granicus.if.org Git - postgresql/blob - contrib/btree_gin/btree_gin.c

   1 /*
   2  * contrib/btree_gin/btree_gin.c
   3  */
   4 #include "postgres.h"
   5
   6 #include <limits.h>
   7
   8 #include "access/skey.h"
   9 #include "utils/builtins.h"
  10 #include "utils/bytea.h"
  11 #include "utils/cash.h"
  12 #include "utils/date.h"
  13 #include "utils/inet.h"
  14 #include "utils/numeric.h"
  15 #include "utils/timestamp.h"
  16 #include "utils/varbit.h"
  17
  18 PG_MODULE_MAGIC;
  19
  20 typedef struct QueryInfo
  21 {
  22         StrategyNumber strategy;
  23         Datum           datum;
  24         bool            is_varlena;
  25         Datum           (*typecmp) (FunctionCallInfo);
  26 } QueryInfo;
  27
  28
  29 /*** GIN support functions shared by all datatypes ***/
  30
  31 static Datum
  32 gin_btree_extract_value(FunctionCallInfo fcinfo, bool is_varlena)
  33 {
  34         Datum           datum = PG_GETARG_DATUM(0);
  35         int32      *nentries = (int32 *) PG_GETARG_POINTER(1);
  36         Datum      *entries = (Datum *) palloc(sizeof(Datum));
  37
  38         if (is_varlena)
  39                 datum = PointerGetDatum(PG_DETOAST_DATUM(datum));
  40         entries[0] = datum;
  41         *nentries = 1;
  42
  43         PG_RETURN_POINTER(entries);
  44 }
  45
  46 /*
  47  * For BTGreaterEqualStrategyNumber, BTGreaterStrategyNumber, and
  48  * BTEqualStrategyNumber we want to start the index scan at the
  49  * supplied query datum, and work forward. For BTLessStrategyNumber
  50  * and BTLessEqualStrategyNumber, we need to start at the leftmost
  51  * key, and work forward until the supplied query datum (which must be
  52  * sent along inside the QueryInfo structure).
  53  */
  54 static Datum
  55 gin_btree_extract_query(FunctionCallInfo fcinfo,
  56                                                 bool is_varlena,
  57                                                 Datum (*leftmostvalue) (void),
  58                                                 Datum (*typecmp) (FunctionCallInfo))
  59 {
  60         Datum           datum = PG_GETARG_DATUM(0);
  61         int32      *nentries = (int32 *) PG_GETARG_POINTER(1);
  62         StrategyNumber strategy = PG_GETARG_UINT16(2);
  63         bool      **partialmatch = (bool **) PG_GETARG_POINTER(3);
  64         Pointer   **extra_data = (Pointer **) PG_GETARG_POINTER(4);
  65         Datum      *entries = (Datum *) palloc(sizeof(Datum));
  66         QueryInfo  *data = (QueryInfo *) palloc(sizeof(QueryInfo));
  67         bool       *ptr_partialmatch;
  68
  69         *nentries = 1;
  70         ptr_partialmatch = *partialmatch = (bool *) palloc(sizeof(bool));
  71         *ptr_partialmatch = false;
  72         if (is_varlena)
  73                 datum = PointerGetDatum(PG_DETOAST_DATUM(datum));
  74         data->strategy = strategy;
  75         data->datum = datum;
  76         data->is_varlena = is_varlena;
  77         data->typecmp = typecmp;
  78         *extra_data = (Pointer *) palloc(sizeof(Pointer));
  79         **extra_data = (Pointer) data;
  80
  81         switch (strategy)
  82         {
  83                 case BTLessStrategyNumber:
  84                 case BTLessEqualStrategyNumber:
  85                         entries[0] = leftmostvalue();
  86                         *ptr_partialmatch = true;
  87                         break;
  88                 case BTGreaterEqualStrategyNumber:
  89                 case BTGreaterStrategyNumber:
  90                         *ptr_partialmatch = true;
  91                 case BTEqualStrategyNumber:
  92                         entries[0] = datum;
  93                         break;
  94                 default:
  95                         elog(ERROR, "unrecognized strategy number: %d", strategy);
  96         }
  97
  98         PG_RETURN_POINTER(entries);
  99 }
 100
 101 /*
 102  * Datum a is a value from extract_query method and for BTLess*
 103  * strategy it is a left-most value.  So, use original datum from QueryInfo
 104  * to decide to stop scanning or not.  Datum b is always from index.
 105  */
 106 static Datum
 107 gin_btree_compare_prefix(FunctionCallInfo fcinfo)
 108 {
 109         Datum           a = PG_GETARG_DATUM(0);
 110         Datum           b = PG_GETARG_DATUM(1);
 111         QueryInfo  *data = (QueryInfo *) PG_GETARG_POINTER(3);
 112         int32           res,
 113                                 cmp;
 114
 115         cmp = DatumGetInt32(DirectFunctionCall2Coll(
 116                                 data->typecmp,
 117                                 PG_GET_COLLATION(),
 118                                 (data->strategy == BTLessStrategyNumber ||
 119                                  data->strategy == BTLessEqualStrategyNumber)
 120                                  ? data->datum : a,
 121                                 b));
 122
 123         switch (data->strategy)
 124         {
 125                 case BTLessStrategyNumber:
 126                         /* If original datum > indexed one then return match */
 127                         if (cmp > 0)
 128                                 res = 0;
 129                         else
 130                                 res = 1;
 131                         break;
 132                 case BTLessEqualStrategyNumber:
 133                         /* The same except equality */
 134                         if (cmp >= 0)
 135                                 res = 0;
 136                         else
 137                                 res = 1;
 138                         break;
 139                 case BTEqualStrategyNumber:
 140                         if (cmp != 0)
 141                                 res = 1;
 142                         else
 143                                 res = 0;
 144                         break;
 145                 case BTGreaterEqualStrategyNumber:
 146                         /* If original datum <= indexed one then return match */
 147                         if (cmp <= 0)
 148                                 res = 0;
 149                         else
 150                                 res = 1;
 151                         break;
 152                 case BTGreaterStrategyNumber:
 153                         /* If original datum <= indexed one then return match */
 154                         /* If original datum == indexed one then continue scan */
 155                         if (cmp < 0)
 156                                 res = 0;
 157                         else if (cmp == 0)
 158                                 res = -1;
 159                         else
 160                                 res = 1;
 161                         break;
 162                 default:
 163                         elog(ERROR, "unrecognized strategy number: %d",
 164                                  data->strategy);
 165                         res = 0;
 166         }
 167
 168         PG_RETURN_INT32(res);
 169 }
 170
 171 PG_FUNCTION_INFO_V1(gin_btree_consistent);
 172 Datum
 173 gin_btree_consistent(PG_FUNCTION_ARGS)
 174 {
 175         bool       *recheck = (bool *) PG_GETARG_POINTER(5);
 176
 177         *recheck = false;
 178         PG_RETURN_BOOL(true);
 179 }
 180
 181 /*** GIN_SUPPORT macro defines the datatype specific functions ***/
 182
 183 #define GIN_SUPPORT(type, is_varlena, leftmostvalue, typecmp)                           \
 184 PG_FUNCTION_INFO_V1(gin_extract_value_##type);                                                          \
 185 Datum                                                                                                                                           \
 186 gin_extract_value_##type(PG_FUNCTION_ARGS)                                                                      \
 187 {                                                                                                                                                       \
 188         return gin_btree_extract_value(fcinfo, is_varlena);                                             \
 189 }                                                                                                                                                       \
 190 PG_FUNCTION_INFO_V1(gin_extract_query_##type);                                                          \
 191 Datum                                                                                                                                           \
 192 gin_extract_query_##type(PG_FUNCTION_ARGS)                                                                      \
 193 {                                                                                                                                                       \
 194         return gin_btree_extract_query(fcinfo,                                                                  \
 195                                                                    is_varlena, leftmostvalue, typecmp);         \
 196 }                                                                                                                                                       \
 197 PG_FUNCTION_INFO_V1(gin_compare_prefix_##type);                                                         \
 198 Datum                                                                                                                                           \
 199 gin_compare_prefix_##type(PG_FUNCTION_ARGS)                                                                     \
 200 {                                                                                                                                                       \
 201         return gin_btree_compare_prefix(fcinfo);                                                                \
 202 }
 203
 204
 205 /*** Datatype specifications ***/
 206
 207 static Datum
 208 leftmostvalue_int2(void)
 209 {
 210         return Int16GetDatum(SHRT_MIN);
 211 }
 212 GIN_SUPPORT(int2, false, leftmostvalue_int2, btint2cmp)
 213
 214 static Datum
 215 leftmostvalue_int4(void)
 216 {
 217         return Int32GetDatum(INT_MIN);
 218 }
 219 GIN_SUPPORT(int4, false, leftmostvalue_int4, btint4cmp)
 220
 221 static Datum
 222 leftmostvalue_int8(void)
 223 {
 224         /*
 225          * Use sequence's definition to keep compatibility.
 226          */
 227         return Int64GetDatum(SEQ_MINVALUE);
 228 }
 229 GIN_SUPPORT(int8, false, leftmostvalue_int8, btint8cmp)
 230
 231 static Datum
 232 leftmostvalue_float4(void)
 233 {
 234         return Float4GetDatum(-get_float4_infinity());
 235 }
 236 GIN_SUPPORT(float4, false, leftmostvalue_float4, btfloat4cmp)
 237
 238 static Datum
 239 leftmostvalue_float8(void)
 240 {
 241         return Float8GetDatum(-get_float8_infinity());
 242 }
 243 GIN_SUPPORT(float8, false, leftmostvalue_float8, btfloat8cmp)
 244
 245 static Datum
 246 leftmostvalue_money(void)
 247 {
 248         /*
 249          * Use sequence's definition to keep compatibility.
 250          */
 251         return Int64GetDatum(SEQ_MINVALUE);
 252 }
 253 GIN_SUPPORT(money, false, leftmostvalue_money, cash_cmp)
 254
 255 static Datum
 256 leftmostvalue_oid(void)
 257 {
 258         return ObjectIdGetDatum(0);
 259 }
 260 GIN_SUPPORT(oid, false, leftmostvalue_oid, btoidcmp)
 261
 262 static Datum
 263 leftmostvalue_timestamp(void)
 264 {
 265         return TimestampGetDatum(DT_NOBEGIN);
 266 }
 267 GIN_SUPPORT(timestamp, false, leftmostvalue_timestamp, timestamp_cmp)
 268
 269 GIN_SUPPORT(timestamptz, false, leftmostvalue_timestamp, timestamp_cmp)
 270
 271 static Datum
 272 leftmostvalue_time(void)
 273 {
 274         return TimeADTGetDatum(0);
 275 }
 276 GIN_SUPPORT(time, false, leftmostvalue_time, time_cmp)
 277
 278 static Datum
 279 leftmostvalue_timetz(void)
 280 {
 281         TimeTzADT  *v = palloc(sizeof(TimeTzADT));
 282
 283         v->time = 0;
 284         v->zone = -24 * 3600;           /* XXX is that true? */
 285
 286         return TimeTzADTPGetDatum(v);
 287 }
 288 GIN_SUPPORT(timetz, false, leftmostvalue_timetz, timetz_cmp)
 289
 290 static Datum
 291 leftmostvalue_date(void)
 292 {
 293         return DateADTGetDatum(DATEVAL_NOBEGIN);
 294 }
 295 GIN_SUPPORT(date, false, leftmostvalue_date, date_cmp)
 296
 297 static Datum
 298 leftmostvalue_interval(void)
 299 {
 300         Interval   *v = palloc(sizeof(Interval));
 301
 302         v->time = DT_NOBEGIN;
 303         v->day = 0;
 304         v->month = 0;
 305         return IntervalPGetDatum(v);
 306 }
 307 GIN_SUPPORT(interval, false, leftmostvalue_interval, interval_cmp)
 308
 309 static Datum
 310 leftmostvalue_macaddr(void)
 311 {
 312         macaddr    *v = palloc0(sizeof(macaddr));
 313
 314         return MacaddrPGetDatum(v);
 315 }
 316 GIN_SUPPORT(macaddr, false, leftmostvalue_macaddr, macaddr_cmp)
 317
 318 static Datum
 319 leftmostvalue_inet(void)
 320 {
 321         return DirectFunctionCall3(inet_in,
 322                                                            CStringGetDatum("0.0.0.0/0"),
 323                                                            ObjectIdGetDatum(0),
 324                                                            Int32GetDatum(-1));
 325 }
 326 GIN_SUPPORT(inet, true, leftmostvalue_inet, network_cmp)
 327
 328 GIN_SUPPORT(cidr, true, leftmostvalue_inet, network_cmp)
 329
 330 static Datum
 331 leftmostvalue_text(void)
 332 {
 333         return PointerGetDatum(cstring_to_text_with_len("", 0));
 334 }
 335 GIN_SUPPORT(text, true, leftmostvalue_text, bttextcmp)
 336
 337 static Datum
 338 leftmostvalue_char(void)
 339 {
 340         return CharGetDatum(SCHAR_MIN);
 341 }
 342 GIN_SUPPORT(char, false, leftmostvalue_char, btcharcmp)
 343
 344 GIN_SUPPORT(bytea, true, leftmostvalue_text, byteacmp)
 345
 346 static Datum
 347 leftmostvalue_bit(void)
 348 {
 349         return DirectFunctionCall3(bit_in,
 350                                                            CStringGetDatum(""),
 351                                                            ObjectIdGetDatum(0),
 352                                                            Int32GetDatum(-1));
 353 }
 354 GIN_SUPPORT(bit, true, leftmostvalue_bit, bitcmp)
 355
 356 static Datum
 357 leftmostvalue_varbit(void)
 358 {
 359         return DirectFunctionCall3(varbit_in,
 360                                                            CStringGetDatum(""),
 361                                                            ObjectIdGetDatum(0),
 362                                                            Int32GetDatum(-1));
 363 }
 364 GIN_SUPPORT(varbit, true, leftmostvalue_varbit, bitcmp)
 365
 366 /*
 367  * Numeric type hasn't a real left-most value, so we use PointerGetDatum(NULL)
 368  * (*not* a SQL NULL) to represent that.  We can get away with that because
 369  * the value returned by our leftmostvalue function will never be stored in
 370  * the index nor passed to anything except our compare and prefix-comparison
 371  * functions.  The same trick could be used for other pass-by-reference types.
 372  */
 373
 374 #define NUMERIC_IS_LEFTMOST(x)  ((x) == NULL)
 375
 376 PG_FUNCTION_INFO_V1(gin_numeric_cmp);
 377
 378 Datum
 379 gin_numeric_cmp(PG_FUNCTION_ARGS)
 380 {
 381         Numeric         a = (Numeric) PG_GETARG_POINTER(0);
 382         Numeric         b = (Numeric) PG_GETARG_POINTER(1);
 383         int                     res = 0;
 384
 385         if (NUMERIC_IS_LEFTMOST(a))
 386         {
 387                 res = (NUMERIC_IS_LEFTMOST(b)) ? 0 : -1;
 388         }
 389         else if (NUMERIC_IS_LEFTMOST(b))
 390         {
 391                 res = 1;
 392         }
 393         else
 394         {
 395                 res = DatumGetInt32(DirectFunctionCall2(numeric_cmp,
 396                                                                                                 NumericGetDatum(a),
 397                                                                                                 NumericGetDatum(b)));
 398         }
 399
 400         PG_RETURN_INT32(res);
 401 }
 402
 403 static Datum
 404 leftmostvalue_numeric(void)
 405 {
 406         return PointerGetDatum(NULL);
 407 }
 408 GIN_SUPPORT(numeric, true, leftmostvalue_numeric, gin_numeric_cmp)