contrib/ltree/ltxtquery_op.c

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