store: Record the data-type of an expression.

[sysdb.git] / src / core / store_expr.c

diff --git a/src/core/store_expr.c b/src/core/store_expr.c
index 0a8757f0911568b5b9b2cf8c66ad1fcc0ade62cd..d5b22c7e89b8c645c1da9f130e1435d90d023122 100644 (file)
--- a/src/core/store_expr.c
+++ b/src/core/store_expr.c
@@ -75,6 +75,9 @@ expr_init(sdb_object_t *obj, va_list ap)
        expr->type  = type;
        expr->left  = left;
        expr->right = right;
+
+       /* unknown for now */
+       expr->data_type = -1;
        return 0;
 } /* expr_init */
 
@@ -103,29 +106,39 @@ sdb_store_expr_t *
 sdb_store_expr_create(int op, sdb_store_expr_t *left, sdb_store_expr_t *right)
 {
        sdb_data_t value = SDB_DATA_INIT;
+       sdb_store_expr_t *e;
 
        if ((op < 0) || (SDB_DATA_CONCAT < op) || (! left) || (! right))
                return NULL;
 
-       if (left->type || right->type)
-               return SDB_STORE_EXPR(sdb_object_create("store-expr", expr_type,
+       if (left->type || right->type) {
+               e = SDB_STORE_EXPR(sdb_object_create("store-expr", expr_type,
                                        op, left, right, NULL));
+               e->data_type = sdb_data_expr_type(op, left->type, right->type);
+               return e;
+       }
        /* else: both expressions are constant values; evaluate now */
 
        if (sdb_data_expr_eval(op, &left->data, &right->data, &value))
                return NULL;
-       return SDB_STORE_EXPR(sdb_object_create("store-constvalue", expr_type,
+       e = SDB_STORE_EXPR(sdb_object_create("store-constvalue", expr_type,
                                0, NULL, NULL, &value));
+       e->data_type = value.type;
+       return e;
 } /* sdb_store_expr_create */
 
 sdb_store_expr_t *
 sdb_store_expr_fieldvalue(int field)
 {
        sdb_data_t value = { SDB_TYPE_INTEGER, { .integer = field } };
+       sdb_store_expr_t *e;
+
        if ((field < 0) || (SDB_FIELD_BACKEND < field))
                return NULL;
-       return SDB_STORE_EXPR(sdb_object_create("store-fieldvalue", expr_type,
+       e = SDB_STORE_EXPR(sdb_object_create("store-fieldvalue", expr_type,
                                FIELD_VALUE, NULL, NULL, &value));
+       e->data_type = SDB_FIELD_TYPE(field);
+       return e;
 } /* sdb_store_expr_fieldvalue */
 
 sdb_store_expr_t *
@@ -142,6 +155,7 @@ sdb_store_expr_attrvalue(const char *name)
                                ATTR_VALUE, NULL, NULL, &value));
        if (! expr)
                free(value.data.string);
+       expr->data_type = -1;
        return expr;
 } /* sdb_store_expr_attrvalue */
 
@@ -149,10 +163,14 @@ sdb_store_expr_t *
 sdb_store_expr_constvalue(const sdb_data_t *value)
 {
        sdb_data_t data = SDB_DATA_INIT;
+       sdb_store_expr_t *e;
+
        if (sdb_data_copy(&data, value))
                return NULL;
-       return SDB_STORE_EXPR(sdb_object_create("store-constvalue", expr_type,
+       e = SDB_STORE_EXPR(sdb_object_create("store-constvalue", expr_type,
                                0, NULL, NULL, &data));
+       e->data_type = data.type;
+       return e;
 } /* sdb_store_expr_constvalue */
 
 int
@@ -172,8 +190,16 @@ sdb_store_expr_eval(sdb_store_expr_t *expr, sdb_store_obj_t *obj,
                return sdb_data_copy(res, &expr->data);
        else if (expr->type == FIELD_VALUE)
                return sdb_store_get_field(obj, (int)expr->data.data.integer, res);
-       else if (expr->type == ATTR_VALUE)
-               return sdb_store_get_attr(obj, expr->data.data.string, res, filter);
+       else if (expr->type == ATTR_VALUE) {
+               status = sdb_store_get_attr(obj, expr->data.data.string, res, filter);
+               if ((status < 0) && obj) {
+                       /* attribute does not exist => NULL */
+                       status = 0;
+                       res->type = SDB_TYPE_STRING;
+                       res->data.string = NULL;
+               }
+               return status;
+       }
 
        if (sdb_store_expr_eval(expr->left, obj, &v1, filter))
                return -1;