Components misc implementations including (ABI changes):

- ComponentStorage and its impls
- ContactCacheService
- ContactUpdater
- HeartbeatProcessor
- SsoProcessor
- QQABot

mirai-core/src/commonMain/kotlin/QQAndroidBot.kt

@@ -105,7 +105,7 @@ internal class QQAndroidBot constructor(
             val components = this // avoid mistakes
             set(SsoProcessorContext, SsoProcessorContextImpl(bot))
             set(SsoProcessor, SsoProcessorImpl(get(SsoProcessorContext)))
-            set(HeartbeatProcessor, HeartbeatProcessor())
+            set(HeartbeatProcessor, HeartbeatProcessorImpl())
             set(KeyRefreshProcessor, KeyRefreshProcessorImpl(networkLogger))
             set(ConfigPushProcessor, ConfigPushProcessorImpl(networkLogger))
 

mirai-core/src/commonMain/kotlin/network/component/ComponentStorage.kt

@@ -12,9 +12,13 @@ package net.mamoe.mirai.internal.network.component
 import org.jetbrains.annotations.TestOnly
 
 /**
- * Facade for [component][ComponentKey]s. Implementation must be thread-safe.
+ * Mediator for [component][ComponentKey]s accessing each other.
+ *
+ * Implementation must be thread-safe.
+ *
  * @see MutableComponentStorage
  * @see ConcurrentComponentStorage
+ * @see plus
  */
 internal interface ComponentStorage {
     @get:TestOnly
@@ -24,6 +28,39 @@ internal interface ComponentStorage {
     operator fun <T : Any> get(key: ComponentKey<T>): T
     fun <T : Any> getOrNull(key: ComponentKey<T>): T?
 
+    val keys: Set<ComponentKey<*>>
+
     override fun toString(): String
 }
 
+internal operator fun ComponentStorage.plus(fallback: ComponentStorage): ComponentStorage =
+    CombinedComponentStorage(this, fallback)
+
+private class CombinedComponentStorage(
+    val main: ComponentStorage,
+    val fallback: ComponentStorage,
+) : ComponentStorage {
+    override val keys: Set<ComponentKey<*>> get() = main.keys + fallback.keys
+    override val size: Int get() = keys.size
+
+    override fun <T : Any> get(key: ComponentKey<T>): T {
+        return main.getOrNull(key) ?: fallback.getOrNull(key) ?: main[key] // let `main` throw exception
+    }
+
+    override fun <T : Any> getOrNull(key: ComponentKey<T>): T? {
+        return main.getOrNull(key) ?: fallback.getOrNull(key)
+    }
+
+    override fun toString(): String = buildString {
+        appendLine("CombinedComponentStorage {")
+        appendLine("* main:")
+        main.toString().lines().forEach {
+            append("  ").appendLine(it)
+        }
+        appendLine("*** fallback:")
+        fallback.toString().lines().forEach {
+            append("  ").appendLine(it)
+        }
+        appendLine("}")
+    }
+}

mirai-core/src/commonMain/kotlin/network/component/ConcurrentComponentStorage.kt

@@ -20,6 +20,7 @@ internal class ConcurrentComponentStorage(
 ) : ComponentStorage, MutableComponentStorage {
     private val map = ConcurrentHashMap<ComponentKey<*>, Any?>()
 
+    override val keys: Set<ComponentKey<*>> get() = map.keys
     override val size: Int get() = map.size
 
     override operator fun <T : Any> get(key: ComponentKey<T>): T {

mirai-core/src/commonMain/kotlin/network/component/NoSuchComponentException.kt

@@ -9,7 +9,14 @@
 
 package net.mamoe.mirai.internal.network.component
 
+/**
+ * Should not be thrown normally.
+ */
 internal data class NoSuchComponentException(
     val key: ComponentKey<*>,
     val storage: ComponentStorage
-) : NoSuchElementException("No such component: $key")
+) : NoSuchElementException() {
+    override val message: String by lazy {
+        "No such component '$key' in storage: \n$storage"
+    }
+}

mirai-core/src/commonMain/kotlin/network/components/BotInitProcessor.kt

@@ -16,6 +16,7 @@ import net.mamoe.mirai.internal.QQAndroidBot
 import net.mamoe.mirai.internal.network.Packet
 import net.mamoe.mirai.internal.network.component.ComponentKey
 import net.mamoe.mirai.internal.network.component.ComponentStorage
+import net.mamoe.mirai.internal.network.handler.NetworkHandler
 import net.mamoe.mirai.internal.network.handler.NetworkHandler.State
 import net.mamoe.mirai.internal.network.handler.state.JobAttachStateObserver
 import net.mamoe.mirai.internal.network.handler.state.StateObserver
@@ -28,6 +29,13 @@ import net.mamoe.mirai.internal.network.protocol.packet.sendAndExpect
 import net.mamoe.mirai.utils.MiraiLogger
 import net.mamoe.mirai.utils.info
 
+
+/**
+ * Facade of [ContactUpdater], [OtherClientUpdater], [ConfigPushSyncer].
+ * Handles initialization jobs after successful logon.
+ *
+ * Attached to handler state [NetworkHandler.State.LOADING] [as state observer][asObserver].
+ */
 internal interface BotInitProcessor {
     suspend fun init()
 

mirai-core/src/commonMain/kotlin/network/components/ContactCacheService.kt

@@ -22,13 +22,16 @@ import net.mamoe.mirai.utils.loadNotBlankAs
 import net.mamoe.mirai.utils.runBIO
 
 /**
- * Maintains cache. Used by [ContactUpdater].
+ * Strategy of caching contacts. Used by [ContactUpdater].
  */
 internal interface ContactCacheService {
-    val friendListCache: FriendListCache?
+    val friendListCache: FriendListCache? // from old code
-    val groupMemberListCaches: GroupMemberListCaches?
+    val groupMemberListCaches: GroupMemberListCaches? // from old code
 
-    fun saveFriendCache()
+    /**
+     * Implementation does not need to be thread-safe.
+     */
+    fun saveFriendCache() // from old code
 
     companion object : ComponentKey<ContactCacheService>
 }

mirai-core/src/commonMain/kotlin/network/components/ContactUpdater.kt

@@ -18,6 +18,7 @@ import kotlinx.coroutines.sync.Semaphore
 import kotlinx.coroutines.sync.withLock
 import kotlinx.coroutines.sync.withPermit
 import net.mamoe.mirai.Mirai
+import net.mamoe.mirai.contact.Contact
 import net.mamoe.mirai.data.FriendInfo
 import net.mamoe.mirai.data.MemberInfo
 import net.mamoe.mirai.internal.QQAndroidBot
@@ -47,11 +48,23 @@ import net.mamoe.mirai.utils.retryCatching
 import net.mamoe.mirai.utils.verbose
 
 /**
- * Uses [ContactCacheService]
+ * Manager of caches for [Contact]s.
+ *
+ * Uses [ContactCacheService].
  */
 internal interface ContactUpdater {
+    /**
+     * Load all caches to the bot this [ContactUpdater] works for.
+     *
+     * Implementation must be thread-safe.
+     */
     suspend fun loadAll(registerResp: SvcRespRegister)
 
+    /**
+     * Closes all contacts and save them to cache if needed.
+     *
+     * Implementation must be thread-safe.
+     */
     fun closeAllContacts(e: CancellationException)
 
     companion object : ComponentKey<ContactUpdater>

mirai-core/src/commonMain/kotlin/network/components/HeartbeatProcessor.kt

@@ -15,16 +15,21 @@ import net.mamoe.mirai.internal.network.handler.NetworkHandler
 import net.mamoe.mirai.internal.network.protocol.packet.login.StatSvc
 import net.mamoe.mirai.internal.network.protocol.packet.sendAndExpect
 
-internal class HeartbeatProcessor {
+internal interface HeartbeatProcessor {
 
     @Throws(Exception::class)
-    suspend fun doHeartbeatNow(networkHandler: NetworkHandler) {
+    suspend fun doHeartbeatNow(networkHandler: NetworkHandler)
+
+    companion object : ComponentKey<HeartbeatProcessor>
+}
+
+internal class HeartbeatProcessorImpl : HeartbeatProcessor {
+    @Throws(Exception::class)
+    override suspend fun doHeartbeatNow(networkHandler: NetworkHandler) {
         StatSvc.SimpleGet(networkHandler.context.bot.client).sendAndExpect(
             networkHandler,
             timeoutMillis = networkHandler.context[SsoProcessorContext].configuration.heartbeatTimeoutMillis,
             retry = 2
         )
     }
-
-    companion object : ComponentKey<HeartbeatProcessor>
 }

mirai-core/src/commonMain/kotlin/network/components/ServerList.kt

@@ -28,10 +28,27 @@ internal data class ServerAddress(
     fun toSocketAddress(): InetSocketAddress = InetSocketAddress.createUnresolved(host, port)
 }
 
+/**
+ * Self-refillable (similarly circular) queue of servers. Pop each time when trying to connect.
+ *
+ * [Preferred][getPreferred] prevails if present than [DEFAULT_SERVER_LIST].
+ *
+ * *+Implementation must be thread-safe**.
+ */
 internal interface ServerList {
+    /**
+     * Set preferred so not using [DEFAULT_SERVER_LIST].
+     */
     fun setPreferred(list: Collection<ServerAddress>)
+
+    /**
+     * Might return [DEFAULT_SERVER_LIST] if not present.
+     */
     fun getPreferred(): Set<ServerAddress>
 
+    /**
+     * Refill the queue. Mostly do not call this function.
+     */
     fun refresh()
 
     /**
@@ -60,9 +77,6 @@ internal interface ServerList {
     }
 }
 
-/**
- * Queue of servers. Pop each time when trying to connect.
- */
 internal class ServerListImpl(
     initial: Collection<ServerAddress> = emptyList()
 ) : ServerList {

mirai-core/src/commonMain/kotlin/network/components/SsoProcessor.kt

@@ -41,7 +41,6 @@ import net.mamoe.mirai.utils.withExceptionCollector
  * Handles login, and acts also as a mediator of [BotInitProcessor], []
  */
 internal interface SsoProcessor {
-    val ssoContext: SsoProcessorContext
     val client: QQAndroidClient
     val ssoSession: SsoSession
 
@@ -50,7 +49,7 @@ internal interface SsoProcessor {
      *
      * E.g. start heartbeat job for [NetworkHandler.State.OK].
      */
-    fun createObserverChain(): StateObserver
+    fun createObserverChain(): StateObserver // todo not used
 
     /**
      * Do login. Throws [LoginFailedException] if failed
@@ -69,7 +68,7 @@ internal interface SsoProcessor {
  * Used by [NettyNetworkHandler.StateConnecting].
  */
 internal class SsoProcessorImpl(
-    override val ssoContext: SsoProcessorContext,
+    val ssoContext: SsoProcessorContext,
 ) : SsoProcessor {
 
     ///////////////////////////////////////////////////////////////////////////