1 /*-------------------------------------------------------------------------
2 *
3 * dict_simple.c
4 * Simple dictionary: just lowercase and check for stopword
5 *
6 * Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group
7 *
8 *
9 * IDENTIFICATION
10 * src/backend/tsearch/dict_simple.c
11 *
12 *-------------------------------------------------------------------------
13 */
14 #include "postgres.h"
15
16 #include "commands/defrem.h"
17 #include "tsearch/ts_locale.h"
18 #include "tsearch/ts_utils.h"
19 #include "utils/builtins.h"
20
21
22 typedef struct
23 {
24 StopList stoplist;
25 bool accept;
26 } DictSimple;
27
28
29 Datum
dsimple_init(PG_FUNCTION_ARGS)30 dsimple_init(PG_FUNCTION_ARGS)
31 {
32 List *dictoptions = (List *) PG_GETARG_POINTER(0);
33 DictSimple *d = (DictSimple *) palloc0(sizeof(DictSimple));
34 bool stoploaded = false,
35 acceptloaded = false;
36 ListCell *l;
37
38 d->accept = true; /* default */
39
40 foreach(l, dictoptions)
41 {
42 DefElem *defel = (DefElem *) lfirst(l);
43
44 if (strcmp(defel->defname, "stopwords") == 0)
45 {
46 if (stoploaded)
47 ereport(ERROR,
48 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
49 errmsg("multiple StopWords parameters")));
50 readstoplist(defGetString(defel), &d->stoplist, lowerstr);
51 stoploaded = true;
52 }
53 else if (strcmp(defel->defname, "accept") == 0)
54 {
55 if (acceptloaded)
56 ereport(ERROR,
57 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
58 errmsg("multiple Accept parameters")));
59 d->accept = defGetBoolean(defel);
60 acceptloaded = true;
61 }
62 else
63 {
64 ereport(ERROR,
65 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
66 errmsg("unrecognized simple dictionary parameter: \"%s\"",
67 defel->defname)));
68 }
69 }
70
71 PG_RETURN_POINTER(d);
72 }
73
74 Datum
dsimple_lexize(PG_FUNCTION_ARGS)75 dsimple_lexize(PG_FUNCTION_ARGS)
76 {
77 DictSimple *d = (DictSimple *) PG_GETARG_POINTER(0);
78 char *in = (char *) PG_GETARG_POINTER(1);
79 int32 len = PG_GETARG_INT32(2);
80 char *txt;
81 TSLexeme *res;
82
83 txt = lowerstr_with_len(in, len);
84
85 if (*txt == '\0' || searchstoplist(&(d->stoplist), txt))
86 {
87 /* reject as stopword */
88 pfree(txt);
89 res = palloc0(sizeof(TSLexeme) * 2);
90 PG_RETURN_POINTER(res);
91 }
92 else if (d->accept)
93 {
94 /* accept */
95 res = palloc0(sizeof(TSLexeme) * 2);
96 res[0].lexeme = txt;
97 PG_RETURN_POINTER(res);
98 }
99 else
100 {
101 /* report as unrecognized */
102 pfree(txt);
103 PG_RETURN_POINTER(NULL);
104 }
105 }
106