random messages for the rdkafka_performance app

[le-cardinal]

Hello, it would be nice to have the possibility to send batch of messages with different random values (different patterns) especially while enabling compression, because otherwise we can reach easily high throughput with adjacent messages that contains same pattern.
for instance right now, default pattern is "librdkafka_performance testing!", so while sending several messages in same batch will generate a batch of messages with "librdkafka_performance testing!librdkafka_performance testing!...librdkafka_performance testing!" in the message payload
If the compression is enabled, it will then reduce drastically the compressed messages to be sent. In real life, messages are quite different, so compression is never optimised. So i'm proposing to add an option to randomize as much as we can the payload of message somehow ?
Regards