Migrate To aioredis v2

[HassanAbouelela]

This PR migrates the aioredis version required for the library to ~= 2, which introduces a lot of breaking changes. I've documented below what can best be described as a changelog/migration guide. There is also a version bump from 0.2 to 1.0 as aioredis 2 is going to be incompatible with projects which use the old version.

Removed:

• Connection Pool pattern (see below)
• RedisSession.pool
• RedisSession.closed (closing sessions is mostly no longer a thing)
• RedisSessionClosed exception (same reason as above)
• Namespace locking (as per deprecation timeline) which includes: namespace_lock, namespace_lock_no_warn and NamespaceLock

Changed:

• RedisSession now takes a mandatory URL parameter. See aioredis.Redis.from_url
• Operations should now be performed on RedisObject.redis_session.client, which now validates namespace as well
• RedisTask now takes a RedisTaskQueue instead of just a RedisQueue.

Added

• RedisSessionNotConnected exception
• RedisSession.connected (can act as a general replacement for closed, since a session will never be closed once created)
• Marked support for python 3.10

Connection Pattern Changes

This is where the bulk of the changes lie. aioredis 2.0 abstracts away all the logic for managing the connection and underlying pool (in fact it's nearly impossible to do now, as each pool connection is supposed to be tied directly to a single instruction). This means that all users need to factor out any pool accessing, and instead replace those blocks with direct calls to the client object.

Migration Guide

To migrate from 0.2 to 1.0.0, you need to do the following:

1. Add the URL parameter when initializing the session
2. Remove all usages of namespace locking if they still exist
3. Make changes according to the API changes listed above

4. If you use aioredis directly, follow the migration guide here. Unfortunately, the guide is incomplete, and the changelog is almost non-existant. This shouldn't be too difficult to overcome if you have a good static analysis tool however. Here is a (incomplete) list of some undocumented API changes which you might find useful:

   • brpoplpush and rpoplpush no longer take sourcekey and destkey, but src and dst
   • hmset_dict has been removed. You can use hset (or hmset, but that's deprecated) with the mapping kwarg instead
   • Exceptions have been rewritten, and have very poor documentation

   I have not noticed any other undocumented changes but YMMV.

[coveralls]

Pull Request Test Coverage Report for Build 2698158605

• 135 of 136 (99.26%) changed or added relevant lines in 8 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+3.7%) to 99.575%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
async_rediscache/session.py	16	17	94.12%
<!--	Total:	135	136	99.26%	-->

Totals
Change from base Build 652299207:	3.7%
Covered Lines:	803
Relevant Lines:	806

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💛 - Coveralls

[SebastiaanZ]

Thank you, I'll have a look at the PR.

[HassanAbouelela]

Hey, I've gone through the PR again now and I'm more or less happy with where it was. I was hoping to get a few more reviews and push out a full release soon, but a more realistic approach might be to release this as a beta or RC within the next week, and work on fixing any reported issues.

If that's alright, I'm planning on doing that on Tuesday or so.

[onerandomusername]

Given that the version was 0.2, this is fine to be 0.3 its widely accepted that projects that haven't reached a 1.0 release can be breaking with each minor release.

[HassanAbouelela]

The bump to 1.0 was to follow the deprecation timeline for the lock decorator. Not that it should matter, this repo is pretty stable and I think a 1.0 should be fine.