Spec: add task-type field to JSON serialization of scan task. add JSO…

…N serialization for StaticDataTask.

core/src/main/java/org/apache/iceberg/DataTaskParser.java

@@ -0,0 +1,80 @@
+/*
+ * 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 com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.databind.JsonNode;
+import java.io.IOException;
+import org.apache.iceberg.relocated.com.google.common.base.Preconditions;
+import org.apache.iceberg.util.JsonUtil;
+
+class DataTaskParser {
+  private static final String SCHEMA = "schema";
+  private static final String PROJECTED_SCHEMA = "projection";
+  private static final String METADATA_FILE = "metadata-file";
+  private static final String ROWS = "rows";
+
+  private DataTaskParser() {}
+
+  static void toJson(StaticDataTask dataTask, JsonGenerator generator) throws IOException {
+    Preconditions.checkArgument(dataTask != null, "Invalid data task: null");
+    Preconditions.checkArgument(generator != null, "Invalid JSON generator: null");
+
+    generator.writeFieldName(SCHEMA);
+    SchemaParser.toJson(dataTask.schema(), generator);
+
+    generator.writeFieldName(PROJECTED_SCHEMA);
+    SchemaParser.toJson(dataTask.projectedSchema(), generator);
+
+    generator.writeFieldName(METADATA_FILE);
+    ContentFileParser.toJson(dataTask.metadataFile(), PartitionSpec.unpartitioned(), generator);
+
+    generator.writeArrayFieldStart(ROWS);
+    for (StructLike row : dataTask.tableRows()) {
+      SingleValueParser.toJson(dataTask.schema().asStruct(), row, generator);
+    }
+
+    generator.writeEndArray();
+  }
+
+  static StaticDataTask fromJson(JsonNode jsonNode) {
+    Preconditions.checkArgument(jsonNode != null, "Invalid JSON node for data task: null");
+    Preconditions.checkArgument(
+        jsonNode.isObject(), "Invalid JSON node for data task: non-object (%s)", jsonNode);
+
+    Schema schema = SchemaParser.fromJson(JsonUtil.get(SCHEMA, jsonNode));
+    Schema projectedSchema = SchemaParser.fromJson(JsonUtil.get(PROJECTED_SCHEMA, jsonNode));
+    DataFile metadataFile =
+        (DataFile)
+            ContentFileParser.fromJson(
+                JsonUtil.get(METADATA_FILE, jsonNode), PartitionSpec.unpartitioned());
+
+    JsonNode rowsArray = jsonNode.get(ROWS);
+    Preconditions.checkArgument(
+        rowsArray.isArray(), "Invalid JSON node for rows: non-array (%s)", rowsArray);
+
+    StructLike[] rows = new StructLike[rowsArray.size()];
+    for (int i = 0; i < rowsArray.size(); ++i) {
+      JsonNode rowNode = rowsArray.get(i);
+      rows[i] = (StructLike) SingleValueParser.fromJson(schema.asStruct(), rowNode);
+    }
+
+    return new StaticDataTask(metadataFile, schema, projectedSchema, rows);
+  }
+}

core/src/main/java/org/apache/iceberg/FileScanTaskParser.java

@@ -40,16 +40,32 @@ public class FileScanTaskParser {
 
   private FileScanTaskParser() {}
 
+  /**
+   * Serialize file scan task to JSON string
+   *
+   * @deprecated Use {@link ScanTaskParser#toJson(FileScanTask)} instead; will be removed in 1.7.0
+   */
+  @Deprecated
   public static String toJson(FileScanTask fileScanTask) {
-    return JsonUtil.generate(
-        generator -> FileScanTaskParser.toJson(fileScanTask, generator), false);
+    Preconditions.checkArgument(fileScanTask != null, "Invalid file scan task: null");
+    return JsonUtil.generate(generator -> toJson(fileScanTask, generator), false);
+  }
+
+  /**
+   * Deserialize file scan task from JSON string
+   *
+   * @deprecated Use {@link ScanTaskParser#fromJson(String, boolean)} instead; will be removed in
+   *     1.7.0
+   */
+  @Deprecated
+  public static FileScanTask fromJson(String json, boolean caseSensitive) {
+    Preconditions.checkArgument(json != null, "Invalid JSON string for file scan task: null");
+    return JsonUtil.parse(json, node -> fromJson(node, caseSensitive));
   }
 
-  private static void toJson(FileScanTask fileScanTask, JsonGenerator generator)
-      throws IOException {
+  static void toJson(FileScanTask fileScanTask, JsonGenerator generator) throws IOException {
     Preconditions.checkArgument(fileScanTask != null, "Invalid file scan task: null");
     Preconditions.checkArgument(generator != null, "Invalid JSON generator: null");
-    generator.writeStartObject();
 
     generator.writeFieldName(SCHEMA);
     SchemaParser.toJson(fileScanTask.schema(), generator);
@@ -78,16 +94,9 @@ private static void toJson(FileScanTask fileScanTask, JsonGenerator generator)
       generator.writeFieldName(RESIDUAL);
       ExpressionParser.toJson(fileScanTask.residual(), generator);
     }
-
-    generator.writeEndObject();
-  }
-
-  public static FileScanTask fromJson(String json, boolean caseSensitive) {
-    Preconditions.checkArgument(json != null, "Invalid JSON string for file scan task: null");
-    return JsonUtil.parse(json, node -> FileScanTaskParser.fromJson(node, caseSensitive));
   }
 
-  private static FileScanTask fromJson(JsonNode jsonNode, boolean caseSensitive) {
+  static FileScanTask fromJson(JsonNode jsonNode, boolean caseSensitive) {
     Preconditions.checkArgument(jsonNode != null, "Invalid JSON node for file scan task: null");
     Preconditions.checkArgument(
         jsonNode.isObject(), "Invalid JSON node for file scan task: non-object (%s)", jsonNode);

core/src/main/java/org/apache/iceberg/ScanTaskParser.java

@@ -0,0 +1,104 @@
+/*
+ * 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 com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.databind.JsonNode;
+import java.io.IOException;
+import org.apache.iceberg.relocated.com.google.common.base.Preconditions;
+import org.apache.iceberg.relocated.com.google.common.base.Strings;
+import org.apache.iceberg.util.JsonUtil;
+
+public class ScanTaskParser {
+  private static final String TASK_TYPE = "task-type";
+
+  private enum TaskType {
+    FILE_SCAN_TASK("file-scan-task"),
+    DATA_TASK("data-task");
+
+    private final String value;
+
+    TaskType(String value) {
+      this.value = value;
+    }
+
+    public static TaskType fromValue(String value) {
+      Preconditions.checkArgument(value != null, "Task type is null");
+      if (FILE_SCAN_TASK.value().equalsIgnoreCase(value)) {
+        return FILE_SCAN_TASK;
+      } else if (DATA_TASK.value().equalsIgnoreCase(value)) {
+        return DATA_TASK;
+      } else {
+        throw new IllegalArgumentException("Unknown task type: " + value);
+      }
+    }
+
+    public String value() {
+      return value;
+    }
+  }
+
+  private ScanTaskParser() {}
+
+  public static String toJson(FileScanTask fileScanTask) {
+    Preconditions.checkArgument(fileScanTask != null, "Invalid file scan task: null");
+    return JsonUtil.generate(generator -> toJson(fileScanTask, generator), false);
+  }
+
+  public static FileScanTask fromJson(String json, boolean caseSensitive) {
+    Preconditions.checkArgument(json != null, "Invalid JSON string for file scan task: null");
+    return JsonUtil.parse(json, node -> fromJson(node, caseSensitive));
+  }
+
+  private static void toJson(FileScanTask fileScanTask, JsonGenerator generator)
+      throws IOException {
+    generator.writeStartObject();
+
+    if (fileScanTask instanceof StaticDataTask) {
+      generator.writeStringField(TASK_TYPE, TaskType.DATA_TASK.value());
+      DataTaskParser.toJson((StaticDataTask) fileScanTask, generator);
+    } else if (fileScanTask instanceof BaseFileScanTask
+        || fileScanTask instanceof BaseFileScanTask.SplitScanTask) {
+      generator.writeStringField(TASK_TYPE, TaskType.FILE_SCAN_TASK.value());
+      FileScanTaskParser.toJson(fileScanTask, generator);
+    } else {
+      throw new UnsupportedOperationException(
+          "Unsupported task type: " + fileScanTask.getClass().getCanonicalName());
+    }
+
+    generator.writeEndObject();
+  }
+
+  private static FileScanTask fromJson(JsonNode jsonNode, boolean caseSensitive) {
+    TaskType taskType = TaskType.FILE_SCAN_TASK;
+    String taskTypeStr = JsonUtil.getStringOrNull(TASK_TYPE, jsonNode);
+    if (!Strings.isNullOrEmpty(taskTypeStr)) {
+      taskType = TaskType.fromValue(taskTypeStr);
+    }
+
+    switch (taskType) {
+      case FILE_SCAN_TASK:
+        return FileScanTaskParser.fromJson(jsonNode, caseSensitive);
+      case DATA_TASK:
+        return DataTaskParser.fromJson(jsonNode);
+      default:
+        throw new UnsupportedOperationException("Unsupported task type: " + taskType.value());
+    }
+  }
+}

core/src/main/java/org/apache/iceberg/SnapshotsTable.java

@@ -19,6 +19,7 @@
 package org.apache.iceberg;
 
 import org.apache.iceberg.io.CloseableIterable;
+import org.apache.iceberg.relocated.com.google.common.annotations.VisibleForTesting;
 import org.apache.iceberg.types.Types;
 
 /**
@@ -27,7 +28,8 @@
  * <p>This does not include snapshots that have been expired using {@link ExpireSnapshots}.
  */
 public class SnapshotsTable extends BaseMetadataTable {
-  private static final Schema SNAPSHOT_SCHEMA =
+  @VisibleForTesting
+  static final Schema SNAPSHOT_SCHEMA =
       new Schema(
           Types.NestedField.required(1, "committed_at", Types.TimestampType.withZone()),
           Types.NestedField.required(2, "snapshot_id", Types.LongType.get()),
@@ -94,7 +96,8 @@ public CloseableIterable<FileScanTask> planFiles() {
     }
   }
 
-  private static StaticDataTask.Row snapshotToRow(Snapshot snap) {
+  @VisibleForTesting
+  static StaticDataTask.Row snapshotToRow(Snapshot snap) {
     return StaticDataTask.Row.of(
         snap.timestampMillis() * 1000,
         snap.snapshotId(),

core/src/main/java/org/apache/iceberg/StaticDataTask.java

@@ -64,6 +64,19 @@ private StaticDataTask(
     this.rows = rows;
   }
 
+  StaticDataTask(
+      DataFile metadataFile, Schema tableSchema, Schema projectedSchema, StructLike[] rows) {
+    this.tableSchema = tableSchema;
+    this.projectedSchema = projectedSchema;
+    this.metadataFile = metadataFile;
+    this.rows = rows;
+  }
+
+  @Override
+  public Schema schema() {
+    return tableSchema;
+  }
+
   @Override
   public List<DeleteFile> deletes() {
     return ImmutableList.of();
@@ -106,6 +119,19 @@ public Iterable<FileScanTask> split(long splitSize) {
     return ImmutableList.of(this);
   }
 
+  Schema projectedSchema() {
+    return projectedSchema;
+  }
+
+  DataFile metadataFile() {
+    return metadataFile;
+  }
+
+  /** @return the full table row before projection */
+  StructLike[] tableRows() {
+    return rows;
+  }
+
   /** Implements {@link StructLike#get} for passing static rows. */
   static class Row implements StructLike, Serializable {
     public static Row of(Object... values) {