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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 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 pg_noreturn void hash_corrupted (HTAB *hashp)
 
static uint32 hash_initial_lookup (HTAB *hashp, uint32 hashvalue, HASHBUCKET **bucketptr)
 
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, const 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_init_with_hash_value (HASH_SEQ_STATUS *status, HTAB *hashp, uint32 hashvalue)
 
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 125 of file dynahash.c.

◆ DEF_SEGSIZE

#define DEF_SEGSIZE   256

Definition at line 123 of file dynahash.c.

◆ DEF_SEGSIZE_SHIFT

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

Definition at line 124 of file dynahash.c.

◆ ELEMENT_FROM_KEY

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

Definition at line 249 of file dynahash.c.

◆ ELEMENTKEY

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

Definition at line 244 of file dynahash.c.

◆ FREELIST_IDX

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

Definition at line 212 of file dynahash.c.

◆ IS_PARTITIONED

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

Definition at line 210 of file dynahash.c.

◆ MAX_SEQ_SCANS

#define MAX_SEQ_SCANS   100

Definition at line 1856 of file dynahash.c.

◆ MOD

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

Definition at line 255 of file dynahash.c.

◆ NUM_FREELISTS

#define NUM_FREELISTS   32

Definition at line 128 of file dynahash.c.

Typedef Documentation

◆ HASHBUCKET

Definition at line 131 of file dynahash.c.

◆ HASHSEGMENT

Definition at line 134 of file dynahash.c.

Function Documentation

◆ AtEOSubXact_HashTables()

void AtEOSubXact_HashTables ( bool  isCommit,
int  nestDepth 
)

Definition at line 1938 of file dynahash.c.

1939{
1940 int i;
1941
1942 /*
1943 * Search backward to make cleanup easy. Note we must check all entries,
1944 * not only those at the end of the array, because deletion technique
1945 * doesn't keep them in order.
1946 */
1947 for (i = num_seq_scans - 1; i >= 0; i--)
1948 {
1949 if (seq_scan_level[i] >= nestDepth)
1950 {
1951 if (isCommit)
1952 elog(WARNING, "leaked hash_seq_search scan for hash table %p",
1956 num_seq_scans--;
1957 }
1958 }
1959}
static HTAB * seq_scan_tables[MAX_SEQ_SCANS]
Definition: dynahash.c:1858
static int seq_scan_level[MAX_SEQ_SCANS]
Definition: dynahash.c:1859
static int num_seq_scans
Definition: dynahash.c:1860
#define WARNING
Definition: elog.h:36
#define elog(elevel,...)
Definition: elog.h:226
int i
Definition: isn.c:77

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

Referenced by AbortSubTransaction(), and CommitSubTransaction().

◆ AtEOXact_HashTables()

void AtEOXact_HashTables ( bool  isCommit)

Definition at line 1912 of file dynahash.c.

1913{
1914 /*
1915 * During abort cleanup, open scans are expected; just silently clean 'em
1916 * out. An open scan at commit means someone forgot a hash_seq_term()
1917 * call, so complain.
1918 *
1919 * Note: it's tempting to try to print the tabname here, but refrain for
1920 * fear of touching deallocated memory. This isn't a user-facing message
1921 * anyway, so it needn't be pretty.
1922 */
1923 if (isCommit)
1924 {
1925 int i;
1926
1927 for (i = 0; i < num_seq_scans; i++)
1928 {
1929 elog(WARNING, "leaked hash_seq_search scan for hash table %p",
1931 }
1932 }
1933 num_seq_scans = 0;
1934}

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

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

◆ calc_bucket()

static uint32 calc_bucket ( HASHHDR hctl,
uint32  hash_val 
)
inlinestatic

Definition at line 918 of file dynahash.c.

919{
920 uint32 bucket;
921
922 bucket = hash_val & hctl->high_mask;
923 if (bucket > hctl->max_bucket)
924 bucket = bucket & hctl->low_mask;
925
926 return bucket;
927}
uint32_t uint32
Definition: c.h:502
uint32 high_mask
Definition: dynahash.c:187
uint32 max_bucket
Definition: dynahash.c:186
uint32 low_mask
Definition: dynahash.c:188

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

Referenced by expand_table(), and hash_initial_lookup().

◆ choose_nelem_alloc()

static int choose_nelem_alloc ( Size  entrysize)
static

Definition at line 656 of file dynahash.c.

657{
658 int nelem_alloc;
659 Size elementSize;
660 Size allocSize;
661
662 /* Each element has a HASHELEMENT header plus user data. */
663 /* NB: this had better match element_alloc() */
664 elementSize = MAXALIGN(sizeof(HASHELEMENT)) + MAXALIGN(entrysize);
665
666 /*
667 * The idea here is to choose nelem_alloc at least 32, but round up so
668 * that the allocation request will be a power of 2 or just less. This
669 * makes little difference for hash tables in shared memory, but for hash
670 * tables managed by palloc, the allocation request will be rounded up to
671 * a power of 2 anyway. If we fail to take this into account, we'll waste
672 * as much as half the allocated space.
673 */
674 allocSize = 32 * 4; /* assume elementSize at least 8 */
675 do
676 {
677 allocSize <<= 1;
678 nelem_alloc = allocSize / elementSize;
679 } while (nelem_alloc < 32);
680
681 return nelem_alloc;
682}
#define MAXALIGN(LEN)
Definition: c.h:782
size_t Size
Definition: c.h:576

References MAXALIGN.

Referenced by hash_estimate_size(), and init_htab().

◆ deregister_seq_scan()

static void deregister_seq_scan ( HTAB hashp)
static

Definition at line 1877 of file dynahash.c.

1878{
1879 int i;
1880
1881 /* Search backward since it's most likely at the stack top */
1882 for (i = num_seq_scans - 1; i >= 0; i--)
1883 {
1884 if (seq_scan_tables[i] == hashp)
1885 {
1888 num_seq_scans--;
1889 return;
1890 }
1891 }
1892 elog(ERROR, "no hash_seq_search scan for hash table \"%s\"",
1893 hashp->tabname);
1894}
#define ERROR
Definition: elog.h:39
char * tabname
Definition: dynahash.c:228

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

Referenced by hash_seq_term().

◆ dir_realloc()

static bool dir_realloc ( HTAB hashp)
static

Definition at line 1648 of file dynahash.c.

1649{
1650 HASHSEGMENT *p;
1651 HASHSEGMENT *old_p;
1652 long new_dsize;
1653 long old_dirsize;
1654 long new_dirsize;
1655
1656 if (hashp->hctl->max_dsize != NO_MAX_DSIZE)
1657 return false;
1658
1659 /* Reallocate directory */
1660 new_dsize = hashp->hctl->dsize << 1;
1661 old_dirsize = hashp->hctl->dsize * sizeof(HASHSEGMENT);
1662 new_dirsize = new_dsize * sizeof(HASHSEGMENT);
1663
1664 old_p = hashp->dir;
1665 CurrentDynaHashCxt = hashp->hcxt;
1666 p = (HASHSEGMENT *) hashp->alloc((Size) new_dirsize);
1667
1668 if (p != NULL)
1669 {
1670 memcpy(p, old_p, old_dirsize);
1671 MemSet(((char *) p) + old_dirsize, 0, new_dirsize - old_dirsize);
1672 hashp->dir = p;
1673 hashp->hctl->dsize = new_dsize;
1674
1675 /* XXX assume the allocator is palloc, so we know how to free */
1676 Assert(hashp->alloc == DynaHashAlloc);
1677 pfree(old_p);
1678
1679 return true;
1680 }
1681
1682 return false;
1683}
#define MemSet(start, val, len)
Definition: c.h:991
static void * DynaHashAlloc(Size size)
Definition: dynahash.c:291
static MemoryContext CurrentDynaHashCxt
Definition: dynahash.c:288
HASHBUCKET * HASHSEGMENT
Definition: dynahash.c:134
Assert(PointerIsAligned(start, uint64))
#define NO_MAX_DSIZE
Definition: hsearch.h:108
void pfree(void *pointer)
Definition: mcxt.c:2147
long max_dsize
Definition: dynahash.c:194
long dsize
Definition: dynahash.c:184
HASHHDR * hctl
Definition: dynahash.c:221
MemoryContext hcxt
Definition: dynahash.c:227
HashAllocFunc alloc
Definition: dynahash.c:226
HASHSEGMENT * dir
Definition: dynahash.c:222

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

Referenced by expand_table().

◆ DynaHashAlloc()

static void * DynaHashAlloc ( Size  size)
static

Definition at line 291 of file dynahash.c.

292{
296}
#define MCXT_ALLOC_NO_OOM
Definition: fe_memutils.h:29
void * MemoryContextAllocExtended(MemoryContext context, Size size, int flags)
Definition: mcxt.c:1313
#define MemoryContextIsValid(context)
Definition: memnodes.h:145

References Assert(), CurrentDynaHashCxt, MCXT_ALLOC_NO_OOM, MemoryContextAllocExtended(), and MemoryContextIsValid.

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

◆ element_alloc()

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

Definition at line 1706 of file dynahash.c.

1707{
1708 HASHHDR *hctl = hashp->hctl;
1709 Size elementSize;
1710 HASHELEMENT *firstElement;
1711 HASHELEMENT *tmpElement;
1712 HASHELEMENT *prevElement;
1713 int i;
1714
1715 if (hashp->isfixed)
1716 return false;
1717
1718 /* Each element has a HASHELEMENT header plus user data. */
1719 elementSize = MAXALIGN(sizeof(HASHELEMENT)) + MAXALIGN(hctl->entrysize);
1720
1721 CurrentDynaHashCxt = hashp->hcxt;
1722 firstElement = (HASHELEMENT *) hashp->alloc(nelem * elementSize);
1723
1724 if (!firstElement)
1725 return false;
1726
1727 /* prepare to link all the new entries into the freelist */
1728 prevElement = NULL;
1729 tmpElement = firstElement;
1730 for (i = 0; i < nelem; i++)
1731 {
1732 tmpElement->link = prevElement;
1733 prevElement = tmpElement;
1734 tmpElement = (HASHELEMENT *) (((char *) tmpElement) + elementSize);
1735 }
1736
1737 /* if partitioned, must lock to touch freeList */
1738 if (IS_PARTITIONED(hctl))
1739 SpinLockAcquire(&hctl->freeList[freelist_idx].mutex);
1740
1741 /* freelist could be nonempty if two backends did this concurrently */
1742 firstElement->link = hctl->freeList[freelist_idx].freeList;
1743 hctl->freeList[freelist_idx].freeList = prevElement;
1744
1745 if (IS_PARTITIONED(hctl))
1746 SpinLockRelease(&hctl->freeList[freelist_idx].mutex);
1747
1748 return true;
1749}
#define IS_PARTITIONED(hctl)
Definition: dynahash.c:210
#define SpinLockRelease(lock)
Definition: spin.h:61
#define SpinLockAcquire(lock)
Definition: spin.h:59
slock_t mutex
Definition: dynahash.c:155
HASHELEMENT * freeList
Definition: dynahash.c:157
struct HASHELEMENT * link
Definition: hsearch.h:53
FreeListData freeList[NUM_FREELISTS]
Definition: dynahash.c:180
Size entrysize
Definition: dynahash.c:192
bool isfixed
Definition: dynahash.c:230

References HTAB::alloc, CurrentDynaHashCxt, 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().

◆ expand_table()

static bool expand_table ( HTAB hashp)
static

Definition at line 1551 of file dynahash.c.

1552{
1553 HASHHDR *hctl = hashp->hctl;
1554 HASHSEGMENT old_seg,
1555 new_seg;
1556 long old_bucket,
1557 new_bucket;
1558 long new_segnum,
1559 new_segndx;
1560 long old_segnum,
1561 old_segndx;
1562 HASHBUCKET *oldlink,
1563 *newlink;
1564 HASHBUCKET currElement,
1565 nextElement;
1566
1567 Assert(!IS_PARTITIONED(hctl));
1568
1569#ifdef HASH_STATISTICS
1570 hash_expansions++;
1571#endif
1572
1573 new_bucket = hctl->max_bucket + 1;
1574 new_segnum = new_bucket >> hashp->sshift;
1575 new_segndx = MOD(new_bucket, hashp->ssize);
1576
1577 if (new_segnum >= hctl->nsegs)
1578 {
1579 /* Allocate new segment if necessary -- could fail if dir full */
1580 if (new_segnum >= hctl->dsize)
1581 if (!dir_realloc(hashp))
1582 return false;
1583 if (!(hashp->dir[new_segnum] = seg_alloc(hashp)))
1584 return false;
1585 hctl->nsegs++;
1586 }
1587
1588 /* OK, we created a new bucket */
1589 hctl->max_bucket++;
1590
1591 /*
1592 * *Before* changing masks, find old bucket corresponding to same hash
1593 * values; values in that bucket may need to be relocated to new bucket.
1594 * Note that new_bucket is certainly larger than low_mask at this point,
1595 * so we can skip the first step of the regular hash mask calc.
1596 */
1597 old_bucket = (new_bucket & hctl->low_mask);
1598
1599 /*
1600 * If we crossed a power of 2, readjust masks.
1601 */
1602 if ((uint32) new_bucket > hctl->high_mask)
1603 {
1604 hctl->low_mask = hctl->high_mask;
1605 hctl->high_mask = (uint32) new_bucket | hctl->low_mask;
1606 }
1607
1608 /*
1609 * Relocate records to the new bucket. NOTE: because of the way the hash
1610 * masking is done in calc_bucket, only one old bucket can need to be
1611 * split at this point. With a different way of reducing the hash value,
1612 * that might not be true!
1613 */
1614 old_segnum = old_bucket >> hashp->sshift;
1615 old_segndx = MOD(old_bucket, hashp->ssize);
1616
1617 old_seg = hashp->dir[old_segnum];
1618 new_seg = hashp->dir[new_segnum];
1619
1620 oldlink = &old_seg[old_segndx];
1621 newlink = &new_seg[new_segndx];
1622
1623 for (currElement = *oldlink;
1624 currElement != NULL;
1625 currElement = nextElement)
1626 {
1627 nextElement = currElement->link;
1628 if ((long) calc_bucket(hctl, currElement->hashvalue) == old_bucket)
1629 {
1630 *oldlink = currElement;
1631 oldlink = &currElement->link;
1632 }
1633 else
1634 {
1635 *newlink = currElement;
1636 newlink = &currElement->link;
1637 }
1638 }
1639 /* don't forget to terminate the rebuilt hash chains... */
1640 *oldlink = NULL;
1641 *newlink = NULL;
1642
1643 return true;
1644}
static HASHSEGMENT seg_alloc(HTAB *hashp)
Definition: dynahash.c:1687
#define MOD(x, y)
Definition: dynahash.c:255
static bool dir_realloc(HTAB *hashp)
Definition: dynahash.c:1648
static uint32 calc_bucket(HASHHDR *hctl, uint32 hash_val)
Definition: dynahash.c:918
uint32 hashvalue
Definition: hsearch.h:54
long nsegs
Definition: dynahash.c:185
long ssize
Definition: dynahash.c:237
int sshift
Definition: dynahash.c:238

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().

◆ get_hash_entry()

static HASHBUCKET get_hash_entry ( HTAB hashp,
int  freelist_idx 
)
static

Definition at line 1256 of file dynahash.c.

1257{
1258 HASHHDR *hctl = hashp->hctl;
1259 HASHBUCKET newElement;
1260
1261 for (;;)
1262 {
1263 /* if partitioned, must lock to touch nentries and freeList */
1264 if (IS_PARTITIONED(hctl))
1265 SpinLockAcquire(&hctl->freeList[freelist_idx].mutex);
1266
1267 /* try to get an entry from the freelist */
1268 newElement = hctl->freeList[freelist_idx].freeList;
1269
1270 if (newElement != NULL)
1271 break;
1272
1273 if (IS_PARTITIONED(hctl))
1274 SpinLockRelease(&hctl->freeList[freelist_idx].mutex);
1275
1276 /*
1277 * No free elements in this freelist. In a partitioned table, there
1278 * might be entries in other freelists, but to reduce contention we
1279 * prefer to first try to get another chunk of buckets from the main
1280 * shmem allocator. If that fails, though, we *MUST* root through all
1281 * the other freelists before giving up. There are multiple callers
1282 * that assume that they can allocate every element in the initially
1283 * requested table size, or that deleting an element guarantees they
1284 * can insert a new element, even if shared memory is entirely full.
1285 * Failing because the needed element is in a different freelist is
1286 * not acceptable.
1287 */
1288 if (!element_alloc(hashp, hctl->nelem_alloc, freelist_idx))
1289 {
1290 int borrow_from_idx;
1291
1292 if (!IS_PARTITIONED(hctl))
1293 return NULL; /* out of memory */
1294
1295 /* try to borrow element from another freelist */
1296 borrow_from_idx = freelist_idx;
1297 for (;;)
1298 {
1299 borrow_from_idx = (borrow_from_idx + 1) % NUM_FREELISTS;
1300 if (borrow_from_idx == freelist_idx)
1301 break; /* examined all freelists, fail */
1302
1303 SpinLockAcquire(&(hctl->freeList[borrow_from_idx].mutex));
1304 newElement = hctl->freeList[borrow_from_idx].freeList;
1305
1306 if (newElement != NULL)
1307 {
1308 hctl->freeList[borrow_from_idx].freeList = newElement->link;
1309 SpinLockRelease(&(hctl->freeList[borrow_from_idx].mutex));
1310
1311 /* careful: count the new element in its proper freelist */
1312 SpinLockAcquire(&hctl->freeList[freelist_idx].mutex);
1313 hctl->freeList[freelist_idx].nentries++;
1314 SpinLockRelease(&hctl->freeList[freelist_idx].mutex);
1315
1316 return newElement;
1317 }
1318
1319 SpinLockRelease(&(hctl->freeList[borrow_from_idx].mutex));
1320 }
1321
1322 /* no elements available to borrow either, so out of memory */
1323 return NULL;
1324 }
1325 }
1326
1327 /* remove entry from freelist, bump nentries */
1328 hctl->freeList[freelist_idx].freeList = newElement->link;
1329 hctl->freeList[freelist_idx].nentries++;
1330
1331 if (IS_PARTITIONED(hctl))
1332 SpinLockRelease(&hctl->freeList[freelist_idx].mutex);
1333
1334 return newElement;
1335}
static bool element_alloc(HTAB *hashp, int nelem, int freelist_idx)
Definition: dynahash.c:1706
#define NUM_FREELISTS
Definition: dynahash.c:128
long nentries
Definition: dynahash.c:156
int nelem_alloc
Definition: dynahash.c:197

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().

◆ get_hash_value()

uint32 get_hash_value ( HTAB hashp,
const void *  keyPtr 
)

Definition at line 911 of file dynahash.c.

912{
913 return hashp->hash(keyPtr, hashp->keysize);
914}
HashValueFunc hash
Definition: dynahash.c:223
Size keysize
Definition: dynahash.c:236

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

Referenced by BufTableHashCode(), LockTagHashCode(), and lookup_type_cache().

◆ has_seq_scans()

static bool has_seq_scans ( HTAB hashp)
static

Definition at line 1898 of file dynahash.c.

1899{
1900 int i;
1901
1902 for (i = 0; i < num_seq_scans; i++)
1903 {
1904 if (seq_scan_tables[i] == hashp)
1905 return true;
1906 }
1907 return false;
1908}

References i, num_seq_scans, and seq_scan_tables.

Referenced by hash_freeze(), and hash_search_with_hash_value().

◆ hash_corrupted()

static void hash_corrupted ( HTAB hashp)
static

Definition at line 1780 of file dynahash.c.

1781{
1782 /*
1783 * If the corruption is in a shared hashtable, we'd better force a
1784 * systemwide restart. Otherwise, just shut down this one backend.
1785 */
1786 if (hashp->isshared)
1787 elog(PANIC, "hash table \"%s\" corrupted", hashp->tabname);
1788 else
1789 elog(FATAL, "hash table \"%s\" corrupted", hashp->tabname);
1790}
#define FATAL
Definition: elog.h:41
#define PANIC
Definition: elog.h:42
bool isshared
Definition: dynahash.c:229

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

Referenced by hash_initial_lookup().

◆ hash_create()

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

Definition at line 352 of file dynahash.c.

353{
354 HTAB *hashp;
355 HASHHDR *hctl;
356
357 /*
358 * Hash tables now allocate space for key and data, but you have to say
359 * how much space to allocate.
360 */
361 Assert(flags & HASH_ELEM);
362 Assert(info->keysize > 0);
363 Assert(info->entrysize >= info->keysize);
364
365 /*
366 * For shared hash tables, we have a local hash header (HTAB struct) that
367 * we allocate in TopMemoryContext; all else is in shared memory.
368 *
369 * For non-shared hash tables, everything including the hash header is in
370 * a memory context created specially for the hash table --- this makes
371 * hash_destroy very simple. The memory context is made a child of either
372 * a context specified by the caller, or TopMemoryContext if nothing is
373 * specified.
374 */
375 if (flags & HASH_SHARED_MEM)
376 {
377 /* Set up to allocate the hash header */
379 }
380 else
381 {
382 /* Create the hash table's private memory context */
383 if (flags & HASH_CONTEXT)
384 CurrentDynaHashCxt = info->hcxt;
385 else
388 "dynahash",
390 }
391
392 /* Initialize the hash header, plus a copy of the table name */
393 hashp = (HTAB *) DynaHashAlloc(sizeof(HTAB) + strlen(tabname) + 1);
394 MemSet(hashp, 0, sizeof(HTAB));
395
396 hashp->tabname = (char *) (hashp + 1);
397 strcpy(hashp->tabname, tabname);
398
399 /* If we have a private context, label it with hashtable's name */
400 if (!(flags & HASH_SHARED_MEM))
402
403 /*
404 * Select the appropriate hash function (see comments at head of file).
405 */
406 if (flags & HASH_FUNCTION)
407 {
408 Assert(!(flags & (HASH_BLOBS | HASH_STRINGS)));
409 hashp->hash = info->hash;
410 }
411 else if (flags & HASH_BLOBS)
412 {
413 Assert(!(flags & HASH_STRINGS));
414 /* We can optimize hashing for common key sizes */
415 if (info->keysize == sizeof(uint32))
416 hashp->hash = uint32_hash;
417 else
418 hashp->hash = tag_hash;
419 }
420 else
421 {
422 /*
423 * string_hash used to be considered the default hash method, and in a
424 * non-assert build it effectively still is. But we now consider it
425 * an assertion error to not say HASH_STRINGS explicitly. To help
426 * catch mistaken usage of HASH_STRINGS, we also insist on a
427 * reasonably long string length: if the keysize is only 4 or 8 bytes,
428 * it's almost certainly an integer or pointer not a string.
429 */
430 Assert(flags & HASH_STRINGS);
431 Assert(info->keysize > 8);
432
433 hashp->hash = string_hash;
434 }
435
436 /*
437 * If you don't specify a match function, it defaults to string_compare if
438 * you used string_hash, and to memcmp otherwise.
439 *
440 * Note: explicitly specifying string_hash is deprecated, because this
441 * might not work for callers in loadable modules on some platforms due to
442 * referencing a trampoline instead of the string_hash function proper.
443 * Specify HASH_STRINGS instead.
444 */
445 if (flags & HASH_COMPARE)
446 hashp->match = info->match;
447 else if (hashp->hash == string_hash)
449 else
450 hashp->match = memcmp;
451
452 /*
453 * Similarly, the key-copying function defaults to strlcpy or memcpy.
454 */
455 if (flags & HASH_KEYCOPY)
456 hashp->keycopy = info->keycopy;
457 else if (hashp->hash == string_hash)
458 {
459 /*
460 * The signature of keycopy is meant for memcpy(), which returns
461 * void*, but strlcpy() returns size_t. Since we never use the return
462 * value of keycopy, and size_t is pretty much always the same size as
463 * void *, this should be safe. The extra cast in the middle is to
464 * avoid warnings from -Wcast-function-type.
465 */
467 }
468 else
469 hashp->keycopy = memcpy;
470
471 /* And select the entry allocation function, too. */
472 if (flags & HASH_ALLOC)
473 hashp->alloc = info->alloc;
474 else
475 hashp->alloc = DynaHashAlloc;
476
477 if (flags & HASH_SHARED_MEM)
478 {
479 /*
480 * ctl structure and directory are preallocated for shared memory
481 * tables. Note that HASH_DIRSIZE and HASH_ALLOC had better be set as
482 * well.
483 */
484 hashp->hctl = info->hctl;
485 hashp->dir = (HASHSEGMENT *) (((char *) info->hctl) + sizeof(HASHHDR));
486 hashp->hcxt = NULL;
487 hashp->isshared = true;
488
489 /* hash table already exists, we're just attaching to it */
490 if (flags & HASH_ATTACH)
491 {
492 /* make local copies of some heavily-used values */
493 hctl = hashp->hctl;
494 hashp->keysize = hctl->keysize;
495 hashp->ssize = hctl->ssize;
496 hashp->sshift = hctl->sshift;
497
498 return hashp;
499 }
500 }
501 else
502 {
503 /* setup hash table defaults */
504 hashp->hctl = NULL;
505 hashp->dir = NULL;
506 hashp->hcxt = CurrentDynaHashCxt;
507 hashp->isshared = false;
508 }
509
510 if (!hashp->hctl)
511 {
512 hashp->hctl = (HASHHDR *) hashp->alloc(sizeof(HASHHDR));
513 if (!hashp->hctl)
515 (errcode(ERRCODE_OUT_OF_MEMORY),
516 errmsg("out of memory")));
517 }
518
519 hashp->frozen = false;
520
521 hdefault(hashp);
522
523 hctl = hashp->hctl;
524
525 if (flags & HASH_PARTITION)
526 {
527 /* Doesn't make sense to partition a local hash table */
528 Assert(flags & HASH_SHARED_MEM);
529
530 /*
531 * The number of partitions had better be a power of 2. Also, it must
532 * be less than INT_MAX (see init_htab()), so call the int version of
533 * next_pow2.
534 */
536
537 hctl->num_partitions = info->num_partitions;
538 }
539
540 if (flags & HASH_SEGMENT)
541 {
542 hctl->ssize = info->ssize;
543 hctl->sshift = my_log2(info->ssize);
544 /* ssize had better be a power of 2 */
545 Assert(hctl->ssize == (1L << hctl->sshift));
546 }
547
548 /*
549 * SHM hash tables have fixed directory size passed by the caller.
550 */
551 if (flags & HASH_DIRSIZE)
552 {
553 hctl->max_dsize = info->max_dsize;
554 hctl->dsize = info->dsize;
555 }
556
557 /* remember the entry sizes, too */
558 hctl->keysize = info->keysize;
559 hctl->entrysize = info->entrysize;
560
561 /* make local copies of heavily-used constant fields */
562 hashp->keysize = hctl->keysize;
563 hashp->ssize = hctl->ssize;
564 hashp->sshift = hctl->sshift;
565
566 /* Build the hash directory structure */
567 if (!init_htab(hashp, nelem))
568 elog(ERROR, "failed to initialize hash table \"%s\"", hashp->tabname);
569
570 /*
571 * For a shared hash table, preallocate the requested number of elements.
572 * This reduces problems with run-time out-of-shared-memory conditions.
573 *
574 * For a non-shared hash table, preallocate the requested number of
575 * elements if it's less than our chosen nelem_alloc. This avoids wasting
576 * space if the caller correctly estimates a small table size.
577 */
578 if ((flags & HASH_SHARED_MEM) ||
579 nelem < hctl->nelem_alloc)
580 {
581 int i,
582 freelist_partitions,
583 nelem_alloc,
584 nelem_alloc_first;
585
586 /*
587 * If hash table is partitioned, give each freelist an equal share of
588 * the initial allocation. Otherwise only freeList[0] is used.
589 */
590 if (IS_PARTITIONED(hashp->hctl))
591 freelist_partitions = NUM_FREELISTS;
592 else
593 freelist_partitions = 1;
594
595 nelem_alloc = nelem / freelist_partitions;
596 if (nelem_alloc <= 0)
597 nelem_alloc = 1;
598
599 /*
600 * Make sure we'll allocate all the requested elements; freeList[0]
601 * gets the excess if the request isn't divisible by NUM_FREELISTS.
602 */
603 if (nelem_alloc * freelist_partitions < nelem)
604 nelem_alloc_first =
605 nelem - nelem_alloc * (freelist_partitions - 1);
606 else
607 nelem_alloc_first = nelem_alloc;
608
609 for (i = 0; i < freelist_partitions; i++)
610 {
611 int temp = (i == 0) ? nelem_alloc_first : nelem_alloc;
612
613 if (!element_alloc(hashp, temp, i))
615 (errcode(ERRCODE_OUT_OF_MEMORY),
616 errmsg("out of memory")));
617 }
618 }
619
620 if (flags & HASH_FIXED_SIZE)
621 hashp->isfixed = true;
622 return hashp;
623}
void(* pg_funcptr_t)(void)
Definition: c.h:424
static bool init_htab(HTAB *hashp, long nelem)
Definition: dynahash.c:689
static int next_pow2_int(long num)
Definition: dynahash.c:1820
static int string_compare(const char *key1, const char *key2, Size keysize)
Definition: dynahash.c:307
static void hdefault(HTAB *hashp)
Definition: dynahash.c:629
int my_log2(long num)
Definition: dynahash.c:1794
int errcode(int sqlerrcode)
Definition: elog.c:854
int errmsg(const char *fmt,...)
Definition: elog.c:1071
#define ereport(elevel,...)
Definition: elog.h:149
uint32 tag_hash(const void *key, Size keysize)
Definition: hashfn.c:677
uint32 uint32_hash(const void *key, Size keysize)
Definition: hashfn.c:688
uint32 string_hash(const void *key, Size keysize)
Definition: hashfn.c:660
#define HASH_KEYCOPY
Definition: hsearch.h:100
#define HASH_STRINGS
Definition: hsearch.h:96
int(* HashCompareFunc)(const void *key1, const void *key2, Size keysize)
Definition: hsearch.h:29
#define HASH_CONTEXT
Definition: hsearch.h:102
#define HASH_ELEM
Definition: hsearch.h:95
#define HASH_ALLOC
Definition: hsearch.h:101
#define HASH_DIRSIZE
Definition: hsearch.h:94
#define HASH_SEGMENT
Definition: hsearch.h:93
#define HASH_ATTACH
Definition: hsearch.h:104
#define HASH_COMPARE
Definition: hsearch.h:99
#define HASH_FUNCTION
Definition: hsearch.h:98
#define HASH_BLOBS
Definition: hsearch.h:97
#define HASH_SHARED_MEM
Definition: hsearch.h:103
#define HASH_FIXED_SIZE
Definition: hsearch.h:105
#define HASH_PARTITION
Definition: hsearch.h:92
void *(* HashCopyFunc)(void *dest, const void *src, Size keysize)
Definition: hsearch.h:37
MemoryContext TopMemoryContext
Definition: mcxt.c:165
void MemoryContextSetIdentifier(MemoryContext context, const char *id)
Definition: mcxt.c:643
#define AllocSetContextCreate
Definition: memutils.h:149
#define ALLOCSET_DEFAULT_SIZES
Definition: memutils.h:180
size_t strlcpy(char *dst, const char *src, size_t siz)
Definition: strlcpy.c:45
long ssize
Definition: hsearch.h:70
HashAllocFunc alloc
Definition: hsearch.h:84
Size keysize
Definition: hsearch.h:75
HashValueFunc hash
Definition: hsearch.h:78
Size entrysize
Definition: hsearch.h:76
long dsize
Definition: hsearch.h:72
HashCompareFunc match
Definition: hsearch.h:80
HASHHDR * hctl
Definition: hsearch.h:88
MemoryContext hcxt
Definition: hsearch.h:86
long num_partitions
Definition: hsearch.h:68
HashCopyFunc keycopy
Definition: hsearch.h:82
long max_dsize
Definition: hsearch.h:73
long num_partitions
Definition: dynahash.c:193
Size keysize
Definition: dynahash.c:191
int sshift
Definition: dynahash.c:196
long ssize
Definition: dynahash.c:195
Definition: dynahash.c:220
HashCompareFunc match
Definition: dynahash.c:224
HashCopyFunc keycopy
Definition: dynahash.c:225
bool frozen
Definition: dynahash.c:233

References HTAB::alloc, HASHCTL::alloc, ALLOCSET_DEFAULT_SIZES, AllocSetContextCreate, Assert(), CurrentDynaHashCxt, HTAB::dir, HASHHDR::dsize, HASHCTL::dsize, DynaHashAlloc(), element_alloc(), elog, HASHHDR::entrysize, HASHCTL::entrysize, ereport, errcode(), errmsg(), ERROR, HTAB::frozen, HTAB::hash, HASHCTL::hash, HASH_ALLOC, HASH_ATTACH, HASH_BLOBS, HASH_COMPARE, HASH_CONTEXT, HASH_DIRSIZE, HASH_ELEM, HASH_FIXED_SIZE, HASH_FUNCTION, HASH_KEYCOPY, HASH_PARTITION, HASH_SEGMENT, HASH_SHARED_MEM, HASH_STRINGS, HTAB::hctl, HASHCTL::hctl, HTAB::hcxt, HASHCTL::hcxt, hdefault(), i, init_htab(), IS_PARTITIONED, HTAB::isfixed, HTAB::isshared, HTAB::keycopy, HASHCTL::keycopy, HASHHDR::keysize, HTAB::keysize, HASHCTL::keysize, HTAB::match, HASHCTL::match, HASHHDR::max_dsize, HASHCTL::max_dsize, MemoryContextSetIdentifier(), MemSet, my_log2(), next_pow2_int(), NUM_FREELISTS, HASHHDR::num_partitions, HASHCTL::num_partitions, HASHHDR::sshift, HTAB::sshift, HASHHDR::ssize, HTAB::ssize, HASHCTL::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_colinfo_names_hash(), build_guc_variables(), build_join_rel_hash(), BuildEventTriggerCache(), cfunc_hashtable_init(), CheckForSessionAndXactLocks(), CompactCheckpointerRequestQueue(), compute_array_stats(), compute_tsvector_stats(), create_seq_hashtable(), createConnHash(), CreateLocalPredicateLockHash(), CreatePartitionDirectory(), do_autovacuum(), EnablePortalManager(), ExecInitModifyTable(), ExecuteTruncateGuts(), find_all_inheritors(), find_oper_cache_entry(), find_rendezvous_variable(), get_json_object_as_hash(), GetComboCommandId(), GetConnection(), gistInitBuildBuffers(), gistInitParentMap(), init_missing_cache(), init_procedure_caches(), init_rel_sync_cache(), init_timezone_hashtable(), init_ts_config_cache(), init_uncommitted_enum_types(), init_uncommitted_enum_values(), InitBufferManagerAccess(), InitializeAttoptCache(), InitializeRelfilenumberMap(), InitializeShippableCache(), InitializeTableSpaceCache(), InitLocalBuffers(), InitLockManagerAccess(), InitQueryHashTable(), InitRecoveryTransactionEnvironment(), InitSync(), json_unique_check_init(), load_categories_hash(), log_invalid_page(), logical_begin_heap_rewrite(), logicalrep_partmap_init(), logicalrep_relmap_init(), lookup_proof_cache(), lookup_ts_dictionary_cache(), lookup_ts_parser_cache(), lookup_type_cache(), LookupOpclassInfo(), pa_allocate_worker(), pg_get_backend_memory_contexts(), plpgsql_estate_setup(), PLy_add_exceptions(), populate_recordset_object_start(), process_syncing_tables_for_apply(), ProcessGetMemoryContextInterrupt(), rebuild_database_list(), record_C_func(), RegisterExtensibleNodeEntry(), RelationCacheInitialize(), ReorderBufferAllocate(), ReorderBufferBuildTupleCidHash(), ReorderBufferToastInitHash(), ResetUnloggedRelationsInDbspaceDir(), ri_InitHashTables(), select_perl_context(), SerializePendingSyncs(), set_rtable_names(), ShmemInitHash(), smgropen(), transformGraph(), and XLogPrefetcherAllocate().

◆ hash_destroy()

void hash_destroy ( HTAB hashp)

Definition at line 865 of file dynahash.c.

866{
867 if (hashp != NULL)
868 {
869 /* allocation method must be one we know how to free, too */
870 Assert(hashp->alloc == DynaHashAlloc);
871 /* so this hashtable must have its own context */
872 Assert(hashp->hcxt != NULL);
873
874 hash_stats("destroy", hashp);
875
876 /*
877 * Free everything by destroying the hash table's memory context.
878 */
880 }
881}
void hash_stats(const char *where, HTAB *hashp)
Definition: dynahash.c:884
void MemoryContextDelete(MemoryContext context)
Definition: mcxt.c:485

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

Referenced by _hash_finish_split(), CheckForSessionAndXactLocks(), CompactCheckpointerRequestQueue(), destroy_colinfo_names_hash(), ExecuteTruncateGuts(), find_all_inheritors(), get_json_object_as_hash(), pg_get_backend_memory_contexts(), pgoutput_shutdown(), populate_recordset_object_end(), PostPrepare_PredicateLocks(), process_syncing_tables_for_apply(), ProcessGetMemoryContextInterrupt(), ReleasePredicateLocksLocal(), ReorderBufferFreeTXN(), ReorderBufferToastReset(), ReorderBufferTruncateTXN(), ResetSequenceCaches(), ResetUnloggedRelationsInDbspaceDir(), SerializePendingSyncs(), set_rtable_names(), ShutdownRecoveryTransactionEnvironment(), XLogCheckInvalidPages(), and XLogPrefetcherFree().

◆ hash_estimate_size()

Size hash_estimate_size ( long  num_entries,
Size  entrysize 
)

Definition at line 783 of file dynahash.c.

784{
785 Size size;
786 long nBuckets,
787 nSegments,
788 nDirEntries,
789 nElementAllocs,
790 elementSize,
791 elementAllocCnt;
792
793 /* estimate number of buckets wanted */
794 nBuckets = next_pow2_long(num_entries);
795 /* # of segments needed for nBuckets */
796 nSegments = next_pow2_long((nBuckets - 1) / DEF_SEGSIZE + 1);
797 /* directory entries */
798 nDirEntries = DEF_DIRSIZE;
799 while (nDirEntries < nSegments)
800 nDirEntries <<= 1; /* dir_alloc doubles dsize at each call */
801
802 /* fixed control info */
803 size = MAXALIGN(sizeof(HASHHDR)); /* but not HTAB, per above */
804 /* directory */
805 size = add_size(size, mul_size(nDirEntries, sizeof(HASHSEGMENT)));
806 /* segments */
807 size = add_size(size, mul_size(nSegments,
808 MAXALIGN(DEF_SEGSIZE * sizeof(HASHBUCKET))));
809 /* elements --- allocated in groups of choose_nelem_alloc() entries */
810 elementAllocCnt = choose_nelem_alloc(entrysize);
811 nElementAllocs = (num_entries - 1) / elementAllocCnt + 1;
812 elementSize = MAXALIGN(sizeof(HASHELEMENT)) + MAXALIGN(entrysize);
813 size = add_size(size,
814 mul_size(nElementAllocs,
815 mul_size(elementAllocCnt, elementSize)));
816
817 return size;
818}
#define DEF_DIRSIZE
Definition: dynahash.c:125
static int choose_nelem_alloc(Size entrysize)
Definition: dynahash.c:656
#define DEF_SEGSIZE
Definition: dynahash.c:123
static long next_pow2_long(long num)
Definition: dynahash.c:1812
Size add_size(Size s1, Size s2)
Definition: shmem.c:493
Size mul_size(Size s1, Size s2)
Definition: shmem.c:510

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

Referenced by BufTableShmemSize(), CalculateShmemSize(), LockManagerShmemSize(), pgss_memsize(), PredicateLockShmemSize(), and WaitEventCustomShmemSize().

◆ hash_freeze()

void hash_freeze ( HTAB hashp)

Definition at line 1534 of file dynahash.c.

1535{
1536 if (hashp->isshared)
1537 elog(ERROR, "cannot freeze shared hashtable \"%s\"", hashp->tabname);
1538 if (!hashp->frozen && has_seq_scans(hashp))
1539 elog(ERROR, "cannot freeze hashtable \"%s\" because it has active scans",
1540 hashp->tabname);
1541 hashp->frozen = true;
1542}
static bool has_seq_scans(HTAB *hashp)
Definition: dynahash.c:1898

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

◆ hash_get_num_entries()

long hash_get_num_entries ( HTAB hashp)

Definition at line 1341 of file dynahash.c.

1342{
1343 int i;
1344 long sum = hashp->hctl->freeList[0].nentries;
1345
1346 /*
1347 * We currently don't bother with acquiring the mutexes; it's only
1348 * sensible to call this function if you've got lock on all partitions of
1349 * the table.
1350 */
1351 if (IS_PARTITIONED(hashp->hctl))
1352 {
1353 for (i = 1; i < NUM_FREELISTS; i++)
1354 sum += hashp->hctl->freeList[i].nentries;
1355 }
1356
1357 return sum;
1358}

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

Referenced by build_guc_variables(), compute_array_stats(), compute_tsvector_stats(), entry_alloc(), entry_dealloc(), entry_reset(), EstimatePendingSyncsSpace(), EstimateUncommittedEnumsSpace(), get_crosstab_tuplestore(), get_explain_guc_options(), get_guc_variables(), GetLockStatusData(), GetPredicateLockStatusData(), GetRunningTransactionLocks(), GetWaitEventCustomNames(), hash_stats(), pgss_shmem_shutdown(), ResetUnloggedRelationsInDbspaceDir(), SerializePendingSyncs(), transformGraph(), and XLogHaveInvalidPages().

◆ hash_get_shared_size()

Size hash_get_shared_size ( HASHCTL info,
int  flags 
)

Definition at line 854 of file dynahash.c.

855{
856 Assert(flags & HASH_DIRSIZE);
857 Assert(info->dsize == info->max_dsize);
858 return sizeof(HASHHDR) + info->dsize * sizeof(HASHSEGMENT);
859}
struct HASHHDR HASHHDR
Definition: hsearch.h:58

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

Referenced by ShmemInitHash().

◆ hash_initial_lookup()

static uint32 hash_initial_lookup ( HTAB hashp,
uint32  hashvalue,
HASHBUCKET **  bucketptr 
)
inlinestatic

Definition at line 1756 of file dynahash.c.

1757{
1758 HASHHDR *hctl = hashp->hctl;
1759 HASHSEGMENT segp;
1760 long segment_num;
1761 long segment_ndx;
1762 uint32 bucket;
1763
1764 bucket = calc_bucket(hctl, hashvalue);
1765
1766 segment_num = bucket >> hashp->sshift;
1767 segment_ndx = MOD(bucket, hashp->ssize);
1768
1769 segp = hashp->dir[segment_num];
1770
1771 if (segp == NULL)
1772 hash_corrupted(hashp);
1773
1774 *bucketptr = &segp[segment_ndx];
1775 return bucket;
1776}
static pg_noreturn void hash_corrupted(HTAB *hashp)
Definition: dynahash.c:1780

References calc_bucket(), HTAB::dir, hash_corrupted(), HTAB::hctl, MOD, HTAB::sshift, and HTAB::ssize.

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

◆ hash_search()

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

Definition at line 955 of file dynahash.c.

959{
960 return hash_search_with_hash_value(hashp,
961 keyPtr,
962 hashp->hash(keyPtr, hashp->keysize),
963 action,
964 foundPtr);
965}
void * hash_search_with_hash_value(HTAB *hashp, const void *keyPtr, uint32 hashvalue, HASHACTION action, bool *foundPtr)
Definition: dynahash.c:968

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

Referenced by _hash_finish_split(), _hash_splitbucket(), add_guc_variable(), add_join_rel(), add_to_names_hash(), AddEnumLabel(), AddEventToPendingNotifies(), AddPendingSync(), ApplyLogicalMappingFile(), assign_record_type_typmod(), AsyncExistsPendingNotify(), AtEOSubXact_RelationCache(), AtEOXact_RelationCache(), build_guc_variables(), build_join_rel_hash(), BuildEventTriggerCache(), cfunc_hashtable_delete(), cfunc_hashtable_insert(), cfunc_hashtable_lookup(), CheckAndPromotePredicateLockRequest(), CheckForSerializableConflictOut(), CheckForSessionAndXactLocks(), colname_is_unique(), CompactCheckpointerRequestQueue(), compile_plperl_function(), compile_pltcl_function(), compute_array_stats(), compute_context_path(), compute_contexts_count_and_ids(), compute_tsvector_stats(), createNewConnection(), define_custom_variable(), delete_rel_type_cache_if_needed(), deleteConnection(), do_autovacuum(), DropAllPredicateLocksFromTable(), DropAllPreparedStatements(), DropPreparedStatement(), entry_alloc(), entry_dealloc(), entry_reset(), EnumTypeUncommitted(), EnumUncommitted(), EnumValuesCreate(), EventCacheLookup(), ExecInitModifyTable(), ExecLookupResultRelByOid(), ExecuteTruncateGuts(), ExtendBufferedRelLocal(), FetchPreparedStatement(), finalize_in_progress_typentries(), find_all_inheritors(), find_join_rel(), find_oper_cache_entry(), find_option(), find_rendezvous_variable(), forget_invalid_pages(), forget_invalid_pages_db(), ForgetPrivateRefCountEntry(), get_attribute_options(), get_cast_hashentry(), get_rel_sync_entry(), get_tablespace(), GetComboCommandId(), GetConnection(), getConnectionByName(), GetExtensibleNodeEntry(), getmissingattr(), GetPrivateRefCountEntry(), getState(), GetWaitEventCustomIdentifier(), gistGetNodeBuffer(), gistGetParent(), gistMemorizeParent(), gistRelocateBuildBuffersOnSplit(), hash_object_field_end(), init_sequence(), insert_rel_type_cache_if_needed(), InvalidateAttoptCacheCallback(), InvalidateLocalBuffer(), InvalidateOprCacheCallBack(), InvalidateShippableCacheCallback(), InvalidateTableSpaceCacheCallback(), is_shippable(), JsObjectGetField(), json_unique_check_key(), LocalBufferAlloc(), LockAcquireExtended(), LockHasWaiters(), LockHeldByMe(), LockRelease(), log_invalid_page(), logical_rewrite_log_mapping(), logicalrep_partition_open(), logicalrep_rel_open(), logicalrep_relmap_update(), lookup_C_func(), lookup_proof_cache(), lookup_ts_config_cache(), lookup_ts_dictionary_cache(), lookup_ts_parser_cache(), lookup_type_cache(), LookupOpclassInfo(), make_oper_cache_entry(), MarkGUCPrefixReserved(), pa_allocate_worker(), pa_find_worker(), pa_free_worker(), PartitionDirectoryLookup(), pg_get_backend_memory_contexts(), pg_tzset(), pgss_store(), plperl_spi_exec_prepared(), plperl_spi_freeplan(), plperl_spi_prepare(), plperl_spi_query_prepared(), pltcl_fetch_interp(), PLy_commit(), PLy_generate_spi_exceptions(), PLy_procedure_get(), PLy_rollback(), PLy_spi_subtransaction_abort(), populate_recordset_object_field_end(), predicatelock_twophase_recover(), PredicateLockExists(), PredicateLockShmemInit(), PredicateLockTwoPhaseFinish(), PrefetchLocalBuffer(), process_syncing_tables_for_apply(), ProcessSyncRequests(), prune_element_hashtable(), prune_lexemes_hashtable(), PutMemoryContextsStatsTupleStore(), rebuild_database_list(), record_C_func(), RegisterExtensibleNodeEntry(), RegisterPredicateLockingXid(), rel_sync_cache_relation_cb(), RelationPreTruncate(), ReleaseOneSerializableXact(), RelFileLocatorSkippingWAL(), RelfilenumberMapInvalidateCallback(), RelidByRelfilenumber(), RememberSyncRequest(), RemoveLocalLock(), ReorderBufferBuildTupleCidHash(), ReorderBufferCleanupTXN(), ReorderBufferToastAppendChunk(), ReorderBufferToastReplace(), ReorderBufferTXNByXid(), ReservePrivateRefCountEntry(), ResetUnloggedRelationsInDbspaceDir(), ResolveCminCmaxDuringDecoding(), RestoreUncommittedEnums(), rewrite_heap_dead_tuple(), rewrite_heap_tuple(), ri_FetchPreparedPlan(), ri_HashCompareOp(), ri_HashPreparedPlan(), ri_LoadConstraintInfo(), select_perl_context(), SerializePendingSyncs(), set_rtable_names(), ShmemInitStruct(), smgrdestroy(), smgrDoPendingSyncs(), smgropen(), smgrreleaserellocator(), StandbyAcquireAccessExclusiveLock(), StandbyReleaseAllLocks(), StandbyReleaseLocks(), StandbyReleaseOldLocks(), StandbyReleaseXidEntryLocks(), StorePreparedStatement(), table_recheck_autovac(), TypeCacheRelCallback(), WaitEventCustomNew(), XLogPrefetcherAddFilter(), XLogPrefetcherCompleteFilters(), and XLogPrefetcherIsFiltered().

◆ 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 968 of file dynahash.c.

973{
974 HASHHDR *hctl = hashp->hctl;
975 int freelist_idx = FREELIST_IDX(hctl, hashvalue);
976 Size keysize;
977 HASHBUCKET currBucket;
978 HASHBUCKET *prevBucketPtr;
979 HashCompareFunc match;
980
981#ifdef HASH_STATISTICS
982 hash_accesses++;
983 hctl->accesses++;
984#endif
985
986 /*
987 * If inserting, check if it is time to split a bucket.
988 *
989 * NOTE: failure to expand table is not a fatal error, it just means we
990 * have to run at higher fill factor than we wanted. However, if we're
991 * using the palloc allocator then it will throw error anyway on
992 * out-of-memory, so we must do this before modifying the table.
993 */
995 {
996 /*
997 * Can't split if running in partitioned mode, nor if frozen, nor if
998 * table is the subject of any active hash_seq_search scans.
999 */
1000 if (hctl->freeList[0].nentries > (long) hctl->max_bucket &&
1001 !IS_PARTITIONED(hctl) && !hashp->frozen &&
1002 !has_seq_scans(hashp))
1003 (void) expand_table(hashp);
1004 }
1005
1006 /*
1007 * Do the initial lookup
1008 */
1009 (void) hash_initial_lookup(hashp, hashvalue, &prevBucketPtr);
1010 currBucket = *prevBucketPtr;
1011
1012 /*
1013 * Follow collision chain looking for matching key
1014 */
1015 match = hashp->match; /* save one fetch in inner loop */
1016 keysize = hashp->keysize; /* ditto */
1017
1018 while (currBucket != NULL)
1019 {
1020 if (currBucket->hashvalue == hashvalue &&
1021 match(ELEMENTKEY(currBucket), keyPtr, keysize) == 0)
1022 break;
1023 prevBucketPtr = &(currBucket->link);
1024 currBucket = *prevBucketPtr;
1025#ifdef HASH_STATISTICS
1026 hash_collisions++;
1027 hctl->collisions++;
1028#endif
1029 }
1030
1031 if (foundPtr)
1032 *foundPtr = (bool) (currBucket != NULL);
1033
1034 /*
1035 * OK, now what?
1036 */
1037 switch (action)
1038 {
1039 case HASH_FIND:
1040 if (currBucket != NULL)
1041 return ELEMENTKEY(currBucket);
1042 return NULL;
1043
1044 case HASH_REMOVE:
1045 if (currBucket != NULL)
1046 {
1047 /* if partitioned, must lock to touch nentries and freeList */
1048 if (IS_PARTITIONED(hctl))
1049 SpinLockAcquire(&(hctl->freeList[freelist_idx].mutex));
1050
1051 /* delete the record from the appropriate nentries counter. */
1052 Assert(hctl->freeList[freelist_idx].nentries > 0);
1053 hctl->freeList[freelist_idx].nentries--;
1054
1055 /* remove record from hash bucket's chain. */
1056 *prevBucketPtr = currBucket->link;
1057
1058 /* add the record to the appropriate freelist. */
1059 currBucket->link = hctl->freeList[freelist_idx].freeList;
1060 hctl->freeList[freelist_idx].freeList = currBucket;
1061
1062 if (IS_PARTITIONED(hctl))
1063 SpinLockRelease(&hctl->freeList[freelist_idx].mutex);
1064
1065 /*
1066 * better hope the caller is synchronizing access to this
1067 * element, because someone else is going to reuse it the next
1068 * time something is added to the table
1069 */
1070 return ELEMENTKEY(currBucket);
1071 }
1072 return NULL;
1073
1074 case HASH_ENTER:
1075 case HASH_ENTER_NULL:
1076 /* Return existing element if found, else create one */
1077 if (currBucket != NULL)
1078 return ELEMENTKEY(currBucket);
1079
1080 /* disallow inserts if frozen */
1081 if (hashp->frozen)
1082 elog(ERROR, "cannot insert into frozen hashtable \"%s\"",
1083 hashp->tabname);
1084
1085 currBucket = get_hash_entry(hashp, freelist_idx);
1086 if (currBucket == NULL)
1087 {
1088 /* out of memory */
1089 if (action == HASH_ENTER_NULL)
1090 return NULL;
1091 /* report a generic message */
1092 if (hashp->isshared)
1093 ereport(ERROR,
1094 (errcode(ERRCODE_OUT_OF_MEMORY),
1095 errmsg("out of shared memory")));
1096 else
1097 ereport(ERROR,
1098 (errcode(ERRCODE_OUT_OF_MEMORY),
1099 errmsg("out of memory")));
1100 }
1101
1102 /* link into hashbucket chain */
1103 *prevBucketPtr = currBucket;
1104 currBucket->link = NULL;
1105
1106 /* copy key into record */
1107 currBucket->hashvalue = hashvalue;
1108 hashp->keycopy(ELEMENTKEY(currBucket), keyPtr, keysize);
1109
1110 /*
1111 * Caller is expected to fill the data field on return. DO NOT
1112 * insert any code that could possibly throw error here, as doing
1113 * so would leave the table entry incomplete and hence corrupt the
1114 * caller's data structure.
1115 */
1116
1117 return ELEMENTKEY(currBucket);
1118 }
1119
1120 elog(ERROR, "unrecognized hash action code: %d", (int) action);
1121
1122 return NULL; /* keep compiler quiet */
1123}
static HASHBUCKET get_hash_entry(HTAB *hashp, int freelist_idx)
Definition: dynahash.c:1256
static bool expand_table(HTAB *hashp)
Definition: dynahash.c:1551
#define ELEMENTKEY(helem)
Definition: dynahash.c:244
#define FREELIST_IDX(hctl, hashcode)
Definition: dynahash.c:212
static uint32 hash_initial_lookup(HTAB *hashp, uint32 hashvalue, HASHBUCKET **bucketptr)
Definition: dynahash.c:1756
@ HASH_FIND
Definition: hsearch.h:113
@ HASH_REMOVE
Definition: hsearch.h:115
@ HASH_ENTER
Definition: hsearch.h:114
@ HASH_ENTER_NULL
Definition: hsearch.h:116

References generate_unaccent_rules::action, Assert(), ELEMENTKEY, elog, ereport, errcode(), errmsg(), ERROR, expand_table(), FreeListData::freeList, HASHHDR::freeList, FREELIST_IDX, HTAB::frozen, get_hash_entry(), has_seq_scans(), HASH_ENTER, HASH_ENTER_NULL, HASH_FIND, hash_initial_lookup(), HASH_REMOVE, HASHELEMENT::hashvalue, HTAB::hctl, IS_PARTITIONED, HTAB::isshared, HTAB::keycopy, HTAB::keysize, HASHELEMENT::link, HTAB::match, HASHHDR::max_bucket, FreeListData::mutex, FreeListData::nentries, SpinLockAcquire, SpinLockRelease, 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().

◆ hash_select_dirsize()

long hash_select_dirsize ( long  num_entries)

Definition at line 830 of file dynahash.c.

831{
832 long nBuckets,
833 nSegments,
834 nDirEntries;
835
836 /* estimate number of buckets wanted */
837 nBuckets = next_pow2_long(num_entries);
838 /* # of segments needed for nBuckets */
839 nSegments = next_pow2_long((nBuckets - 1) / DEF_SEGSIZE + 1);
840 /* directory entries */
841 nDirEntries = DEF_DIRSIZE;
842 while (nDirEntries < nSegments)
843 nDirEntries <<= 1; /* dir_alloc doubles dsize at each call */
844
845 return nDirEntries;
846}

References DEF_DIRSIZE, DEF_SEGSIZE, and next_pow2_long().

Referenced by ShmemInitHash().

◆ hash_seq_init()

void hash_seq_init ( HASH_SEQ_STATUS status,
HTAB hashp 
)

Definition at line 1385 of file dynahash.c.

1386{
1387 status->hashp = hashp;
1388 status->curBucket = 0;
1389 status->curEntry = NULL;
1390 status->hasHashvalue = false;
1391 if (!hashp->frozen)
1392 register_seq_scan(hashp);
1393}
static void register_seq_scan(HTAB *hashp)
Definition: dynahash.c:1865
HASHELEMENT * curEntry
Definition: hsearch.h:124
uint32 curBucket
Definition: hsearch.h:123
HTAB * hashp
Definition: hsearch.h:122
bool hasHashvalue
Definition: hsearch.h:125

References HASH_SEQ_STATUS::curBucket, HASH_SEQ_STATUS::curEntry, HTAB::frozen, HASH_SEQ_STATUS::hasHashvalue, 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(), BeginReportingGUCOptions(), CheckForBufferLeaks(), CheckForSessionAndXactLocks(), CheckTableForSerializableConflictIn(), cleanup_rel_sync_cache(), compute_array_stats(), compute_tsvector_stats(), dblink_get_connections(), DestroyPartitionDirectory(), disconnect_cached_connections(), DropAllPredicateLocksFromTable(), DropAllPreparedStatements(), end_heap_rewrite(), entry_dealloc(), entry_reset(), ExecuteTruncateGuts(), forget_invalid_pages(), forget_invalid_pages_db(), ForgetPortalSnapshots(), gc_qtexts(), get_guc_variables(), GetLockStatusData(), GetPredicateLockStatusData(), GetRunningTransactionLocks(), GetWaitEventCustomNames(), hash_seq_init_with_hash_value(), HoldPinnedPortals(), InitializeGUCOptions(), InvalidateAttoptCacheCallback(), InvalidateOprCacheCallBack(), InvalidateOprProofCacheCallBack(), InvalidateShippableCacheCallback(), InvalidateTableSpaceCacheCallback(), InvalidateTSCacheCallBack(), LockReassignCurrentOwner(), LockReleaseAll(), LockReleaseCurrentOwner(), LockReleaseSession(), logical_end_heap_rewrite(), logical_heap_rewrite_flush_mappings(), logicalrep_partmap_invalidate_cb(), logicalrep_partmap_reset_relmap(), logicalrep_relmap_invalidate_cb(), MarkGUCPrefixReserved(), packGraph(), pg_cursor(), pg_get_shmem_allocations(), pg_get_shmem_allocations_numa(), pg_prepared_statement(), pg_stat_statements_internal(), pgfdw_inval_callback(), pgfdw_subxact_callback(), pgfdw_xact_callback(), pgss_shmem_shutdown(), plperl_fini(), PortalErrorCleanup(), PortalHashTableDeleteAll(), postgres_fdw_get_connections_internal(), PostPrepare_Locks(), PreCommit_Portals(), ProcessConfigFileInternal(), ProcessSyncRequests(), prune_element_hashtable(), prune_lexemes_hashtable(), rebuild_database_list(), rel_sync_cache_publication_cb(), rel_sync_cache_relation_cb(), RelationCacheInitializePhase3(), RelationCacheInvalidate(), RelfilenumberMapInvalidateCallback(), RememberSyncRequest(), ReorderBufferToastReset(), selectColorTrigrams(), SerializePendingSyncs(), SerializeUncommittedEnums(), smgrDoPendingSyncs(), smgrreleaseall(), StandbyReleaseAllLocks(), StandbyReleaseOldLocks(), ThereAreNoReadyPortals(), TypeCacheOpcCallback(), TypeCacheRelCallback(), TypeCacheTypCallback(), write_relcache_init_file(), and XLogCheckInvalidPages().

◆ hash_seq_init_with_hash_value()

void hash_seq_init_with_hash_value ( HASH_SEQ_STATUS status,
HTAB hashp,
uint32  hashvalue 
)

Definition at line 1405 of file dynahash.c.

1407{
1408 HASHBUCKET *bucketPtr;
1409
1410 hash_seq_init(status, hashp);
1411
1412 status->hasHashvalue = true;
1413 status->hashvalue = hashvalue;
1414
1415 status->curBucket = hash_initial_lookup(hashp, hashvalue, &bucketPtr);
1416 status->curEntry = *bucketPtr;
1417}
void hash_seq_init(HASH_SEQ_STATUS *status, HTAB *hashp)
Definition: dynahash.c:1385
uint32 hashvalue
Definition: hsearch.h:126

References HASH_SEQ_STATUS::curBucket, HASH_SEQ_STATUS::curEntry, hash_initial_lookup(), hash_seq_init(), HASH_SEQ_STATUS::hasHashvalue, and HASH_SEQ_STATUS::hashvalue.

Referenced by InvalidateAttoptCacheCallback(), and TypeCacheTypCallback().

◆ hash_seq_search()

void * hash_seq_search ( HASH_SEQ_STATUS status)

Definition at line 1420 of file dynahash.c.

1421{
1422 HTAB *hashp;
1423 HASHHDR *hctl;
1424 uint32 max_bucket;
1425 long ssize;
1426 long segment_num;
1427 long segment_ndx;
1428 HASHSEGMENT segp;
1429 uint32 curBucket;
1430 HASHELEMENT *curElem;
1431
1432 if (status->hasHashvalue)
1433 {
1434 /*
1435 * Scan entries only in the current bucket because only this bucket
1436 * can contain entries with the given hash value.
1437 */
1438 while ((curElem = status->curEntry) != NULL)
1439 {
1440 status->curEntry = curElem->link;
1441 if (status->hashvalue != curElem->hashvalue)
1442 continue;
1443 return (void *) ELEMENTKEY(curElem);
1444 }
1445
1446 hash_seq_term(status);
1447 return NULL;
1448 }
1449
1450 if ((curElem = status->curEntry) != NULL)
1451 {
1452 /* Continuing scan of curBucket... */
1453 status->curEntry = curElem->link;
1454 if (status->curEntry == NULL) /* end of this bucket */
1455 ++status->curBucket;
1456 return ELEMENTKEY(curElem);
1457 }
1458
1459 /*
1460 * Search for next nonempty bucket starting at curBucket.
1461 */
1462 curBucket = status->curBucket;
1463 hashp = status->hashp;
1464 hctl = hashp->hctl;
1465 ssize = hashp->ssize;
1466 max_bucket = hctl->max_bucket;
1467
1468 if (curBucket > max_bucket)
1469 {
1470 hash_seq_term(status);
1471 return NULL; /* search is done */
1472 }
1473
1474 /*
1475 * first find the right segment in the table directory.
1476 */
1477 segment_num = curBucket >> hashp->sshift;
1478 segment_ndx = MOD(curBucket, ssize);
1479
1480 segp = hashp->dir[segment_num];
1481
1482 /*
1483 * Pick up the first item in this bucket's chain. If chain is not empty
1484 * we can begin searching it. Otherwise we have to advance to find the
1485 * next nonempty bucket. We try to optimize that case since searching a
1486 * near-empty hashtable has to iterate this loop a lot.
1487 */
1488 while ((curElem = segp[segment_ndx]) == NULL)
1489 {
1490 /* empty bucket, advance to next */
1491 if (++curBucket > max_bucket)
1492 {
1493 status->curBucket = curBucket;
1494 hash_seq_term(status);
1495 return NULL; /* search is done */
1496 }
1497 if (++segment_ndx >= ssize)
1498 {
1499 segment_num++;
1500 segment_ndx = 0;
1501 segp = hashp->dir[segment_num];
1502 }
1503 }
1504
1505 /* Begin scan of curBucket... */
1506 status->curEntry = curElem->link;
1507 if (status->curEntry == NULL) /* end of this bucket */
1508 ++curBucket;
1509 status->curBucket = curBucket;
1510 return ELEMENTKEY(curElem);
1511}
void hash_seq_term(HASH_SEQ_STATUS *status)
Definition: dynahash.c:1514

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

Referenced by AtAbort_Portals(), AtCleanup_Portals(), AtEOSubXact_RelationCache(), AtEOXact_RelationCache(), AtPrepare_Locks(), AtSubAbort_Portals(), AtSubCleanup_Portals(), AtSubCommit_Portals(), BeginReportingGUCOptions(), CheckForBufferLeaks(), CheckForSessionAndXactLocks(), CheckTableForSerializableConflictIn(), cleanup_rel_sync_cache(), compute_array_stats(), compute_tsvector_stats(), dblink_get_connections(), DestroyPartitionDirectory(), disconnect_cached_connections(), DropAllPredicateLocksFromTable(), DropAllPreparedStatements(), end_heap_rewrite(), entry_dealloc(), entry_reset(), ExecuteTruncateGuts(), forget_invalid_pages(), forget_invalid_pages_db(), ForgetPortalSnapshots(), gc_qtexts(), get_guc_variables(), GetLockStatusData(), GetPredicateLockStatusData(), GetRunningTransactionLocks(), GetWaitEventCustomNames(), HoldPinnedPortals(), InitializeGUCOptions(), InvalidateAttoptCacheCallback(), InvalidateOprCacheCallBack(), InvalidateOprProofCacheCallBack(), InvalidateShippableCacheCallback(), InvalidateTableSpaceCacheCallback(), InvalidateTSCacheCallBack(), LockReassignCurrentOwner(), LockReleaseAll(), LockReleaseCurrentOwner(), LockReleaseSession(), logical_end_heap_rewrite(), logical_heap_rewrite_flush_mappings(), logicalrep_partmap_invalidate_cb(), logicalrep_partmap_reset_relmap(), logicalrep_relmap_invalidate_cb(), MarkGUCPrefixReserved(), packGraph(), pg_cursor(), pg_get_shmem_allocations(), pg_get_shmem_allocations_numa(), pg_prepared_statement(), pg_stat_statements_internal(), pgfdw_inval_callback(), pgfdw_subxact_callback(), pgfdw_xact_callback(), pgss_shmem_shutdown(), plperl_fini(), PortalErrorCleanup(), PortalHashTableDeleteAll(), postgres_fdw_get_connections_internal(), PostPrepare_Locks(), PreCommit_Portals(), ProcessConfigFileInternal(), ProcessSyncRequests(), prune_element_hashtable(), prune_lexemes_hashtable(), rebuild_database_list(), rel_sync_cache_publication_cb(), rel_sync_cache_relation_cb(), RelationCacheInitializePhase3(), RelationCacheInvalidate(), RelfilenumberMapInvalidateCallback(), RememberSyncRequest(), ReorderBufferToastReset(), selectColorTrigrams(), SerializePendingSyncs(), SerializeUncommittedEnums(), smgrDoPendingSyncs(), smgrreleaseall(), StandbyReleaseAllLocks(), StandbyReleaseOldLocks(), ThereAreNoReadyPortals(), TypeCacheOpcCallback(), TypeCacheRelCallback(), TypeCacheTypCallback(), write_relcache_init_file(), and XLogCheckInvalidPages().

◆ hash_seq_term()

◆ hash_stats()

void hash_stats ( const char *  where,
HTAB hashp 
)

Definition at line 884 of file dynahash.c.

885{
886#ifdef HASH_STATISTICS
887 fprintf(stderr, "%s: this HTAB -- accesses %ld collisions %ld\n",
888 where, hashp->hctl->accesses, hashp->hctl->collisions);
889
890 fprintf(stderr, "hash_stats: entries %ld keysize %ld maxp %u segmentcount %ld\n",
891 hash_get_num_entries(hashp), (long) hashp->hctl->keysize,
892 hashp->hctl->max_bucket, hashp->hctl->nsegs);
893 fprintf(stderr, "%s: total accesses %ld total collisions %ld\n",
894 where, hash_accesses, hash_collisions);
895 fprintf(stderr, "hash_stats: total expansions %ld\n",
896 hash_expansions);
897#endif
898}
#define fprintf(file, fmt, msg)
Definition: cubescan.l:21
long hash_get_num_entries(HTAB *hashp)
Definition: dynahash.c:1341

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

Referenced by hash_destroy().

◆ hash_update_hash_key()

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

Definition at line 1145 of file dynahash.c.

1148{
1149 HASHELEMENT *existingElement = ELEMENT_FROM_KEY(existingEntry);
1150 uint32 newhashvalue;
1151 Size keysize;
1152 uint32 bucket;
1153 uint32 newbucket;
1154 HASHBUCKET currBucket;
1155 HASHBUCKET *prevBucketPtr;
1156 HASHBUCKET *oldPrevPtr;
1157 HashCompareFunc match;
1158
1159#ifdef HASH_STATISTICS
1160 hash_accesses++;
1161 hctl->accesses++;
1162#endif
1163
1164 /* disallow updates if frozen */
1165 if (hashp->frozen)
1166 elog(ERROR, "cannot update in frozen hashtable \"%s\"",
1167 hashp->tabname);
1168
1169 /*
1170 * Lookup the existing element using its saved hash value. We need to do
1171 * this to be able to unlink it from its hash chain, but as a side benefit
1172 * we can verify the validity of the passed existingEntry pointer.
1173 */
1174 bucket = hash_initial_lookup(hashp, existingElement->hashvalue,
1175 &prevBucketPtr);
1176 currBucket = *prevBucketPtr;
1177
1178 while (currBucket != NULL)
1179 {
1180 if (currBucket == existingElement)
1181 break;
1182 prevBucketPtr = &(currBucket->link);
1183 currBucket = *prevBucketPtr;
1184 }
1185
1186 if (currBucket == NULL)
1187 elog(ERROR, "hash_update_hash_key argument is not in hashtable \"%s\"",
1188 hashp->tabname);
1189
1190 oldPrevPtr = prevBucketPtr;
1191
1192 /*
1193 * Now perform the equivalent of a HASH_ENTER operation to locate the hash
1194 * chain we want to put the entry into.
1195 */
1196 newhashvalue = hashp->hash(newKeyPtr, hashp->keysize);
1197 newbucket = hash_initial_lookup(hashp, newhashvalue, &prevBucketPtr);
1198 currBucket = *prevBucketPtr;
1199
1200 /*
1201 * Follow collision chain looking for matching key
1202 */
1203 match = hashp->match; /* save one fetch in inner loop */
1204 keysize = hashp->keysize; /* ditto */
1205
1206 while (currBucket != NULL)
1207 {
1208 if (currBucket->hashvalue == newhashvalue &&
1209 match(ELEMENTKEY(currBucket), newKeyPtr, keysize) == 0)
1210 break;
1211 prevBucketPtr = &(currBucket->link);
1212 currBucket = *prevBucketPtr;
1213#ifdef HASH_STATISTICS
1214 hash_collisions++;
1215 hctl->collisions++;
1216#endif
1217 }
1218
1219 if (currBucket != NULL)
1220 return false; /* collision with an existing entry */
1221
1222 currBucket = existingElement;
1223
1224 /*
1225 * If old and new hash values belong to the same bucket, we need not
1226 * change any chain links, and indeed should not since this simplistic
1227 * update will corrupt the list if currBucket is the last element. (We
1228 * cannot fall out earlier, however, since we need to scan the bucket to
1229 * check for duplicate keys.)
1230 */
1231 if (bucket != newbucket)
1232 {
1233 /* OK to remove record from old hash bucket's chain. */
1234 *oldPrevPtr = currBucket->link;
1235
1236 /* link into new hashbucket chain */
1237 *prevBucketPtr = currBucket;
1238 currBucket->link = NULL;
1239 }
1240
1241 /* copy new key into record */
1242 currBucket->hashvalue = newhashvalue;
1243 hashp->keycopy(ELEMENTKEY(currBucket), newKeyPtr, keysize);
1244
1245 /* rest of record is untouched */
1246
1247 return true;
1248}
#define ELEMENT_FROM_KEY(key)
Definition: dynahash.c:249

References ELEMENT_FROM_KEY, ELEMENTKEY, elog, ERROR, HTAB::frozen, HTAB::hash, hash_initial_lookup(), HASHELEMENT::hashvalue, HTAB::keycopy, HTAB::keysize, HASHELEMENT::link, HTAB::match, and HTAB::tabname.

Referenced by PostPrepare_Locks().

◆ hdefault()

static void hdefault ( HTAB hashp)
static

Definition at line 629 of file dynahash.c.

630{
631 HASHHDR *hctl = hashp->hctl;
632
633 MemSet(hctl, 0, sizeof(HASHHDR));
634
635 hctl->dsize = DEF_DIRSIZE;
636 hctl->nsegs = 0;
637
638 hctl->num_partitions = 0; /* not partitioned */
639
640 /* table has no fixed maximum size */
641 hctl->max_dsize = NO_MAX_DSIZE;
642
643 hctl->ssize = DEF_SEGSIZE;
645
646#ifdef HASH_STATISTICS
647 hctl->accesses = hctl->collisions = 0;
648#endif
649}
#define DEF_SEGSIZE_SHIFT
Definition: dynahash.c:124

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

Referenced by hash_create().

◆ init_htab()

static bool init_htab ( HTAB hashp,
long  nelem 
)
static

Definition at line 689 of file dynahash.c.

690{
691 HASHHDR *hctl = hashp->hctl;
692 HASHSEGMENT *segp;
693 int nbuckets;
694 int nsegs;
695 int i;
696
697 /*
698 * initialize mutexes if it's a partitioned table
699 */
700 if (IS_PARTITIONED(hctl))
701 for (i = 0; i < NUM_FREELISTS; i++)
702 SpinLockInit(&(hctl->freeList[i].mutex));
703
704 /*
705 * Allocate space for the next greater power of two number of buckets,
706 * assuming a desired maximum load factor of 1.
707 */
708 nbuckets = next_pow2_int(nelem);
709
710 /*
711 * In a partitioned table, nbuckets must be at least equal to
712 * num_partitions; were it less, keys with apparently different partition
713 * numbers would map to the same bucket, breaking partition independence.
714 * (Normally nbuckets will be much bigger; this is just a safety check.)
715 */
716 while (nbuckets < hctl->num_partitions)
717 nbuckets <<= 1;
718
719 hctl->max_bucket = hctl->low_mask = nbuckets - 1;
720 hctl->high_mask = (nbuckets << 1) - 1;
721
722 /*
723 * Figure number of directory segments needed, round up to a power of 2
724 */
725 nsegs = (nbuckets - 1) / hctl->ssize + 1;
726 nsegs = next_pow2_int(nsegs);
727
728 /*
729 * Make sure directory is big enough. If pre-allocated directory is too
730 * small, choke (caller screwed up).
731 */
732 if (nsegs > hctl->dsize)
733 {
734 if (!(hashp->dir))
735 hctl->dsize = nsegs;
736 else
737 return false;
738 }
739
740 /* Allocate a directory */
741 if (!(hashp->dir))
742 {
743 CurrentDynaHashCxt = hashp->hcxt;
744 hashp->dir = (HASHSEGMENT *)
745 hashp->alloc(hctl->dsize * sizeof(HASHSEGMENT));
746 if (!hashp->dir)
747 return false;
748 }
749
750 /* Allocate initial segments */
751 for (segp = hashp->dir; hctl->nsegs < nsegs; hctl->nsegs++, segp++)
752 {
753 *segp = seg_alloc(hashp);
754 if (*segp == NULL)
755 return false;
756 }
757
758 /* Choose number of entries to allocate at a time */
760
761#ifdef HASH_DEBUG
762 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",
763 "TABLE POINTER ", hashp,
764 "DIRECTORY SIZE ", hctl->dsize,
765 "SEGMENT SIZE ", hctl->ssize,
766 "SEGMENT SHIFT ", hctl->sshift,
767 "MAX BUCKET ", hctl->max_bucket,
768 "HIGH MASK ", hctl->high_mask,
769 "LOW MASK ", hctl->low_mask,
770 "NSEGS ", hctl->nsegs);
771#endif
772 return true;
773}
#define SpinLockInit(lock)
Definition: spin.h:57

References HTAB::alloc, choose_nelem_alloc(), CurrentDynaHashCxt, HTAB::dir, HASHHDR::dsize, HASHHDR::entrysize, 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, seg_alloc(), SpinLockInit, HASHHDR::sshift, and HASHHDR::ssize.

Referenced by hash_create().

◆ my_log2()

int my_log2 ( long  num)

Definition at line 1794 of file dynahash.c.

1795{
1796 /*
1797 * guard against too-large input, which would be invalid for
1798 * pg_ceil_log2_*()
1799 */
1800 if (num > LONG_MAX / 2)
1801 num = LONG_MAX / 2;
1802
1803#if SIZEOF_LONG < 8
1804 return pg_ceil_log2_32(num);
1805#else
1806 return pg_ceil_log2_64(num);
1807#endif
1808}
static uint64 pg_ceil_log2_64(uint64 num)
Definition: pg_bitutils.h:271
static uint32 pg_ceil_log2_32(uint32 num)
Definition: pg_bitutils.h:258

References pg_ceil_log2_32(), and pg_ceil_log2_64().

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

◆ next_pow2_int()

static int next_pow2_int ( long  num)
static

Definition at line 1820 of file dynahash.c.

1821{
1822 if (num > INT_MAX / 2)
1823 num = INT_MAX / 2;
1824 return 1 << my_log2(num);
1825}

References my_log2().

Referenced by hash_create(), and init_htab().

◆ next_pow2_long()

static long next_pow2_long ( long  num)
static

Definition at line 1812 of file dynahash.c.

1813{
1814 /* my_log2's internal range check is sufficient */
1815 return 1L << my_log2(num);
1816}

References my_log2().

Referenced by hash_estimate_size(), and hash_select_dirsize().

◆ register_seq_scan()

static void register_seq_scan ( HTAB hashp)
static

Definition at line 1865 of file dynahash.c.

1866{
1868 elog(ERROR, "too many active hash_seq_search scans, cannot start one on \"%s\"",
1869 hashp->tabname);
1872 num_seq_scans++;
1873}
#define MAX_SEQ_SCANS
Definition: dynahash.c:1856
int GetCurrentTransactionNestLevel(void)
Definition: xact.c:929

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

Referenced by hash_seq_init().

◆ seg_alloc()

static HASHSEGMENT seg_alloc ( HTAB hashp)
static

Definition at line 1687 of file dynahash.c.

1688{
1689 HASHSEGMENT segp;
1690
1691 CurrentDynaHashCxt = hashp->hcxt;
1692 segp = (HASHSEGMENT) hashp->alloc(sizeof(HASHBUCKET) * hashp->ssize);
1693
1694 if (!segp)
1695 return NULL;
1696
1697 MemSet(segp, 0, sizeof(HASHBUCKET) * hashp->ssize);
1698
1699 return segp;
1700}

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

Referenced by expand_table(), and init_htab().

◆ string_compare()

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

Definition at line 307 of file dynahash.c.

308{
309 return strncmp(key1, key2, keysize - 1);
310}

Referenced by hash_create().

Variable Documentation

◆ CurrentDynaHashCxt

MemoryContext CurrentDynaHashCxt = NULL
static

Definition at line 288 of file dynahash.c.

Referenced by dir_realloc(), DynaHashAlloc(), element_alloc(), hash_create(), init_htab(), and seg_alloc().

◆ num_seq_scans

int num_seq_scans = 0
static

◆ seq_scan_level

int seq_scan_level[MAX_SEQ_SCANS]
static

Definition at line 1859 of file dynahash.c.

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

◆ seq_scan_tables