH_SEQ_STATUS status)

Definition at line 1391 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, HTAB::sshift, HASHHDR::ssize, 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(), DestroyPartitionDirectory(), DropAllPredicateLocksFromTable(), DropAllPreparedStatements(), end_heap_rewrite(), entry_dealloc(), entry_reset(), forget_invalid_pages(), forget_invalid_pages_db(), gc_qtexts(), GetLockmodeName(), GetLockStatusData(), GetPredicateLockStatusData(), GetRunningTransactionLocks(), HoldPinnedPortals(), InvalidateAttoptCacheCallback(), InvalidateOprCacheCallBack(), InvalidateOprProofCacheCallBack(), InvalidateShippableCacheCallback(), InvalidateTableSpaceCacheCallback(), InvalidateTSCacheCallBack(), LockReassignCurrentOwner(), LockReleaseAll(), LockReleaseCurrentOwner(), LockReleaseSession(), logical_end_heap_rewrite(), logical_heap_rewrite_flush_mappings(), logicalrep_partmap_invalidate_cb(), logicalrep_relmap_invalidate_cb(), packArcInfoCmp(), packGraph(), pg_cursor(), pg_get_shmem_allocations(), 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(), PortalErrorCleanup(), PortalHashTableDeleteAll(), PostPrepare_Locks(), PreCommit_Portals(), ProcessSyncRequests(), prune_element_hashtable(), prune_lexemes_hashtable(), rebuild_database_list(), rel_sync_cache_publication_cb(), RelationCacheInitializePhase3(), RelationCacheInvalidate(), RelfilenodeMapInvalidateCallback(), RememberSyncRequest(), RememberToFreeTupleDescAtEOX(), ReorderBufferLargestTXN(), ReorderBufferToastReset(), selectColorTrigrams(), SerializeEnumBlacklist(), SerializePendingSyncs(), smgrcloseall(), smgrDoPendingSyncs(), StandbyReleaseAllLocks(), StandbyReleaseOldLocks(), ThereAreNoReadyPortals(), TypeCacheOpcCallback(), TypeCacheRelCallback(), TypeCacheTypCallback(), write_relcache_init_file(), and XLogCheckInvalidPages().

1392 {
1393  HTAB *hashp;
1394  HASHHDR *hctl;
1395  uint32 max_bucket;
1396  long ssize;
1397  long segment_num;
1398  long segment_ndx;
1399  HASHSEGMENT segp;
1400  uint32 curBucket;
1401  HASHELEMENT *curElem;
1402 
1403  if ((curElem = status->curEntry) != NULL)
1404  {
1405  /* Continuing scan of curBucket... */
1406  status->curEntry = curElem->link;
1407  if (status->curEntry == NULL) /* end of this bucket */
1408  ++status->curBucket;
1409  return (void *) ELEMENTKEY(curElem);
1410  }
1411 
1412  /*
1413  * Search for next nonempty bucket starting at curBucket.
1414  */
1415  curBucket = status->curBucket;
1416  hashp = status->hashp;
1417  hctl = hashp->hctl;
1418  ssize = hashp->ssize;
1419  max_bucket = hctl->max_bucket;
1420 
1421  if (curBucket > max_bucket)
1422  {
1423  hash_seq_term(status);
1424  return NULL; /* search is done */
1425  }
1426 
1427  /*
1428  * first find the right segment in the table directory.
1429  */
1430  segment_num = curBucket >> hashp->sshift;
1431  segment_ndx = MOD(curBucket, ssize);
1432 
1433  segp = hashp->dir[segment_num];
1434 
1435  /*
1436  * Pick up the first item in this bucket's chain. If chain is not empty
1437  * we can begin searching it. Otherwise we have to advance to find the
1438  * next nonempty bucket. We try to optimize that case since searching a
1439  * near-empty hashtable has to iterate this loop a lot.
1440  */
1441  while ((curElem = segp[segment_ndx]) == NULL)
1442  {
1443  /* empty bucket, advance to next */
1444  if (++curBucket > max_bucket)
1445  {
1446  status->curBucket = curBucket;
1447  hash_seq_term(status);
1448  return NULL; /* search is done */
1449  }
1450  if (++segment_ndx >= ssize)
1451  {
1452  segment_num++;
1453  segment_ndx = 0;
1454  segp = hashp->dir[segment_num];
1455  }
1456  }
1457 
1458  /* Begin scan of curBucket... */
1459  status->curEntry = curElem->link;
1460  if (status->curEntry == NULL) /* end of this bucket */
1461  ++curBucket;
1462  status->curBucket = curBucket;
1463  return (void *) ELEMENTKEY(curElem);
1464 }
uint32 curBucket
Definition: hsearch.h:115
uint32 max_bucket
Definition: dynahash.c:176
#define ELEMENTKEY(helem)
Definition: dynahash.c:235
HASHELEMENT * curEntry
Definition: hsearch.h:116
Definition: dynahash.c:210
long ssize
Definition: dynahash.c:228
int sshift
Definition: dynahash.c:229
#define MOD(x, y)
Definition: dynahash.c:246
HASHHDR * hctl
Definition: dynahash.c:212
unsigned int uint32
Definition: c.h:367
HTAB * hashp
Definition: hsearch.h:114
struct HASHELEMENT * link
Definition: hsearch.h:53
HASHSEGMENT * dir
Definition: dynahash.c:213
void hash_seq_term(HASH_SEQ_STATUS *status)
Definition: dynahash.c:1467

◆ hash_seq_term()

void hash_seq_term ( HASH_SEQ_STATUS status)

◆ hash_stats()

void hash_stats ( const char *  where,
HTAB hashp 
)

Definition at line 835 of file dynahash.c.

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

Referenced by hash_destroy().

836 {
837 #ifdef HASH_STATISTICS
838  fprintf(stderr, "%s: this HTAB -- accesses %ld collisions %ld\n",
839  where, hashp->hctl->accesses, hashp->hctl->collisions);
840 
841  fprintf(stderr, "hash_stats: entries %ld keysize %ld maxp %u segmentcount %ld\n",
842  hash_get_num_entries(hashp), (long) hashp->hctl->keysize,
843  hashp->hctl->max_bucket, hashp->hctl->nsegs);
844  fprintf(stderr, "%s: total accesses %ld total collisions %ld\n",
845  where, hash_accesses, hash_collisions);
846  fprintf(stderr, "hash_stats: total expansions %ld\n",
847  hash_expansions);
848 #endif
849 }
Size keysize
Definition: dynahash.c:181
uint32 max_bucket
Definition: dynahash.c:176
long hash_get_num_entries(HTAB *hashp)
Definition: dynahash.c:1337
#define fprintf
Definition: port.h:197
HASHHDR * hctl
Definition: dynahash.c:212
long nsegs
Definition: dynahash.c:175

◆ hash_update_hash_key()

bool hash_update_hash_key ( HTAB hashp,
void *  existingEntry,
const void *  newKeyPtr 
)

Definition at line 1117 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, HASHHDR::keysize, HTAB::keysize, HASHELEMENT::link, HTAB::match, MOD, HTAB::sshift, HTAB::ssize, and HTAB::tabname.

Referenced by PostPrepare_Locks().

1120 {
1121  HASHELEMENT *existingElement = ELEMENT_FROM_KEY(existingEntry);
1122  HASHHDR *hctl = hashp->hctl;
1123  uint32 newhashvalue;
1124  Size keysize;
1125  uint32 bucket;
1126  uint32 newbucket;
1127  long segment_num;
1128  long segment_ndx;
1129  HASHSEGMENT segp;
1130  HASHBUCKET currBucket;
1131  HASHBUCKET *prevBucketPtr;
1132  HASHBUCKET *oldPrevPtr;
1133  HashCompareFunc match;
1134 
1135 #ifdef HASH_STATISTICS
1136  hash_accesses++;
1137  hctl->accesses++;
1138 #endif
1139 
1140  /* disallow updates if frozen */
1141  if (hashp->frozen)
1142  elog(ERROR, "cannot update in frozen hashtable \"%s\"",
1143  hashp->tabname);
1144 
1145  /*
1146  * Lookup the existing element using its saved hash value. We need to do
1147  * this to be able to unlink it from its hash chain, but as a side benefit
1148  * we can verify the validity of the passed existingEntry pointer.
1149  */
1150  bucket = calc_bucket(hctl, existingElement->hashvalue);
1151 
1152  segment_num = bucket >> hashp->sshift;
1153  segment_ndx = MOD(bucket, hashp->ssize);
1154 
1155  segp = hashp->dir[segment_num];
1156 
1157  if (segp == NULL)
1158  hash_corrupted(hashp);
1159 
1160  prevBucketPtr = &segp[segment_ndx];
1161  currBucket = *prevBucketPtr;
1162 
1163  while (currBucket != NULL)
1164  {
1165  if (currBucket == existingElement)
1166  break;
1167  prevBucketPtr = &(currBucket->link);
1168  currBucket = *prevBucketPtr;
1169  }
1170 
1171  if (currBucket == NULL)
1172  elog(ERROR, "hash_update_hash_key argument is not in hashtable \"%s\"",
1173  hashp->tabname);
1174 
1175  oldPrevPtr = prevBucketPtr;
1176 
1177  /*
1178  * Now perform the equivalent of a HASH_ENTER operation to locate the hash
1179  * chain we want to put the entry into.
1180  */
1181  newhashvalue = hashp->hash(newKeyPtr, hashp->keysize);
1182 
1183  newbucket = calc_bucket(hctl, newhashvalue);
1184 
1185  segment_num = newbucket >> hashp->sshift;
1186  segment_ndx = MOD(newbucket, hashp->ssize);
1187 
1188  segp = hashp->dir[segment_num];
1189 
1190  if (segp == NULL)
1191  hash_corrupted(hashp);
1192 
1193  prevBucketPtr = &segp[segment_ndx];
1194  currBucket = *prevBucketPtr;
1195 
1196  /*
1197  * Follow collision chain looking for matching key
1198  */
1199  match = hashp->match; /* save one fetch in inner loop */
1200  keysize = hashp->keysize; /* ditto */
1201 
1202  while (currBucket != NULL)
1203  {
1204  if (currBucket->hashvalue == newhashvalue &&
1205  match(ELEMENTKEY(currBucket), newKeyPtr, keysize) == 0)
1206  break;
1207  prevBucketPtr = &(currBucket->link);
1208  currBucket = *prevBucketPtr;
1209 #ifdef HASH_STATISTICS
1210  hash_collisions++;
1211  hctl->collisions++;
1212 #endif
1213  }
1214 
1215  if (currBucket != NULL)
1216  return false; /* collision with an existing entry */
1217 
1218  currBucket = existingElement;
1219 
1220  /*
1221  * If old and new hash values belong to the same bucket, we need not
1222  * change any chain links, and indeed should not since this simplistic
1223  * update will corrupt the list if currBucket is the last element. (We
1224  * cannot fall out earlier, however, since we need to scan the bucket to
1225  * check for duplicate keys.)
1226  */
1227  if (bucket != newbucket)
1228  {
1229  /* OK to remove record from old hash bucket's chain. */
1230  *oldPrevPtr = currBucket->link;
1231 
1232  /* link into new hashbucket chain */
1233  *prevBucketPtr = currBucket;
1234  currBucket->link = NULL;
1235  }
1236 
1237  /* copy new key into record */
1238  currBucket->hashvalue = newhashvalue;
1239  hashp->keycopy(ELEMENTKEY(currBucket), newKeyPtr, keysize);
1240 
1241  /* rest of record is untouched */
1242 
1243  return true;
1244 }
int(* HashCompareFunc)(const void *key1, const void *key2, Size keysize)
Definition: hsearch.h:29
Size keysize
Definition: dynahash.c:227
static uint32 calc_bucket(HASHHDR *hctl, uint32 hash_val)
Definition: dynahash.c:869
#define ELEMENTKEY(helem)
Definition: dynahash.c:235
#define ELEMENT_FROM_KEY(key)
Definition: dynahash.c:240
HashValueFunc hash
Definition: dynahash.c:214
long ssize
Definition: dynahash.c:228
#define ERROR
Definition: elog.h:43
int sshift
Definition: dynahash.c:229
#define MOD(x, y)
Definition: dynahash.c:246
HASHHDR * hctl
Definition: dynahash.c:212
static void hash_corrupted(HTAB *hashp)
Definition: dynahash.c:1706
unsigned int uint32
Definition: c.h:367
HashCompareFunc match
Definition: dynahash.c:215
bool frozen
Definition: dynahash.c:224
HashCopyFunc keycopy
Definition: dynahash.c:216
size_t Size
Definition: c.h:466
char * tabname
Definition: dynahash.c:219
struct HASHELEMENT * link
Definition: hsearch.h:53
#define elog(elevel,...)
Definition: elog.h:214
HASHSEGMENT * dir
Definition: dynahash.c:213
uint32 hashvalue
Definition: hsearch.h:54

◆ hdefault()

static void hdefault ( HTAB hashp)
static

Definition at line 572 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().

573 {
574  HASHHDR *hctl = hashp->hctl;
575 
576  MemSet(hctl, 0, sizeof(HASHHDR));
577 
578  hctl->dsize = DEF_DIRSIZE;
579  hctl->nsegs = 0;
580 
581  /* rather pointless defaults for key & entry size */
582  hctl->keysize = sizeof(char *);
583  hctl->entrysize = 2 * sizeof(char *);
584 
585  hctl->num_partitions = 0; /* not partitioned */
586 
587  hctl->ffactor = DEF_FFACTOR;
588 
589  /* table has no fixed maximum size */
590  hctl->max_dsize = NO_MAX_DSIZE;
591 
592  hctl->ssize = DEF_SEGSIZE;
593  hctl->sshift = DEF_SEGSIZE_SHIFT;
594 
595 #ifdef HASH_STATISTICS
596  hctl->accesses = hctl->collisions = 0;
597 #endif
598 }
Size keysize
Definition: dynahash.c:181
long dsize
Definition: dynahash.c:174
Size entrysize
Definition: dynahash.c:182
#define NO_MAX_DSIZE
Definition: hsearch.h:100
long num_partitions
Definition: dynahash.c:183
#define MemSet(start, val, len)
Definition: c.h:971
long ffactor
Definition: dynahash.c:184
#define DEF_SEGSIZE_SHIFT
Definition: dynahash.c:113
long max_dsize
Definition: dynahash.c:185
HASHHDR * hctl
Definition: dynahash.c:212
long ssize
Definition: dynahash.c:186
int sshift
Definition: dynahash.c:187
#define DEF_FFACTOR
Definition: dynahash.c:115
#define DEF_SEGSIZE
Definition: dynahash.c:112
#define DEF_DIRSIZE
Definition: dynahash.c:114
long nsegs
Definition: dynahash.c:175

◆ init_htab()

static bool init_htab ( HTAB hashp,
long  nelem 
)
static

Definition at line 638 of file dynahash.c.

References HTAB::alloc, choose_nelem_alloc(), HTAB::dir, HASHHDR::dsize, HASHHDR::entrysize, HASHHDR::ffactor, fprintf, HASHHDR::freeList, 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, NUM_FREELISTS, HASHHDR::num_partitions, seg_alloc(), SpinLockInit, HASHHDR::sshift, and HASHHDR::ssize.

Referenced by hash_create().

639 {
640  HASHHDR *hctl = hashp->hctl;
641  HASHSEGMENT *segp;
642  int nbuckets;
643  int nsegs;
644  int i;
645 
646  /*
647  * initialize mutexes if it's a partitioned table
648  */
649  if (IS_PARTITIONED(hctl))
650  for (i = 0; i < NUM_FREELISTS; i++)
651  SpinLockInit(&(hctl->freeList[i].mutex));
652 
653  /*
654  * Divide number of elements by the fill factor to determine a desired
655  * number of buckets. Allocate space for the next greater power of two
656  * number of buckets
657  */
658  nbuckets = next_pow2_int((nelem - 1) / hctl->ffactor + 1);
659 
660  /*
661  * In a partitioned table, nbuckets must be at least equal to
662  * num_partitions; were it less, keys with apparently different partition
663  * numbers would map to the same bucket, breaking partition independence.
664  * (Normally nbuckets will be much bigger; this is just a safety check.)
665  */
666  while (nbuckets < hctl->num_partitions)
667  nbuckets <<= 1;
668 
669  hctl->max_bucket = hctl->low_mask = nbuckets - 1;
670  hctl->high_mask = (nbuckets << 1) - 1;
671 
672  /*
673  * Figure number of directory segments needed, round up to a power of 2
674  */
675  nsegs = (nbuckets - 1) / hctl->ssize + 1;
676  nsegs = next_pow2_int(nsegs);
677 
678  /*
679  * Make sure directory is big enough. If pre-allocated directory is too
680  * small, choke (caller screwed up).
681  */
682  if (nsegs > hctl->dsize)
683  {
684  if (!(hashp->dir))
685  hctl->dsize = nsegs;
686  else
687  return false;
688  }
689 
690  /* Allocate a directory */
691  if (!(hashp->dir))
692  {
693  CurrentDynaHashCxt = hashp->hcxt;
694  hashp->dir = (HASHSEGMENT *)
695  hashp->alloc(hctl->dsize * sizeof(HASHSEGMENT));
696  if (!hashp->dir)
697  return false;
698  }
699 
700  /* Allocate initial segments */
701  for (segp = hashp->dir; hctl->nsegs < nsegs; hctl->nsegs++, segp++)
702  {
703  *segp = seg_alloc(hashp);
704  if (*segp == NULL)
705  return false;
706  }
707 
708  /* Choose number of entries to allocate at a time */
710 
711 #ifdef HASH_DEBUG
712  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",
713  "TABLE POINTER ", hashp,
714  "DIRECTORY SIZE ", hctl->dsize,
715  "SEGMENT SIZE ", hctl->ssize,
716  "SEGMENT SHIFT ", hctl->sshift,
717  "FILL FACTOR ", hctl->ffactor,
718  "MAX BUCKET ", hctl->max_bucket,
719  "HIGH MASK ", hctl->high_mask,
720  "LOW MASK ", hctl->low_mask,
721  "NSEGS ", hctl->nsegs);
722 #endif
723  return true;
724 }
long dsize
Definition: dynahash.c:174
uint32 max_bucket
Definition: dynahash.c:176
Size entrysize
Definition: dynahash.c:182
#define IS_PARTITIONED(hctl)
Definition: dynahash.c:201
#define SpinLockInit(lock)
Definition: spin.h:60
#define NUM_FREELISTS
Definition: dynahash.c:118
HashAllocFunc alloc
Definition: dynahash.c:217
slock_t mutex
Definition: dynahash.c:145
uint32 low_mask
Definition: dynahash.c:178
#define fprintf
Definition: port.h:197
long ffactor
Definition: dynahash.c:184
HASHHDR * hctl
Definition: dynahash.c:212
uint32 high_mask
Definition: dynahash.c:177
static int next_pow2_int(long num)
Definition: dynahash.c:1746
long ssize
Definition: dynahash.c:186
FreeListData freeList[NUM_FREELISTS]
Definition: dynahash.c:170
MemoryContext hcxt
Definition: dynahash.c:218
int nelem_alloc
Definition: dynahash.c:188
static HASHSEGMENT seg_alloc(HTAB *hashp)
Definition: dynahash.c:1640
static int choose_nelem_alloc(Size entrysize)
Definition: dynahash.c:605
static MemoryContext CurrentDynaHashCxt
Definition: dynahash.c:277
int i
HASHSEGMENT * dir
Definition: dynahash.c:213
int sshift
Definition: dynahash.c:187
long nsegs
Definition: dynahash.c:175

◆ my_log2()

int my_log2 ( long  num)

Definition at line 1720 of file dynahash.c.

References pg_ceil_log2_32(), and pg_ceil_log2_64().

Referenced by ExecChooseHashTableSize(), ExecHashTableCreate(), ExecParallelHashIncreaseNumBatches(), ExecParallelHashTableSetCurrentBatch(), hash_choose_num_partitions(), hash_create(), MultiExecParallelHash(), next_pow2_int(), and next_pow2_long().

1721 {
1722  /*
1723  * guard against too-large input, which would be invalid for
1724  * pg_ceil_log2_*()
1725  */
1726  if (num > LONG_MAX / 2)
1727  num = LONG_MAX / 2;
1728 
1729 #if SIZEOF_LONG < 8
1730  return pg_ceil_log2_32(num);
1731 #else
1732  return pg_ceil_log2_64(num);
1733 #endif
1734 }
static uint64 pg_ceil_log2_64(uint64 num)
Definition: pg_bitutils.h:202
static uint32 pg_ceil_log2_32(uint32 num)
Definition: pg_bitutils.h:189

◆ next_pow2_int()

static int next_pow2_int ( long  num)
static

Definition at line 1746 of file dynahash.c.

References my_log2().

Referenced by hash_create(), and init_htab().

1747 {
1748  if (num > INT_MAX / 2)
1749  num = INT_MAX / 2;
1750  return 1 << my_log2(num);
1751 }
int my_log2(long num)
Definition: dynahash.c:1720

◆ next_pow2_long()

static long next_pow2_long ( long  num)
static

Definition at line 1738 of file dynahash.c.

References my_log2().

Referenced by hash_estimate_size(), and hash_select_dirsize().

1739 {
1740  /* my_log2's internal range check is sufficient */
1741  return 1L << my_log2(num);
1742 }
int my_log2(long num)
Definition: dynahash.c:1720

◆ register_seq_scan()

static void register_seq_scan ( HTAB hashp)
static

Definition at line 1791 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().

1792 {
1794  elog(ERROR, "too many active hash_seq_search scans, cannot start one on \"%s\"",
1795  hashp->tabname);
1796  seq_scan_tables[num_seq_scans] = hashp;
1798  num_seq_scans++;
1799 }
static int seq_scan_level[MAX_SEQ_SCANS]
Definition: dynahash.c:1785
#define ERROR
Definition: elog.h:43
#define MAX_SEQ_SCANS
Definition: dynahash.c:1782
static int num_seq_scans
Definition: dynahash.c:1786
static HTAB * seq_scan_tables[MAX_SEQ_SCANS]
Definition: dynahash.c:1784
int GetCurrentTransactionNestLevel(void)
Definition: xact.c:842
char * tabname
Definition: dynahash.c:219
#define elog(elevel,...)
Definition: elog.h:214

◆ seg_alloc()

static HASHSEGMENT seg_alloc ( HTAB hashp)
static

Definition at line 1640 of file dynahash.c.

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

Referenced by expand_table(), and init_htab().

1641 {
1642  HASHSEGMENT segp;
1643 
1644  CurrentDynaHashCxt = hashp->hcxt;
1645  segp = (HASHSEGMENT) hashp->alloc(sizeof(HASHBUCKET) * hashp->ssize);
1646 
1647  if (!segp)
1648  return NULL;
1649 
1650  MemSet(segp, 0, sizeof(HASHBUCKET) * hashp->ssize);
1651 
1652  return segp;
1653 }
HashAllocFunc alloc
Definition: dynahash.c:217
#define MemSet(start, val, len)
Definition: c.h:971
HASHBUCKET * HASHSEGMENT
Definition: dynahash.c:124
long ssize
Definition: dynahash.c:228
MemoryContext hcxt
Definition: dynahash.c:218
static MemoryContext CurrentDynaHashCxt
Definition: dynahash.c:277

◆ string_compare()

static int string_compare ( const char *  key1,
const char *  key2,
Size  keysize 
)
static

Definition at line 295 of file dynahash.c.

Referenced by hash_create().

296 {
297  return strncmp(key1, key2, keysize - 1);
298 }

Variable Documentation

◆ CurrentDynaHashCxt

MemoryContext CurrentDynaHashCxt = NULL
static

Definition at line 277 of file dynahash.c.

Referenced by hash_create().

◆ num_seq_scans

int num_seq_scans = 0
static

◆ seq_scan_level

int seq_scan_level[MAX_SEQ_SCANS]
static

Definition at line 1785 of file dynahash.c.

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

◆ seq_scan_tables

HTAB* seq_scan_tables[MAX_SEQ_SCANS]
static

Definition at line 1784 of file dynahash.c.