1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
|
/*
* txtquery operations with ltree
* Teodor Sigaev <teodor@stack.net>
* contrib/ltree/ltxtquery_op.c
*/
#include "postgres.h"
#include <ctype.h>
#include "ltree.h"
#include "miscadmin.h"
PG_FUNCTION_INFO_V1(ltxtq_exec);
PG_FUNCTION_INFO_V1(ltxtq_rexec);
/*
* check for boolean condition
*/
bool
ltree_execute(ITEM *curitem, void *checkval, bool calcnot, bool (*chkcond) (void *checkval, ITEM *val))
{
/* since this function recurses, it could be driven to stack overflow */
check_stack_depth();
if (curitem->type == VAL)
return (*chkcond) (checkval, curitem);
else if (curitem->val == (int32) '!')
{
return calcnot ?
((ltree_execute(curitem + 1, checkval, calcnot, chkcond)) ? false : true)
: true;
}
else if (curitem->val == (int32) '&')
{
if (ltree_execute(curitem + curitem->left, checkval, calcnot, chkcond))
return ltree_execute(curitem + 1, checkval, calcnot, chkcond);
else
return false;
}
else
{ /* |-operator */
if (ltree_execute(curitem + curitem->left, checkval, calcnot, chkcond))
return true;
else
return ltree_execute(curitem + 1, checkval, calcnot, chkcond);
}
}
typedef struct
{
ltree *node;
char *operand;
} CHKVAL;
static bool
checkcondition_str(void *checkval, ITEM *val)
{
ltree_level *level = LTREE_FIRST(((CHKVAL *) checkval)->node);
int tlen = ((CHKVAL *) checkval)->node->numlevel;
char *op = ((CHKVAL *) checkval)->operand + val->distance;
int (*cmpptr) (const char *, const char *, size_t);
cmpptr = (val->flag & LVAR_INCASE) ? ltree_strncasecmp : strncmp;
while (tlen > 0)
{
if (val->flag & LVAR_SUBLEXEME)
{
if (compare_subnode(level, op, val->length, cmpptr, (val->flag & LVAR_ANYEND)))
return true;
}
else if ((val->length == level->len ||
(level->len > val->length && (val->flag & LVAR_ANYEND))) &&
(*cmpptr) (op, level->name, val->length) == 0)
return true;
tlen--;
level = LEVEL_NEXT(level);
}
return false;
}
Datum
ltxtq_exec(PG_FUNCTION_ARGS)
{
ltree *val = PG_GETARG_LTREE_P(0);
ltxtquery *query = PG_GETARG_LTXTQUERY_P(1);
CHKVAL chkval;
bool result;
chkval.node = val;
chkval.operand = GETOPERAND(query);
result = ltree_execute(GETQUERY(query),
&chkval,
true,
checkcondition_str);
PG_FREE_IF_COPY(val, 0);
PG_FREE_IF_COPY(query, 1);
PG_RETURN_BOOL(result);
}
Datum
ltxtq_rexec(PG_FUNCTION_ARGS)
{
PG_RETURN_DATUM(DirectFunctionCall2(ltxtq_exec,
PG_GETARG_DATUM(1),
PG_GETARG_DATUM(0)
));
}
|
