Hi, I’m studying the inside of a compose SlotTable...

# compose

[Ji Sungbin]

Hi, I’m studying the inside of a compose SlotTable.
Is the invalidateGroupsWithKey(key: Int) function in SlotTable only used for testing? I followed the final call of invalidateGroupsWithKey and arrived at the invalidateGroupsWithKey function with @TestOnly attached, and this function is not used. I figured out that the only use case of the findEffectiveRecomposeScope(group: Int) function, which is i think an important function of SlotTable, is invalidateGroupsWithKey, and I wanted to know where invalidateGroupsWithKey is called.

@TestOnly
fun invalidateGroupsWithKey(key: Int) = HotReloader.invalidateGroupsWithKey(key)

And in the process of reaching final TestOnly function, I saw a function like the one below.

fun invalidateGroupsWithKey(key: Int) {
    val compositions: List<ControlledComposition> = synchronized(stateLock) {
        knownCompositions.toMutableList()
    }
    compositions
        .fastMapNotNull { it as? CompositionImpl }
        .fastForEach { it.invalidateGroupsWithKey(key) }
     }
}

knownCompositions is already a MutableList, but why change MutableList to MutableList?

[Albert Chang]

The function is invoked by Studio to support hot reload (Live Edit).
Obviously the purpose of toMutableList() is to create a copy of the original list.

[Ji Sungbin]

Wow, how cool is it to call a function from AS! thank you! Thanks for the purpose of toMutableList() too!