Parameterize cache key to support calls with different inputs

[Dartlexx]

Right now, CoroutineCache doesn't support caching similar data requests with different parameters.

Lets say, we are caching a search request for Products with string parameter 'productName'. Any such request would be cached under the same key, that was set in @ProviderKey("ProductsSearch"). So we may encounter following situation:

• Search Products with 'snacks' substring;
• This request is being stored under "ProductsSearch" cache;
• Search Products with 'water' substring;
• Instead of making actual call, CoroutineCache will return results stored for 'snacks' request.

I suggest to add another lambda into getData signature, that will be written by CoroutinesCache user and that will do required modifications to @ProviderKey based on input parameters. Example:

interface CacheProviders {

    @ProviderKey("TestKey", EntryClass(Data::class))
    @LifeTime(value = 1L, unit = TimeUnit.MINUTES)
    @Expirable
    @UseIfExpired
    suspend fun getData(dataProvider: suspend () -> Data,
                                      keyModifier: (String) -> String = { s -> s }): Data
}

If such modifier is present, than base key will be modified according to provided lambda. Default implementation can be created, that takes a list of Objects to calculate overall hash of parameters.

[Dartlexx]

As I found out, it's extremely hard to work with KCallables in such solution, as each parametrized call is converted into generated class with contains a field with parameters. So that it makes a nightmare to call them via reflection.

So I suggest another approach now:

interface DataProvider { suspend fun getData(): Data fun parametrizeKey(baseKey: String): String = baseKey }

interface CacheProviders {

@ProviderKey("TestKey", EntryClass(Data::class))
@LifeTime(value = 1L, unit = TimeUnit.MINUTES)
@Expirable
@UseIfExpired
suspend fun getData(dataProvider: DataProvider): Data

}