X-Git-Url: https://arthur.barton.de/gitweb/?a=blobdiff_plain;f=src%2Feval.h;h=d68b9af474ce7f5806746dc7db2321d059104b7f;hb=0444aa8ff91dce4d4ab5971187944ed894b550e2;hp=da3be130979aa8908ede8ab32344379e198dad86;hpb=cd39ffd3753f705d3edc290df0f2856df9f581f7;p=netdata.git

diff --git a/src/eval.h b/src/eval.h
index da3be130..d68b9af4 100644
--- a/src/eval.h
+++ b/src/eval.h
@@ -1,38 +1,73 @@
 #ifndef NETDATA_EVAL_H
 #define NETDATA_EVAL_H
 
-typedef struct variable {
+#define EVAL_MAX_VARIABLE_NAME_LENGTH 300
+
+typedef struct eval_variable {
     char *name;
+    uint32_t hash;
     struct rrdvar *rrdvar;
-    struct variable *next;
-} VARIABLE;
-
-#define EVAL_OPERAND_INVALID 0
-#define EVAL_OPERAND_NUMBER 1
-#define EVAL_OPERAND_VARIABLE 2
-#define EVAL_OPERAND_EXPRESSION 3
-
-// these are used for EVAL_OPERAND.operator
-#define EVAL_OPERATOR_NOP   '\0'
-#define EVAL_OPERATOR_NOT   '!'
-#define EVAL_OPERATOR_PLUS  '+'
-#define EVAL_OPERATOR_MINUS '-'
-
-typedef struct eval_value {
-    int type;
-
-    union {
-        calculated_number number;
-        VARIABLE *variable;
-        struct eval_operand *expression;
-    };
-} EVAL_VALUE;
-
-typedef struct eval_operand {
-    char operator;
-
-    int count;
-    EVAL_VALUE ops[];
-} EVAL_OPERAND;
+    struct eval_variable *next;
+} EVAL_VARIABLE;
+
+typedef struct eval_expression {
+    const char *source;
+    const char *parsed_as;
+
+    int *status;
+    calculated_number *this;
+    time_t *after;
+    time_t *before;
+
+    calculated_number result;
+
+    int error;
+    BUFFER *error_msg;
+
+    // hidden EVAL_NODE *
+    void *nodes;
+
+    // custom data to be used for looking up variables
+    struct rrdcalc *rrdcalc;
+} EVAL_EXPRESSION;
+
+#define EVAL_VALUE_INVALID    0
+#define EVAL_VALUE_NUMBER     1
+#define EVAL_VALUE_VARIABLE   2
+#define EVAL_VALUE_EXPRESSION 3
+
+// parsing and evaluation
+#define EVAL_ERROR_OK                             0
+
+// parsing errors
+#define EVAL_ERROR_MISSING_CLOSE_SUBEXPRESSION    1
+#define EVAL_ERROR_UNKNOWN_OPERAND                2
+#define EVAL_ERROR_MISSING_OPERAND                3
+#define EVAL_ERROR_MISSING_OPERATOR               4
+#define EVAL_ERROR_REMAINING_GARBAGE              5
+#define EVAL_ERROR_IF_THEN_ELSE_MISSING_ELSE      6
+
+// evaluation errors
+#define EVAL_ERROR_INVALID_VALUE                101
+#define EVAL_ERROR_INVALID_NUMBER_OF_OPERANDS   102
+#define EVAL_ERROR_VALUE_IS_NAN                 103
+#define EVAL_ERROR_VALUE_IS_INFINITE            104
+#define EVAL_ERROR_UNKNOWN_VARIABLE             105
+
+// parse the given string as an expression and return:
+//   a pointer to an expression if it parsed OK
+//   NULL in which case the pointer to error has the error code
+extern EVAL_EXPRESSION *expression_parse(const char *string, const char **failed_at, int *error);
+
+// free all resources allocated for an expression
+extern void expression_free(EVAL_EXPRESSION *op);
+
+// convert an error code to a message
+extern const char *expression_strerror(int error);
+
+// evaluate an expression and return
+// 1 = OK, the result is in: expression->result
+// 2 = FAILED, the error message is in: buffer_tostring(expression->error_msg)
+extern int expression_evaluate(EVAL_EXPRESSION *expression);
 
 #endif //NETDATA_EVAL_H