Merge branch 'account-cache-retries'

3 files changed, 34 insertions, 13 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8725e50f26..f43e4b1c8f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -59,6 +59,7 @@ Line wrap the file at 100 chars.                                              Th
 - Fix UI losing any settings updates that happen after leaving the app and then coming back.
 - Fix account expiration date disappearing in some circumstances.
 - Fix notification reappearing after quitting the application.
+- Retry when fetching account expiration fails.
 
 
 ## [2020.4] - 2020-05-12
diff --git a/android/src/main/kotlin/net/mullvad/mullvadvpn/service/AccountCache.kt b/android/src/main/kotlin/net/mullvad/mullvadvpn/service/AccountCache.kt
index 07fa7911fc..8cae8baee1 100644
--- a/android/src/main/kotlin/net/mullvad/mullvadvpn/service/AccountCache.kt
+++ b/android/src/main/kotlin/net/mullvad/mullvadvpn/service/AccountCache.kt
@@ -1,5 +1,7 @@
 package net.mullvad.mullvadvpn.service
 
+import kotlin.math.min
+import kotlinx.coroutines.delay
 import net.mullvad.mullvadvpn.model.GetAccountDataResult
 import net.mullvad.mullvadvpn.util.JobTracker
 import org.joda.time.DateTime
@@ -27,24 +29,22 @@ class AccountCache(val daemon: MullvadDaemon, val settingsListener: SettingsList
         }
 
     fun fetchAccountExpiry() {
-        accountNumber?.let { accountNumberUsedForFetch ->
+        accountNumber?.let { account ->
             jobTracker.newBackgroundJob("fetch") {
-                val accountData = accountNumberUsedForFetch?.let { account ->
+                var retryAttempt = 0
+
+                while (onAccountDataChange != null) {
                     val result = daemon.getAccountData(account)
 
-                    when (result) {
-                        is GetAccountDataResult.Ok -> result.accountData
-                        else -> null
+                    if (result is GetAccountDataResult.Ok) {
+                        handleNewExpiry(account, result.accountData.expiry)
+                        break
+                    } else if (result is GetAccountDataResult.InvalidAccount) {
+                        break
                     }
-                }
 
-                synchronized(this@AccountCache) {
-                    if (this@AccountCache.accountNumber === accountNumberUsedForFetch) {
-                        accountData?.expiry?.let { expiry ->
-                            accountExpiry = DateTime.parse(expiry, EXPIRY_FORMAT)
-                            notifyChange()
-                        }
-                    }
+                    retryAttempt += 1
+                    delay(calculateRetryFetchDelay(retryAttempt))
                 }
             }
         }
@@ -65,7 +65,23 @@ class AccountCache(val daemon: MullvadDaemon, val settingsListener: SettingsList
         }
     }
 
+    private fun handleNewExpiry(accountNumberUsedForFetch: String, expiryString: String) {
+        synchronized(this) {
+            if (accountNumber === accountNumberUsedForFetch) {
+                accountExpiry = DateTime.parse(expiryString, EXPIRY_FORMAT)
+                notifyChange()
+            }
+        }
+    }
+
     private fun notifyChange() {
         onAccountDataChange?.invoke(accountNumber, accountExpiry)
     }
+
+    private fun calculateRetryFetchDelay(retryAttempt: Int): Long {
+        // delay in seconds = 2 ^ retryAttempt capped at 2^13 (8192)
+        val exponent = min(retryAttempt, 13)
+
+        return (1L shl exponent) * 1000L
+    }
 }
diff --git a/android/src/main/kotlin/net/mullvad/mullvadvpn/ui/AccountFragment.kt b/android/src/main/kotlin/net/mullvad/mullvadvpn/ui/AccountFragment.kt
index 6d993a8a55..01615b7d7a 100644
--- a/android/src/main/kotlin/net/mullvad/mullvadvpn/ui/AccountFragment.kt
+++ b/android/src/main/kotlin/net/mullvad/mullvadvpn/ui/AccountFragment.kt
@@ -43,6 +43,10 @@ class AccountFragment : ServiceDependentFragment(OnNoService.GoBack) {
     override fun onSafelyResume() {
         accountCache.onAccountDataChange = { accountNumber, accountExpiry ->
             updateViewJob = updateView(accountNumber, accountExpiry)
+
+            if (accountExpiry == null) {
+                accountCache.fetchAccountExpiry()
+            }
         }
     }