quinn-perf table output not suppressed in json mode

[Zotyamester]

Problem

While neither the command-line help nor the comments in the code elaborate on the expected behavior when --json is specified in a quinn-perf client's arguments, based on intuition and experience using iperf3, one would assume that enabling it automatically suppresses all text- or table-based output (at least when the JSON output target is stdout, e.g., when specifying --json -).

Currently, this is not the case.

Possible Resolution

Since json output is implemented as an optional compile-time feature, the easiest solution I can imagine for disabling is to add a conditionally included if expression before invoking stats.print() and any additional println! macros present in client.rs. This feels a bit quirky though.

[Ralith]

It looks like the design intent is to write it to a file, rather than stdout? You could use a named pipe if you want to stream it somewhere.

I wouldn't be opposed to a change to make the stdout behavior friendlier. You could avoid too much conditional compilation by having a flag that's syntactically valid in either configuration but is always false when json support is disabled, maybe.

[Zotyamester]

Fair point, thanks!
I was thinking if it ever made sense to have both the table output written to stdout and the JSON dump written to the specified file at the same time, but I guess changing on this behavior would break compatibility for those relying on this tool already.

[Ralith]

It's fine to break the CLI interface for quinn-perf.