Merge "[kairos] use arraylist for TransactionStore" into main

import com.android.systemui.kairos.CoalescingPolicy

import com.android.systemui.kairos.State

import com.android.systemui.kairos.internal.util.HeteroMap

import com.android.systemui.kairos.internal.util.LogIndent

import com.android.systemui.kairos.internal.util.logDuration

import com.android.systemui.kairos.util.Maybe

    }

}

internal class TransactionStore private constructor(private val storage: HeteroMap) {

    constructor(capacity: Int) : this(HeteroMap(capacity))

internal class TransactionStore private constructor(private val storage: ArrayList<Any?>) {

    constructor(capacity: Int) : this(ArrayList(capacity))

    constructor() : this(HeteroMap())

    constructor() : this(ArrayList())

    operator fun <A> get(key: HeteroMap.Key<A>): A =

        storage.getOrError(key) { "no value for $key in this transaction" }

    @Suppress("UNCHECKED_CAST")

    operator fun <A> get(key: Key<A>): A =

        storage.getOrElse(key.index) { error("no value for $key in this transaction") } as A

    operator fun <A> set(key: HeteroMap.Key<A>, value: A) {

        storage[key] = value

    fun <A> put(value: A): Key<A> {

        val index = storage.size

        storage.add(value)

        return Key(index)

    }

    fun clear() = storage.clear()

    @JvmInline value class Key<A>(val index: Int)

}

internal class TransactionCache<A> {

    private val key = object : HeteroMap.Key<A> {}

    private var key: TransactionStore.Key<A>? = null

    var epoch: Long = Long.MIN_VALUE

        private set

    fun getOrPut(evalScope: EvalScope, block: () -> A): A =

        if (epoch < evalScope.epoch) {

            epoch = evalScope.epoch

            block().also { evalScope.transactionStore[key] = it }

            block().also { key = evalScope.transactionStore.put(it) }

        } else {

            evalScope.transactionStore[key]

            evalScope.transactionStore[key!!]

        }

    fun put(evalScope: EvalScope, value: A) {

        epoch = evalScope.epoch

        evalScope.transactionStore[key] = value

        key = evalScope.transactionStore.put(value)

    }

    fun getCurrentValue(evalScope: EvalScope): A = evalScope.transactionStore[key]

    fun getCurrentValue(evalScope: EvalScope): A {

        check(epoch == evalScope.epoch) { "no value for $key in this transaction" }

        return evalScope.transactionStore[key!!]

    }

}