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// SPDX-License-Identifier: GPL-3.0-or-later
#ifndef NETDATA_EVAL_H
#define NETDATA_EVAL_H 1
#include "../libnetdata.h"
#define EVAL_MAX_VARIABLE_NAME_LENGTH 300
typedef enum rrdcalc_status {
RRDCALC_STATUS_REMOVED = -2,
RRDCALC_STATUS_UNDEFINED = -1,
RRDCALC_STATUS_UNINITIALIZED = 0,
RRDCALC_STATUS_CLEAR = 1,
RRDCALC_STATUS_RAISED = 2,
RRDCALC_STATUS_WARNING = 3,
RRDCALC_STATUS_CRITICAL = 4
} RRDCALC_STATUS;
typedef struct eval_variable {
char *name;
uint32_t hash;
struct eval_variable *next;
} EVAL_VARIABLE;
typedef struct eval_expression {
const char *source;
const char *parsed_as;
RRDCALC_STATUS *status;
NETDATA_DOUBLE *myself;
time_t *after;
time_t *before;
NETDATA_DOUBLE 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 *expression);
// 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);
extern int health_variable_lookup(const char *variable, uint32_t hash, struct rrdcalc *rc, NETDATA_DOUBLE *result);
#endif //NETDATA_EVAL_H
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