From: Sebastian Harl <sh@tokkee.org>
Date: Thu, 31 Jul 2014 21:09:29 +0000 (+0200)
Subject: store_expr: Added support to include field values in an expression.
X-Git-Tag: sysdb-0.3.0~5
X-Git-Url: https://git.tokkee.org/?a=commitdiff_plain;h=45e97a5c2c641995c7a6fd036ca11a6341f227c8;p=sysdb.git

store_expr: Added support to include field values in an expression.

Added sdb_store_expr_fieldvalue() to create such an expression object and pass
a stored object to sdb_store_expr_eval() to be able to extract the field value
when evaluation the expression.
---

diff --git a/src/core/store_expr.c b/src/core/store_expr.c
index 4d1fccb..7d674bc 100644
--- a/src/core/store_expr.c
+++ b/src/core/store_expr.c
@@ -35,6 +35,7 @@
 
 #include "sysdb.h"
 #include "core/store-private.h"
+#include "core/data.h"
 #include "core/object.h"
 
 #include <assert.h>
@@ -46,7 +47,14 @@
 struct sdb_store_expr {
 	sdb_object_t super;
 
+	/*
+	 * type:
+	 * -1: field value (field type store in data.data.integer)
+	 *  0: const value (stored in data)
+	 * >0: operator id
+	 */
 	int type;
+
 	sdb_store_expr_t *left;
 	sdb_store_expr_t *right;
 
@@ -67,7 +75,7 @@ expr_init(sdb_object_t *obj, va_list ap)
 
 	sdb_store_expr_t *expr = SDB_STORE_EXPR(obj);
 
-	if (! type) {
+	if (type <= 0) {
 		if (! value)
 			return -1;
 	} else {
@@ -114,10 +122,22 @@ static sdb_type_t expr_type = {
 sdb_store_expr_t *
 sdb_store_expr_create(int op, sdb_store_expr_t *left, sdb_store_expr_t *right)
 {
+	if ((op < 0) || (SDB_DATA_CONCAT < op))
+		return NULL;
 	return SDB_STORE_EXPR(sdb_object_create("store-expr", expr_type,
 				op, left, right, NULL));
 } /* sdb_store_expr_create */
 
+sdb_store_expr_t *
+sdb_store_expr_fieldvalue(int field)
+{
+	sdb_data_t value = { SDB_TYPE_INTEGER, { .integer = field } };
+	if ((field < 0) || (SDB_FIELD_BACKEND < field))
+		return NULL;
+	return SDB_STORE_EXPR(sdb_object_create("store-fieldvalue", expr_type,
+				-1, NULL, NULL, &value));
+} /* sdb_store_expr_fieldvalue */
+
 sdb_store_expr_t *
 sdb_store_expr_constvalue(const sdb_data_t *value)
 {
@@ -126,7 +146,8 @@ sdb_store_expr_constvalue(const sdb_data_t *value)
 } /* sdb_store_expr_constvalue */
 
 int
-sdb_store_expr_eval(sdb_store_expr_t *expr, sdb_data_t *res)
+sdb_store_expr_eval(sdb_store_expr_t *expr, sdb_store_obj_t *obj,
+		sdb_data_t *res)
 {
 	sdb_data_t v1 = SDB_DATA_INIT, v2 = SDB_DATA_INIT;
 
@@ -135,10 +156,12 @@ sdb_store_expr_eval(sdb_store_expr_t *expr, sdb_data_t *res)
 
 	if (! expr->type)
 		return sdb_data_copy(res, &expr->data);
+	else if (expr->type < 0)
+		return sdb_store_get_field(obj, (int)expr->data.data.integer, res);
 
-	if (sdb_store_expr_eval(expr->left, &v1))
+	if (sdb_store_expr_eval(expr->left, obj, &v1))
 		return -1;
-	if (sdb_store_expr_eval(expr->right, &v2)) {
+	if (sdb_store_expr_eval(expr->right, obj, &v2)) {
 		sdb_data_free_datum(&v1);
 		return -1;
 	}
diff --git a/src/core/store_lookup.c b/src/core/store_lookup.c
index 1ec1dbb..0ef5f46 100644
--- a/src/core/store_lookup.c
+++ b/src/core/store_lookup.c
@@ -114,7 +114,7 @@ attr_cmp(sdb_store_obj_t *obj, sdb_store_cond_t *cond,
 	if (obj->type != SDB_HOST)
 		return INT_MAX;
 
-	if (sdb_store_expr_eval(ATTR_C(cond)->expr, &value))
+	if (sdb_store_expr_eval(ATTR_C(cond)->expr, obj, &value))
 		return INT_MAX;
 
 	attr = attr_get(HOST(obj), ATTR_C(cond)->name, filter);
@@ -138,7 +138,7 @@ obj_cmp(sdb_store_obj_t *obj, sdb_store_cond_t *cond,
 
 	if (sdb_store_get_field(obj, OBJ_C(cond)->field, &obj_value))
 		return INT_MAX;
-	if (sdb_store_expr_eval(OBJ_C(cond)->expr, &value))
+	if (sdb_store_expr_eval(OBJ_C(cond)->expr, obj, &value))
 		return INT_MAX;
 
 	if (obj_value.type != value.type) {
@@ -577,7 +577,7 @@ cond_tostring(sdb_store_matcher_t *m, char *buf, size_t buflen)
 		return buf;
 	}
 
-	if (sdb_store_expr_eval(expr, &value))
+	if (sdb_store_expr_eval(expr, NULL, &value))
 		snprintf(value_str, sizeof(value_str), "ERR");
 	else if (sdb_data_format(&value, value_str, sizeof(value_str),
 				SDB_SINGLE_QUOTED) < 0)
@@ -966,7 +966,7 @@ sdb_store_matcher_parse_cmp(const char *obj_type, const char *attr,
 	if (! expr)
 		return NULL;
 
-	if (sdb_store_expr_eval(expr, &value))
+	if (sdb_store_expr_eval(expr, NULL, &value))
 		return NULL;
 	if (value.type != SDB_TYPE_STRING) {
 		sdb_data_free_datum(&value);
diff --git a/src/include/core/store.h b/src/include/core/store.h
index 533f408..760c23d 100644
--- a/src/include/core/store.h
+++ b/src/include/core/store.h
@@ -210,6 +210,18 @@ typedef struct sdb_store_expr sdb_store_expr_t;
 sdb_store_expr_t *
 sdb_store_expr_create(int op, sdb_store_expr_t *left, sdb_store_expr_t *right);
 
+/*
+ * sdb_store_expr_fieldvalue:
+ * Creates an expression which evaluates to the value of the specified
+ * queryable field of a stored object.
+ *
+ * Returns:
+ *  - an expression object on success
+ *  - NULL else
+ */
+sdb_store_expr_t *
+sdb_store_expr_fieldvalue(int field);
+
 /*
  * sdb_store_expr_constvalue:
  * Creates an expression which evaluates to the specified constant value.
@@ -223,16 +235,19 @@ sdb_store_expr_constvalue(const sdb_data_t *value);
 
 /*
  * sdb_store_expr_eval:
- * Evaluate an expression and stores the result in 'res'. The result's value
- * will be allocated dynamically if necessary and, thus, should be free'd by
- * the caller (e.g. using sdb_data_free_datum);
+ * Evaluate an expression for the specified stored object and stores the
+ * result in 'res'. The result's value will be allocated dynamically if
+ * necessary and, thus, should be free'd by the caller (e.g. using
+ * sdb_data_free_datum). The object may be NULL, in which case the expression
+ * needs to evaluate to a constant value.
  *
  * Returns:
  *  - 0 on success
  *  - a negative value else
  */
 int
-sdb_store_expr_eval(sdb_store_expr_t *expr, sdb_data_t *res);
+sdb_store_expr_eval(sdb_store_expr_t *expr, sdb_store_obj_t *obj,
+		sdb_data_t *res);
 
 /*
  * Conditionals may be used to lookup hosts from the store based on a