Gzip file seems to be invalid

[aseemk]

I'm generating my profile as instructed, I think (and which used to work before the gzip change):

profiler = require 'streamline-flamegraph/lib/record'
# ...
    recorder = profiler.create().start()
    res.on 'finish', ->
        recorder.stop()

When I run the gen-graphs.sh command on the generated perf-recorded.gz:

$ ./node_modules/streamline-flamegraph/bin/gen-graphs.sh 

/path/to/project/node_modules/streamline/lib/callbacks/runtime.js:139
                throw err;
                      ^
TypeError: Cannot call method 'substring' of undefined
    <<< async stack >>>
    at exports_fold__1 (/path/to/project/node_modules/streamline-flamegraph/lib/fold._js:26:36)
    <<< raw stack >>>
    at ___ (/path/to/project/node_modules/streamline-flamegraph/lib/fold._js:26:102)
    at ___ (/path/to/project/node_modules/streamline/lib/callbacks/runtime.js:108:13)
    at Object._onImmediate (/path/to/project/node_modules/streamline-flamegraph/node_modules/ez-streams/lib/devices/uturn._js:26:15)
    at processImmediate [as _immediateCallback] (timers.js:330:15)

ERROR: No stack counts found
ERROR: No stack counts found

It looks like the culprit is that the gzip file is invalid:

$ gunzip perf-recorded.gz 
gunzip: perf-recorded.gz: unexpected end of file
gunzip: perf-recorded.gz: uncompress failed

Running the current/latest version 0.1.4.

[bjouhier]

How do you stop the process? If you call process.exit() just after recorder.stop() the unzip output buffers won't be flushed.

But it could also be a bug. I haven't re-tested recorder.stop() after the change. I'm using ^C with a SIGINT handler in our code.

[bjouhier]

@aseemk I'm suspecting that you are running streamline in callbacks mode. I just fixed a serious bug in the nodify call which is used to zip the data. It may fix your problem: https://github.com/Sage/ez-streams/issues/8

We're running streamline in fibers mode in-house so we don't always catch problems in other modes. Sorry for that.

[bjouhier]

@aseemk I haven't published the ez-streams fix to npm yet. I'll do a bit later in the week-end.