fix(calendar): cancel blocking HTTP calls

Author: alvin000009238

android/app/src/main/java/com/clhs/score/data/InterruptibleHttp.kt

@@ -1,9 +1,13 @@
 package com.clhs.score.data
 
+import kotlinx.coroutines.CancellationException
 import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.Job
 import kotlinx.coroutines.currentCoroutineContext
 import kotlinx.coroutines.ensureActive
 import kotlinx.coroutines.runInterruptible
+import okhttp3.Call
+import okhttp3.Response
 import java.io.InterruptedIOException
 
 internal suspend fun <T> runInterruptibleHttp(block: () -> T): T = try {
@@ -12,3 +16,14 @@ internal suspend fun <T> runInterruptibleHttp(block: () -> T): T = try {
     currentCoroutineContext().ensureActive()
     throw error
 }
+
+internal suspend fun <T> Call.executeCancellable(block: (Response) -> T): T {
+    val cancellation = currentCoroutineContext()[Job]?.invokeOnCompletion { cause ->
+        if (cause is CancellationException) cancel()
+    }
+    return try {
+        runInterruptibleHttp { execute().use(block) }
+    } finally {
+        cancellation?.dispose()
+    }
+}

android/app/src/main/java/com/clhs/score/data/SchoolCalendar.kt

@@ -60,17 +60,17 @@ class NetworkSchoolCalendarRepository(
         readCache()
     }
 
-    suspend fun load(forceRefresh: Boolean): SchoolCalendarSnapshot = runInterruptibleHttp {
+    suspend fun load(forceRefresh: Boolean): SchoolCalendarSnapshot {
         val now = nowProvider()
-        val cached = readCache()
+        val cached = runInterruptibleHttp { readCache() }
         if (!forceRefresh && cached != null &&
             Duration.between(cached.fetchedAt, now).let { !it.isNegative && it <= CACHE_MAX_AGE }
         ) {
-            return@runInterruptibleHttp cached
+            return cached
         }
 
         val request = Request.Builder().url(feedUrl).get().build()
-        client.newCall(request).execute().use { response ->
+        return client.newCall(request).executeCancellable { response ->
             if (!response.isSuccessful) {
                 throw IOException("Calendar request failed with HTTP ${response.code}")
             }