Separate kern.cp_time module

[netdata.git] / src / eval.h

diff --git a/src/eval.h b/src/eval.h
index a645b31b07896e7c7ee871594c6b6c7ac171f549..d68b9af474ce7f5806746dc7db2321d059104b7f 100644 (file)
--- a/src/eval.h
+++ b/src/eval.h
@@ -1,74 +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;
+    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;
 
-#define EVAL_VALUE_INVALID 0
-#define EVAL_VALUE_NUMBER 1
-#define EVAL_VALUE_VARIABLE 2
+    // 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
 
-// these are used for EVAL_NODE.operator
-#define EVAL_OPERATOR_NOP                   '\0'
-#define EVAL_OPERATOR_VALUE                 ':'
-#define EVAL_OPERATOR_EXPRESSION_OPEN       '('
-#define EVAL_OPERATOR_EXPRESSION_CLOSE      ')'
-#define EVAL_OPERATOR_NOT                   '!'
-#define EVAL_OPERATOR_PLUS                  '+'
-#define EVAL_OPERATOR_MINUS                 '-'
-#define EVAL_OPERATOR_AND                   '&'
-#define EVAL_OPERATOR_OR                    '|'
-#define EVAL_OPERATOR_GREATER_THAN_OR_EQUAL 'G'
-#define EVAL_OPERATOR_LESS_THAN_OR_EQUAL    'L'
-#define EVAL_OPERATOR_NOT_EQUAL             '~'
-#define EVAL_OPERATOR_EQUAL                 '='
-#define EVAL_OPERATOR_LESS                  '<'
-#define EVAL_OPERATOR_GREATER               '>'
-#define EVAL_OPERATOR_MULTIPLY              '*'
-#define EVAL_OPERATOR_DIVIDE                '/'
-#define EVAL_OPERATOR_SIGN_PLUS             'P'
-#define EVAL_OPERATOR_SIGN_MINUS            'M'
-
-#define EVAL_ERROR_OK 0
+// 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_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 5
-#define EVAL_ERROR_INVALID_NUMBER_OF_OPERANDS 6
-#define EVAL_ERROR_VALUE_IS_NAN 7
-#define EVAL_ERROR_VALUE_IS_INFINITE 8
-
-typedef struct eval_value {
-    int type;
-
-    union {
-        calculated_number number;
-        VARIABLE *variable;
-        struct eval_node *expression;
-    };
-} EVAL_VALUE;
-
-typedef struct eval_node {
-    int id;
-    unsigned char operator;
-    int precedence;
-
-    int count;
-    EVAL_VALUE ops[];
-} EVAL_NODE;
-
-extern EVAL_NODE *expression_parse(const char *string, const char **failed_at, int *error);
-extern calculated_number expression_evaluate(EVAL_NODE *expression, int *error);
-extern void expression_free(EVAL_NODE *op);
+#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