refactor: request rate reduction (#646)

* refactor: reduce off screen page limit to reduce preemptive loading

* refactor: add last sync marker for syncing local - remote user state

* chore: minor refactoring and optimisations

* chore: add documentation to public APIs

* refactor: add `getModel` to ActivityBase

app/src/main/assets/changelog.md

@@ -6,7 +6,7 @@ Read the **FAQ** for issues regarding NSFW and notifications. Goto **Options** -
 ## What's Changed
 
 ### Enhancements
-- Reduce the number of items loaded per page, hopefully will result in less request timeouts
+- Additional optimizations to reduce the number of requests should result in slightly lower rate limit issues
 
 ### Current Issues
 - Gifs may show artifacts if more than one is playing at a given moment (with experimental markdown support in settings)

app/src/main/java/com/mxt/anitrend/base/custom/activity/ActivityBase.java

@@ -21,6 +21,7 @@
 import androidx.core.app.ActivityCompat;
 import androidx.core.content.ContextCompat;
 import androidx.lifecycle.Observer;
+import androidx.lifecycle.ViewModelProvider;
 import androidx.lifecycle.ViewModelProviders;
 
 import com.miguelcatalan.materialsearchview.MaterialSearchView;
@@ -73,7 +74,7 @@ public abstract class ActivityBase<M, P extends CommonPresenter> extends AppComp
 
     protected long id;
 
-    protected int offScreenLimit = 3;
+    protected int offScreenLimit = 2;
     protected boolean disableNavigationStyle;
     protected static final int REQUEST_PERMISSION = 102;
 
@@ -366,7 +367,8 @@ protected ViewModelBase<M> getViewModel() {
     @SuppressWarnings("unchecked")
     protected void setViewModel(boolean stateSupported) {
         if(viewModel == null) {
-            viewModel = ViewModelProviders.of(this).get(ViewModelBase.class);
+            ViewModelProvider provider = new ViewModelProvider(this);
+            viewModel = provider.get(ViewModelBase.class);
             viewModel.setContext(this);
             if(!viewModel.getModel().hasActiveObservers())
                 viewModel.getModel().observe(this, this);
@@ -375,6 +377,11 @@ protected void setViewModel(boolean stateSupported) {
         }
     }
 
+    @Nullable
+    protected M getModel() {
+        return viewModel != null ? viewModel.snapshot() : null;
+    }
+
     /**
      * Called when the model state is changed.
      *

app/src/main/java/com/mxt/anitrend/base/custom/fragment/FragmentBase.java

@@ -19,6 +19,7 @@
 import androidx.fragment.app.Fragment;
 import androidx.lifecycle.Lifecycle;
 import androidx.lifecycle.Observer;
+import androidx.lifecycle.ViewModelProvider;
 import androidx.lifecycle.ViewModelProviders;
 
 import com.annimon.stream.IntPair;
@@ -229,7 +230,8 @@ public ViewModelBase<VM> getViewModel() {
     @SuppressWarnings("unchecked")
     protected void setViewModel(boolean stateSupported) {
         if(viewModel == null) {
-            viewModel = ViewModelProviders.of(this).get(ViewModelBase.class);
+            ViewModelProvider provider = new ViewModelProvider(this);
+            viewModel = provider.get(ViewModelBase.class);
             viewModel.setContext(getContext());
             if(!viewModel.getModel().hasActiveObservers())
                 viewModel.getModel().observe(this, this);

app/src/main/java/com/mxt/anitrend/base/custom/view/image/AvatarIndicatorView.kt

@@ -47,7 +47,6 @@ class AvatarIndicatorView : FrameLayout, CustomView, View.OnClickListener, BaseC
         get() = presenter.database?.currentUser
 
     private lateinit var binding: WidgetAvatarIndicatorBinding
-    private var mLastSynced: Long = 0
 
     override fun onInit() {
         binding = WidgetAvatarIndicatorBinding.inflate(context.getLayoutInflater(), this, true)
@@ -76,8 +75,6 @@ class AvatarIndicatorView : FrameLayout, CustomView, View.OnClickListener, BaseC
     @Subscribe(threadMode = ThreadMode.MAIN_ORDERED)
     override fun onModelChanged(consumer: BaseConsumer<User>) {
         if (consumer.requestMode == KeyUtil.USER_CURRENT_REQ) {
-            if (DateUtil.timeDifferenceSatisfied(KeyUtil.TIME_UNIT_MINUTES, mLastSynced, 15))
-                mLastSynced = System.currentTimeMillis()
             checkLastSyncTime()
         }
     }

app/src/main/java/com/mxt/anitrend/base/custom/viewmodel/ViewModelBase.kt

@@ -33,6 +33,11 @@ class ViewModelBase<T>: ViewModel(), RetroCallback<T> {
 
     val params = Bundle()
 
+    /**
+     * @return A live data snapshot value [T]? at the time this function is invoked
+     */
+    fun snapshot(): T? = model.value
+
     fun setContext(context: Context?) {
         context?.apply {
             emptyMessage = getString(R.string.layout_empty_response)

app/src/main/java/com/mxt/anitrend/presenter/base/BasePresenter.kt

@@ -35,6 +35,23 @@ open class BasePresenter(context: Context?) : CommonPresenter(context) {
     private var favouriteYears: List<String>? = null
     private var favouriteFormats: List<String>? = null
 
+    /**
+     * Avoids running a delegate if the specified interval time has not elapsed since the last
+     * call of this function
+     *
+     * @param intervalInMinutes time interval in minutes
+     * @param action delegate to invoke if the the time interval has elapsed since the last run
+     *
+     * @see KeyUtil.TIME_UNIT_MINUTES
+     */
+    inline fun updateUserLastSyncTimeStampIf(intervalInMinutes: Int = 15, action: () -> Unit) {
+        val lastSyncedAt = settings.lastUserSyncTime
+        if (DateUtil.timeDifferenceSatisfied(KeyUtil.TIME_UNIT_MINUTES, lastSyncedAt, intervalInMinutes)) {
+            action()
+            settings.lastUserSyncTime = System.currentTimeMillis()
+        }
+    }
+
     @IdRes
     fun getNavigationItem(): Int {
         return when (settings.startupPage) {

app/src/main/java/com/mxt/anitrend/util/Settings.kt

@@ -341,6 +341,14 @@ class Settings(
             }
         }
 
+    var lastUserSyncTime: Long
+        get() = getLong(_lastUserSyncTime, 0)
+        set(value) {
+            edit {
+                putLong(_lastUserSyncTime, value)
+            }
+        }
+
     fun saveSeasonYear(year: Int) {
         edit {
             putInt(KeyUtil.arg_seasonYear, year)
@@ -391,5 +399,6 @@ class Settings(
         private const val _reviewSort = "_reviewSort"
         private const val _staffSort = "_staffSort"
         private const val _experimentalMarkdown = "_experimentalMarkdown"
+        private const val _lastUserSyncTime = "_lastUserSyncTime"
     }
 }

app/src/main/java/com/mxt/anitrend/util/graphql/AniGraphErrorUtil.kt

@@ -13,8 +13,6 @@ private const val HTTP_LIMIT_REACHED = 429
 
 private const val TAG = "ErrorUtil"
 private const val Retry_After = "Retry-After"
-private const val RateLimit_Limit = "X-RateLimit-Limit"
-private const val RateLimit_Remaining = "X-RateLimit-Remaining"
 
 /**
  * Converts the response error response into an object.
@@ -28,16 +26,18 @@ fun Response<*>?.apiError(): String {
             val headers = headers()
             val errors = getError()
             return if (code() != HTTP_LIMIT_REACHED) {
-                errors?.firstOrNull()?.message ?: "Unable to provide information regarding error!"
-            } else
-                "${headers.get(RateLimit_Remaining)} of ${headers.get(RateLimit_Limit)} requests remaining, please retry after ${headers.get(Retry_After)} seconds"
+                errors?.firstOrNull()?.message ?: "Unexpected HTTP/${code()} from server"
+            } else {
+                val waitPeriod = headers.get(Retry_After) ?: 60
+                "Too many requests, please retry after $waitPeriod seconds"
+            }
         }
     } catch (ex: Exception) {
         ex.printStackTrace()
         Timber.tag(TAG).e(ex)
-        return "Unexpected error encountered"
+        return "Unable to recover from encountered error"
     }
 
-    return "Unable to provide information regarding error!"
+    return "Unable to provide information regarding error"
 }
 

app/src/main/java/com/mxt/anitrend/view/activity/detail/CharacterActivity.java

@@ -40,8 +40,6 @@ public class CharacterActivity extends ActivityBase<CharacterBase, BasePresenter
     protected @BindView(R.id.smart_tab) SmartTabLayout smartTabLayout;
     protected @BindView(R.id.coordinator) CoordinatorLayout coordinatorLayout;
 
-    private CharacterBase model;
-
     private FavouriteToolbarWidget favouriteWidget;
 
     @Override
@@ -71,6 +69,7 @@ public boolean onCreateOptionsMenu(Menu menu) {
         if(isAuth) {
             MenuItem favouriteMenuItem = menu.findItem(R.id.action_favourite);
             favouriteWidget = (FavouriteToolbarWidget) favouriteMenuItem.getActionView();
+            CharacterBase model = getModel();
             if(model != null)
                 favouriteWidget.setModel(model);
         }
@@ -79,6 +78,7 @@ public boolean onCreateOptionsMenu(Menu menu) {
 
     @Override
     public boolean onOptionsItemSelected(MenuItem item) {
+        CharacterBase model = getModel();
         if(model != null) {
             switch (item.getItemId()) {
                 case R.id.action_share:
@@ -111,14 +111,15 @@ protected void onActivityReady() {
     @Override
     protected void onResume() {
         super.onResume();
-        if(model == null)
+        if(getModel() == null)
             makeRequest();
         else
             updateUI();
     }
 
     @Override
     protected void updateUI() {
+        CharacterBase model = getModel();
         if(model != null)
             if(favouriteWidget != null)
                 favouriteWidget.setModel(model);
@@ -141,7 +142,6 @@ protected void makeRequest() {
     @Override
     public void onChanged(@Nullable CharacterBase model) {
         super.onChanged(model);
-        this.model = model;
         updateUI();
     }
 }

app/src/main/java/com/mxt/anitrend/view/activity/detail/MediaActivity.java

@@ -47,7 +47,6 @@
 public class MediaActivity extends ActivityBase<MediaBase, MediaPresenter> implements View.OnClickListener {
 
     private ActivitySeriesBinding binding;
-    private MediaBase model;
 
     private @KeyUtil.MediaType String mediaType;
 
@@ -87,6 +86,7 @@ public boolean onCreateOptionsMenu(Menu menu) {
         getMenuInflater().inflate(R.menu.media_base_menu, menu);
         menu.findItem(R.id.action_favourite).setVisible(isAuth);
 
+        MediaBase model = getModel();
         malMenuItem = menu.findItem(R.id.action_mal);
         malMenuItem.setVisible(model != null && model.getIdMal() > 0);
 
@@ -104,6 +104,7 @@ public boolean onCreateOptionsMenu(Menu menu) {
 
     @Override
     public boolean onOptionsItemSelected(MenuItem item) {
+        MediaBase model = getModel();
         if(model != null) {
             switch (item.getItemId()) { 
                 case R.id.action_manage:
@@ -153,14 +154,15 @@ protected void onActivityReady() {
     @Override
     protected void onResume() {
         super.onResume();
-        if(model == null)
+        if(getModel() == null)
             makeRequest();
         else
             updateUI();
     }
 
     @Override
     protected void updateUI() {
+        MediaBase model = getModel();
         if(model != null) {
             binding.setModel(model);
             binding.setOnClickListener(this);
@@ -196,15 +198,17 @@ protected void makeRequest() {
     @Override
     public void onChanged(@Nullable MediaBase model) {
         super.onChanged(model);
-        this.model = model;
         updateUI();
     }
 
     @Override
     public void onClick(View view) {
         switch (view.getId()) {
             case R.id.series_banner:
-                CompatUtil.INSTANCE.imagePreview(view, model.getBannerImage(), R.string.image_preview_error_series_banner);
+                MediaBase model = getModel();
+                if (model != null) {
+                    CompatUtil.INSTANCE.imagePreview(view, model.getBannerImage(), R.string.image_preview_error_series_banner);
+                }
                 break;
         }
     }
@@ -217,6 +221,7 @@ protected void onDestroy() {
     }
 
     private void setMenuItemIcons() {
+        MediaBase model = getModel();
         if (model != null) {
             if (model.getMediaListEntry() != null && manageMenuItem != null)
                 manageMenuItem.setIcon(CompatUtil.INSTANCE.getDrawable(this, R.drawable.ic_mode_edit_white_24dp));
@@ -226,6 +231,7 @@ private void setMenuItemIcons() {
     }
 
     private void setFavouriteWidgetMenuItemIcon() {
+        MediaBase model = getModel();
         if(model != null && favouriteWidget != null)
             favouriteWidget.setModel(model);
     }

app/src/main/java/com/mxt/anitrend/view/activity/detail/MediaListActivity.java

@@ -86,7 +86,7 @@ protected void onActivityReady() {
     @Override
     protected void updateUI() {
         viewPager.setAdapter(pageAdapter);
-        viewPager.setOffscreenPageLimit(offScreenLimit + 2);
+        viewPager.setOffscreenPageLimit(offScreenLimit);
         smartTabLayout.setViewPager(viewPager);
     }
 

app/src/main/java/com/mxt/anitrend/view/activity/detail/ProfileActivity.java

@@ -18,6 +18,7 @@
 import com.mxt.anitrend.base.custom.consumer.BaseConsumer;
 import com.mxt.anitrend.base.custom.view.image.WideImageView;
 import com.mxt.anitrend.databinding.ActivityProfileBinding;
+import com.mxt.anitrend.model.entity.base.StaffBase;
 import com.mxt.anitrend.model.entity.base.UserBase;
 import com.mxt.anitrend.presenter.base.BasePresenter;
 import com.mxt.anitrend.util.CompatUtil;
@@ -47,7 +48,6 @@ public class ProfileActivity extends ActivityBase<UserBase, BasePresenter> imple
 
     private ActivityProfileBinding binding;
     private String userName;
-    private UserBase model;
 
     @Override
     protected void onCreate(@Nullable Bundle savedInstanceState) {
@@ -84,7 +84,7 @@ protected void onPostCreate(@Nullable Bundle savedInstanceState) {
     @Override
     protected void onPostResume() {
         super.onPostResume();
-        if(model == null)
+        if(getModel() == null)
             onActivityReady();
         else
             updateUI();
@@ -100,6 +100,7 @@ public boolean onCreateOptionsMenu(Menu menu) {
 
     @Override
     public boolean onOptionsItemSelected(MenuItem item) {
+        UserBase model = getModel();
         switch (item.getItemId()) {
             case R.id.action_notification:
                 startActivity(new Intent(ProfileActivity.this, NotificationActivity.class));
@@ -150,6 +151,7 @@ protected void onActivityReady() {
     protected void updateUI() {
         binding.setOnClickListener(this);
         binding.profileStatsWidget.setParams(getIntent().getExtras());
+        UserBase model = getModel();
         WideImageView.setImage(binding.profileBanner, model.getBannerImage());
         if(getPresenter().isCurrentUser(model.getId())) {
             new TutorialUtil().setContext(this)
@@ -191,7 +193,6 @@ public void onChanged(@Nullable UserBase model) {
         super.onChanged(model);
         if(model != null) {
             this.id = model.getId();
-            this.model = model;
             updateUI();
         } else
             NotifyUtil.INSTANCE.createAlerter(this, R.string.text_user_model, R.string.layout_empty_response, R.drawable.ic_warning_white_18dp, R.color.colorStateRed);
@@ -201,7 +202,10 @@ public void onChanged(@Nullable UserBase model) {
     public void onClick(View view) {
         switch (view.getId()) {
             case R.id.profile_banner:
-                CompatUtil.INSTANCE.imagePreview(view, model.getBannerImage(), R.string.image_preview_error_profile_banner);
+                UserBase model = getModel();
+                if (model != null) {
+                    CompatUtil.INSTANCE.imagePreview(view, model.getBannerImage(), R.string.image_preview_error_profile_banner);
+                }
                 break;
         }
     }