data: Added sdb_data_expr_eval().

[sysdb.git] / src / include / core / data.h

diff --git a/src/include/core/data.h b/src/include/core/data.h
index 4d7fda31c11d590a865fc6aff0665292249f0014..2e9b90bcfd55af660d3cb576b1c5e3e21427730e 100644 (file)
--- a/src/include/core/data.h
+++ b/src/include/core/data.h
@@ -75,6 +75,7 @@ typedef struct {
                } binary;             /* SDB_TYPE_BINARY */
        } data;
 } sdb_data_t;
+#define SDB_DATA_INIT { 0, { .integer = 0 } }
 
 /*
  * sdb_data_copy:
@@ -114,6 +115,46 @@ sdb_data_free_datum(sdb_data_t *datum);
 int
 sdb_data_cmp(const sdb_data_t *d1, const sdb_data_t *d2);
 
+/*
+ * Operators supported by sdb_data_eval_expr.
+ */
+enum {
+       SDB_DATA_ADD = 1, /* addition */
+       SDB_DATA_SUB,     /* substraction */
+       SDB_DATA_MUL,     /* multiplication */
+       SDB_DATA_DIV,     /* division */
+       SDB_DATA_MOD,     /* modulo */
+       SDB_DATA_CONCAT,  /* string / binary data concatenation */
+};
+
+#define SDB_DATA_OP_TO_STRING(op) \
+       (((op) == SDB_DATA_ADD) \
+               ? "+" \
+               : ((op) == SDB_DATA_SUB) \
+                       ? "-" \
+                       : ((op) == SDB_DATA_MUL) \
+                               ? "*" \
+                               : ((op) == SDB_DATA_DIV) \
+                                       ? "/" \
+                                       : ((op) == SDB_DATA_MOD) \
+                                               ? "%" \
+                                               : ((op) == SDB_DATA_CONCAT) \
+                                                       ? "||" : "UNKNOWN")
+
+/*
+ * sdb_data_expr_eval:
+ * Evaluate a simple arithmetic expression on two data points. The data-type
+ * of d1 and d2 have to be the same. String and binary data only support
+ * concatenation and all other data types only support the other operators.
+ *
+ * Returns:
+ *  - 0 on success
+ *  - a negative value else
+ */
+int
+sdb_data_expr_eval(int op, const sdb_data_t *d1, const sdb_data_t *d2,
+               sdb_data_t *res);
+
 /*
  * sdb_data_strlen:
  * Returns a (worst-case) estimate for the number of bytes required to format