Compare etags before updating

Author: marcosholgado

app/src/main/java/com/duckduckgo/app/global/db/AppDatabase.kt

@@ -410,6 +410,7 @@ class MigrationsProvider(
             database.execSQL("DELETE FROM tds_domain_entity")
             database.execSQL("DELETE FROM tds_entity")
             database.execSQL("DELETE FROM tds_tracker")
+            database.execSQL("DELETE FROM tdsMetadata")
         }
     }
 

app/src/main/java/com/duckduckgo/app/trackerdetection/api/TrackerDataDownloader.kt

@@ -22,6 +22,7 @@ import com.duckduckgo.app.global.filterBlankItems
 import com.duckduckgo.app.global.store.BinaryDataStore
 import com.duckduckgo.app.trackerdetection.Client.ClientName.*
 import com.duckduckgo.app.trackerdetection.TrackerDataLoader
+import com.duckduckgo.app.trackerdetection.db.TdsMetadataDao
 import com.duckduckgo.app.trackerdetection.db.TdsTrackerDao
 import com.duckduckgo.app.trackerdetection.db.TemporaryTrackingWhitelistDao
 import com.duckduckgo.app.trackerdetection.model.TemporaryTrackingWhitelistedDomain
@@ -34,9 +35,9 @@ class TrackerDataDownloader @Inject constructor(
     private val trackerListService: TrackerListService,
     private val binaryDataStore: BinaryDataStore,
     private val trackerDataLoader: TrackerDataLoader,
-    private val tdsTrackerDao: TdsTrackerDao,
     private val temporaryTrackingWhitelistDao: TemporaryTrackingWhitelistDao,
-    private val appDatabase: AppDatabase
+    private val appDatabase: AppDatabase,
+    private val metadataDao: TdsMetadataDao
 ) {
 
     fun downloadTds(): Completable {
@@ -51,17 +52,16 @@ class TrackerDataDownloader @Inject constructor(
             if (!response.isSuccessful) {
                 throw IOException("Status: ${response.code()} - ${response.errorBody()?.string()}")
             }
-            if (response.isCached && tdsTrackerDao.count() != 0) {
-                Timber.d("Tds data already cached and stored")
-                return@fromAction
-            }
 
-            Timber.d("Updating tds data from server")
             val body = response.body()!!
             val eTag = response.headers()["eTag"]?.removeSurrounding("W/\"", "\"").orEmpty() // removes weak eTag validator
-            appDatabase.runInTransaction {
-                trackerDataLoader.persistTds(eTag, body)
-                trackerDataLoader.loadTrackers()
+            val oldEtag = metadataDao.eTag()
+            if (eTag != oldEtag) {
+                Timber.d("Updating tds data from server")
+                appDatabase.runInTransaction {
+                    trackerDataLoader.persistTds(eTag, body)
+                    trackerDataLoader.loadTrackers()
+                }
             }
         }
     }