Read the offset in the correct way

[Gsantomaggio]

Fixes #117

[Gsantomaggio]

@kyrylokovalenko you are right it was a bug.

Do you have a chance to test this PR? It solves the problem

[kyrylokovalenko]

Hi @Gsantomaggio, now code from #117 works fine, but if I set offset_specification in subscribe call like this:

    await consumer.subscribe(
        stream=STREAM,
        callback=on_message,
        decoder=amqp_decoder,
        offset_specification=ConsumerOffsetSpecification(OffsetType.OFFSET, 50)
    )

I receive following output:

Got message: hello: 50 from stream my-test-stream, offset 32
Got message: hello: 51 from stream my-test-stream, offset 33
Got message: hello: 52 from stream my-test-stream, offset 34
Got message: hello: 53 from stream my-test-stream, offset 35
Got message: hello: 54 from stream my-test-stream, offset 36
...
...
Got message: hello: 93 from stream my-test-stream, offset 75
Got message: hello: 94 from stream my-test-stream, offset 76
Got message: hello: 95 from stream my-test-stream, offset 77
Got message: hello: 96 from stream my-test-stream, offset 96
Got message: hello: 97 from stream my-test-stream, offset 97
Got message: hello: 98 from stream my-test-stream, offset 98
Got message: hello: 99 from stream my-test-stream, offset 99

[kyrylokovalenko]

Maybe line 275 of consumer.py

offset = frame.chunk_first_offset

should be

offset = subscriber.offset

?

It seems to solve this issue.

[Gsantomaggio]

@kyrylokovalenko ok it should be okay now! I'd need to add some test

[kyrylokovalenko]

@Gsantomaggio yeah, works as intended, many thanks!