Add DataLockAPI.java

api/src/main/java/com/alttd/DataLockAPI.java

@@ -0,0 +1,31 @@
+package com.alttd;
+
+import org.jetbrains.annotations.ApiStatus;
+
+public interface DataLockAPI {
+
+    static DataLockAPI get() {
+        return Provider.instance;
+    }
+
+    final class Provider {
+        private static DataLockAPI instance = null;
+
+        @ApiStatus.Internal
+        static void register(DataLockAPI instance) {
+            if (Provider.instance != null)
+                throw new UnsupportedOperationException("Cannot redefine singleton");
+
+            Provider.instance = instance;
+        }
+    }
+
+    void tryLock(String channel, String data);
+
+    void tryUnlock(String channel, String data);
+
+    void registerChannel(String channel);
+
+    boolean isActiveChannel(String channel);
+
+}