Hi,
For our use case, we end up performing a lot of string comparisons to determine the state of the system via libchrony. Also, we must duplicate string constants. This is due to message.c containing values that are "hidden" from our application. Namely, the sources_state_enums:
Ideally, we'd be able to compare the integer values, rather than the strings. This would enable us to drop the duplicated string constants and no longer perform string comparisons.
In effect, what do you think about defining constants in a header file, instead? Something along the lines of:
static const Constant sources_state_enums[] = {
{ CHRONY_SOURCE_SELECTED, "Selected" },
{ CHRONY_SOURCE_NONSELECTABLE, "Nonselectable" },
{ CHRONY_SOURCE_FALSE_TICKER, "Falseticker" },
{ CHRONY_SOURCE_JITTERY, "Jittery" },
{ CHRONY_SOURCE_UNSELECTED, "Unselected" },
{ CHRONY_SOURCE_SELECTABLE, "Selectable" },
{ 0 }
};Or perhaps even eliminating the dependency on strings altogether in the API in favour of enumerated values? Offering a lookup for the values would still be useful, and even internationalizable.
We do:
get_field_uinteger( ... )
get_constant_name( ... )
Then compare the constant name against our duplicated string values. We could probably compare the value returned from get_field_uinteger, but we'd still have to duplicate the constant values, which could lead to runtime breakages rather than compile-time errors.
The following would be preferred:
#include <message.h>
chrony_state cs = get_field_state( .... )
if( cs.value == CHRONY_SOURCE_SELECTED ) { ... }
Or possibly hide the query behind an API call, leading to a simpler check:
// prototype for is_field_state and constant values
#include <message.h>
// query the state, provide the session, returns a Boolean
if( is_field_state( ..., CHRONY_SOURCE_SELECTED ) ) { ... }
Thoughts?