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hashfunc.c File Reference
#include "postgres.h"
#include "common/hashfn.h"
#include "utils/float.h"
#include "utils/fmgrprotos.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)
 
Datum hashbytea (PG_FUNCTION_ARGS)
 
Datum hashbyteaextended (PG_FUNCTION_ARGS)
 

Function Documentation

◆ hashbytea()

Datum hashbytea ( PG_FUNCTION_ARGS  )

Definition at line 416 of file hashfunc.c.

417{
418 return hashvarlena(fcinfo);
419}
Datum hashvarlena(PG_FUNCTION_ARGS)
Definition: hashfunc.c:386

References hashvarlena().

◆ hashbyteaextended()

Datum hashbyteaextended ( PG_FUNCTION_ARGS  )

Definition at line 422 of file hashfunc.c.

423{
424 return hashvarlenaextended(fcinfo);
425}
Datum hashvarlenaextended(PG_FUNCTION_ARGS)
Definition: hashfunc.c:401

References hashvarlenaextended().

◆ hashchar()

Datum hashchar ( PG_FUNCTION_ARGS  )

Definition at line 47 of file hashfunc.c.

48{
49 return hash_uint32((int32) PG_GETARG_CHAR(0));
50}
int32_t int32
Definition: c.h:481
#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 53 of file hashfunc.c.

54{
56}
#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 128 of file hashfunc.c.

129{
130 return hash_uint32((uint32) PG_GETARG_OID(0));
131}
uint32_t uint32
Definition: c.h:485
#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 134 of file hashfunc.c.

135{
137}

References hash_uint32_extended(), PG_GETARG_INT64, and PG_GETARG_OID.

◆ hashfloat4()

Datum hashfloat4 ( PG_FUNCTION_ARGS  )

Definition at line 140 of file hashfunc.c.

141{
143 float8 key8;
144
145 /*
146 * On IEEE-float machines, minus zero and zero have different bit patterns
147 * but should compare as equal. We must ensure that they have the same
148 * hash value, which is most reliably done this way:
149 */
150 if (key == (float4) 0)
152
153 /*
154 * To support cross-type hashing of float8 and float4, we want to return
155 * the same hash value hashfloat8 would produce for an equal float8 value.
156 * So, widen the value to float8 and hash that. (We must do this rather
157 * than have hashfloat8 try to narrow its value to float4; that could fail
158 * on overflow.)
159 */
160 key8 = key;
161
162 /*
163 * Similarly, NaNs can have different bit patterns but they should all
164 * compare as equal. For backwards-compatibility reasons we force them to
165 * have the hash value of a standard float8 NaN. (You'd think we could
166 * replace key with a float4 NaN and then widen it; but on some old
167 * platforms, that way produces a different bit pattern.)
168 */
169 if (isnan(key8))
170 key8 = get_float8_nan();
171
172 return hash_any((unsigned char *) &key8, sizeof(key8));
173}
double float8
Definition: c.h:584
float float4
Definition: c.h:583
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 176 of file hashfunc.c.

177{
179 uint64 seed = PG_GETARG_INT64(1);
180 float8 key8;
181
182 /* Same approach as hashfloat4 */
183 if (key == (float4) 0)
184 PG_RETURN_UINT64(seed);
185 key8 = key;
186 if (isnan(key8))
187 key8 = get_float8_nan();
188
189 return hash_any_extended((unsigned char *) &key8, sizeof(key8), seed);
190}
uint64_t uint64
Definition: c.h:486
#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 193 of file hashfunc.c.

194{
196
197 /*
198 * On IEEE-float machines, minus zero and zero have different bit patterns
199 * but should compare as equal. We must ensure that they have the same
200 * hash value, which is most reliably done this way:
201 */
202 if (key == (float8) 0)
204
205 /*
206 * Similarly, NaNs can have different bit patterns but they should all
207 * compare as equal. For backwards-compatibility reasons we force them to
208 * have the hash value of a standard NaN.
209 */
210 if (isnan(key))
212
213 return hash_any((unsigned char *) &key, sizeof(key));
214}
#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 217 of file hashfunc.c.

218{
220 uint64 seed = PG_GETARG_INT64(1);
221
222 /* Same approach as hashfloat8 */
223 if (key == (float8) 0)
224 PG_RETURN_UINT64(seed);
225 if (isnan(key))
227
228 return hash_any_extended((unsigned char *) &key, sizeof(key), seed);
229}

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 59 of file hashfunc.c.

60{
62}
#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 65 of file hashfunc.c.

References hash_uint32_extended(), PG_GETARG_INT16, and PG_GETARG_INT64.

◆ hashint4()

Datum hashint4 ( PG_FUNCTION_ARGS  )

Definition at line 71 of file hashfunc.c.

72{
74}
#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 77 of file hashfunc.c.

References hash_uint32_extended(), PG_GETARG_INT32, and PG_GETARG_INT64.

◆ hashint8()

Datum hashint8 ( PG_FUNCTION_ARGS  )

Definition at line 83 of file hashfunc.c.

84{
85 /*
86 * The idea here is to produce a hash value compatible with the values
87 * produced by hashint4 and hashint2 for logically equal inputs; this is
88 * necessary to support cross-type hash joins across these input types.
89 * Since all three types are signed, we can xor the high half of the int8
90 * value if the sign is positive, or the complement of the high half when
91 * the sign is negative.
92 */
94 uint32 lohalf = (uint32) val;
95 uint32 hihalf = (uint32) (val >> 32);
96
97 lohalf ^= (val >= 0) ? hihalf : ~hihalf;
98
99 return hash_uint32(lohalf);
100}
int64_t int64
Definition: c.h:482
long val
Definition: informix.c:689

References hash_uint32(), PG_GETARG_INT64, and val.

Referenced by hashxid8(), interval_hash(), pg_lsn_hash(), time_hash(), timestamp_hash(), timestamptz_hash(), and timetz_hash().

◆ hashint8extended()

Datum hashint8extended ( PG_FUNCTION_ARGS  )

Definition at line 103 of file hashfunc.c.

104{
105 /* Same approach as hashint8 */
107 uint32 lohalf = (uint32) val;
108 uint32 hihalf = (uint32) (val >> 32);
109
110 lohalf ^= (val >= 0) ? hihalf : ~hihalf;
111
112 return hash_uint32_extended(lohalf, PG_GETARG_INT64(1));
113}

References hash_uint32_extended(), PG_GETARG_INT64, and val.

Referenced by hashxid8extended(), interval_hash_extended(), pg_lsn_hash_extended(), time_hash_extended(), timestamp_hash_extended(), timestamptz_hash_extended(), and timetz_hash_extended().

◆ hashname()

Datum hashname ( PG_FUNCTION_ARGS  )

Definition at line 250 of file hashfunc.c.

251{
252 char *key = NameStr(*PG_GETARG_NAME(0));
253
254 return hash_any((unsigned char *) key, strlen(key));
255}
#define NameStr(name)
Definition: c.h:700
#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 258 of file hashfunc.c.

259{
260 char *key = NameStr(*PG_GETARG_NAME(0));
261
262 return hash_any_extended((unsigned char *) key, strlen(key),
263 PG_GETARG_INT64(1));
264}

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

◆ hashoid()

Datum hashoid ( PG_FUNCTION_ARGS  )

Definition at line 116 of file hashfunc.c.

117{
118 return hash_uint32((uint32) PG_GETARG_OID(0));
119}

References hash_uint32(), and PG_GETARG_OID.

◆ hashoidextended()

Datum hashoidextended ( PG_FUNCTION_ARGS  )

Definition at line 122 of file hashfunc.c.

123{
125}

References hash_uint32_extended(), PG_GETARG_INT64, and PG_GETARG_OID.

◆ hashoidvector()

Datum hashoidvector ( PG_FUNCTION_ARGS  )

Definition at line 232 of file hashfunc.c.

233{
235
236 return hash_any((unsigned char *) key->values, key->dim1 * sizeof(Oid));
237}
#define PG_GETARG_POINTER(n)
Definition: fmgr.h:276
unsigned int Oid
Definition: postgres_ext.h:31
Definition: c.h:680

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

Referenced by oidvectorhashfast().

◆ hashoidvectorextended()

Datum hashoidvectorextended ( PG_FUNCTION_ARGS  )

Definition at line 240 of file hashfunc.c.

241{
243
244 return hash_any_extended((unsigned char *) key->values,
245 key->dim1 * sizeof(Oid),
246 PG_GETARG_INT64(1));
247}

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

◆ hashtext()

Datum hashtext ( PG_FUNCTION_ARGS  )

Definition at line 267 of file hashfunc.c.

268{
271 pg_locale_t mylocale;
272 Datum result;
273
274 if (!collid)
276 (errcode(ERRCODE_INDETERMINATE_COLLATION),
277 errmsg("could not determine which collation to use for string hashing"),
278 errhint("Use the COLLATE clause to set the collation explicitly.")));
279
281
282 if (mylocale->deterministic)
283 {
284 result = hash_any((unsigned char *) VARDATA_ANY(key),
286 }
287 else
288 {
289 Size bsize,
290 rsize;
291 char *buf;
292 const char *keydata = VARDATA_ANY(key);
293 size_t keylen = VARSIZE_ANY_EXHDR(key);
294
295
296 bsize = pg_strnxfrm(NULL, 0, keydata, keylen, mylocale);
297 buf = palloc(bsize + 1);
298
299 rsize = pg_strnxfrm(buf, bsize + 1, keydata, keylen, mylocale);
300
301 /* the second call may return a smaller value than the first */
302 if (rsize > bsize)
303 elog(ERROR, "pg_strnxfrm() returned unexpected result");
304
305 /*
306 * In principle, there's no reason to include the terminating NUL
307 * character in the hash, but it was done before and the behavior must
308 * be preserved.
309 */
310 result = hash_any((uint8_t *) buf, bsize + 1);
311
312 pfree(buf);
313 }
314
315 /* Avoid leaking memory for toasted inputs */
317
318 return result;
319}
size_t Size
Definition: c.h:559
Oid collid
int errhint(const char *fmt,...)
Definition: elog.c:1317
int errcode(int sqlerrcode)
Definition: elog.c:853
int errmsg(const char *fmt,...)
Definition: elog.c:1070
#define ERROR
Definition: elog.h:39
#define elog(elevel,...)
Definition: elog.h:225
#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:1521
void * palloc(Size size)
Definition: mcxt.c:1317
size_t pg_strnxfrm(char *dest, size_t destsize, const char *src, ssize_t srclen, pg_locale_t locale)
Definition: pg_locale.c:1680
pg_locale_t pg_newlocale_from_collation(Oid collid)
Definition: pg_locale.c:1341
static char * buf
Definition: pg_test_fsync.c:72
uintptr_t Datum
Definition: postgres.h:64
bool deterministic
Definition: pg_locale.h:69
Definition: c.h:641
#define VARDATA_ANY(PTR)
Definition: varatt.h:324
#define VARSIZE_ANY_EXHDR(PTR)
Definition: varatt.h:317

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

Referenced by texthashfast().

◆ hashtextextended()

Datum hashtextextended ( PG_FUNCTION_ARGS  )

Definition at line 322 of file hashfunc.c.

323{
326 pg_locale_t mylocale;
327 Datum result;
328
329 if (!collid)
331 (errcode(ERRCODE_INDETERMINATE_COLLATION),
332 errmsg("could not determine which collation to use for string hashing"),
333 errhint("Use the COLLATE clause to set the collation explicitly.")));
334
336
337 if (mylocale->deterministic)
338 {
339 result = hash_any_extended((unsigned char *) VARDATA_ANY(key),
341 PG_GETARG_INT64(1));
342 }
343 else
344 {
345 Size bsize,
346 rsize;
347 char *buf;
348 const char *keydata = VARDATA_ANY(key);
349 size_t keylen = VARSIZE_ANY_EXHDR(key);
350
351 bsize = pg_strnxfrm(NULL, 0, keydata, keylen, mylocale);
352 buf = palloc(bsize + 1);
353
354 rsize = pg_strnxfrm(buf, bsize + 1, keydata, keylen, mylocale);
355
356 /* the second call may return a smaller value than the first */
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
372
373 return result;
374}

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

◆ hashvarlena()

Datum hashvarlena ( PG_FUNCTION_ARGS  )

Definition at line 386 of file hashfunc.c.

387{
388 struct varlena *key = PG_GETARG_VARLENA_PP(0);
389 Datum result;
390
391 result = hash_any((unsigned char *) VARDATA_ANY(key),
393
394 /* Avoid leaking memory for toasted inputs */
396
397 return result;
398}
#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.

Referenced by hashbytea().

◆ hashvarlenaextended()

Datum hashvarlenaextended ( PG_FUNCTION_ARGS  )

Definition at line 401 of file hashfunc.c.

402{
403 struct varlena *key = PG_GETARG_VARLENA_PP(0);
404 Datum result;
405
406 result = hash_any_extended((unsigned char *) VARDATA_ANY(key),
408 PG_GETARG_INT64(1));
409
411
412 return result;
413}

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

Referenced by hashbyteaextended().