[IDLE-468] 웹소켓 연결 실패시 2의 배수만큼 기다렸다가 연결을 재시도 하도록 변경 및 최대 대기시간은 10초

Author: tgyuuAn

core/data/src/main/java/com/idle/data/repository/chatting/ChattingRepositoryImpl.kt

@@ -17,7 +17,7 @@ class ChattingRepositoryImpl @Inject constructor(
         webSocketDataSource.disconnectWebSocket()
 
     override fun subscribeChatMessage(): Flow<ChatMessage> =
-        webSocketDataSource.getChatMessageFlow()
+        webSocketDataSource.chatMessageFlow
             .filterNotNull()
             .map { it.toVO() }
-}
+}

core/network/src/main/java/com/idle/network/source/websocket/WebSocketDataSource.kt

@@ -3,23 +3,29 @@ package com.idle.network.source.websocket
 import com.idle.network.BuildConfig
 import com.idle.network.di.WebSocketOkHttpClient
 import com.idle.network.model.chatting.ChatMessageResponse
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.delay
 import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.withContext
 import okhttp3.OkHttpClient
 import okhttp3.Request
 import okhttp3.WebSocket
 import javax.inject.Inject
 import javax.inject.Singleton
+import kotlin.math.pow
 
 @Singleton
 class WebSocketDataSource @Inject constructor(
     @WebSocketOkHttpClient private val client: OkHttpClient,
     private val chatMessageListener: ChatMessageListener,
 ) {
+    val chatMessageFlow: StateFlow<ChatMessageResponse?> = chatMessageListener.chatMessageFlow
+
     private lateinit var chatMessageWebSocket: WebSocket
     private var connectionAttempts = 0
 
-    fun connectWebSocket(): Result<Unit> {
-        return try {
+    suspend fun connectWebSocket(): Result<Unit> = withContext(Dispatchers.IO) {
+        try {
             val chatMessageRequest: Request = Request.Builder()
                 .url(BuildConfig.CARE_WEBSOCKET_URL)
                 .build()
@@ -29,6 +35,8 @@ class WebSocketDataSource @Inject constructor(
             Result.success(Unit)
         } catch (e: Exception) {
             if (connectionAttempts < MAX_RETRY_ATTEMPTS) {
+                val waitTime = minOf(calculateBackoffTime(connectionAttempts), MAX_WAIT_TIME)
+                delay(waitTime)
                 connectionAttempts++
                 connectWebSocket()
             } else {
@@ -48,9 +56,11 @@ class WebSocketDataSource @Inject constructor(
         }
     }
 
-    fun getChatMessageFlow(): StateFlow<ChatMessageResponse?> = chatMessageListener.chatMessageFlow
+    private fun calculateBackoffTime(attempt: Int): Long =
+        (2.0.pow(attempt) * 1000).toLong()
 
     companion object {
         private const val MAX_RETRY_ATTEMPTS = 5
+        private const val MAX_WAIT_TIME = 10_000L // 10 seconds
     }
 }