On Mar 1, 2014, at 9:01 PM, James Peach <jpe...@apache.org> wrote:

> On Feb 28, 2014, at 3:21 PM, Leif Hedstrom <zw...@apache.org> wrote:
> 
>> The internals of ATS has some static functions to convert from internal enum 
>> values to a descriptive string. This includes:
>> 
>>      HttpDebugNames::get_server_state_name()
>>      HttpDebugNames::get_event_name()
>>      HttpDebugNames::get_action_name()
>>      HttpDebugNames::get_cache_action_name()
>>      HttpDebugNames::get_api_hook_name()
>> 
>> 
>> I would like to expose these (and any future such Debug functions) to plugin 
>> APIs. A new one that would come to mind is a “id to overridable 
>> configuration” function (but, that’s for later). I think there’s at least 
>> two ways to do this, the first would be e.g.
>> 
>> typedef enum
>> {
>> TS_HTTP_DEBUG_NAMES_NULL = -1,
>> TS_HTTP_DEBUG_NAMES_SERVER_STATE,
>> TS_HTTP_DEBUG_NAMES_EVENT_NAME,
>> TS_HTTP_DEBUG_NAMES_ACTION_NAME,
>> TS_HTTP_DEBUG_NAMES_CACHE_ACTION_NAME,
>> TS_HTTP_DEBUG_NAMES_API_HOOK_NAME,
>> TS_HTTP_DEBUG_NAMES_LAST_ENTRY
>> } TSHttpDebugNamesType;
>> 
>> tsapi const char* TSHttpDebugNameGet(TSHttpDebugNamesType name, int value);
>> 
>> 
>> This has the advantage that it’s really easy to extend with future 
>> additions, easy to use / remember, and trivial to implement. The downside is 
>> there’s no type safety on the “value” parameter other than the fact that the 
>> underlying methods (see above) deals with them.
>> 
>> 
>> The other alternative is to add one C function for each type, e.g.
>> 
>> tsapi const char* TSHttpServerStateNameGet(TSServerState value);
>> tsapi const char* TSHttpEventNameGet(TSEvent value);
>> tsapi const char* TSHttpActionNameGet(int value);
>> 
>> 
>> This has better type safety (in most cases), but makes it slightly harder to 
>> use and extend.
>> 
>> 
>> Please discuss which would be preferable. There’s currently no compatibility 
>> concerns regarding this addition, it’s a brand spanking new API. But we 
>> should design it for future compatibility.
> 
> I prefer the function-based API; it's simpler to describe and use. I don't 
> mind the suggested naming convention, but consider 
> TSHttpServerStateNameLookup(), which would match TSHttpHdrReasonLookup().
> 
> What values would TSHttpActionNameGet() accept?
> 
> J

I prefer function names myself too.  I prefer using *Get() since this is used a 
lot more in the APIs vs *Lookup().  We should use Get as a common action for 
APIs for consistency reasons.

-Bryan

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