Remove footer constants from OnDiskSequentialGraphIndexWriter in favor of ones in AbstractGraphIndexWriter (#535)

Author: michaeljmarshall

jvector-base/src/main/java/io/github/jbellis/jvector/graph/disk/OnDiskGraphIndex.java

@@ -52,7 +52,9 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import static io.github.jbellis.jvector.graph.disk.OnDiskSequentialGraphIndexWriter.*;
+import static io.github.jbellis.jvector.graph.disk.AbstractGraphIndexWriter.FOOTER_MAGIC;
+import static io.github.jbellis.jvector.graph.disk.AbstractGraphIndexWriter.FOOTER_MAGIC_SIZE;
+import static io.github.jbellis.jvector.graph.disk.AbstractGraphIndexWriter.FOOTER_OFFSET_SIZE;
 
 /**
  * A class representing a graph index stored on disk. The base graph contains only graph structure.

jvector-base/src/main/java/io/github/jbellis/jvector/graph/disk/OnDiskSequentialGraphIndexWriter.java

@@ -54,10 +54,6 @@
  * </ul>
  */
 public class OnDiskSequentialGraphIndexWriter extends AbstractGraphIndexWriter<IndexWriter> {
-    public static final int FOOTER_MAGIC = 0x4a564244; // "EOF magic"
-    public static final int FOOTER_OFFSET_SIZE = Long.BYTES; // The size of the offset in the footer
-    public static final int FOOTER_MAGIC_SIZE = Integer.BYTES; // The size of the magic number in the footer
-    public static final int FOOTER_SIZE = FOOTER_MAGIC_SIZE + FOOTER_OFFSET_SIZE; // The total size of the footer
 
     OnDiskSequentialGraphIndexWriter(IndexWriter out,
                                              int version,