Add EXPIRATION_TIME property flag and new debug flags (#798)

Author: greenrobot

objectbox-java/src/main/java/io/objectbox/DebugFlags.java

@@ -33,5 +33,15 @@ private DebugFlags() { }
   public static final int LOG_CACHE_HITS = 32;
   public static final int LOG_CACHE_ALL = 64;
   public static final int LOG_TREE = 128;
+  /**
+   * For a limited number of error conditions, this will try to print stack traces.
+   * Note: this is Linux-only, experimental, and has several limitations:
+   * The usefulness of these stack traces depends on several factors and might not be helpful at all.
+   */
+  public static final int LOG_EXCEPTION_STACK_TRACE = 256;
+  /**
+   * Run a quick self-test to verify basic threading; somewhat paranoia to check the platform and the library setup.
+   */
+  public static final int RUN_THREADING_SELF_TEST = 512;
 }
 

objectbox-java/src/main/java/io/objectbox/model/PropertyFlags.java

@@ -97,5 +97,11 @@ private PropertyFlags() { }
    * Unique on-conflict strategy: the object being put replaces any existing conflicting object (deletes it).
    */
   public static final int UNIQUE_ON_CONFLICT_REPLACE = 32768;
+  /**
+   * If a date property has this flag (max. one per entity type), the date value specifies the time by which
+   * the object expires, at which point it MAY be deleted. There's no strict guarantee when the deletion happens.
+   * However, the deletion process can be triggered by an API call.
+   */
+  public static final int EXPIRATION_TIME = 65536;
 }