[Refacto] Add delegate generic type and improve lazy loading extension code in preloading collection

[antoinebhs]

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What kind of change does this PR introduce?

• Closes cleanup PreloadingNetworkStoreClient assumes its delegate is CachedNetworkStoreClient #420

  • Add delegate generic type in AbstractForwardingNetworkStoreClient. This explains that all NetworkStoreClient can't be used in any order (for example that a PreloadingNetworkStoreClient needs to be backed by a CachedNetworkStoreClient to work). This was already the case in the different client constructors, for example here:

    powsybl-network-store/network-store-client/src/main/java/com/powsybl/network/store/client/PreloadingNetworkStoreClient.java

    Lines 60 to 65 in 6a31f41

    	public PreloadingNetworkStoreClient(CachedNetworkStoreClient delegate, boolean allCollectionsNeededForBusView,
    	ExecutorService executorService) {
    	super(delegate);
    	this.allCollectionsNeededForBusView = allCollectionsNeededForBusView;
    	this.executorService = Objects.requireNonNull(executorService);
    	}

  • In PreloadingNetworkStoreClient, there was some logic to know if the resourceType is cached. This logic is already implemented in the CachedNetworkStoreClient (and especially in CollectionCache). I removed this logic and maintain the code only to know if all collections needed for bus view have been loaded in the client. It avoids calling loadAllCollectionsNeededForBusView if it's not necessary.
  • As specified in the issue, I avoid to call the delegate.getGenerators() twice in the method getGenerators() if we are not in ALL_COLLECTION_NEED_FOR_BUS_VIEW (and same for all types of equipments). Now, the delegate is only called once in this case. In the case where we are in ALL_COLLECTION_NEED_FOR_BUS_VIEW, we first load all the collections and then retrieve the generator collection.

• Code improvements:

  • getAllExtensionsAttributesByResourceType and getAllExtensionsAttributesByResourceTypeAndExtensionName() are now only used to fetch resources from the server (implemented only in RestNetworkStoreClient).
  • there are new methods in CachedNetworkStoreClient (method load*) that only load extension attributes to cache but does not return anything (the returns were not used anyway) it fixes the TODO from Fix looking on all resources when retrieving extensions for preloading collection #463
  • some tests improvements or fixes because some tests were using the return of the methods that only load extension attributes to cache
  • I added some tests to cover method in PreloadingNetworkStoreClient as it was poorly covered. As an example, I took the groundCache test which was quite complete. It's not extensive but better than no tests.

This PR does not change any feature, it's only about code refactoring.

[sonarcloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
92.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud