PostgreSQL Source Code  git master
hashfunc.c File Reference
#include "postgres.h"
#include "access/hash.h"
#include "catalog/pg_collation.h"
#include "common/hashfn.h"
#include "utils/builtins.h"
#include "utils/float.h"
#include "utils/pg_locale.h"
#include "varatt.h"
Include dependency graph for hashfunc.c:

Go to the source code of this file.

Functions

Datum hashchar (PG_FUNCTION_ARGS)
 
Datum hashcharextended (PG_FUNCTION_ARGS)
 
Datum hashint2 (PG_FUNCTION_ARGS)
 
Datum hashint2extended (PG_FUNCTION_ARGS)
 
Datum hashint4 (PG_FUNCTION_ARGS)
 
Datum hashint4extended (PG_FUNCTION_ARGS)
 
Datum hashint8 (PG_FUNCTION_ARGS)
 
Datum hashint8extended (PG_FUNCTION_ARGS)
 
Datum hashoid (PG_FUNCTION_ARGS)
 
Datum hashoidextended (PG_FUNCTION_ARGS)
 
Datum hashenum (PG_FUNCTION_ARGS)
 
Datum hashenumextended (PG_FUNCTION_ARGS)
 
Datum hashfloat4 (PG_FUNCTION_ARGS)
 
Datum hashfloat4extended (PG_FUNCTION_ARGS)
 
Datum hashfloat8 (PG_FUNCTION_ARGS)
 
Datum hashfloat8extended (PG_FUNCTION_ARGS)
 
Datum hashoidvector (PG_FUNCTION_ARGS)
 
Datum hashoidvectorextended (PG_FUNCTION_ARGS)
 
Datum hashname (PG_FUNCTION_ARGS)
 
Datum hashnameextended (PG_FUNCTION_ARGS)
 
Datum hashtext (PG_FUNCTION_ARGS)
 
Datum hashtextextended (PG_FUNCTION_ARGS)
 
Datum hashvarlena (PG_FUNCTION_ARGS)
 
Datum hashvarlenaextended (PG_FUNCTION_ARGS)
 

Function Documentation

◆ hashchar()

Datum hashchar ( PG_FUNCTION_ARGS  )

Definition at line 49 of file hashfunc.c.

50 {
51  return hash_uint32((int32) PG_GETARG_CHAR(0));
52 }
signed int int32
Definition: c.h:483
#define PG_GETARG_CHAR(n)
Definition: fmgr.h:273
static Datum hash_uint32(uint32 k)
Definition: hashfn.h:43

References hash_uint32(), and PG_GETARG_CHAR.

◆ hashcharextended()

Datum hashcharextended ( PG_FUNCTION_ARGS  )

Definition at line 55 of file hashfunc.c.

56 {
58 }
#define PG_GETARG_INT64(n)
Definition: fmgr.h:283
static Datum hash_uint32_extended(uint32 k, uint64 seed)
Definition: hashfn.h:49

References hash_uint32_extended(), PG_GETARG_CHAR, and PG_GETARG_INT64.

Referenced by JsonbHashScalarValueExtended().

◆ hashenum()

Datum hashenum ( PG_FUNCTION_ARGS  )

Definition at line 130 of file hashfunc.c.

131 {
132  return hash_uint32((uint32) PG_GETARG_OID(0));
133 }
unsigned int uint32
Definition: c.h:495
#define PG_GETARG_OID(n)
Definition: fmgr.h:275

References hash_uint32(), and PG_GETARG_OID.

◆ hashenumextended()

Datum hashenumextended ( PG_FUNCTION_ARGS  )

Definition at line 136 of file hashfunc.c.

137 {
139 }

References hash_uint32_extended(), PG_GETARG_INT64, and PG_GETARG_OID.

◆ hashfloat4()

Datum hashfloat4 ( PG_FUNCTION_ARGS  )

Definition at line 142 of file hashfunc.c.

143 {
145  float8 key8;
146 
147  /*
148  * On IEEE-float machines, minus zero and zero have different bit patterns
149  * but should compare as equal. We must ensure that they have the same
150  * hash value, which is most reliably done this way:
151  */
152  if (key == (float4) 0)
153  PG_RETURN_UINT32(0);
154 
155  /*
156  * To support cross-type hashing of float8 and float4, we want to return
157  * the same hash value hashfloat8 would produce for an equal float8 value.
158  * So, widen the value to float8 and hash that. (We must do this rather
159  * than have hashfloat8 try to narrow its value to float4; that could fail
160  * on overflow.)
161  */
162  key8 = key;
163 
164  /*
165  * Similarly, NaNs can have different bit patterns but they should all
166  * compare as equal. For backwards-compatibility reasons we force them to
167  * have the hash value of a standard float8 NaN. (You'd think we could
168  * replace key with a float4 NaN and then widen it; but on some old
169  * platforms, that way produces a different bit pattern.)
170  */
171  if (isnan(key8))
172  key8 = get_float8_nan();
173 
174  return hash_any((unsigned char *) &key8, sizeof(key8));
175 }
double float8
Definition: c.h:619
float float4
Definition: c.h:618
static float8 get_float8_nan(void)
Definition: float.h:123
#define PG_RETURN_UINT32(x)
Definition: fmgr.h:355
#define PG_GETARG_FLOAT4(n)
Definition: fmgr.h:281
static Datum hash_any(const unsigned char *k, int keylen)
Definition: hashfn.h:31

References get_float8_nan(), hash_any(), sort-test::key, PG_GETARG_FLOAT4, and PG_RETURN_UINT32.

◆ hashfloat4extended()

Datum hashfloat4extended ( PG_FUNCTION_ARGS  )

Definition at line 178 of file hashfunc.c.

179 {
181  uint64 seed = PG_GETARG_INT64(1);
182  float8 key8;
183 
184  /* Same approach as hashfloat4 */
185  if (key == (float4) 0)
186  PG_RETURN_UINT64(seed);
187  key8 = key;
188  if (isnan(key8))
189  key8 = get_float8_nan();
190 
191  return hash_any_extended((unsigned char *) &key8, sizeof(key8), seed);
192 }
#define PG_RETURN_UINT64(x)
Definition: fmgr.h:369
static Datum hash_any_extended(const unsigned char *k, int keylen, uint64 seed)
Definition: hashfn.h:37

References get_float8_nan(), hash_any_extended(), sort-test::key, PG_GETARG_FLOAT4, PG_GETARG_INT64, and PG_RETURN_UINT64.

◆ hashfloat8()

Datum hashfloat8 ( PG_FUNCTION_ARGS  )

Definition at line 195 of file hashfunc.c.

196 {
198 
199  /*
200  * On IEEE-float machines, minus zero and zero have different bit patterns
201  * but should compare as equal. We must ensure that they have the same
202  * hash value, which is most reliably done this way:
203  */
204  if (key == (float8) 0)
205  PG_RETURN_UINT32(0);
206 
207  /*
208  * Similarly, NaNs can have different bit patterns but they should all
209  * compare as equal. For backwards-compatibility reasons we force them to
210  * have the hash value of a standard NaN.
211  */
212  if (isnan(key))
213  key = get_float8_nan();
214 
215  return hash_any((unsigned char *) &key, sizeof(key));
216 }
#define PG_GETARG_FLOAT8(n)
Definition: fmgr.h:282

References get_float8_nan(), hash_any(), sort-test::key, PG_GETARG_FLOAT8, and PG_RETURN_UINT32.

Referenced by tablesample_init().

◆ hashfloat8extended()

Datum hashfloat8extended ( PG_FUNCTION_ARGS  )

Definition at line 219 of file hashfunc.c.

220 {
222  uint64 seed = PG_GETARG_INT64(1);
223 
224  /* Same approach as hashfloat8 */
225  if (key == (float8) 0)
226  PG_RETURN_UINT64(seed);
227  if (isnan(key))
228  key = get_float8_nan();
229 
230  return hash_any_extended((unsigned char *) &key, sizeof(key), seed);
231 }

References get_float8_nan(), hash_any_extended(), sort-test::key, PG_GETARG_FLOAT8, PG_GETARG_INT64, and PG_RETURN_UINT64.

◆ hashint2()

Datum hashint2 ( PG_FUNCTION_ARGS  )

Definition at line 61 of file hashfunc.c.

62 {
63  return hash_uint32((int32) PG_GETARG_INT16(0));
64 }
#define PG_GETARG_INT16(n)
Definition: fmgr.h:271

References hash_uint32(), and PG_GETARG_INT16.

◆ hashint2extended()

Datum hashint2extended ( PG_FUNCTION_ARGS  )

Definition at line 67 of file hashfunc.c.

68 {
70 }

References hash_uint32_extended(), PG_GETARG_INT16, and PG_GETARG_INT64.

◆ hashint4()

Datum hashint4 ( PG_FUNCTION_ARGS  )

Definition at line 73 of file hashfunc.c.

74 {
75  return hash_uint32(PG_GETARG_INT32(0));
76 }
#define PG_GETARG_INT32(n)
Definition: fmgr.h:269

References hash_uint32(), and PG_GETARG_INT32.

◆ hashint4extended()

Datum hashint4extended ( PG_FUNCTION_ARGS  )

Definition at line 79 of file hashfunc.c.

80 {
82 }

References hash_uint32_extended(), PG_GETARG_INT32, and PG_GETARG_INT64.

◆ hashint8()

Datum hashint8 ( PG_FUNCTION_ARGS  )

Definition at line 85 of file hashfunc.c.

86 {
87  /*
88  * The idea here is to produce a hash value compatible with the values
89  * produced by hashint4 and hashint2 for logically equal inputs; this is
90  * necessary to support cross-type hash joins across these input types.
91  * Since all three types are signed, we can xor the high half of the int8
92  * value if the sign is positive, or the complement of the high half when
93  * the sign is negative.
94  */
95  int64 val = PG_GETARG_INT64(0);
96  uint32 lohalf = (uint32) val;
97  uint32 hihalf = (uint32) (val >> 32);
98 
99  lohalf ^= (val >= 0) ? hihalf : ~hihalf;
100 
101  return hash_uint32(lohalf);
102 }
long val
Definition: informix.c:664

References hash_uint32(), PG_GETARG_INT64, and val.

Referenced by interval_hash(), pg_lsn_hash(), time_hash(), timestamp_hash(), and timetz_hash().

◆ hashint8extended()

Datum hashint8extended ( PG_FUNCTION_ARGS  )

Definition at line 105 of file hashfunc.c.

106 {
107  /* Same approach as hashint8 */
108  int64 val = PG_GETARG_INT64(0);
109  uint32 lohalf = (uint32) val;
110  uint32 hihalf = (uint32) (val >> 32);
111 
112  lohalf ^= (val >= 0) ? hihalf : ~hihalf;
113 
114  return hash_uint32_extended(lohalf, PG_GETARG_INT64(1));
115 }

References hash_uint32_extended(), PG_GETARG_INT64, and val.

Referenced by interval_hash_extended(), pg_lsn_hash_extended(), time_hash_extended(), timestamp_hash_extended(), and timetz_hash_extended().

◆ hashname()

Datum hashname ( PG_FUNCTION_ARGS  )

Definition at line 252 of file hashfunc.c.

253 {
254  char *key = NameStr(*PG_GETARG_NAME(0));
255 
256  return hash_any((unsigned char *) key, strlen(key));
257 }
#define NameStr(name)
Definition: c.h:735
#define PG_GETARG_NAME(n)
Definition: fmgr.h:278

References hash_any(), sort-test::key, NameStr, and PG_GETARG_NAME.

◆ hashnameextended()

Datum hashnameextended ( PG_FUNCTION_ARGS  )

Definition at line 260 of file hashfunc.c.

261 {
262  char *key = NameStr(*PG_GETARG_NAME(0));
263 
264  return hash_any_extended((unsigned char *) key, strlen(key),
265  PG_GETARG_INT64(1));
266 }

References hash_any_extended(), sort-test::key, NameStr, PG_GETARG_INT64, and PG_GETARG_NAME.

◆ hashoid()

Datum hashoid ( PG_FUNCTION_ARGS  )

Definition at line 118 of file hashfunc.c.

119 {
120  return hash_uint32((uint32) PG_GETARG_OID(0));
121 }

References hash_uint32(), and PG_GETARG_OID.

◆ hashoidextended()

Datum hashoidextended ( PG_FUNCTION_ARGS  )

Definition at line 124 of file hashfunc.c.

125 {
127 }

References hash_uint32_extended(), PG_GETARG_INT64, and PG_GETARG_OID.

◆ hashoidvector()

Datum hashoidvector ( PG_FUNCTION_ARGS  )

Definition at line 234 of file hashfunc.c.

235 {
237 
238  return hash_any((unsigned char *) key->values, key->dim1 * sizeof(Oid));
239 }
#define PG_GETARG_POINTER(n)
Definition: fmgr.h:276
unsigned int Oid
Definition: postgres_ext.h:31
Definition: c.h:715

References hash_any(), sort-test::key, and PG_GETARG_POINTER.

Referenced by oidvectorhashfast().

◆ hashoidvectorextended()

Datum hashoidvectorextended ( PG_FUNCTION_ARGS  )

Definition at line 242 of file hashfunc.c.

243 {
245 
246  return hash_any_extended((unsigned char *) key->values,
247  key->dim1 * sizeof(Oid),
248  PG_GETARG_INT64(1));
249 }

References hash_any_extended(), sort-test::key, PG_GETARG_INT64, and PG_GETARG_POINTER.

◆ hashtext()

Datum hashtext ( PG_FUNCTION_ARGS  )

Definition at line 269 of file hashfunc.c.

270 {
271  text *key = PG_GETARG_TEXT_PP(0);
273  pg_locale_t mylocale = 0;
274  Datum result;
275 
276  if (!collid)
277  ereport(ERROR,
278  (errcode(ERRCODE_INDETERMINATE_COLLATION),
279  errmsg("could not determine which collation to use for string hashing"),
280  errhint("Use the COLLATE clause to set the collation explicitly.")));
281 
282  if (!lc_collate_is_c(collid))
284 
285  if (pg_locale_deterministic(mylocale))
286  {
287  result = hash_any((unsigned char *) VARDATA_ANY(key),
289  }
290  else
291  {
292  Size bsize,
293  rsize;
294  char *buf;
295  const char *keydata = VARDATA_ANY(key);
296  size_t keylen = VARSIZE_ANY_EXHDR(key);
297 
298 
299  bsize = pg_strnxfrm(NULL, 0, keydata, keylen, mylocale);
300  buf = palloc(bsize + 1);
301 
302  rsize = pg_strnxfrm(buf, bsize + 1, keydata, keylen, mylocale);
303  if (rsize != bsize)
304  elog(ERROR, "pg_strnxfrm() returned unexpected result");
305 
306  /*
307  * In principle, there's no reason to include the terminating NUL
308  * character in the hash, but it was done before and the behavior must
309  * be preserved.
310  */
311  result = hash_any((uint8_t *) buf, bsize + 1);
312 
313  pfree(buf);
314  }
315 
316  /* Avoid leaking memory for toasted inputs */
317  PG_FREE_IF_COPY(key, 0);
318 
319  return result;
320 }
size_t Size
Definition: c.h:594
Oid collid
int errhint(const char *fmt,...)
Definition: elog.c:1316
int errcode(int sqlerrcode)
Definition: elog.c:858
int errmsg(const char *fmt,...)
Definition: elog.c:1069
#define ERROR
Definition: elog.h:39
#define ereport(elevel,...)
Definition: elog.h:149
#define PG_FREE_IF_COPY(ptr, n)
Definition: fmgr.h:260
#define PG_GETARG_TEXT_PP(n)
Definition: fmgr.h:309
#define PG_GET_COLLATION()
Definition: fmgr.h:198
void pfree(void *pointer)
Definition: mcxt.c:1456
void * palloc(Size size)
Definition: mcxt.c:1226
size_t pg_strnxfrm(char *dest, size_t destsize, const char *src, size_t srclen, pg_locale_t locale)
Definition: pg_locale.c:2345
bool lc_collate_is_c(Oid collation)
Definition: pg_locale.c:1307
pg_locale_t pg_newlocale_from_collation(Oid collid)
Definition: pg_locale.c:1514
bool pg_locale_deterministic(pg_locale_t locale)
Definition: pg_locale.c:1494
static char * buf
Definition: pg_test_fsync.c:73
uintptr_t Datum
Definition: postgres.h:64
Definition: c.h:676
#define VARDATA_ANY(PTR)
Definition: varatt.h:324
#define VARSIZE_ANY_EXHDR(PTR)
Definition: varatt.h:317

References buf, collid, elog(), ereport, errcode(), errhint(), errmsg(), ERROR, hash_any(), sort-test::key, lc_collate_is_c(), palloc(), pfree(), PG_FREE_IF_COPY, PG_GET_COLLATION, PG_GETARG_TEXT_PP, pg_locale_deterministic(), pg_newlocale_from_collation(), pg_strnxfrm(), VARDATA_ANY, and VARSIZE_ANY_EXHDR.

Referenced by texthashfast().

◆ hashtextextended()

Datum hashtextextended ( PG_FUNCTION_ARGS  )

Definition at line 323 of file hashfunc.c.

324 {
325  text *key = PG_GETARG_TEXT_PP(0);
327  pg_locale_t mylocale = 0;
328  Datum result;
329 
330  if (!collid)
331  ereport(ERROR,
332  (errcode(ERRCODE_INDETERMINATE_COLLATION),
333  errmsg("could not determine which collation to use for string hashing"),
334  errhint("Use the COLLATE clause to set the collation explicitly.")));
335 
336  if (!lc_collate_is_c(collid))
338 
339  if (pg_locale_deterministic(mylocale))
340  {
341  result = hash_any_extended((unsigned char *) VARDATA_ANY(key),
343  PG_GETARG_INT64(1));
344  }
345  else
346  {
347  Size bsize,
348  rsize;
349  char *buf;
350  const char *keydata = VARDATA_ANY(key);
351  size_t keylen = VARSIZE_ANY_EXHDR(key);
352 
353  bsize = pg_strnxfrm(NULL, 0, keydata, keylen, mylocale);
354  buf = palloc(bsize + 1);
355 
356  rsize = pg_strnxfrm(buf, bsize + 1, keydata, keylen, mylocale);
357  if (rsize != bsize)
358  elog(ERROR, "pg_strnxfrm() returned unexpected result");
359 
360  /*
361  * In principle, there's no reason to include the terminating NUL
362  * character in the hash, but it was done before and the behavior must
363  * be preserved.
364  */
365  result = hash_any_extended((uint8_t *) buf, bsize + 1,
366  PG_GETARG_INT64(1));
367 
368  pfree(buf);
369  }
370 
371  PG_FREE_IF_COPY(key, 0);
372 
373  return result;
374 }

References buf, collid, elog(), ereport, errcode(), errhint(), errmsg(), ERROR, hash_any_extended(), sort-test::key, lc_collate_is_c(), palloc(), pfree(), PG_FREE_IF_COPY, PG_GET_COLLATION, PG_GETARG_INT64, PG_GETARG_TEXT_PP, pg_locale_deterministic(), pg_newlocale_from_collation(), pg_strnxfrm(), VARDATA_ANY, and VARSIZE_ANY_EXHDR.

◆ hashvarlena()

Datum hashvarlena ( PG_FUNCTION_ARGS  )

Definition at line 381 of file hashfunc.c.

382 {
383  struct varlena *key = PG_GETARG_VARLENA_PP(0);
384  Datum result;
385 
386  result = hash_any((unsigned char *) VARDATA_ANY(key),
388 
389  /* Avoid leaking memory for toasted inputs */
390  PG_FREE_IF_COPY(key, 0);
391 
392  return result;
393 }
#define PG_GETARG_VARLENA_PP(n)
Definition: fmgr.h:289

References hash_any(), sort-test::key, PG_FREE_IF_COPY, PG_GETARG_VARLENA_PP, VARDATA_ANY, and VARSIZE_ANY_EXHDR.

◆ hashvarlenaextended()

Datum hashvarlenaextended ( PG_FUNCTION_ARGS  )

Definition at line 396 of file hashfunc.c.

397 {
398  struct varlena *key = PG_GETARG_VARLENA_PP(0);
399  Datum result;
400 
401  result = hash_any_extended((unsigned char *) VARDATA_ANY(key),
403  PG_GETARG_INT64(1));
404 
405  PG_FREE_IF_COPY(key, 0);
406 
407  return result;
408 }

References hash_any_extended(), sort-test::key, PG_FREE_IF_COPY, PG_GETARG_INT64, PG_GETARG_VARLENA_PP, VARDATA_ANY, and VARSIZE_ANY_EXHDR.