[dpdk-dev] [PATCH] kvargs: return error if key not find in kvlist

[Wiles, Keith]

> On Aug 9, 2017, at 8:53 AM, Ananyev, Konstantin <konstantin.ananyev at intel.com> wrote:
> 
> 
> 
>> -----Original Message-----
>> From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Keith Wiles
>> Sent: Wednesday, August 9, 2017 4:30 PM
>> To: dev at dpdk.org
>> Subject: [dpdk-dev] [PATCH] kvargs: return error if key not find in kvlist
>> 
>> rte_kvargs_process() should return error if the key
>> is not found in the kvlist or kvlist is NULL.
> 
> Looks like an API breakage for me…

To me it is not an ABI breakage only fixing the routine to return the correct status.

> Could you probably explain why do you think it is necessary?

For the no key found surely seems like an error to me, but I guess you can always require someone to call the rte_kvargs_count() API first which is not stated any place.

As for the kvlist being null that is an error IMO and returning success is not valid.

But to save a huge discussion I rejected the patch in patchwork for now.

> Konstantin
> 
>> 
>> Minor documentation changes and update for when an
>> error is returned.
>> 
>> Signed-off-by: Keith Wiles <keith.wiles at intel.com>
>> ---
>> lib/librte_kvargs/rte_kvargs.c | 7 ++++---
>> lib/librte_kvargs/rte_kvargs.h | 7 ++++---
>> 2 files changed, 8 insertions(+), 6 deletions(-)
>> 
>> diff --git a/lib/librte_kvargs/rte_kvargs.c b/lib/librte_kvargs/rte_kvargs.c
>> index 854ac83f5..c8e8f4b28 100755
>> --- a/lib/librte_kvargs/rte_kvargs.c
>> +++ b/lib/librte_kvargs/rte_kvargs.c
>> @@ -158,16 +158,17 @@ rte_kvargs_process(const struct rte_kvargs *kvlist,
>> 		void *opaque_arg)
>> {
>> 	const struct rte_kvargs_pair *pair;
>> -	unsigned i;
>> +	unsigned int i, found = 0;
>> 
>> 	for (i = 0; i < kvlist->count; i++) {
>> 		pair = &kvlist->pairs[i];
>> -		if (key_match == NULL || strcmp(pair->key, key_match) == 0) {
>> +		if (!key_match || strcmp(pair->key, key_match) == 0) {
>> +			found++;
>> 			if ((*handler)(pair->key, pair->value, opaque_arg) < 0)
>> 				return -1;
>> 		}
>> 	}
>> -	return 0;
>> +	return (!found) ? -1 : 0;
>> }
>> 
>> /* free the rte_kvargs structure */
>> diff --git a/lib/librte_kvargs/rte_kvargs.h b/lib/librte_kvargs/rte_kvargs.h
>> index 5821c726a..260d4db5b 100755
>> --- a/lib/librte_kvargs/rte_kvargs.h
>> +++ b/lib/librte_kvargs/rte_kvargs.h
>> @@ -115,9 +115,9 @@ void rte_kvargs_free(struct rte_kvargs *kvlist);
>>  * Call a handler function for each key/value matching the key
>>  *
>>  * For each key/value association that matches the given key, calls the
>> - * handler function with the for a given arg_name passing the value on the
>> + * handler function with the given arg_name passing the value in the
>>  * dictionary for that key and a given extra argument. If *kvlist* is NULL
>> - * function does nothing.
>> + * function does nothing and returns error.
>>  *
>>  * @param kvlist
>>  *   The rte_kvargs structure
>> @@ -131,7 +131,8 @@ void rte_kvargs_free(struct rte_kvargs *kvlist);
>>  *
>>  * @return
>>  *   - 0 on success
>> - *   - Negative on error
>> + *   - Negative on error or
>> + *       if *key_match* does not match an entry in *kvlist*
>>  */
>> int rte_kvargs_process(const struct rte_kvargs *kvlist,
>> 	const char *key_match, arg_handler_t handler, void *opaque_arg);
>> --
>> 2.11.0
> 

Regards,
Keith