Re: [dpdk-dev] [PATCH v3 5/8] examples/power: add json string handling

["Burakov, Anatoly" <anatoly.burakov@intel.com>]

On 25-Sep-18 3:00 PM, Hunt, David wrote:
>> Now you're removing those newlines you added in previous commit :)
>>
> 
> Fixed in previous patch in the next version.
> 
> 
>>>       if (pol->pkt.core_type == CORE_TYPE_VIRTUAL) {
>>>           /*
>>>            * If the cores in the policy are virtual, we need to map them
>>> @@ -295,8 +423,6 @@ apply_traffic_profile(struct policy *pol)
>>>         diff = get_pkt_diff(pol);
>>>   -    RTE_LOG(INFO, CHANNEL_MONITOR, "Applying traffic profile\n");
>>> -
>>
>> Here and in a few other places: these log message removals look to be 
>> unrelated to this commit. Also, in my experience, more logging is 
>> better than less logging, especially when something goes wrong - maybe 
>> instead of removing them, just switch the level to debug?
>>
> 
> Changed to Debug instead. Was causing quite a verbose output.

Hopefully in a separate commit :)

> 
>>>       if (diff >= (pol->pkt.traffic_policy.max_max_packet_thresh)) {
>>>           for (count = 0; count < pol->pkt.num_vcpu; count++) {
>>>               if (pol->core_share[count].status != 1)
>>> @@ -340,9 +466,6 @@ apply_time_profile(struct policy *pol)
>>>                   if (pol->core_share[count].status != 1) {
>>>                       power_manager_scale_core_max(
>>>                           pol->core_share[count].pcpu);
>>> -                RTE_LOG(INFO, CHANNEL_MONITOR,
>>
>> <snip>
>>
>>> +        int idx = 0;
>>> +        int indent = 0;
>>> +        do {
>>> +            n_bytes = read(chan_info->fd, &json_data[idx], 1);
>>> +            if (n_bytes == 0)
>>> +                break;
>>> +            if (json_data[idx] == '{')
>>> +                indent++;
>>> +            if (json_data[idx] == '}')
>>> +                indent--;
>>
>> What happens if someone sends a string with a "{" or "}" inside?
>>
> 
> If we get to the end of the buffer without a "}", it calls the library 
> to convert, will fail, and move on.  No damage done (I hope).
> Also, a short un-terminated (by "}") string will also exit when no 
> characters read.
> So any invalid JSON string that's send to Jansson will fail to parse, 
> and the application will be ready for the next (hopefully valid) JSON 
> string.

No, what i meant is something like this:

{ "json_value": "{"}

According to JSON validator, this is a valid JSON string, but it will 
break your code :)

-- 
Thanks,
Anatoly