Add jgvariant-ostree module.

Change-Id: Idf7bacad28d7cf65eb1ddd0994dcc2c2c2a7e18e
diff --git a/jgvariant-ostree/src/main/java/eu/mulk/jgvariant/ostree/FileMeta.java b/jgvariant-ostree/src/main/java/eu/mulk/jgvariant/ostree/FileMeta.java
new file mode 100644
index 0000000..19e0677
--- /dev/null
+++ b/jgvariant-ostree/src/main/java/eu/mulk/jgvariant/ostree/FileMeta.java
@@ -0,0 +1,25 @@
+package eu.mulk.jgvariant.ostree;
+
+import eu.mulk.jgvariant.core.Decoder;
+import java.nio.ByteOrder;
+import java.util.List;
+
+/**
+ * Permission bits and extended attributes for a file.
+ *
+ * <p>Reference: {@code ostree-core.h#OSTREE_FILEMETA_GVARIANT_STRING}
+ */
+public record FileMeta(int uid, int gid, int mode, List<Xattr> xattrs) {
+
+  private static final Decoder<FileMeta> DECODER =
+      Decoder.ofStructure(
+          FileMeta.class,
+          Decoder.ofInt().withByteOrder(ByteOrder.BIG_ENDIAN),
+          Decoder.ofInt().withByteOrder(ByteOrder.BIG_ENDIAN),
+          Decoder.ofInt().withByteOrder(ByteOrder.BIG_ENDIAN),
+          Decoder.ofArray(Xattr.decoder()));
+
+  public static Decoder<FileMeta> decoder() {
+    return DECODER;
+  }
+}