Migrated to locally-assigned RecipientId's.

Oh boy.

src/org/thoughtcrime/securesms/recipients/LiveRecipientCache.java

@@ -0,0 +1,62 @@
+package org.thoughtcrime.securesms.recipients;
+
+import android.annotation.SuppressLint;
+import android.content.Context;
+
+import androidx.annotation.AnyThread;
+import androidx.annotation.NonNull;
+import androidx.annotation.WorkerThread;
+import androidx.lifecycle.MutableLiveData;
+
+import org.thoughtcrime.securesms.database.DatabaseFactory;
+import org.thoughtcrime.securesms.database.RecipientDatabase;
+import org.thoughtcrime.securesms.util.LRUCache;
+import org.thoughtcrime.securesms.util.TextSecurePreferences;
+import org.thoughtcrime.securesms.util.concurrent.SignalExecutors;
+
+import java.util.Map;
+
+public final class LiveRecipientCache {
+
+
+  private final Context                         context;
+  private final RecipientDatabase               recipientDatabase;
+  private final Map<RecipientId, LiveRecipient> recipients;
+  private final LiveRecipient                   unknown;
+
+  private RecipientId localRecipientId;
+
+  @SuppressLint("UseSparseArrays")
+  public LiveRecipientCache(@NonNull Context context) {
+    this.context           = context.getApplicationContext();
+    this.recipientDatabase = DatabaseFactory.getRecipientDatabase(context);
+    this.recipients        = new LRUCache<>(1000);
+    this.unknown           = new LiveRecipient(context, new MutableLiveData<>(), Recipient.UNKNOWN);
+  }
+
+  @AnyThread
+  synchronized @NonNull LiveRecipient getLive(@NonNull RecipientId id) {
+    if (id.isUnknown()) return unknown;
+
+    LiveRecipient live = recipients.get(id);
+
+    if (live == null) {
+      final LiveRecipient newLive = new LiveRecipient(context, new MutableLiveData<>(), new Recipient(id));
+
+      recipients.put(id, newLive);
+      SignalExecutors.BOUNDED.execute(newLive::resolve);
+
+      live = newLive;
+    }
+
+    return live;
+  }
+
+  synchronized @NonNull Recipient getSelf() {
+    if (localRecipientId == null) {
+      localRecipientId = recipientDatabase.getOrInsertFromE164(TextSecurePreferences.getLocalNumber(context));
+    }
+
+    return getLive(localRecipientId).resolve();
+  }
+}