hot_and_cold.kt

fun main() {
//    coldFlow()
    hotFlow()
}

fun coldFlow() {
    val scope = CoroutineScope(Dispatchers.IO)
    var count = 10
    val coldFlow = flow {
        while (count > 0) {
            println("cold flow emitting...")
            emit(count--)
            delay(1000)
        }
    }
    val favoriteAndWatchingChangedFlow: Flow<Int> =
        coldFlow
            .distinctUntilChanged()

    scope.launch {
        delay(5000)
        favoriteAndWatchingChangedFlow.collect {
            println("1st collector: $it")
        }
    }
    scope.launch {
        delay(5000)
        favoriteAndWatchingChangedFlow.collect {
            println("2nd collector: $it")
        }
    }

    runBlocking {
        delay(10_000)
    }
}

fun hotFlow() {
    val scope = CoroutineScope(Dispatchers.IO)
    val _favoriteAndWatchingChangedFlow = MutableSharedFlow<String>()
    var count = 10
    val favoriteAndWatchingChangedFlow: Flow<String> =
        _favoriteAndWatchingChangedFlow
            .onEach { println("before shareIn") }
            .distinctUntilChanged()
//            .shareIn(scope, SharingStarted.Eagerly)

    scope.launch {
        while (count > 0) {
            println("hot flow emitting...")
            _favoriteAndWatchingChangedFlow.emit("hello world! $count")
            delay(1000)
            count--
        }
    }

    scope.launch {
        delay(5000)
        favoriteAndWatchingChangedFlow.collect {
            println("1st collector: $it")
        }
    }
    scope.launch {
        delay(5000)
        favoriteAndWatchingChangedFlow.collect {
            println("2nd collector: $it")
        }
    }

    runBlocking {
        delay(10_000)
    }
}