Convert global continuations to completable deferred

6 files changed, 39 insertions, 50 deletions

diff --git a/app/src/main/kotlin/com/pitchedapps/frost/facebook/requests/FbRequest.kt b/app/src/main/kotlin/com/pitchedapps/frost/facebook/requests/FbRequest.kt
index 53ea6e67..3663f908 100644
--- a/app/src/main/kotlin/com/pitchedapps/frost/facebook/requests/FbRequest.kt
+++ b/app/src/main/kotlin/com/pitchedapps/frost/facebook/requests/FbRequest.kt
@@ -45,22 +45,6 @@ val fbAuth = Flyweight<String, RequestAuth>(GlobalScope, 100, 3600000 /* an hour
 }
 
 /**
- * Synchronously fetch [RequestAuth] from cookie
- * [action] will only be called if a valid auth is found.
- * Otherwise, [fail] will be called
- */
-fun String?.fbRequest(fail: () -> Unit = {}, action: RequestAuth.() -> Unit) {
-    if (this == null) return fail()
-    try {
-        val auth = runBlocking { fbAuth.fetch(this@fbRequest) }
-        auth.action()
-    } catch (e: Exception) {
-        L.e { "Failed auth for ${hashCode()}: ${e.message}" }
-        fail()
-    }
-}
-
-/**
  * Underlying container for all fb requests
  */
 data class RequestAuth(
diff --git a/app/src/main/kotlin/com/pitchedapps/frost/facebook/requests/Images.kt b/app/src/main/kotlin/com/pitchedapps/frost/facebook/requests/Images.kt
index ee18e15e..36dff6ff 100644
--- a/app/src/main/kotlin/com/pitchedapps/frost/facebook/requests/Images.kt
+++ b/app/src/main/kotlin/com/pitchedapps/frost/facebook/requests/Images.kt
@@ -133,7 +133,7 @@ class HdImageFetcher(private val model: HdImageMaybe) : DataFetcher<InputStream>
         val result: Result<InputStream?> = runCatching {
             runBlocking {
                 withTimeout(20000L) {
-                    val auth = fbAuth.fetch(model.cookie)
+                    val auth = fbAuth.fetch(model.cookie).await()
                     if (cancelled) throw RuntimeException("Cancelled")
                     val url = auth.getFullSizedImage(model.id).invoke() ?: throw RuntimeException("Null url")
                     if (cancelled) throw RuntimeException("Cancelled")
diff --git a/app/src/main/kotlin/com/pitchedapps/frost/fragments/RecyclerFragments.kt b/app/src/main/kotlin/com/pitchedapps/frost/fragments/RecyclerFragments.kt
index f7ed9937..d9d518b1 100644
--- a/app/src/main/kotlin/com/pitchedapps/frost/fragments/RecyclerFragments.kt
+++ b/app/src/main/kotlin/com/pitchedapps/frost/fragments/RecyclerFragments.kt
@@ -74,7 +74,7 @@ class MenuFragment : GenericRecyclerFragment<MenuItemData, IItem<*, *>>() {
     override suspend fun reloadImpl(progress: (Int) -> Unit): List<MenuItemData>? = withContext(Dispatchers.IO) {
         val cookie = FbCookie.webCookie ?: return@withContext null
         progress(10)
-        val auth = fbAuth.fetch(cookie)
+        val auth = fbAuth.fetch(cookie).await()
         progress(30)
         val data = auth.getMenuData().invoke() ?: return@withContext null
         if (data.data.isEmpty()) return@withContext null
diff --git a/app/src/main/kotlin/com/pitchedapps/frost/kotlin/Flyweight.kt b/app/src/main/kotlin/com/pitchedapps/frost/kotlin/Flyweight.kt
index 7ac80147..a22022de 100644
--- a/app/src/main/kotlin/com/pitchedapps/frost/kotlin/Flyweight.kt
+++ b/app/src/main/kotlin/com/pitchedapps/frost/kotlin/Flyweight.kt
@@ -17,6 +17,7 @@
 package com.pitchedapps.frost.kotlin
 
 import kotlinx.coroutines.CancellationException
+import kotlinx.coroutines.CompletableDeferred
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.Job
@@ -25,7 +26,6 @@ import kotlinx.coroutines.isActive
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.selects.select
 import java.util.concurrent.ConcurrentHashMap
-import kotlin.coroutines.Continuation
 import kotlin.coroutines.resumeWithException
 import kotlin.coroutines.suspendCoroutine
 
@@ -44,7 +44,7 @@ class Flyweight<K, V>(
 ) {
 
     // Receives a key and a pending request
-    private val actionChannel = Channel<Pair<K, Continuation<V>>>(capacity)
+    private val actionChannel = Channel<Pair<K, CompletableDeferred<V>>>(capacity)
     // Receives a key to invalidate the associated value
     private val invalidatorChannel = Channel<K>(capacity)
     // Receives a key to fetch the value
@@ -58,10 +58,17 @@ class Flyweight<K, V>(
     private val resultMap: MutableMap<K, Result<V>> = mutableMapOf()
     // Keeps track of unfulfilled actions
     // Note that the explicit type is very important here. See https://youtrack.jetbrains.net/issue/KT-18053
-    private val pendingMap: MutableMap<K, MutableList<Continuation<V>>> = ConcurrentHashMap()
+    private val pendingMap: MutableMap<K, MutableList<CompletableDeferred<V>>> = ConcurrentHashMap()
 
     private val job: Job
 
+    private fun CompletableDeferred<V>.completeWith(result: Result<V>) {
+        if (result.isSuccess)
+            complete(result.getOrNull()!!)
+        else
+            completeExceptionally(result.exceptionOrNull()!!)
+    }
+
     init {
         job = scope.launch(Dispatchers.IO) {
             launch {
@@ -70,15 +77,15 @@ class Flyweight<K, V>(
                         /*
                          * New request received. Continuation should be fulfilled eventually
                          */
-                        actionChannel.onReceive { (key, continuation) ->
+                        actionChannel.onReceive { (key, completable) ->
                             val lastUpdate = conditionMap[key]
                             val lastResult = resultMap[key]
                             // Valid value, retrieved within acceptable time
                             if (lastResult != null && lastUpdate != null && System.currentTimeMillis() - lastUpdate < maxAge) {
-                                continuation.resumeWith(lastResult)
+                                completable.completeWith(lastResult)
                             } else {
                                 val valueRequestPending = key in pendingMap
-                                pendingMap.getOrPut(key) { mutableListOf() }.add(continuation)
+                                pendingMap.getOrPut(key) { mutableListOf() }.add(completable)
                                 if (!valueRequestPending)
                                     requesterChannel.send(key)
                             }
@@ -106,7 +113,7 @@ class Flyweight<K, V>(
                             conditionMap[key] = System.currentTimeMillis()
                             resultMap[key] = result
                             pendingMap.remove(key)?.forEach {
-                                it.resumeWith(result)
+                                it.completeWith(result)
                             }
                         }
                     }
@@ -126,11 +133,15 @@ class Flyweight<K, V>(
         }
     }
 
-    suspend fun fetch(key: K): V = suspendCoroutine {
-        if (!job.isActive) it.resumeWithException(IllegalStateException("Flyweight is not active"))
-        else scope.launch {
-            actionChannel.send(key to it)
-        }
+    /**
+     * Queues the request, and returns a completable once it is sent to a channel.
+     * The fetcher will only be suspended if the channels are full
+     */
+    suspend fun fetch(key: K): CompletableDeferred<V> {
+        val completable = CompletableDeferred<V>(job)
+        if (!job.isActive) completable.completeExceptionally(IllegalStateException("Flyweight is not active"))
+        else actionChannel.send(key to completable)
+        return completable
     }
 
     suspend fun invalidate(key: K) {
@@ -141,7 +152,7 @@ class Flyweight<K, V>(
         job.cancel()
         if (pendingMap.isNotEmpty()) {
             val error = CancellationException("Flyweight cancelled")
-            pendingMap.values.flatten().forEach { it.resumeWithException(error) }
+            pendingMap.values.flatten().forEach { it.completeExceptionally(error) }
             pendingMap.clear()
         }
         actionChannel.close()
diff --git a/app/src/main/kotlin/com/pitchedapps/frost/services/FrostRequestService.kt b/app/src/main/kotlin/com/pitchedapps/frost/services/FrostRequestService.kt
index c88f3946..a8ecb27d 100644
--- a/app/src/main/kotlin/com/pitchedapps/frost/services/FrostRequestService.kt
+++ b/app/src/main/kotlin/com/pitchedapps/frost/services/FrostRequestService.kt
@@ -179,7 +179,7 @@ class FrostRequestService : BaseJobService() {
         }
         launch(Dispatchers.IO) {
             try {
-                val auth = fbAuth.fetch(cookie)
+                val auth = fbAuth.fetch(cookie).await()
                 command.invoke(auth, bundle)
                 L.d {
                     "Finished frost service for ${command.name} in ${System.currentTimeMillis() - startTime} ms"
diff --git a/app/src/main/kotlin/com/pitchedapps/frost/web/LoginWebView.kt b/app/src/main/kotlin/com/pitchedapps/frost/web/LoginWebView.kt
index 8132382a..c21ce93b 100644
--- a/app/src/main/kotlin/com/pitchedapps/frost/web/LoginWebView.kt
+++ b/app/src/main/kotlin/com/pitchedapps/frost/web/LoginWebView.kt
@@ -28,7 +28,7 @@ import android.webkit.WebResourceRequest
 import android.webkit.WebView
 import ca.allanwang.kau.utils.fadeIn
 import ca.allanwang.kau.utils.isVisible
-import ca.allanwang.kau.utils.withMainContext
+import ca.allanwang.kau.utils.launchMain
 import com.pitchedapps.frost.dbflow.CookieModel
 import com.pitchedapps.frost.facebook.FB_LOGIN_URL
 import com.pitchedapps.frost.facebook.FB_USER_MATCHER
@@ -40,10 +40,8 @@ import com.pitchedapps.frost.injectors.jsInject
 import com.pitchedapps.frost.utils.L
 import com.pitchedapps.frost.utils.Prefs
 import com.pitchedapps.frost.utils.isFacebookUrl
+import kotlinx.coroutines.CompletableDeferred
 import kotlinx.coroutines.coroutineScope
-import kotlinx.coroutines.launch
-import kotlinx.coroutines.suspendCancellableCoroutine
-import kotlin.coroutines.resume
 
 /**
  * Created by Allan Wang on 2017-05-29.
@@ -54,7 +52,7 @@ class LoginWebView @JvmOverloads constructor(
     defStyleAttr: Int = 0
 ) : WebView(context, attrs, defStyleAttr) {
 
-    private lateinit var loginCallback: (CookieModel) -> Unit
+    private val completable: CompletableDeferred<CookieModel> = CompletableDeferred()
     private lateinit var progressCallback: (Int) -> Unit
 
     @SuppressLint("SetJavaScriptEnabled")
@@ -65,19 +63,15 @@ class LoginWebView @JvmOverloads constructor(
         webChromeClient = LoginChromeClient()
     }
 
-    suspend fun loadLogin(progressCallback: (Int) -> Unit): CookieModel = withMainContext {
-        coroutineScope {
-            suspendCancellableCoroutine<CookieModel> { cont ->
-                this@LoginWebView.progressCallback = progressCallback
-                this@LoginWebView.loginCallback = { cont.resume(it) }
-                L.d { "Begin loading login" }
-                launch {
-                    FbCookie.reset()
-                    setupWebview()
-                    loadUrl(FB_LOGIN_URL)
-                }
-            }
+    suspend fun loadLogin(progressCallback: (Int) -> Unit): CompletableDeferred<CookieModel> = coroutineScope {
+        this@LoginWebView.progressCallback = progressCallback
+        L.d { "Begin loading login" }
+        launchMain {
+            FbCookie.reset()
+            setupWebview()
+            loadUrl(FB_LOGIN_URL)
         }
+        completable
     }
 
     private inner class LoginClient : BaseWebViewClient() {
@@ -86,7 +80,7 @@ class LoginWebView @JvmOverloads constructor(
             super.onPageFinished(view, url)
             val cookieModel = checkForLogin(url)
             if (cookieModel != null)
-                loginCallback(cookieModel)
+                completable.complete(cookieModel)
             if (!view.isVisible) view.fadeIn()
         }