Improved Performance and Added Documentation

AnkiDroid/build.gradle

@@ -329,9 +329,6 @@ dependencies {
     androidTestImplementation 'androidx.test.ext:junit:1.1.3'
     androidTestImplementation 'androidx.test:rules:1.4.0'
 
-    // GSON
-    implementation 'com.google.code.gson:gson:2.9.0'
-
     // Work Manager
     implementation "androidx.work:work-runtime-ktx:2.7.1"
 }

AnkiDroid/src/main/java/com/ichi2/anki/AnkiDroidApp.java

@@ -428,7 +428,7 @@ public static String getWebViewErrorMessage() {
     private void setupDeckMetaDataWorker() {
         Timber.tag("META").e("Setting up deck meta data worker...");
 
-        PeriodicWorkRequest deckMetaDataWorker = new PeriodicWorkRequest.Builder(DeckMetaDataWorker.class, 2, TimeUnit.MINUTES)
+        PeriodicWorkRequest deckMetaDataWorker = new PeriodicWorkRequest.Builder(DeckMetaDataWorker.class, 30, TimeUnit.MINUTES)
                 .addTag(DeckMetaDataWorker.DECK_META_WORKER)
                 .build();
 
@@ -438,6 +438,9 @@ private void setupDeckMetaDataWorker() {
                         ExistingPeriodicWorkPolicy.REPLACE,
                         deckMetaDataWorker
                 );
+
+        // Does the required work in setting up new Worker.
+        DeckMetaDataWorker.Companion.setupNewWorker(this);
     }
 
 

AnkiDroid/src/main/java/com/ichi2/anki/DeckMetaDataPreference.kt

@@ -18,41 +18,109 @@ package com.ichi2.anki
 
 import android.content.Context
 import android.content.SharedPreferences
-import com.google.gson.Gson
+import androidx.core.content.edit
 import com.ichi2.anki.worker.DeckMetaDataWorker
+import com.ichi2.utils.JSONException
+import com.ichi2.utils.JSONObject
 import timber.log.Timber
 
 class DeckMetaDataPreference(context: Context) {
 
     private val sharedPreferences: SharedPreferences =
         context.getSharedPreferences("DeckMetaData", Context.MODE_PRIVATE)
 
+    /**
+     * Use this to store data in shared preference.
+     * @param key The Key of value. Used in fetching the data.
+     * @param value Value that needs to be stored <b>(VALUE MUST BE STRING)</b>.
+     * */
     fun putString(key: String, value: String) {
-        sharedPreferences.edit()
-            .putString(key, value)
-            .apply()
+        sharedPreferences.edit {
+            putString(key, value)
+            apply()
+        }
     }
 
+    /**
+     * Use this to fetch string from shared preference.
+     * @prams The Key of deck whose data you want to fetch.
+     * @return Value that needs to be fetched <b>(VALUE WILL BE STRING)</b>.
+     * */
     fun getString(key: String, default: String): String {
         return sharedPreferences.getString(key, default)!!
     }
 
+    /**
+     * Use this to store int in shared preference.
+     * @param key The Key of value. Created while storing the data.
+     * @param value Value that needs to be stored <b>(VALUE MUST BE INTEGER)</b>.
+     * */
+    fun putInt(key: String, value: Int) {
+        sharedPreferences.edit {
+            putInt(key, value)
+            apply()
+        }
+    }
+
+    /**
+     * Use this to fetch integer from shared preference.
+     * @prams The Key of deck whose data you want to fetch.
+     * @return Value that needs to be fetched <b>(VALUE WILL BE INTEGER)</b>.
+     * */
+    fun getInt(key: String, default: Int): Int {
+        return sharedPreferences.getInt(key, default)
+    }
+
+    /**
+     * Use this to store meta data in shared preference.
+     * @param key The Key of deck whose data you want to fetch. (deck id is the for deck)
+     * @param value Object of Metadata Model
+     * */
     fun setMetaData(key: String, value: DeckMetaDataWorker.Meta) {
-        val json: String = Gson().toJson(value)
-        sharedPreferences.edit()
-            .putString(key, json)
-            .apply()
+        val jsonObject = JSONObject()
+
+        try {
+            jsonObject.put("did", value.did)
+            jsonObject.put("deckName", value.deckName)
+            jsonObject.put("new", value.new)
+            jsonObject.put("lrn", value.lrn)
+            jsonObject.put("rev", value.rev)
+            jsonObject.put("eta", value.eta)
+        } catch (e: JSONException) {
+            Timber.tag("META").e(e)
+            return
+        }
+
+        val json = jsonObject.toString()
+
+        sharedPreferences.edit {
+            putString(key, json)
+            apply()
+        }
         Timber.tag("META").e(json)
     }
 
+    /**
+     * Use this to fetch meta data from shared preference if Deck ID (did) is known.
+     * @prams The Key of deck whose data you want to fetch. (deck id is the for deck)
+     * @return Object of Metadata Model.
+     * */
     fun getMetaData(key: String): DeckMetaDataWorker.Meta? {
         val jsonData = sharedPreferences
             .getString(key, null)
 
         return if (jsonData == null) {
             null
         } else {
-            Gson().fromJson(jsonData, DeckMetaDataWorker.Meta::class.java)
+            val jsonObject = JSONObject(jsonData)
+            return DeckMetaDataWorker.Meta(
+                jsonObject.getLong("did"),
+                jsonObject.getString("deckName"),
+                jsonObject.getInt("new"),
+                jsonObject.getInt("lrn"),
+                jsonObject.getInt("rev"),
+                jsonObject.getInt("eta"),
+            )
         }
     }
 }

AnkiDroid/src/main/java/com/ichi2/anki/worker/DeckMetaDataWorker.kt

@@ -21,7 +21,9 @@ import androidx.work.Worker
 import androidx.work.WorkerParameters
 import com.ichi2.anki.CollectionHelper
 import com.ichi2.anki.DeckMetaDataPreference
+import com.ichi2.libanki.Collection
 import com.ichi2.libanki.sched.Counts
+import com.ichi2.libanki.sched.DeckDueTreeNode
 import timber.log.Timber
 
 /**
@@ -31,18 +33,27 @@ import timber.log.Timber
  * */
 class DeckMetaDataWorker(val context: Context, workerParameters: WorkerParameters) : Worker(context, workerParameters) {
 
-    private lateinit var colHelper: CollectionHelper
+    // Lambda to check the collection is not null.
+    private val mCollection: (context: Context) -> Collection? = {
+        val collection = CollectionHelper.getInstance()
+        if (collection.getColSafe(it) != null) {
+            collection.getCol(it)
+        } else {
+            null
+        }
+    }
 
     override fun doWork(): Result {
 
-        colHelper = CollectionHelper.getInstance()
+        val date = CollectionHelper.getInstance().getTimeSafe(context).currentDate
 
-        Timber.tag("META").e("Deck Meta Data Worker started at: ${colHelper.getTimeSafe(context).currentDate}")
+        Timber.tag("META").e("Deck Meta Data Worker started at: $date")
 
         // Update the data of Deck Metadata from HERE
-        val col = colHelper.getCol(context)
-        val deckList = col.sched.deckDueList()
+        val deckList: List<DeckDueTreeNode?> =
+            mCollection(context)?.sched?.deckDueList() ?: return Result.failure()
 
+        val sched = mCollection(context)?.sched ?: return Result.failure()
         deckList.forEach {
             val new = it?.newCount ?: -1
             val lrn = it?.lrnCount ?: -1
@@ -53,19 +64,21 @@ class DeckMetaDataWorker(val context: Context, workerParameters: WorkerParameter
                 new,
                 lrn,
                 rev,
-                col.sched.eta(Counts(new, lrn, rev), false)
+                sched.eta(Counts(new, lrn, rev), false)
             )
             storeInPreference(data)
         }
 
-        updateLastFetch(colHelper.getTimeSafe(context).toString())
+        updateLastFetch(date.toString())
 
         return Result.success() // Done work successfully...
     }
 
     private fun updateLastFetch(time: String) {
         val metaPreference = DeckMetaDataPreference(context)
         metaPreference.putString(LAST_FETCH_TIME, time)
+        val prevData = metaPreference.getInt(TIMES_FETCHED, 0)
+        metaPreference.putInt(TIMES_FETCHED, prevData + 1)
     }
 
     /**
@@ -74,6 +87,8 @@ class DeckMetaDataWorker(val context: Context, workerParameters: WorkerParameter
     private fun storeInPreference(list: Meta) {
         val metaPreference = DeckMetaDataPreference(context)
         metaPreference.setMetaData(list.did.toString(), list)
+        val data = metaPreference.getMetaData(list.did.toString())
+        data.toString()
     }
 
     data class Meta(
@@ -88,5 +103,17 @@ class DeckMetaDataWorker(val context: Context, workerParameters: WorkerParameter
     companion object {
         const val DECK_META_WORKER = "DeckMetaData"
         const val LAST_FETCH_TIME = "LAST_FETCH"
+        const val TIMES_FETCHED = "TIMES_FETCHED"
+        const val WORKER_CREATED = "WORKER_CREATED"
+
+        fun setupNewWorker(context: Context) {
+            Timber.tag("META").e("Setting up Preference for new Worker.")
+
+            val time = CollectionHelper.getInstance().getTimeSafe(context)
+
+            val metaDataPreference = DeckMetaDataPreference(context)
+            metaDataPreference.putString(WORKER_CREATED, time.currentDate.toString())
+            metaDataPreference.putInt(TIMES_FETCHED, 0)
+        }
     }
 }