Core: V4 write direction wrappers

api/src/main/java/org/apache/iceberg/ManifestFile.java

@@ -29,6 +29,12 @@
 public interface ManifestFile {
   int PARTITION_SUMMARIES_ELEMENT_ID = 508;
 
+  /** Value of {@link #formatVersion()} for v4 manifest files. */
+  int V4_FORMAT_VERSION = 4;
+
+  /** Value of {@link #formatVersion()} for pre-v4 manifest files (v1, v2, and v3). */
+  int LEGACY_FORMAT_VERSION = 0;
+
   Types.NestedField PATH =
       required(500, "manifest_path", Types.StringType.get(), "Location URI with FS scheme");
   Types.NestedField LENGTH =
@@ -186,6 +192,26 @@ default boolean hasDeletedFiles() {
   /** Returns the total number of rows in all files with status DELETED in the manifest file. */
   Long deletedRowsCount();
 
+  /**
+   * Returns the number of files with status REPLACED in the manifest file, or null if not tracked.
+   *
+   * <p>REPLACED files are the prior-state entries of v4 REPLACED/MODIFIED pairs and are not live.
+   * Returns null for manifest files written by pre-v4 writers.
+   */
+  default Integer replacedFilesCount() {
+    return null;
+  }
+
+  /**
+   * Returns the total number of rows in all files with status REPLACED in the manifest file, or
+   * null if not tracked.
+   *
+   * <p>Returns null for manifest files written by pre-v4 writers.
+   */
+  default Long replacedRowsCount() {
+    return null;
+  }
+
   /**
    * Returns a list of {@link PartitionFieldSummary partition field summaries}.
    *
@@ -210,6 +236,19 @@ default Long firstRowId() {
     return null;
   }
 
+  /** Returns the number of records in the manifest file, or {@code null} for pre-v4 manifests. */
+  default Long recordCount() {
+    return null;
+  }
+
+  /**
+   * Returns the format version of the manifest file, or {@link #LEGACY_FORMAT_VERSION} for pre-v4
+   * manifests.
+   */
+  default int formatVersion() {
+    return LEGACY_FORMAT_VERSION;
+  }
+
   /**
    * Copies this {@link ManifestFile manifest file}. Readers can reuse manifest file instances; use
    * this method to make defensive copies.