only add new filter when not existent prevoisly

[krombel]

To avoid more filters then really needed I would like to have unique filters.
What do you think of to check before adding the new filter if we not have already have one with the same definition?

[matrixbot]

Can one of the admins verify this patch?

[matrixbot]

Can one of the admins verify this patch?

[matrixbot]

Can one of the admins verify this patch?

[erikjohnston]

I don't think json.dumps necessarily encodes the same dict to the exact same bytes. It'd probably be better to use encode_canonical_json which does?

@matrixbot ok to test

[krombel]

I thought it would be good to check for the same dict that would get inserted later if the filter does not exist. Or do you think to replace `json.dumps` with another function in this step as well?

…

I don't think |json.dumps| necessarily encodes the same dict to the exact same bytes. It'd probably be better to use |encode_canonical_json| which does?

[erikjohnston]

Yeah, I'd replace json.dumps(..) with encode_canonical_json(..)

[erikjohnston]

(I like and approve of the idea though!)

[krombel]

I would replace json.dumps(...) with encode_canonical_json(...) in another step as it is used in other parts of synapse as well.
A simple grep over all .py-files of the repo shows, that json.dumps(...) is 66 and encode_canonical_json(...) 23 times used.

[erikjohnston]

Thanks!