|
| 1 | +/* |
| 2 | + * array_iterator.c -- |
| 3 | + * |
| 4 | + * This file defines a new group of operators which take an |
| 5 | + * array and a scalar value, iterate a scalar operator over the |
| 6 | + * elements of the array and the value and compute a result as |
| 7 | + * the logical OR or AND of the results. |
| 8 | + * For example array_int4eq returns true if some of the elements |
| 9 | + * of an array of int4 is equal to the given value: |
| 10 | + * |
| 11 | + * array_int4eq({1,2,3}, 1) --> true |
| 12 | + * array_int4eq({1,2,3}, 4) --> false |
| 13 | + * |
| 14 | + * If we have defined T array types and O scalar operators |
| 15 | + * we can define T x O array operators, each of them has a name |
| 16 | + * like "array_<basetype><operation>" and takes an array of type T |
| 17 | + * iterating the operator O over all the elements. Note however |
| 18 | + * that some of the possible combination are invalid, for example |
| 19 | + * the array_int4_like because there is no like operator for int4. |
| 20 | + * It is now possible to write queries which look inside the arrays: |
| 21 | + * |
| 22 | + * create table t(id int4[], txt text[]); |
| 23 | + * select * from t where t.id *= 123; |
| 24 | + * select * from t where t.txt *~ '[a-z]'; |
| 25 | + * select * from t where t.txt[1:3] **~ '[a-z]'; |
| 26 | + * |
| 27 | + * Copyright (c) 1996, Massimo Dal Zotto <dz@cs.unitn.it> |
| 28 | + */ |
| 29 | + |
| 30 | +#include <ctype.h> |
| 31 | +#include <stdio.h> |
| 32 | +#include <sys/types.h> |
| 33 | +#include <string.h> |
| 34 | + |
| 35 | +#include "postgres.h" |
| 36 | +#include "pg_type.h" |
| 37 | +#include "miscadmin.h" |
| 38 | +#include "syscache.h" |
| 39 | +#include "access/xact.h" |
| 40 | +#include "utils/builtins.h" |
| 41 | +#include "utils/elog.h" |
| 42 | + |
| 43 | +static int32 |
| 44 | +array_iterator(Oid elemtype, Oid proc, int and, ArrayType *array, Datum value) |
| 45 | +{ |
| 46 | + HeapTuple typ_tuple; |
| 47 | + TypeTupleForm typ_struct; |
| 48 | + bool typbyval; |
| 49 | + int typlen; |
| 50 | + func_ptr proc_fn; |
| 51 | + int pronargs; |
| 52 | + int nitems, i, result; |
| 53 | + int ndim, *dim; |
| 54 | + char *p; |
| 55 | + |
| 56 | + /* Sanity checks */ |
| 57 | + if ((array == (ArrayType *) NULL) |
| 58 | + || (ARR_IS_LO(array) == true)) { |
| 59 | + /* elog(NOTICE, "array_iterator: array is null"); */ |
| 60 | + return (0); |
| 61 | + } |
| 62 | + ndim = ARR_NDIM(array); |
| 63 | + dim = ARR_DIMS(array); |
| 64 | + nitems = getNitems(ndim, dim); |
| 65 | + if (nitems == 0) { |
| 66 | + /* elog(NOTICE, "array_iterator: nitems = 0"); */ |
| 67 | + return (0); |
| 68 | + } |
| 69 | + |
| 70 | + /* Lookup element type information */ |
| 71 | + typ_tuple = SearchSysCacheTuple(TYPOID, ObjectIdGetDatum(elemtype),0,0,0); |
| 72 | + if (!HeapTupleIsValid(typ_tuple)) { |
| 73 | + elog(WARN,"array_iterator: cache lookup failed for type %d", elemtype); |
| 74 | + return 0; |
| 75 | + } |
| 76 | + typ_struct = (TypeTupleForm) GETSTRUCT(typ_tuple); |
| 77 | + typlen = typ_struct->typlen; |
| 78 | + typbyval = typ_struct->typbyval; |
| 79 | + |
| 80 | + /* Lookup the function entry point */ |
| 81 | + proc_fn == (func_ptr) NULL; |
| 82 | + fmgr_info(proc, &proc_fn, &pronargs); |
| 83 | + if ((proc_fn == NULL) || (pronargs != 2)) { |
| 84 | + elog(WARN, "array_iterator: fmgr_info lookup failed for oid %d", proc); |
| 85 | + return (0); |
| 86 | + } |
| 87 | + |
| 88 | + /* Scan the array and apply the operator to each element */ |
| 89 | + result = 0; |
| 90 | + p = ARR_DATA_PTR(array); |
| 91 | + for (i = 0; i < nitems; i++) { |
| 92 | + if (typbyval) { |
| 93 | + switch(typlen) { |
| 94 | + case 1: |
| 95 | + result = (int) (*proc_fn)(*p, value); |
| 96 | + break; |
| 97 | + case 2: |
| 98 | + result = (int) (*proc_fn)(* (int16 *) p, value); |
| 99 | + break; |
| 100 | + case 3: |
| 101 | + case 4: |
| 102 | + result = (int) (*proc_fn)(* (int32 *) p, value); |
| 103 | + break; |
| 104 | + } |
| 105 | + p += typlen; |
| 106 | + } else { |
| 107 | + result = (int) (*proc_fn)(p, value); |
| 108 | + if (typlen > 0) { |
| 109 | + p += typlen; |
| 110 | + } else { |
| 111 | + p += INTALIGN(* (int32 *) p); |
| 112 | + } |
| 113 | + } |
| 114 | + if (result) { |
| 115 | + if (!and) { |
| 116 | + return (1); |
| 117 | + } |
| 118 | + } else { |
| 119 | + if (and) { |
| 120 | + return (0); |
| 121 | + } |
| 122 | + } |
| 123 | + } |
| 124 | + |
| 125 | + if (and && result) { |
| 126 | + return (1); |
| 127 | + } else { |
| 128 | + return (0); |
| 129 | + } |
| 130 | +} |
| 131 | + |
| 132 | +/* |
| 133 | + * Iterators for type _text |
| 134 | + */ |
| 135 | + |
| 136 | +int32 |
| 137 | +array_texteq(ArrayType *array, char* value) |
| 138 | +{ |
| 139 | + return array_iterator((Oid) 25, /* text */ |
| 140 | + (Oid) 67, /* texteq */ |
| 141 | + 0, /* logical or */ |
| 142 | + array, (Datum)value); |
| 143 | +} |
| 144 | + |
| 145 | +int32 |
| 146 | +array_all_texteq(ArrayType *array, char* value) |
| 147 | +{ |
| 148 | + return array_iterator((Oid) 25, /* text */ |
| 149 | + (Oid) 67, /* texteq */ |
| 150 | + 1, /* logical and */ |
| 151 | + array, (Datum)value); |
| 152 | +} |
| 153 | + |
| 154 | +int32 |
| 155 | +array_textregexeq(ArrayType *array, char* value) |
| 156 | +{ |
| 157 | + return array_iterator((Oid) 25, /* text */ |
| 158 | + (Oid) 81, /* textregexeq */ |
| 159 | + 0, /* logical or */ |
| 160 | + array, (Datum)value); |
| 161 | +} |
| 162 | + |
| 163 | +int32 |
| 164 | +array_all_textregexeq(ArrayType *array, char* value) |
| 165 | +{ |
| 166 | + return array_iterator((Oid) 25, /* text */ |
| 167 | + (Oid) 81, /* textregexeq */ |
| 168 | + 1, /* logical and */ |
| 169 | + array, (Datum)value); |
| 170 | +} |
| 171 | + |
| 172 | +/* |
| 173 | + * Iterators for type _char16. Note that the regexp operators |
| 174 | + * take the second argument of type text. |
| 175 | + */ |
| 176 | + |
| 177 | +int32 |
| 178 | +array_char16eq(ArrayType *array, char* value) |
| 179 | +{ |
| 180 | + return array_iterator((Oid) 20, /* char16 */ |
| 181 | + (Oid) 490, /* char16eq */ |
| 182 | + 0, /* logical or */ |
| 183 | + array, (Datum)value); |
| 184 | +} |
| 185 | + |
| 186 | +int32 |
| 187 | +array_all_char16eq(ArrayType *array, char* value) |
| 188 | +{ |
| 189 | + return array_iterator((Oid) 20, /* char16 */ |
| 190 | + (Oid) 490, /* char16eq */ |
| 191 | + 1, /* logical and */ |
| 192 | + array, (Datum)value); |
| 193 | +} |
| 194 | + |
| 195 | +int32 |
| 196 | +array_char16regexeq(ArrayType *array, char* value) |
| 197 | +{ |
| 198 | + return array_iterator((Oid) 20, /* char16 */ |
| 199 | + (Oid) 700, /* char16regexeq */ |
| 200 | + 0, /* logical or */ |
| 201 | + array, (Datum)value); |
| 202 | +} |
| 203 | + |
| 204 | +int32 |
| 205 | +array_all_char16regexeq(ArrayType *array, char* value) |
| 206 | +{ |
| 207 | + return array_iterator((Oid) 20, /* char16 */ |
| 208 | + (Oid) 700, /* char16regexeq */ |
| 209 | + 1, /* logical and */ |
| 210 | + array, (Datum)value); |
| 211 | +} |
| 212 | + |
| 213 | +/* |
| 214 | + * Iterators for type _int4 |
| 215 | + */ |
| 216 | + |
| 217 | +int32 |
| 218 | +array_int4eq(ArrayType *array, int4 value) |
| 219 | +{ |
| 220 | + return array_iterator((Oid) 23, /* int4 */ |
| 221 | + (Oid) 65, /* int4eq */ |
| 222 | + 0, /* logical or */ |
| 223 | + array, (Datum)value); |
| 224 | +} |
| 225 | + |
| 226 | +int32 |
| 227 | +array_all_int4eq(ArrayType *array, int4 value) |
| 228 | +{ |
| 229 | + return array_iterator((Oid) 23, /* int4 */ |
| 230 | + (Oid) 65, /* int4eq */ |
| 231 | + 1, /* logical and */ |
| 232 | + array, (Datum)value); |
| 233 | +} |
| 234 | + |
| 235 | +int32 |
| 236 | +array_int4gt(ArrayType *array, int4 value) |
| 237 | +{ |
| 238 | + return array_iterator((Oid) 23, /* int4 */ |
| 239 | + (Oid) 147, /* int4gt */ |
| 240 | + 0, /* logical or */ |
| 241 | + array, (Datum)value); |
| 242 | +} |
| 243 | + |
| 244 | +int32 |
| 245 | +array_all_int4gt(ArrayType *array, int4 value) |
| 246 | +{ |
| 247 | + return array_iterator((Oid) 23, /* int4 */ |
| 248 | + (Oid) 147, /* int4gt */ |
| 249 | + 1, /* logical and */ |
| 250 | + array, (Datum)value); |
| 251 | +} |
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