[IVY-399] Flexible Cache Management

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Labels: patch

Environment

ALL

• Assignee: Unassigned
• Reporter: Eric Crahen
• Created: 29/Jan/07 15:54
• Updated: 15/Aug/12 15:52
• Resolved: 15/Aug/12 15:52

Description

Creating an issue at Xaviers request for improving the approach to cache management

On 1/29/07, Xavier Hanin <[e-mail]> wrote:

Supporting this kind of graph
could be interesting, and what makes it difficult for Ivy is that Ivy
heavily relies on its cache mechanism, which makes it impossible to do
what you want (i.e. never put anything from your local repository to
the cache).

This would be a very powerful feature to add. In 2.0, is there any reason for the cache to have to be so baked into everything? In otherwords, why not implement every resolver and all of the internal management w/ no caching what so ever baked in anywhere? Instead all caching is done in a decorator fashion by wrapping a caching resolver around any other resolver? In otherwords, the core of Ivy only knows about resolvers, no concept of cache exists in the heart of Ivy.

It seems to me this would be much more flexible, and it would still be very possible to provide the syntactic sugar to make it very simple and even seemless to configure these wrappers by default. At the same time, people who will use the flexibility have the power to set up chains that might go something like.

(logical chain)
localresolver
cacheresolver
httpresolver url="..."
cacheresolver
httpresolver url="..."

There is no longer any need to have things like useLocal flags. Its already expressed that the local resolver is not cached because its just not wrapped in a caching resolver.

I think this idiom should be applied to both artifact and metadata resolution.

One cool thing about this, is that in this way, since all caching is simply a type of resolver we'd provide people who don't like the particular method we use to perform caching in the resolver we provide are free to provide their own. This would address lots of the issues that have been raised about caching, consistency, doing anything remotely fancy with local resolvers - right now its very hard to address any of that because caching is not very plugable as it stands.

I think the only drawback is that it seems like its harder to configure out of the box because most people by default would want to wrap every resolver with a cacheresolver - but like I said, this is easily solvable by providing some simple syntactic sugar. For instance the simplehttpresolver might be the name of an undecorated resolver for power users, and the things named httpresolver would simple be an alias for the cacheresolver wrapped around the simplehttpresolver (or subclass, whatever is the most sensible choice)

Issue Links

• is related to: IVY-321 Advanced cache cleaning
• is related to: IVY-654 Share cache with locking
• is related to: IVY-694 cache dynamic revision resolution
• is related to: IVY-628 split the cache into an downloaded artifacts cache and a metadata cache
• is related to: IVY-700 move useOrigin to repository cache manager
• is related to: IVY-685 Remove cache attribute on Ant tasks