[WIP] V4 Manifest Read Support

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

@@ -0,0 +1,58 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.iceberg;
+
+import org.apache.iceberg.types.Types;
+
+/**
+ * Metadata about externally stored content such as deletion vectors.
+ *
+ * <p>The deletion vector content is stored at the specified offset and size within the file
+ * referenced by {@link TrackedFile#location()}.
+ *
+ * <p>This struct must be defined when content_type is POSITION_DELETES, and must be null otherwise.
+ *
+ * <p>Note: For manifest-level deletion vectors (marking entries in a manifest as deleted), see
+ * {@link TrackedFile#manifestDV()} which stores the DV inline as a binary field.
+ */
+public interface ContentInfo {
+  Types.NestedField OFFSET =
+      Types.NestedField.required(
+          144, "offset", Types.LongType.get(), "Offset in the file where the content starts");
+  Types.NestedField SIZE_IN_BYTES =
+      Types.NestedField.required(
+          145,
+          "size_in_bytes",
+          Types.LongType.get(),
+          "Length of the referenced content stored in the file");
+
+  static Types.StructType schema() {
+    return Types.StructType.of(OFFSET, SIZE_IN_BYTES);
+  }
+
+  /**
+   * Returns the offset in the file where the deletion vector content starts.
+   *
+   * <p>The file location is specified in the {@link TrackedFile#location()} field.
+   */
+  long offset();
+
+  /** Returns the size in bytes of the deletion vector content. */
+  long sizeInBytes();
+}

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

@@ -18,11 +18,21 @@
  */
 package org.apache.iceberg;
 
-/** Content type stored in a file, one of DATA, POSITION_DELETES, or EQUALITY_DELETES. */
+/**
+ * Content type stored in a file.
+ *
+ * <p>For V1-V3 tables: DATA, POSITION_DELETES, or EQUALITY_DELETES.
+ *
+ * <p>For V4 tables: DATA, POSITION_DELETES, EQUALITY_DELETES, DATA_MANIFEST, or DELETE_MANIFEST.
+ */
 public enum FileContent {
   DATA(0),
   POSITION_DELETES(1),
-  EQUALITY_DELETES(2);
+  EQUALITY_DELETES(2),
+  /** Data manifest entry (V4+ only) - references data files in a root manifest. */
+  DATA_MANIFEST(3),
+  /** Delete manifest entry (V4+ only) - references delete files in a root manifest. */
+  DELETE_MANIFEST(4);
 
   private final int id;
 

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

@@ -0,0 +1,86 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.iceberg;
+
+import org.apache.iceberg.types.Types;
+
+/**
+ * Statistics for manifest entries in a V4 tracked file.
+ *
+ * <p>This encapsulates added/removed/existing files/row counts and min_sequence_number for a
+ * manifest. This must be defined when the content_type is a manifest (3 or 4), and null otherwise.
+ */
+public interface ManifestStats {
+  Types.NestedField ADDED_FILES_COUNT =
+      Types.NestedField.required(
+          504, "added_files_count", Types.IntegerType.get(), "Number of files added");
+  Types.NestedField EXISTING_FILES_COUNT =
+      Types.NestedField.required(
+          505, "existing_files_count", Types.IntegerType.get(), "Number of existing files");
+  Types.NestedField DELETED_FILES_COUNT =
+      Types.NestedField.required(
+          506, "deleted_files_count", Types.IntegerType.get(), "Number of deleted files");
+  Types.NestedField ADDED_ROWS_COUNT =
+      Types.NestedField.required(
+          512, "added_rows_count", Types.LongType.get(), "Number of rows in added files");
+  Types.NestedField EXISTING_ROWS_COUNT =
+      Types.NestedField.required(
+          513, "existing_rows_count", Types.LongType.get(), "Number of rows in existing files");
+  Types.NestedField DELETED_ROWS_COUNT =
+      Types.NestedField.required(
+          514, "deleted_rows_count", Types.LongType.get(), "Number of rows in deleted files");
+  Types.NestedField MIN_SEQUENCE_NUMBER =
+      Types.NestedField.required(
+          516,
+          "min_sequence_number",
+          Types.LongType.get(),
+          "Minimum sequence number of files in this manifest");
+
+  static Types.StructType schema() {
+    return Types.StructType.of(
+        ADDED_FILES_COUNT,
+        EXISTING_FILES_COUNT,
+        DELETED_FILES_COUNT,
+        ADDED_ROWS_COUNT,
+        EXISTING_ROWS_COUNT,
+        DELETED_ROWS_COUNT,
+        MIN_SEQUENCE_NUMBER);
+  }
+
+  /** Returns the number of files added by this manifest. */
+  int addedFilesCount();
+
+  /** Returns the number of existing files referenced by this manifest. */
+  int existingFilesCount();
+
+  /** Returns the number of deleted files in this manifest. */
+  int deletedFilesCount();
+
+  /** Returns the number of rows in added files. */
+  long addedRowsCount();
+
+  /** Returns the number of rows in existing files. */
+  long existingRowsCount();
+
+  /** Returns the number of rows in deleted files. */
+  long deletedRowsCount();
+
+  /** Returns the minimum sequence number of files in this manifest. */
+  long minSequenceNumber();
+}