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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 111 of file dynahash.c.

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

#define DEF_FFACTOR   1 /* default fill factor */

Definition at line 112 of file dynahash.c.

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

#define DEF_SEGSIZE   256

Definition at line 109 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 110 of file dynahash.c.

Referenced by hdefault().

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

Definition at line 223 of file dynahash.c.

Referenced by hash_update_hash_key().

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

Definition at line 218 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 186 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 1742 of file dynahash.c.

Referenced by register_seq_scan().

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

Definition at line 115 of file dynahash.c.

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

Typedef Documentation

Definition at line 118 of file dynahash.c.

Definition at line 121 of file dynahash.c.

Function Documentation

void AtEOSubXact_HashTables ( bool  isCommit,
int  nestDepth 
)

Definition at line 1824 of file dynahash.c.

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

Referenced by AbortSubTransaction(), and CommitSubTransaction().

1825 {
1826  int i;
1827 
1828  /*
1829  * Search backward to make cleanup easy. Note we must check all entries,
1830  * not only those at the end of the array, because deletion technique
1831  * doesn't keep them in order.
1832  */
1833  for (i = num_seq_scans - 1; i >= 0; i--)
1834  {
1835  if (seq_scan_level[i] >= nestDepth)
1836  {
1837  if (isCommit)
1838  elog(WARNING, "leaked hash_seq_search scan for hash table %p",
1839  seq_scan_tables[i]);
1842  num_seq_scans--;
1843  }
1844  }
1845 }
static int seq_scan_level[MAX_SEQ_SCANS]
Definition: dynahash.c:1745
#define WARNING
Definition: elog.h:40
static int num_seq_scans
Definition: dynahash.c:1746
static HTAB * seq_scan_tables[MAX_SEQ_SCANS]
Definition: dynahash.c:1744
int i
#define elog
Definition: elog.h:219
void AtEOXact_HashTables ( bool  isCommit)

Definition at line 1798 of file dynahash.c.

References elog, i, num_seq_scans, and WARNING.

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

1799 {
1800  /*
1801  * During abort cleanup, open scans are expected; just silently clean 'em
1802  * out. An open scan at commit means someone forgot a hash_seq_term()
1803  * call, so complain.
1804  *
1805  * Note: it's tempting to try to print the tabname here, but refrain for
1806  * fear of touching deallocated memory. This isn't a user-facing message
1807  * anyway, so it needn't be pretty.
1808  */
1809  if (isCommit)
1810  {
1811  int i;
1812 
1813  for (i = 0; i < num_seq_scans; i++)
1814  {
1815  elog(WARNING, "leaked hash_seq_search scan for hash table %p",
1816  seq_scan_tables[i]);
1817  }
1818  }
1819  num_seq_scans = 0;
1820 }
#define WARNING
Definition: elog.h:40
static int num_seq_scans
Definition: dynahash.c:1746
static HTAB * seq_scan_tables[MAX_SEQ_SCANS]
Definition: dynahash.c:1744
int i
#define elog
Definition: elog.h:219
static uint32 calc_bucket ( HASHHDR hctl,
uint32  hash_val 
)
inlinestatic

Definition at line 846 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().

847 {
848  uint32 bucket;
849 
850  bucket = hash_val & hctl->high_mask;
851  if (bucket > hctl->max_bucket)
852  bucket = bucket & hctl->low_mask;
853 
854  return bucket;
855 }
uint32 max_bucket
Definition: dynahash.c:159
uint32 low_mask
Definition: dynahash.c:161
unsigned int uint32
Definition: c.h:265
uint32 high_mask
Definition: dynahash.c:160
static int choose_nelem_alloc ( Size  entrysize)
static

Definition at line 581 of file dynahash.c.

References MAXALIGN.

Referenced by hash_estimate_size(), and init_htab().

582 {
583  int nelem_alloc;
584  Size elementSize;
585  Size allocSize;
586 
587  /* Each element has a HASHELEMENT header plus user data. */
588  /* NB: this had better match element_alloc() */
589  elementSize = MAXALIGN(sizeof(HASHELEMENT)) + MAXALIGN(entrysize);
590 
591  /*
592  * The idea here is to choose nelem_alloc at least 32, but round up so
593  * that the allocation request will be a power of 2 or just less. This
594  * makes little difference for hash tables in shared memory, but for hash
595  * tables managed by palloc, the allocation request will be rounded up to
596  * a power of 2 anyway. If we fail to take this into account, we'll waste
597  * as much as half the allocated space.
598  */
599  allocSize = 32 * 4; /* assume elementSize at least 8 */
600  do
601  {
602  allocSize <<= 1;
603  nelem_alloc = allocSize / elementSize;
604  } while (nelem_alloc < 32);
605 
606  return nelem_alloc;
607 }
size_t Size
Definition: c.h:353
#define MAXALIGN(LEN)
Definition: c.h:584
static void deregister_seq_scan ( HTAB hashp)
static

Definition at line 1763 of file dynahash.c.

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

Referenced by hash_seq_term().

1764 {
1765  int i;
1766 
1767  /* Search backward since it's most likely at the stack top */
1768  for (i = num_seq_scans - 1; i >= 0; i--)
1769  {
1770  if (seq_scan_tables[i] == hashp)
1771  {
1774  num_seq_scans--;
1775  return;
1776  }
1777  }
1778  elog(ERROR, "no hash_seq_search scan for hash table \"%s\"",
1779  hashp->tabname);
1780 }
static int seq_scan_level[MAX_SEQ_SCANS]
Definition: dynahash.c:1745
#define ERROR
Definition: elog.h:43
static int num_seq_scans
Definition: dynahash.c:1746
static HTAB * seq_scan_tables[MAX_SEQ_SCANS]
Definition: dynahash.c:1744
char * tabname
Definition: dynahash.c:202
int i
#define elog
Definition: elog.h:219
static bool dir_realloc ( HTAB hashp)
static

Definition at line 1563 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().

1564 {
1565  HASHSEGMENT *p;
1566  HASHSEGMENT *old_p;
1567  long new_dsize;
1568  long old_dirsize;
1569  long new_dirsize;
1570 
1571  if (hashp->hctl->max_dsize != NO_MAX_DSIZE)
1572  return false;
1573 
1574  /* Reallocate directory */
1575  new_dsize = hashp->hctl->dsize << 1;
1576  old_dirsize = hashp->hctl->dsize * sizeof(HASHSEGMENT);
1577  new_dirsize = new_dsize * sizeof(HASHSEGMENT);
1578 
1579  old_p = hashp->dir;
1580  CurrentDynaHashCxt = hashp->hcxt;
1581  p = (HASHSEGMENT *) hashp->alloc((Size) new_dirsize);
1582 
1583  if (p != NULL)
1584  {
1585  memcpy(p, old_p, old_dirsize);
1586  MemSet(((char *) p) + old_dirsize, 0, new_dirsize - old_dirsize);
1587  hashp->dir = p;
1588  hashp->hctl->dsize = new_dsize;
1589 
1590  /* XXX assume the allocator is palloc, so we know how to free */
1591  Assert(hashp->alloc == DynaHashAlloc);
1592  pfree(old_p);
1593 
1594  return true;
1595  }
1596 
1597  return false;
1598 }
long dsize
Definition: dynahash.c:157
#define NO_MAX_DSIZE
Definition: hsearch.h:100
HashAllocFunc alloc
Definition: dynahash.c:200
#define MemSet(start, val, len)
Definition: c.h:853
void pfree(void *pointer)
Definition: mcxt.c:992
HASHBUCKET * HASHSEGMENT
Definition: dynahash.c:121
long max_dsize
Definition: dynahash.c:168
HASHHDR * hctl
Definition: dynahash.c:195
MemoryContext hcxt
Definition: dynahash.c:201
#define NULL
Definition: c.h:226
#define Assert(condition)
Definition: c.h:671
size_t Size
Definition: c.h:353
static void * DynaHashAlloc(Size size)
Definition: dynahash.c:263
static MemoryContext CurrentDynaHashCxt
Definition: dynahash.c:260
HASHSEGMENT * dir
Definition: dynahash.c:196
static void * DynaHashAlloc ( Size  size)
static

Definition at line 263 of file dynahash.c.

References Assert, MemoryContextAlloc(), and MemoryContextIsValid.

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

264 {
267 }
#define MemoryContextIsValid(context)
Definition: memnodes.h:97
#define Assert(condition)
Definition: c.h:671
void * MemoryContextAlloc(MemoryContext context, Size size)
Definition: mcxt.c:749
static MemoryContext CurrentDynaHashCxt
Definition: dynahash.c:260
static bool element_alloc ( HTAB hashp,
int  nelem,
int  freelist_idx 
)
static

Definition at line 1621 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().

1622 {
1623  HASHHDR *hctl = hashp->hctl;
1624  Size elementSize;
1625  HASHELEMENT *firstElement;
1626  HASHELEMENT *tmpElement;
1627  HASHELEMENT *prevElement;
1628  int i;
1629 
1630  if (hashp->isfixed)
1631  return false;
1632 
1633  /* Each element has a HASHELEMENT header plus user data. */
1634  elementSize = MAXALIGN(sizeof(HASHELEMENT)) + MAXALIGN(hctl->entrysize);
1635 
1636  CurrentDynaHashCxt = hashp->hcxt;
1637  firstElement = (HASHELEMENT *) hashp->alloc(nelem * elementSize);
1638 
1639  if (!firstElement)
1640  return false;
1641 
1642  /* prepare to link all the new entries into the freelist */
1643  prevElement = NULL;
1644  tmpElement = firstElement;
1645  for (i = 0; i < nelem; i++)
1646  {
1647  tmpElement->link = prevElement;
1648  prevElement = tmpElement;
1649  tmpElement = (HASHELEMENT *) (((char *) tmpElement) + elementSize);
1650  }
1651 
1652  /* if partitioned, must lock to touch freeList */
1653  if (IS_PARTITIONED(hctl))
1654  SpinLockAcquire(&hctl->freeList[freelist_idx].mutex);
1655 
1656  /* freelist could be nonempty if two backends did this concurrently */
1657  firstElement->link = hctl->freeList[freelist_idx].freeList;
1658  hctl->freeList[freelist_idx].freeList = prevElement;
1659 
1660  if (IS_PARTITIONED(hctl))
1661  SpinLockRelease(&hctl->freeList[freelist_idx].mutex);
1662 
1663  return true;
1664 }
Size entrysize
Definition: dynahash.c:165
#define IS_PARTITIONED(hctl)
Definition: dynahash.c:184
HashAllocFunc alloc
Definition: dynahash.c:200
slock_t mutex
Definition: dynahash.c:130
#define SpinLockAcquire(lock)
Definition: spin.h:62
HASHHDR * hctl
Definition: dynahash.c:195
#define SpinLockRelease(lock)
Definition: spin.h:64
FreeListData freeList[NUM_FREELISTS]
Definition: dynahash.c:153
MemoryContext hcxt
Definition: dynahash.c:201
#define NULL
Definition: c.h:226
size_t Size
Definition: c.h:353
#define MAXALIGN(LEN)
Definition: c.h:584
bool isfixed
Definition: dynahash.c:204
struct HASHELEMENT * link
Definition: hsearch.h:53
static MemoryContext CurrentDynaHashCxt
Definition: dynahash.c:260
int i
HASHELEMENT * freeList
Definition: dynahash.c:132
static bool expand_table ( HTAB hashp)
static

Definition at line 1466 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().

1467 {
1468  HASHHDR *hctl = hashp->hctl;
1469  HASHSEGMENT old_seg,
1470  new_seg;
1471  long old_bucket,
1472  new_bucket;
1473  long new_segnum,
1474  new_segndx;
1475  long old_segnum,
1476  old_segndx;
1477  HASHBUCKET *oldlink,
1478  *newlink;
1479  HASHBUCKET currElement,
1480  nextElement;
1481 
1482  Assert(!IS_PARTITIONED(hctl));
1483 
1484 #ifdef HASH_STATISTICS
1485  hash_expansions++;
1486 #endif
1487 
1488  new_bucket = hctl->max_bucket + 1;
1489  new_segnum = new_bucket >> hashp->sshift;
1490  new_segndx = MOD(new_bucket, hashp->ssize);
1491 
1492  if (new_segnum >= hctl->nsegs)
1493  {
1494  /* Allocate new segment if necessary -- could fail if dir full */
1495  if (new_segnum >= hctl->dsize)
1496  if (!dir_realloc(hashp))
1497  return false;
1498  if (!(hashp->dir[new_segnum] = seg_alloc(hashp)))
1499  return false;
1500  hctl->nsegs++;
1501  }
1502 
1503  /* OK, we created a new bucket */
1504  hctl->max_bucket++;
1505 
1506  /*
1507  * *Before* changing masks, find old bucket corresponding to same hash
1508  * values; values in that bucket may need to be relocated to new bucket.
1509  * Note that new_bucket is certainly larger than low_mask at this point,
1510  * so we can skip the first step of the regular hash mask calc.
1511  */
1512  old_bucket = (new_bucket & hctl->low_mask);
1513 
1514  /*
1515  * If we crossed a power of 2, readjust masks.
1516  */
1517  if ((uint32) new_bucket > hctl->high_mask)
1518  {
1519  hctl->low_mask = hctl->high_mask;
1520  hctl->high_mask = (uint32) new_bucket | hctl->low_mask;
1521  }
1522 
1523  /*
1524  * Relocate records to the new bucket. NOTE: because of the way the hash
1525  * masking is done in calc_bucket, only one old bucket can need to be
1526  * split at this point. With a different way of reducing the hash value,
1527  * that might not be true!
1528  */
1529  old_segnum = old_bucket >> hashp->sshift;
1530  old_segndx = MOD(old_bucket, hashp->ssize);
1531 
1532  old_seg = hashp->dir[old_segnum];
1533  new_seg = hashp->dir[new_segnum];
1534 
1535  oldlink = &old_seg[old_segndx];
1536  newlink = &new_seg[new_segndx];
1537 
1538  for (currElement = *oldlink;
1539  currElement != NULL;
1540  currElement = nextElement)
1541  {
1542  nextElement = currElement->link;
1543  if ((long) calc_bucket(hctl, currElement->hashvalue) == old_bucket)
1544  {
1545  *oldlink = currElement;
1546  oldlink = &currElement->link;
1547  }
1548  else
1549  {
1550  *newlink = currElement;
1551  newlink = &currElement->link;
1552  }
1553  }
1554  /* don't forget to terminate the rebuilt hash chains... */
1555  *oldlink = NULL;
1556  *newlink = NULL;
1557 
1558  return true;
1559 }
long dsize
Definition: dynahash.c:157
uint32 max_bucket
Definition: dynahash.c:159
static uint32 calc_bucket(HASHHDR *hctl, uint32 hash_val)
Definition: dynahash.c:846
#define IS_PARTITIONED(hctl)
Definition: dynahash.c:184
uint32 low_mask
Definition: dynahash.c:161
long ssize
Definition: dynahash.c:211
int sshift
Definition: dynahash.c:212
#define MOD(x, y)
Definition: dynahash.c:229
HASHHDR * hctl
Definition: dynahash.c:195
unsigned int uint32
Definition: c.h:265
uint32 high_mask
Definition: dynahash.c:160
#define NULL
Definition: c.h:226
#define Assert(condition)
Definition: c.h:671
static HASHSEGMENT seg_alloc(HTAB *hashp)
Definition: dynahash.c:1602
struct HASHELEMENT * link
Definition: hsearch.h:53
HASHSEGMENT * dir
Definition: dynahash.c:196
static bool dir_realloc(HTAB *hashp)
Definition: dynahash.c:1563
uint32 hashvalue
Definition: hsearch.h:54
long nsegs
Definition: dynahash.c:158
static HASHBUCKET get_hash_entry ( HTAB hashp,
int  freelist_idx 
)
static

Definition at line 1226 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().

1227 {
1228  HASHHDR *hctl = hashp->hctl;
1229  HASHBUCKET newElement;
1230  int borrow_from_idx;
1231 
1232  for (;;)
1233  {
1234  /* if partitioned, must lock to touch nentries and freeList */
1235  if (IS_PARTITIONED(hctl))
1236  SpinLockAcquire(&hctl->freeList[freelist_idx].mutex);
1237 
1238  /* try to get an entry from the freelist */
1239  newElement = hctl->freeList[freelist_idx].freeList;
1240 
1241  if (newElement != NULL)
1242  break;
1243 
1244  if (IS_PARTITIONED(hctl))
1245  SpinLockRelease(&hctl->freeList[freelist_idx].mutex);
1246 
1247  /* no free elements. allocate another chunk of buckets */
1248  if (!element_alloc(hashp, hctl->nelem_alloc, freelist_idx))
1249  {
1250  if (!IS_PARTITIONED(hctl))
1251  return NULL; /* out of memory */
1252 
1253  /* try to borrow element from another partition */
1254  borrow_from_idx = freelist_idx;
1255  for (;;)
1256  {
1257  borrow_from_idx = (borrow_from_idx + 1) % NUM_FREELISTS;
1258  if (borrow_from_idx == freelist_idx)
1259  break;
1260 
1261  SpinLockAcquire(&(hctl->freeList[borrow_from_idx].mutex));
1262  newElement = hctl->freeList[borrow_from_idx].freeList;
1263 
1264  if (newElement != NULL)
1265  {
1266  hctl->freeList[borrow_from_idx].freeList = newElement->link;
1267  SpinLockRelease(&(hctl->freeList[borrow_from_idx].mutex));
1268 
1269  SpinLockAcquire(&hctl->freeList[freelist_idx].mutex);
1270  hctl->freeList[freelist_idx].nentries++;
1271  SpinLockRelease(&hctl->freeList[freelist_idx].mutex);
1272 
1273  break;
1274  }
1275 
1276  SpinLockRelease(&(hctl->freeList[borrow_from_idx].mutex));
1277  }
1278 
1279  return newElement;
1280  }
1281  }
1282 
1283  /* remove entry from freelist, bump nentries */
1284  hctl->freeList[freelist_idx].freeList = newElement->link;
1285  hctl->freeList[freelist_idx].nentries++;
1286 
1287  if (IS_PARTITIONED(hctl))
1288  SpinLockRelease(&hctl->freeList[freelist_idx].mutex);
1289 
1290  return newElement;
1291 }
#define IS_PARTITIONED(hctl)
Definition: dynahash.c:184
#define NUM_FREELISTS
Definition: dynahash.c:115
slock_t mutex
Definition: dynahash.c:130
#define SpinLockAcquire(lock)
Definition: spin.h:62
HASHHDR * hctl
Definition: dynahash.c:195
long nentries
Definition: dynahash.c:131
#define SpinLockRelease(lock)
Definition: spin.h:64
FreeListData freeList[NUM_FREELISTS]
Definition: dynahash.c:153
#define NULL
Definition: c.h:226
int nelem_alloc
Definition: dynahash.c:171
struct HASHELEMENT * link
Definition: hsearch.h:53
HASHELEMENT * freeList
Definition: dynahash.c:132
static bool element_alloc(HTAB *hashp, int nelem, int freelist_idx)
Definition: dynahash.c:1621
uint32 get_hash_value ( HTAB hashp,
const void *  keyPtr 
)

Definition at line 839 of file dynahash.c.

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

Referenced by BufTableHashCode(), and LockTagHashCode().

840 {
841  return hashp->hash(keyPtr, hashp->keysize);
842 }
Size keysize
Definition: dynahash.c:210
HashValueFunc hash
Definition: dynahash.c:197
static bool has_seq_scans ( HTAB hashp)
static

Definition at line 1784 of file dynahash.c.

References i, and num_seq_scans.

Referenced by hash_freeze(), and hash_search_with_hash_value().

1785 {
1786  int i;
1787 
1788  for (i = 0; i < num_seq_scans; i++)
1789  {
1790  if (seq_scan_tables[i] == hashp)
1791  return true;
1792  }
1793  return false;
1794 }
static int num_seq_scans
Definition: dynahash.c:1746
static HTAB * seq_scan_tables[MAX_SEQ_SCANS]
Definition: dynahash.c:1744
int i
static void hash_corrupted ( HTAB hashp)
static

Definition at line 1668 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().

1669 {
1670  /*
1671  * If the corruption is in a shared hashtable, we'd better force a
1672  * systemwide restart. Otherwise, just shut down this one backend.
1673  */
1674  if (hashp->isshared)
1675  elog(PANIC, "hash table \"%s\" corrupted", hashp->tabname);
1676  else
1677  elog(FATAL, "hash table \"%s\" corrupted", hashp->tabname);
1678 }
#define PANIC
Definition: elog.h:53
#define FATAL
Definition: elog.h:52
bool isshared
Definition: dynahash.c:203
char * tabname
Definition: dynahash.c:202
#define elog
Definition: elog.h:219
HTAB* hash_create ( const char *  tabname,
long  nelem,
HASHCTL info,
int  flags 
)

Definition at line 301 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_oper_cache_entry(), find_rendezvous_variable(), get_json_object_as_hash(), 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(), 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().

302 {
303  HTAB *hashp;
304  HASHHDR *hctl;
305 
306  /*
307  * For shared hash tables, we have a local hash header (HTAB struct) that
308  * we allocate in TopMemoryContext; all else is in shared memory.
309  *
310  * For non-shared hash tables, everything including the hash header is in
311  * a memory context created specially for the hash table --- this makes
312  * hash_destroy very simple. The memory context is made a child of either
313  * a context specified by the caller, or TopMemoryContext if nothing is
314  * specified.
315  */
316  if (flags & HASH_SHARED_MEM)
317  {
318  /* Set up to allocate the hash header */
320  }
321  else
322  {
323  /* Create the hash table's private memory context */
324  if (flags & HASH_CONTEXT)
325  CurrentDynaHashCxt = info->hcxt;
326  else
329  tabname,
331  }
332 
333  /* Initialize the hash header, plus a copy of the table name */
334  hashp = (HTAB *) DynaHashAlloc(sizeof(HTAB) + strlen(tabname) +1);
335  MemSet(hashp, 0, sizeof(HTAB));
336 
337  hashp->tabname = (char *) (hashp + 1);
338  strcpy(hashp->tabname, tabname);
339 
340  /*
341  * Select the appropriate hash function (see comments at head of file).
342  */
343  if (flags & HASH_FUNCTION)
344  hashp->hash = info->hash;
345  else if (flags & HASH_BLOBS)
346  {
347  /* We can optimize hashing for common key sizes */
348  Assert(flags & HASH_ELEM);
349  if (info->keysize == sizeof(uint32))
350  hashp->hash = uint32_hash;
351  else
352  hashp->hash = tag_hash;
353  }
354  else
355  hashp->hash = string_hash; /* default hash function */
356 
357  /*
358  * If you don't specify a match function, it defaults to string_compare if
359  * you used string_hash (either explicitly or by default) and to memcmp
360  * otherwise.
361  *
362  * Note: explicitly specifying string_hash is deprecated, because this
363  * might not work for callers in loadable modules on some platforms due to
364  * referencing a trampoline instead of the string_hash function proper.
365  * Just let it default, eh?
366  */
367  if (flags & HASH_COMPARE)
368  hashp->match = info->match;
369  else if (hashp->hash == string_hash)
371  else
372  hashp->match = memcmp;
373 
374  /*
375  * Similarly, the key-copying function defaults to strlcpy or memcpy.
376  */
377  if (flags & HASH_KEYCOPY)
378  hashp->keycopy = info->keycopy;
379  else if (hashp->hash == string_hash)
380  hashp->keycopy = (HashCopyFunc) strlcpy;
381  else
382  hashp->keycopy = memcpy;
383 
384  /* And select the entry allocation function, too. */
385  if (flags & HASH_ALLOC)
386  hashp->alloc = info->alloc;
387  else
388  hashp->alloc = DynaHashAlloc;
389 
390  if (flags & HASH_SHARED_MEM)
391  {
392  /*
393  * ctl structure and directory are preallocated for shared memory
394  * tables. Note that HASH_DIRSIZE and HASH_ALLOC had better be set as
395  * well.
396  */
397  hashp->hctl = info->hctl;
398  hashp->dir = (HASHSEGMENT *) (((char *) info->hctl) + sizeof(HASHHDR));
399  hashp->hcxt = NULL;
400  hashp->isshared = true;
401 
402  /* hash table already exists, we're just attaching to it */
403  if (flags & HASH_ATTACH)
404  {
405  /* make local copies of some heavily-used values */
406  hctl = hashp->hctl;
407  hashp->keysize = hctl->keysize;
408  hashp->ssize = hctl->ssize;
409  hashp->sshift = hctl->sshift;
410 
411  return hashp;
412  }
413  }
414  else
415  {
416  /* setup hash table defaults */
417  hashp->hctl = NULL;
418  hashp->dir = NULL;
419  hashp->hcxt = CurrentDynaHashCxt;
420  hashp->isshared = false;
421  }
422 
423  if (!hashp->hctl)
424  {
425  hashp->hctl = (HASHHDR *) hashp->alloc(sizeof(HASHHDR));
426  if (!hashp->hctl)
427  ereport(ERROR,
428  (errcode(ERRCODE_OUT_OF_MEMORY),
429  errmsg("out of memory")));
430  }
431 
432  hashp->frozen = false;
433 
434  hdefault(hashp);
435 
436  hctl = hashp->hctl;
437 
438  if (flags & HASH_PARTITION)
439  {
440  /* Doesn't make sense to partition a local hash table */
441  Assert(flags & HASH_SHARED_MEM);
442 
443  /*
444  * The number of partitions had better be a power of 2. Also, it must
445  * be less than INT_MAX (see init_htab()), so call the int version of
446  * next_pow2.
447  */
449 
450  hctl->num_partitions = info->num_partitions;
451  }
452 
453  if (flags & HASH_SEGMENT)
454  {
455  hctl->ssize = info->ssize;
456  hctl->sshift = my_log2(info->ssize);
457  /* ssize had better be a power of 2 */
458  Assert(hctl->ssize == (1L << hctl->sshift));
459  }
460  if (flags & HASH_FFACTOR)
461  hctl->ffactor = info->ffactor;
462 
463  /*
464  * SHM hash tables have fixed directory size passed by the caller.
465  */
466  if (flags & HASH_DIRSIZE)
467  {
468  hctl->max_dsize = info->max_dsize;
469  hctl->dsize = info->dsize;
470  }
471 
472  /*
473  * hash table now allocates space for key and data but you have to say how
474  * much space to allocate
475  */
476  if (flags & HASH_ELEM)
477  {
478  Assert(info->entrysize >= info->keysize);
479  hctl->keysize = info->keysize;
480  hctl->entrysize = info->entrysize;
481  }
482 
483  /* make local copies of heavily-used constant fields */
484  hashp->keysize = hctl->keysize;
485  hashp->ssize = hctl->ssize;
486  hashp->sshift = hctl->sshift;
487 
488  /* Build the hash directory structure */
489  if (!init_htab(hashp, nelem))
490  elog(ERROR, "failed to initialize hash table \"%s\"", hashp->tabname);
491 
492  /*
493  * For a shared hash table, preallocate the requested number of elements.
494  * This reduces problems with run-time out-of-shared-memory conditions.
495  *
496  * For a non-shared hash table, preallocate the requested number of
497  * elements if it's less than our chosen nelem_alloc. This avoids wasting
498  * space if the caller correctly estimates a small table size.
499  */
500  if ((flags & HASH_SHARED_MEM) ||
501  nelem < hctl->nelem_alloc)
502  {
503  int i,
504  freelist_partitions,
505  nelem_alloc,
506  nelem_alloc_first;
507 
508  /*
509  * If hash table is partitioned all freeLists have equal number of
510  * elements. Otherwise only freeList[0] is used.
511  */
512  if (IS_PARTITIONED(hashp->hctl))
513  freelist_partitions = NUM_FREELISTS;
514  else
515  freelist_partitions = 1;
516 
517  nelem_alloc = nelem / freelist_partitions;
518  if (nelem_alloc == 0)
519  nelem_alloc = 1;
520 
521  /* Make sure all memory will be used */
522  if (nelem_alloc * freelist_partitions < nelem)
523  nelem_alloc_first =
524  nelem - nelem_alloc * (freelist_partitions - 1);
525  else
526  nelem_alloc_first = nelem_alloc;
527 
528  for (i = 0; i < freelist_partitions; i++)
529  {
530  int temp = (i == 0) ? nelem_alloc_first : nelem_alloc;
531 
532  if (!element_alloc(hashp, temp, i))
533  ereport(ERROR,
534  (errcode(ERRCODE_OUT_OF_MEMORY),
535  errmsg("out of memory")));
536  }
537  }
538 
539  if (flags & HASH_FIXED_SIZE)
540  hashp->isfixed = true;
541  return hashp;
542 }
Size keysize
Definition: dynahash.c:164
Size keysize
Definition: dynahash.c:210
long dsize
Definition: dynahash.c:157
#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:165
#define IS_PARTITIONED(hctl)
Definition: dynahash.c:184
uint32 string_hash(const void *key, Size keysize)
Definition: hashfn.c:34
long num_partitions
Definition: dynahash.c:166
Size entrysize
Definition: hsearch.h:73
#define NUM_FREELISTS
Definition: dynahash.c:115
int errcode(int sqlerrcode)
Definition: elog.c:575
HashAllocFunc alloc
Definition: dynahash.c:200
#define MemSet(start, val, len)
Definition: c.h:853
#define HASH_SHARED_MEM
Definition: hsearch.h:94
static int string_compare(const char *key1, const char *key2, Size keysize)
Definition: dynahash.c:278
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:167
HashValueFunc hash
Definition: dynahash.c:197
Definition: dynahash.c:193
long max_dsize
Definition: hsearch.h:70
long ssize
Definition: dynahash.c:211
#define ERROR
Definition: elog.h:43
long num_partitions
Definition: hsearch.h:67
int sshift
Definition: dynahash.c:212
#define ALLOCSET_DEFAULT_SIZES
Definition: memutils.h:145
HashAllocFunc alloc
Definition: hsearch.h:77
#define HASH_KEYCOPY
Definition: hsearch.h:91
long max_dsize
Definition: dynahash.c:168
static void hdefault(HTAB *hashp)
Definition: dynahash.c:548
HASHHDR * hctl
Definition: dynahash.c:195
unsigned int uint32
Definition: c.h:265
static bool init_htab(HTAB *hashp, long nelem)
Definition: dynahash.c:614
#define ereport(elevel, rest)
Definition: elog.h:122
MemoryContext TopMemoryContext
Definition: mcxt.c:43
int my_log2(long num)
Definition: dynahash.c:1682
HashCompareFunc match
Definition: dynahash.c:198
static int next_pow2_int(long num)
Definition: dynahash.c:1706
bool isshared
Definition: dynahash.c:203
#define HASH_BLOBS
Definition: hsearch.h:88
bool frozen
Definition: dynahash.c:207
MemoryContext AllocSetContextCreate(MemoryContext parent, const char *name, Size minContextSize, Size initBlockSize, Size maxBlockSize)
Definition: aset.c:440
uint32 tag_hash(const void *key, Size keysize)
Definition: hashfn.c:52
long ssize
Definition: dynahash.c:169
Size keysize
Definition: hsearch.h:72
HashCompareFunc match
Definition: hsearch.h:75
MemoryContext hcxt
Definition: dynahash.c:201
HashCopyFunc keycopy
Definition: dynahash.c:199
#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:226
#define Assert(condition)
Definition: c.h:671
#define HASH_COMPARE
Definition: hsearch.h:90
HASHHDR * hctl
Definition: hsearch.h:79
long ffactor
Definition: hsearch.h:71
char * tabname
Definition: dynahash.c:202
#define HASH_FIXED_SIZE
Definition: hsearch.h:96
bool isfixed
Definition: dynahash.c:204
#define HASH_FFACTOR
Definition: hsearch.h:86
static void * DynaHashAlloc(Size size)
Definition: dynahash.c:263
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:260
int i
#define HASH_ALLOC
Definition: hsearch.h:92
HASHSEGMENT * dir
Definition: dynahash.c:196
#define elog
Definition: elog.h:219
static bool element_alloc(HTAB *hashp, int nelem, int freelist_idx)
Definition: dynahash.c:1621
int sshift
Definition: dynahash.c:170
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 793 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(), InitLocks(), pgoutput_shutdown(), pgstat_recv_dropdb(), pgstat_recv_resetcounter(), pgstat_vacuum_stat(), populate_record_worker(), populate_recordset_object_end(), PostPrepare_PredicateLocks(), ReleasePredicateLocks(), ReorderBufferReturnTXN(), ReorderBufferToastReset(), ResetSequenceCaches(), ResetUnloggedRelationsInDbspaceDir(), set_rtable_names(), SetForwardFsyncRequests(), tqueueDestroyReceiver(), and XLogCheckInvalidPages().

794 {
795  if (hashp != NULL)
796  {
797  /* allocation method must be one we know how to free, too */
798  Assert(hashp->alloc == DynaHashAlloc);
799  /* so this hashtable must have it's own context */
800  Assert(hashp->hcxt != NULL);
801 
802  hash_stats("destroy", hashp);
803 
804  /*
805  * Free everything by destroying the hash table's memory context.
806  */
807  MemoryContextDelete(hashp->hcxt);
808  }
809 }
void MemoryContextDelete(MemoryContext context)
Definition: mcxt.c:200
void hash_stats(const char *where, HTAB *hashp)
Definition: dynahash.c:812
HashAllocFunc alloc
Definition: dynahash.c:200
MemoryContext hcxt
Definition: dynahash.c:201
#define NULL
Definition: c.h:226
#define Assert(condition)
Definition: c.h:671
static void * DynaHashAlloc(Size size)
Definition: dynahash.c:263
Size hash_estimate_size ( long  num_entries,
Size  entrysize 
)

Definition at line 711 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().

712 {
713  Size size;
714  long nBuckets,
715  nSegments,
716  nDirEntries,
717  nElementAllocs,
718  elementSize,
719  elementAllocCnt;
720 
721  /* estimate number of buckets wanted */
722  nBuckets = next_pow2_long((num_entries - 1) / DEF_FFACTOR + 1);
723  /* # of segments needed for nBuckets */
724  nSegments = next_pow2_long((nBuckets - 1) / DEF_SEGSIZE + 1);
725  /* directory entries */
726  nDirEntries = DEF_DIRSIZE;
727  while (nDirEntries < nSegments)
728  nDirEntries <<= 1; /* dir_alloc doubles dsize at each call */
729 
730  /* fixed control info */
731  size = MAXALIGN(sizeof(HASHHDR)); /* but not HTAB, per above */
732  /* directory */
733  size = add_size(size, mul_size(nDirEntries, sizeof(HASHSEGMENT)));
734  /* segments */
735  size = add_size(size, mul_size(nSegments,
736  MAXALIGN(DEF_SEGSIZE * sizeof(HASHBUCKET))));
737  /* elements --- allocated in groups of choose_nelem_alloc() entries */
738  elementAllocCnt = choose_nelem_alloc(entrysize);
739  nElementAllocs = (num_entries - 1) / elementAllocCnt + 1;
740  elementSize = MAXALIGN(sizeof(HASHELEMENT)) + MAXALIGN(entrysize);
741  size = add_size(size,
742  mul_size(nElementAllocs,
743  mul_size(elementAllocCnt, elementSize)));
744 
745  return size;
746 }
static long next_pow2_long(long num)
Definition: dynahash.c:1698
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:353
#define MAXALIGN(LEN)
Definition: c.h:584
static int choose_nelem_alloc(Size entrysize)
Definition: dynahash.c:581
#define DEF_FFACTOR
Definition: dynahash.c:112
#define DEF_SEGSIZE
Definition: dynahash.c:109
#define DEF_DIRSIZE
Definition: dynahash.c:111
void hash_freeze ( HTAB hashp)

Definition at line 1449 of file dynahash.c.

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

1450 {
1451  if (hashp->isshared)
1452  elog(ERROR, "cannot freeze shared hashtable \"%s\"", hashp->tabname);
1453  if (!hashp->frozen && has_seq_scans(hashp))
1454  elog(ERROR, "cannot freeze hashtable \"%s\" because it has active scans",
1455  hashp->tabname);
1456  hashp->frozen = true;
1457 }
#define ERROR
Definition: elog.h:43
static bool has_seq_scans(HTAB *hashp)
Definition: dynahash.c:1784
bool isshared
Definition: dynahash.c:203
bool frozen
Definition: dynahash.c:207
char * tabname
Definition: dynahash.c:202
#define elog
Definition: elog.h:219
long hash_get_num_entries ( HTAB hashp)

Definition at line 1297 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(), populate_record_worker(), ResetUnloggedRelationsInDbspaceDir(), transformGraph(), and XLogHaveInvalidPages().

1298 {
1299  int i;
1300  long sum = hashp->hctl->freeList[0].nentries;
1301 
1302  /*
1303  * We currently don't bother with the mutex; it's only sensible to call
1304  * this function if you've got lock on all partitions of the table.
1305  */
1306 
1307  if (!IS_PARTITIONED(hashp->hctl))
1308  return sum;
1309 
1310  for (i = 1; i < NUM_FREELISTS; i++)
1311  sum += hashp->hctl->freeList[i].nentries;
1312 
1313  return sum;
1314 }
#define IS_PARTITIONED(hctl)
Definition: dynahash.c:184
#define NUM_FREELISTS
Definition: dynahash.c:115
HASHHDR * hctl
Definition: dynahash.c:195
long nentries
Definition: dynahash.c:131
FreeListData freeList[NUM_FREELISTS]
Definition: dynahash.c:153
int i
Size hash_get_shared_size ( HASHCTL info,
int  flags 
)

Definition at line 782 of file dynahash.c.

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

Referenced by ShmemInitHash().

783 {
784  Assert(flags & HASH_DIRSIZE);
785  Assert(info->dsize == info->max_dsize);
786  return sizeof(HASHHDR) + info->dsize * sizeof(HASHSEGMENT);
787 }
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:671
#define HASH_DIRSIZE
Definition: hsearch.h:85
void* hash_search ( HTAB hashp,
const void *  keyPtr,
HASHACTION  action,
bool foundPtr 
)

Definition at line 885 of file dynahash.c.

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

Referenced by _hash_finish_split(), _hash_splitbucket_guts(), ApplyLogicalMappingFile(), assign_record_type_typmod(), AtEOSubXact_RelationCache(), AtEOXact_RelationCache(), build_join_rel(), 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_funcstat_entry(), find_join_rel(), find_oper_cache_entry(), find_rendezvous_variable(), forget_invalid_pages(), forget_invalid_pages_db(), ForgetPrivateRefCountEntry(), get_attribute_options(), get_cast_hashentry(), get_pgstat_tabentry_relid(), get_rel_sync_entry(), get_tablespace(), GetComboCommandId(), GetConnection(), getConnectionByName(), GetExtensibleNodeEntry(), GetPrivateRefCountEntry(), getState(), gistGetNodeBuffer(), gistGetParent(), gistMemorizeParent(), gistRelocateBuildBuffersOnSplit(), hash_object_field_end(), init_sequence(), InitPredicateLocks(), InvalidateAttoptCacheCallback(), InvalidateOprCacheCallBack(), InvalidateShippableCacheCallback(), InvalidateTableSpaceCacheCallback(), is_shippable(), 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_record_worker(), populate_recordset_object_end(), populate_recordset_object_field_end(), predicatelock_twophase_recover(), PredicateLockExists(), PredicateLockTwoPhaseFinish(), 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().

889 {
890  return hash_search_with_hash_value(hashp,
891  keyPtr,
892  hashp->hash(keyPtr, hashp->keysize),
893  action,
894  foundPtr);
895 }
void * hash_search_with_hash_value(HTAB *hashp, const void *keyPtr, uint32 hashvalue, HASHACTION action, bool *foundPtr)
Definition: dynahash.c:898
Size keysize
Definition: dynahash.c:210
HashValueFunc hash
Definition: dynahash.c:197
void* hash_search_with_hash_value ( HTAB hashp,
const void *  keyPtr,
uint32  hashvalue,
HASHACTION  action,
bool foundPtr 
)

Definition at line 898 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().

903 {
904  HASHHDR *hctl = hashp->hctl;
905  Size keysize;
906  uint32 bucket;
907  long segment_num;
908  long segment_ndx;
909  HASHSEGMENT segp;
910  HASHBUCKET currBucket;
911  HASHBUCKET *prevBucketPtr;
912  HashCompareFunc match;
913  int freelist_idx = FREELIST_IDX(hctl, hashvalue);
914 
915 #if HASH_STATISTICS
916  hash_accesses++;
917  hctl->accesses++;
918 #endif
919 
920  /*
921  * If inserting, check if it is time to split a bucket.
922  *
923  * NOTE: failure to expand table is not a fatal error, it just means we
924  * have to run at higher fill factor than we wanted. However, if we're
925  * using the palloc allocator then it will throw error anyway on
926  * out-of-memory, so we must do this before modifying the table.
927  */
928  if (action == HASH_ENTER || action == HASH_ENTER_NULL)
929  {
930  /*
931  * Can't split if running in partitioned mode, nor if frozen, nor if
932  * table is the subject of any active hash_seq_search scans. Strange
933  * order of these tests is to try to check cheaper conditions first.
934  */
935  if (!IS_PARTITIONED(hctl) && !hashp->frozen &&
936  hctl->freeList[0].nentries / (long) (hctl->max_bucket + 1) >= hctl->ffactor &&
937  !has_seq_scans(hashp))
938  (void) expand_table(hashp);
939  }
940 
941  /*
942  * Do the initial lookup
943  */
944  bucket = calc_bucket(hctl, hashvalue);
945 
946  segment_num = bucket >> hashp->sshift;
947  segment_ndx = MOD(bucket, hashp->ssize);
948 
949  segp = hashp->dir[segment_num];
950 
951  if (segp == NULL)
952  hash_corrupted(hashp);
953 
954  prevBucketPtr = &segp[segment_ndx];
955  currBucket = *prevBucketPtr;
956 
957  /*
958  * Follow collision chain looking for matching key
959  */
960  match = hashp->match; /* save one fetch in inner loop */
961  keysize = hashp->keysize; /* ditto */
962 
963  while (currBucket != NULL)
964  {
965  if (currBucket->hashvalue == hashvalue &&
966  match(ELEMENTKEY(currBucket), keyPtr, keysize) == 0)
967  break;
968  prevBucketPtr = &(currBucket->link);
969  currBucket = *prevBucketPtr;
970 #if HASH_STATISTICS
971  hash_collisions++;
972  hctl->collisions++;
973 #endif
974  }
975 
976  if (foundPtr)
977  *foundPtr = (bool) (currBucket != NULL);
978 
979  /*
980  * OK, now what?
981  */
982  switch (action)
983  {
984  case HASH_FIND:
985  if (currBucket != NULL)
986  return (void *) ELEMENTKEY(currBucket);
987  return NULL;
988 
989  case HASH_REMOVE:
990  if (currBucket != NULL)
991  {
992  /* if partitioned, must lock to touch nentries and freeList */
993  if (IS_PARTITIONED(hctl))
994  SpinLockAcquire(&(hctl->freeList[freelist_idx].mutex));
995 
996  Assert(hctl->freeList[freelist_idx].nentries > 0);
997  hctl->freeList[freelist_idx].nentries--;
998 
999  /* remove record from hash bucket's chain. */
1000  *prevBucketPtr = currBucket->link;
1001 
1002  /* add the record to the freelist for this table. */
1003  currBucket->link = hctl->freeList[freelist_idx].freeList;
1004  hctl->freeList[freelist_idx].freeList = currBucket;
1005 
1006  if (IS_PARTITIONED(hctl))
1007  SpinLockRelease(&hctl->freeList[freelist_idx].mutex);
1008 
1009  /*
1010  * better hope the caller is synchronizing access to this
1011  * element, because someone else is going to reuse it the next
1012  * time something is added to the table
1013  */
1014  return (void *) ELEMENTKEY(currBucket);
1015  }
1016  return NULL;
1017 
1018  case HASH_ENTER_NULL:
1019  /* ENTER_NULL does not work with palloc-based allocator */
1020  Assert(hashp->alloc != DynaHashAlloc);
1021  /* FALL THRU */
1022 
1023  case HASH_ENTER:
1024  /* Return existing element if found, else create one */
1025  if (currBucket != NULL)
1026  return (void *) ELEMENTKEY(currBucket);
1027 
1028  /* disallow inserts if frozen */
1029  if (hashp->frozen)
1030  elog(ERROR, "cannot insert into frozen hashtable \"%s\"",
1031  hashp->tabname);
1032 
1033  currBucket = get_hash_entry(hashp, freelist_idx);
1034  if (currBucket == NULL)
1035  {
1036  /* out of memory */
1037  if (action == HASH_ENTER_NULL)
1038  return NULL;
1039  /* report a generic message */
1040  if (hashp->isshared)
1041  ereport(ERROR,
1042  (errcode(ERRCODE_OUT_OF_MEMORY),
1043  errmsg("out of shared memory")));
1044  else
1045  ereport(ERROR,
1046  (errcode(ERRCODE_OUT_OF_MEMORY),
1047  errmsg("out of memory")));
1048  }
1049 
1050  /* link into hashbucket chain */
1051  *prevBucketPtr = currBucket;
1052  currBucket->link = NULL;
1053 
1054  /* copy key into record */
1055  currBucket->hashvalue = hashvalue;
1056  hashp->keycopy(ELEMENTKEY(currBucket), keyPtr, keysize);
1057 
1058  /*
1059  * Caller is expected to fill the data field on return. DO NOT
1060  * insert any code that could possibly throw error here, as doing
1061  * so would leave the table entry incomplete and hence corrupt the
1062  * caller's data structure.
1063  */
1064 
1065  return (void *) ELEMENTKEY(currBucket);
1066  }
1067 
1068  elog(ERROR, "unrecognized hash action code: %d", (int) action);
1069 
1070  return NULL; /* keep compiler quiet */
1071 }
Size keysize
Definition: dynahash.c:210
uint32 max_bucket
Definition: dynahash.c:159
static uint32 calc_bucket(HASHHDR *hctl, uint32 hash_val)
Definition: dynahash.c:846
#define IS_PARTITIONED(hctl)
Definition: dynahash.c:184
#define ELEMENTKEY(helem)
Definition: dynahash.c:218
int errcode(int sqlerrcode)
Definition: elog.c:575
HashAllocFunc alloc
Definition: dynahash.c:200
slock_t mutex
Definition: dynahash.c:130
static HASHBUCKET get_hash_entry(HTAB *hashp, int freelist_idx)
Definition: dynahash.c:1226
char bool
Definition: c.h:199
long ffactor
Definition: dynahash.c:167
#define SpinLockAcquire(lock)
Definition: spin.h:62
long ssize
Definition: dynahash.c:211
#define ERROR
Definition: elog.h:43
int sshift
Definition: dynahash.c:212
#define MOD(x, y)
Definition: dynahash.c:229
HASHHDR * hctl
Definition: dynahash.c:195
static void hash_corrupted(HTAB *hashp)
Definition: dynahash.c:1668
static bool has_seq_scans(HTAB *hashp)
Definition: dynahash.c:1784
unsigned int uint32
Definition: c.h:265
long nentries
Definition: dynahash.c:131
#define ereport(elevel, rest)
Definition: elog.h:122
HashCompareFunc match
Definition: dynahash.c:198
bool isshared
Definition: dynahash.c:203
#define SpinLockRelease(lock)
Definition: spin.h:64
bool frozen
Definition: dynahash.c:207
FreeListData freeList[NUM_FREELISTS]
Definition: dynahash.c:153
HashCopyFunc keycopy
Definition: dynahash.c:199
#define NULL
Definition: c.h:226
#define Assert(condition)
Definition: c.h:671
size_t Size
Definition: c.h:353
static bool expand_table(HTAB *hashp)
Definition: dynahash.c:1466
char * tabname
Definition: dynahash.c:202
static void * DynaHashAlloc(Size size)
Definition: dynahash.c:263
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:132
HASHSEGMENT * dir
Definition: dynahash.c:196
#define elog
Definition: elog.h:219
#define FREELIST_IDX(hctl, hashcode)
Definition: dynahash.c:186
uint32 hashvalue
Definition: hsearch.h:54
long hash_select_dirsize ( long  num_entries)

Definition at line 758 of file dynahash.c.

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

Referenced by ShmemInitHash().

759 {
760  long nBuckets,
761  nSegments,
762  nDirEntries;
763 
764  /* estimate number of buckets wanted */
765  nBuckets = next_pow2_long((num_entries - 1) / DEF_FFACTOR + 1);
766  /* # of segments needed for nBuckets */
767  nSegments = next_pow2_long((nBuckets - 1) / DEF_SEGSIZE + 1);
768  /* directory entries */
769  nDirEntries = DEF_DIRSIZE;
770  while (nDirEntries < nSegments)
771  nDirEntries <<= 1; /* dir_alloc doubles dsize at each call */
772 
773  return nDirEntries;
774 }
static long next_pow2_long(long num)
Definition: dynahash.c:1698
#define DEF_FFACTOR
Definition: dynahash.c:112
#define DEF_SEGSIZE
Definition: dynahash.c:109
#define DEF_DIRSIZE
Definition: dynahash.c:111
void hash_seq_init ( HASH_SEQ_STATUS status,
HTAB hashp 
)

Definition at line 1343 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_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().

1344 {
1345  status->hashp = hashp;
1346  status->curBucket = 0;
1347  status->curEntry = NULL;
1348  if (!hashp->frozen)
1349  register_seq_scan(hashp);
1350 }
uint32 curBucket
Definition: hsearch.h:115
HASHELEMENT * curEntry
Definition: hsearch.h:116
HTAB * hashp
Definition: hsearch.h:114
bool frozen
Definition: dynahash.c:207
#define NULL
Definition: c.h:226
static void register_seq_scan(HTAB *hashp)
Definition: dynahash.c:1751
void* hash_seq_search ( HASH_SEQ_STATUS status)

Definition at line 1353 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_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().

1354 {
1355  HTAB *hashp;
1356  HASHHDR *hctl;
1357  uint32 max_bucket;
1358  long ssize;
1359  long segment_num;
1360  long segment_ndx;
1361  HASHSEGMENT segp;
1362  uint32 curBucket;
1363  HASHELEMENT *curElem;
1364 
1365  if ((curElem = status->curEntry) != NULL)
1366  {
1367  /* Continuing scan of curBucket... */
1368  status->curEntry = curElem->link;
1369  if (status->curEntry == NULL) /* end of this bucket */
1370  ++status->curBucket;
1371  return (void *) ELEMENTKEY(curElem);
1372  }
1373 
1374  /*
1375  * Search for next nonempty bucket starting at curBucket.
1376  */
1377  curBucket = status->curBucket;
1378  hashp = status->hashp;
1379  hctl = hashp->hctl;
1380  ssize = hashp->ssize;
1381  max_bucket = hctl->max_bucket;
1382 
1383  if (curBucket > max_bucket)
1384  {
1385  hash_seq_term(status);
1386  return NULL; /* search is done */
1387  }
1388 
1389  /*
1390  * first find the right segment in the table directory.
1391  */
1392  segment_num = curBucket >> hashp->sshift;
1393  segment_ndx = MOD(curBucket, ssize);
1394 
1395  segp = hashp->dir[segment_num];
1396 
1397  /*
1398  * Pick up the first item in this bucket's chain. If chain is not empty
1399  * we can begin searching it. Otherwise we have to advance to find the
1400  * next nonempty bucket. We try to optimize that case since searching a
1401  * near-empty hashtable has to iterate this loop a lot.
1402  */
1403  while ((curElem = segp[segment_ndx]) == NULL)
1404  {
1405  /* empty bucket, advance to next */
1406  if (++curBucket > max_bucket)
1407  {
1408  status->curBucket = curBucket;
1409  hash_seq_term(status);
1410  return NULL; /* search is done */
1411  }
1412  if (++segment_ndx >= ssize)
1413  {
1414  segment_num++;
1415  segment_ndx = 0;
1416  segp = hashp->dir[segment_num];
1417  }
1418  }
1419 
1420  /* Begin scan of curBucket... */
1421  status->curEntry = curElem->link;
1422  if (status->curEntry == NULL) /* end of this bucket */
1423  ++curBucket;
1424  status->curBucket = curBucket;
1425  return (void *) ELEMENTKEY(curElem);
1426 }
uint32 curBucket
Definition: hsearch.h:115
uint32 max_bucket
Definition: dynahash.c:159
#define ELEMENTKEY(helem)
Definition: dynahash.c:218
HASHELEMENT * curEntry
Definition: hsearch.h:116
Definition: dynahash.c:193
long ssize
Definition: dynahash.c:211
int sshift
Definition: dynahash.c:212
#define MOD(x, y)
Definition: dynahash.c:229
HASHHDR * hctl
Definition: dynahash.c:195
unsigned int uint32
Definition: c.h:265
HTAB * hashp
Definition: hsearch.h:114
#define NULL
Definition: c.h:226
struct HASHELEMENT * link
Definition: hsearch.h:53
HASHSEGMENT * dir
Definition: dynahash.c:196
void hash_seq_term(HASH_SEQ_STATUS *status)
Definition: dynahash.c:1429
void hash_seq_term ( HASH_SEQ_STATUS status)

Definition at line 1429 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().

1430 {
1431  if (!status->hashp->frozen)
1432  deregister_seq_scan(status->hashp);
1433 }
HTAB * hashp
Definition: hsearch.h:114
bool frozen
Definition: dynahash.c:207
static void deregister_seq_scan(HTAB *hashp)
Definition: dynahash.c:1763
void hash_stats ( const char *  where,
HTAB hashp 
)

Definition at line 812 of file dynahash.c.

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

Referenced by hash_destroy().

813 {
814 #if HASH_STATISTICS
815  fprintf(stderr, "%s: this HTAB -- accesses %ld collisions %ld\n",
816  where, hashp->hctl->accesses, hashp->hctl->collisions);
817 
818  fprintf(stderr, "hash_stats: entries %ld keysize %ld maxp %u segmentcount %ld\n",
819  hash_get_num_entries(hashp), (long) hashp->hctl->keysize,
820  hashp->hctl->max_bucket, hashp->hctl->nsegs);
821  fprintf(stderr, "%s: total accesses %ld total collisions %ld\n",
822  where, hash_accesses, hash_collisions);
823  fprintf(stderr, "hash_stats: total expansions %ld\n",
824  hash_expansions);
825 #endif
826 }
Size keysize
Definition: dynahash.c:164
uint32 max_bucket
Definition: dynahash.c:159
long hash_get_num_entries(HTAB *hashp)
Definition: dynahash.c:1297
HASHHDR * hctl
Definition: dynahash.c:195
long nsegs
Definition: dynahash.c:158
bool hash_update_hash_key ( HTAB hashp,
void *  existingEntry,
const void *  newKeyPtr 
)

Definition at line 1093 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().

1096 {
1097  HASHELEMENT *existingElement = ELEMENT_FROM_KEY(existingEntry);
1098  HASHHDR *hctl = hashp->hctl;
1099  uint32 newhashvalue;
1100  Size keysize;
1101  uint32 bucket;
1102  uint32 newbucket;
1103  long segment_num;
1104  long segment_ndx;
1105  HASHSEGMENT segp;
1106  HASHBUCKET currBucket;
1107  HASHBUCKET *prevBucketPtr;
1108  HASHBUCKET *oldPrevPtr;
1109  HashCompareFunc match;
1110 
1111 #if HASH_STATISTICS
1112  hash_accesses++;
1113  hctl->accesses++;
1114 #endif
1115 
1116  /* disallow updates if frozen */
1117  if (hashp->frozen)
1118  elog(ERROR, "cannot update in frozen hashtable \"%s\"",
1119  hashp->tabname);
1120 
1121  /*
1122  * Lookup the existing element using its saved hash value. We need to do
1123  * this to be able to unlink it from its hash chain, but as a side benefit
1124  * we can verify the validity of the passed existingEntry pointer.
1125  */
1126  bucket = calc_bucket(hctl, existingElement->hashvalue);
1127 
1128  segment_num = bucket >> hashp->sshift;
1129  segment_ndx = MOD(bucket, hashp->ssize);
1130 
1131  segp = hashp->dir[segment_num];
1132 
1133  if (segp == NULL)
1134  hash_corrupted(hashp);
1135 
1136  prevBucketPtr = &segp[segment_ndx];
1137  currBucket = *prevBucketPtr;
1138 
1139  while (currBucket != NULL)
1140  {
1141  if (currBucket == existingElement)
1142  break;
1143  prevBucketPtr = &(currBucket->link);
1144  currBucket = *prevBucketPtr;
1145  }
1146 
1147  if (currBucket == NULL)
1148  elog(ERROR, "hash_update_hash_key argument is not in hashtable \"%s\"",
1149  hashp->tabname);
1150 
1151  oldPrevPtr = prevBucketPtr;
1152 
1153  /*
1154  * Now perform the equivalent of a HASH_ENTER operation to locate the hash
1155  * chain we want to put the entry into.
1156  */
1157  newhashvalue = hashp->hash(newKeyPtr, hashp->keysize);
1158 
1159  newbucket = calc_bucket(hctl, newhashvalue);
1160 
1161  segment_num = newbucket >> hashp->sshift;
1162  segment_ndx = MOD(newbucket, hashp->ssize);
1163 
1164  segp = hashp->dir[segment_num];
1165 
1166  if (segp == NULL)
1167  hash_corrupted(hashp);
1168 
1169  prevBucketPtr = &segp[segment_ndx];
1170  currBucket = *prevBucketPtr;
1171 
1172  /*
1173  * Follow collision chain looking for matching key
1174  */
1175  match = hashp->match; /* save one fetch in inner loop */
1176  keysize = hashp->keysize; /* ditto */
1177 
1178  while (currBucket != NULL)
1179  {
1180  if (currBucket->hashvalue == newhashvalue &&
1181  match(ELEMENTKEY(currBucket), newKeyPtr, keysize) == 0)
1182  break;
1183  prevBucketPtr = &(currBucket->link);
1184  currBucket = *prevBucketPtr;
1185 #if HASH_STATISTICS
1186  hash_collisions++;
1187  hctl->collisions++;
1188 #endif
1189  }
1190 
1191  if (currBucket != NULL)
1192  return false; /* collision with an existing entry */
1193 
1194  currBucket = existingElement;
1195 
1196  /*
1197  * If old and new hash values belong to the same bucket, we need not
1198  * change any chain links, and indeed should not since this simplistic
1199  * update will corrupt the list if currBucket is the last element. (We
1200  * cannot fall out earlier, however, since we need to scan the bucket to
1201  * check for duplicate keys.)
1202  */
1203  if (bucket != newbucket)
1204  {
1205  /* OK to remove record from old hash bucket's chain. */
1206  *oldPrevPtr = currBucket->link;
1207 
1208  /* link into new hashbucket chain */
1209  *prevBucketPtr = currBucket;
1210  currBucket->link = NULL;
1211  }
1212 
1213  /* copy new key into record */
1214  currBucket->hashvalue = newhashvalue;
1215  hashp->keycopy(ELEMENTKEY(currBucket), newKeyPtr, keysize);
1216 
1217  /* rest of record is untouched */
1218 
1219  return true;
1220 }
Size keysize
Definition: dynahash.c:210
static uint32 calc_bucket(HASHHDR *hctl, uint32 hash_val)
Definition: dynahash.c:846
#define ELEMENTKEY(helem)
Definition: dynahash.c:218
#define ELEMENT_FROM_KEY(key)
Definition: dynahash.c:223
HashValueFunc hash
Definition: dynahash.c:197
long ssize
Definition: dynahash.c:211
#define ERROR
Definition: elog.h:43
int sshift
Definition: dynahash.c:212
#define MOD(x, y)
Definition: dynahash.c:229
HASHHDR * hctl
Definition: dynahash.c:195
static void hash_corrupted(HTAB *hashp)
Definition: dynahash.c:1668
unsigned int uint32
Definition: c.h:265
HashCompareFunc match
Definition: dynahash.c:198
bool frozen
Definition: dynahash.c:207
HashCopyFunc keycopy
Definition: dynahash.c:199
#define NULL
Definition: c.h:226
size_t Size
Definition: c.h:353
char * tabname
Definition: dynahash.c:202
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:196
#define elog
Definition: elog.h:219
uint32 hashvalue
Definition: hsearch.h:54
static void hdefault ( HTAB hashp)
static

Definition at line 548 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().

549 {
550  HASHHDR *hctl = hashp->hctl;
551 
552  MemSet(hctl, 0, sizeof(HASHHDR));
553 
554  hctl->dsize = DEF_DIRSIZE;
555  hctl->nsegs = 0;
556 
557  /* rather pointless defaults for key & entry size */
558  hctl->keysize = sizeof(char *);
559  hctl->entrysize = 2 * sizeof(char *);
560 
561  hctl->num_partitions = 0; /* not partitioned */
562 
563  hctl->ffactor = DEF_FFACTOR;
564 
565  /* table has no fixed maximum size */
566  hctl->max_dsize = NO_MAX_DSIZE;
567 
568  hctl->ssize = DEF_SEGSIZE;
569  hctl->sshift = DEF_SEGSIZE_SHIFT;
570 
571 #ifdef HASH_STATISTICS
572  hctl->accesses = hctl->collisions = 0;
573 #endif
574 }
Size keysize
Definition: dynahash.c:164
long dsize
Definition: dynahash.c:157
Size entrysize
Definition: dynahash.c:165
#define NO_MAX_DSIZE
Definition: hsearch.h:100
long num_partitions
Definition: dynahash.c:166
#define MemSet(start, val, len)
Definition: c.h:853
long ffactor
Definition: dynahash.c:167
#define DEF_SEGSIZE_SHIFT
Definition: dynahash.c:110
long max_dsize
Definition: dynahash.c:168
HASHHDR * hctl
Definition: dynahash.c:195
long ssize
Definition: dynahash.c:169
int sshift
Definition: dynahash.c:170
#define DEF_FFACTOR
Definition: dynahash.c:112
#define DEF_SEGSIZE
Definition: dynahash.c:109
#define DEF_DIRSIZE
Definition: dynahash.c:111
long nsegs
Definition: dynahash.c:158
static bool init_htab ( HTAB hashp,
long  nelem 
)
static

Definition at line 614 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().

615 {
616  HASHHDR *hctl = hashp->hctl;
617  HASHSEGMENT *segp;
618  int nbuckets;
619  int nsegs;
620  int i;
621 
622  /*
623  * initialize mutex if it's a partitioned table
624  */
625  if (IS_PARTITIONED(hctl))
626  for (i = 0; i < NUM_FREELISTS; i++)
627  SpinLockInit(&(hctl->freeList[i].mutex));
628 
629  /*
630  * Divide number of elements by the fill factor to determine a desired
631  * number of buckets. Allocate space for the next greater power of two
632  * number of buckets
633  */
634  nbuckets = next_pow2_int((nelem - 1) / hctl->ffactor + 1);
635 
636  /*
637  * In a partitioned table, nbuckets must be at least equal to
638  * num_partitions; were it less, keys with apparently different partition
639  * numbers would map to the same bucket, breaking partition independence.
640  * (Normally nbuckets will be much bigger; this is just a safety check.)
641  */
642  while (nbuckets < hctl->num_partitions)
643  nbuckets <<= 1;
644 
645  hctl->max_bucket = hctl->low_mask = nbuckets - 1;
646  hctl->high_mask = (nbuckets << 1) - 1;
647 
648  /*
649  * Figure number of directory segments needed, round up to a power of 2
650  */
651  nsegs = (nbuckets - 1) / hctl->ssize + 1;
652  nsegs = next_pow2_int(nsegs);
653 
654  /*
655  * Make sure directory is big enough. If pre-allocated directory is too
656  * small, choke (caller screwed up).
657  */
658  if (nsegs > hctl->dsize)
659  {
660  if (!(hashp->dir))
661  hctl->dsize = nsegs;
662  else
663  return false;
664  }
665 
666  /* Allocate a directory */
667  if (!(hashp->dir))
668  {
669  CurrentDynaHashCxt = hashp->hcxt;
670  hashp->dir = (HASHSEGMENT *)
671  hashp->alloc(hctl->dsize * sizeof(HASHSEGMENT));
672  if (!hashp->dir)
673  return false;
674  }
675 
676  /* Allocate initial segments */
677  for (segp = hashp->dir; hctl->nsegs < nsegs; hctl->nsegs++, segp++)
678  {
679  *segp = seg_alloc(hashp);
680  if (*segp == NULL)
681  return false;
682  }
683 
684  /* Choose number of entries to allocate at a time */
686 
687 #if HASH_DEBUG
688  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",
689  "TABLE POINTER ", hashp,
690  "DIRECTORY SIZE ", hctl->dsize,
691  "SEGMENT SIZE ", hctl->ssize,
692  "SEGMENT SHIFT ", hctl->sshift,
693  "FILL FACTOR ", hctl->ffactor,
694  "MAX BUCKET ", hctl->max_bucket,
695  "HIGH MASK ", hctl->high_mask,
696  "LOW MASK ", hctl->low_mask,
697  "NSEGS ", hctl->nsegs,
698  "NENTRIES ", hash_get_num_entries(hctl));
699 #endif
700  return true;
701 }
long dsize
Definition: dynahash.c:157
uint32 max_bucket
Definition: dynahash.c:159
Size entrysize
Definition: dynahash.c:165
#define IS_PARTITIONED(hctl)
Definition: dynahash.c:184
#define SpinLockInit(lock)
Definition: spin.h:60
#define NUM_FREELISTS
Definition: dynahash.c:115
HashAllocFunc alloc
Definition: dynahash.c:200
long hash_get_num_entries(HTAB *hashp)
Definition: dynahash.c:1297
slock_t mutex
Definition: dynahash.c:130
uint32 low_mask
Definition: dynahash.c:161
long ffactor
Definition: dynahash.c:167
HASHHDR * hctl
Definition: dynahash.c:195
uint32 high_mask
Definition: dynahash.c:160
static int next_pow2_int(long num)
Definition: dynahash.c:1706
long ssize
Definition: dynahash.c:169
FreeListData freeList[NUM_FREELISTS]
Definition: dynahash.c:153
MemoryContext hcxt
Definition: dynahash.c:201
#define NULL
Definition: c.h:226
int nelem_alloc
Definition: dynahash.c:171
static HASHSEGMENT seg_alloc(HTAB *hashp)
Definition: dynahash.c:1602
static int choose_nelem_alloc(Size entrysize)
Definition: dynahash.c:581
static MemoryContext CurrentDynaHashCxt
Definition: dynahash.c:260
int i
HASHSEGMENT * dir
Definition: dynahash.c:196
int sshift
Definition: dynahash.c:170
long nsegs
Definition: dynahash.c:158
int my_log2 ( long  num)

Definition at line 1682 of file dynahash.c.

References i.

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

1683 {
1684  int i;
1685  long limit;
1686 
1687  /* guard against too-large input, which would put us into infinite loop */
1688  if (num > LONG_MAX / 2)
1689  num = LONG_MAX / 2;
1690 
1691  for (i = 0, limit = 1; limit < num; i++, limit <<= 1)
1692  ;
1693  return i;
1694 }
int i
static int next_pow2_int ( long  num)
static

Definition at line 1706 of file dynahash.c.

References my_log2().

Referenced by hash_create(), and init_htab().

1707 {
1708  if (num > INT_MAX / 2)
1709  num = INT_MAX / 2;
1710  return 1 << my_log2(num);
1711 }
int my_log2(long num)
Definition: dynahash.c:1682
static long next_pow2_long ( long  num)
static

Definition at line 1698 of file dynahash.c.

References my_log2().

Referenced by hash_estimate_size(), and hash_select_dirsize().

1699 {
1700  /* my_log2's internal range check is sufficient */
1701  return 1L << my_log2(num);
1702 }
int my_log2(long num)
Definition: dynahash.c:1682
static void register_seq_scan ( HTAB hashp)
static

Definition at line 1751 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().

1752 {
1754  elog(ERROR, "too many active hash_seq_search scans, cannot start one on \"%s\"",
1755  hashp->tabname);
1756  seq_scan_tables[num_seq_scans] = hashp;
1758  num_seq_scans++;
1759 }
static int seq_scan_level[MAX_SEQ_SCANS]
Definition: dynahash.c:1745
#define ERROR
Definition: elog.h:43
#define MAX_SEQ_SCANS
Definition: dynahash.c:1742
static int num_seq_scans
Definition: dynahash.c:1746
static HTAB * seq_scan_tables[MAX_SEQ_SCANS]
Definition: dynahash.c:1744
int GetCurrentTransactionNestLevel(void)
Definition: xact.c:760
char * tabname
Definition: dynahash.c:202
#define elog
Definition: elog.h:219
static HASHSEGMENT seg_alloc ( HTAB hashp)
static

Definition at line 1602 of file dynahash.c.

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

Referenced by expand_table(), and init_htab().

1603 {
1604  HASHSEGMENT segp;
1605 
1606  CurrentDynaHashCxt = hashp->hcxt;
1607  segp = (HASHSEGMENT) hashp->alloc(sizeof(HASHBUCKET) * hashp->ssize);
1608 
1609  if (!segp)
1610  return NULL;
1611 
1612  MemSet(segp, 0, sizeof(HASHBUCKET) * hashp->ssize);
1613 
1614  return segp;
1615 }
HashAllocFunc alloc
Definition: dynahash.c:200
#define MemSet(start, val, len)
Definition: c.h:853
HASHBUCKET * HASHSEGMENT
Definition: dynahash.c:121
long ssize
Definition: dynahash.c:211
MemoryContext hcxt
Definition: dynahash.c:201
#define NULL
Definition: c.h:226
static MemoryContext CurrentDynaHashCxt
Definition: dynahash.c:260
static int string_compare ( const char *  key1,
const char *  key2,
Size  keysize 
)
static

Definition at line 278 of file dynahash.c.

Referenced by hash_create().

279 {
280  return strncmp(key1, key2, keysize - 1);
281 }

Variable Documentation

MemoryContext CurrentDynaHashCxt = NULL
static

Definition at line 260 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 1745 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 1744 of file dynahash.c.