feat(inspect): Add base class for metadata table support

Author: All-less

src/iceberg/CMakeLists.txt

@@ -42,6 +42,9 @@ set(ICEBERG_SOURCES
     expression/term.cc
     file_reader.cc
     file_writer.cc
+    inspect/history_table.cc
+    inspect/metadata_table_factory.cc
+    inspect/snapshots_table.cc
     inheritable_metadata.cc
     json_serde.cc
     location_provider.cc
@@ -57,6 +60,7 @@ set(ICEBERG_SOURCES
     manifest/v2_metadata.cc
     manifest/v3_metadata.cc
     metadata_columns.cc
+    inspect/metadata_table.cc
     metrics_config.cc
     name_mapping.cc
     partition_field.cc

src/iceberg/inspect/history_table.cc

@@ -0,0 +1,56 @@
+/*
+ * 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.
+ */
+
+#include "iceberg/inspect/history_table.h"
+
+#include <memory>
+#include <utility>
+
+#include "iceberg/inspect/metadata_table.h"
+#include "iceberg/schema.h"
+#include "iceberg/schema_field.h"
+#include "iceberg/table_identifier.h"
+#include "iceberg/type.h"
+
+namespace iceberg {
+
+HistoryTable::HistoryTable(std::shared_ptr<Table> table)
+    : BaseMetadataTable(table, CreateName(table->name()), CreateSchema()) {}
+
+HistoryTable::~HistoryTable() = default;
+
+std::shared_ptr<Schema> HistoryTable::CreateSchema() {
+  return std::make_shared<Schema>(
+      std::vector<SchemaField>{
+          SchemaField::MakeRequired(1, "made_current_at", int64()),
+          SchemaField::MakeRequired(2, "snapshot_id", int64()),
+          SchemaField::MakeOptional(3, "parent_id", int64()),
+          SchemaField::MakeRequired(4, "is_current_ancestor", boolean())},
+      1);
+}
+
+TableIdentifier HistoryTable::CreateName(const TableIdentifier& source_name) {
+  return TableIdentifier{source_name.ns, source_name.name + ".history"};
+}
+
+Result<std::shared_ptr<HistoryTable>> HistoryTable::Make(std::shared_ptr<Table> table) {
+  return std::shared_ptr<HistoryTable>(new HistoryTable(table));
+}
+
+}  // namespace iceberg

src/iceberg/inspect/history_table.h

@@ -0,0 +1,57 @@
+/*
+ * 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.
+ */
+
+#pragma once
+
+#include <memory>
+
+#include "iceberg/iceberg_export.h"
+#include "iceberg/inspect/metadata_table.h"
+#include "iceberg/result.h"
+#include "iceberg/table.h"
+
+namespace iceberg {
+
+/// \brief History metadata table
+///
+/// History is based on the table's snapshot log, which logs each update
+/// to the table's current snapshot. Each row has columns:
+/// - made_current_at (long, timestamp)
+/// - snapshot_id (long)
+/// - parent_id (long, optional)
+/// - is_current_ancestor (bool)
+class ICEBERG_EXPORT HistoryTable : public BaseMetadataTable {
+ public:
+  /// \brief Create a HistoryTable from table metadata
+  ///
+  /// \param[in] table The source table
+  /// \return A HistoryTable instance or error status
+  static Result<std::shared_ptr<HistoryTable>> Make(std::shared_ptr<Table> table);
+
+  ~HistoryTable() override;
+
+ private:
+  HistoryTable(std::shared_ptr<Table> table);
+
+  std::shared_ptr<Schema> CreateSchema();
+
+  TableIdentifier CreateName(const TableIdentifier& source_name);
+};
+
+}  // namespace iceberg

src/iceberg/inspect/metadata_table.cc

@@ -0,0 +1,87 @@
+/*
+ * 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.
+ */
+
+#include "iceberg/inspect/metadata_table.h"
+
+#include <memory>
+#include <string>
+#include <utility>
+
+#include "iceberg/file_io.h"
+#include "iceberg/schema.h"
+#include "iceberg/schema_field.h"
+#include "iceberg/table_identifier.h"
+#include "iceberg/table_metadata.h"
+#include "iceberg/table_scan.h"
+#include "iceberg/type.h"
+#include "iceberg/util/uuid.h"
+
+namespace iceberg {
+
+BaseMetadataTable::BaseMetadataTable(std::shared_ptr<Table> source_table,
+                                     TableIdentifier identifier,
+                                     std::shared_ptr<Schema> schema)
+    : Table(identifier, source_table->metadata(),
+            std::string(source_table->metadata_file_location()), source_table->io(),
+            source_table->catalog()),
+      source_table_(std::move(source_table)),
+      schema_(schema) {
+  uuid_ = Uuid::GenerateV4().ToString();
+  schemas_[schema->schema_id()] = schema;
+}
+
+BaseMetadataTable::~BaseMetadataTable() = default;
+
+Status BaseMetadataTable::Refresh() {
+  return NotSupported("Cannot refresh a metadata table");
+}
+
+Result<std::unique_ptr<TableScanBuilder>> BaseMetadataTable::NewScan() const {
+  return NotSupported("TODO: Scanning metadata tables is not yet supported");
+};
+
+Result<std::shared_ptr<Transaction>> BaseMetadataTable::NewTransaction() {
+  return NotSupported("Cannot create a transaction for a metadata table");
+}
+
+Result<std::shared_ptr<UpdateProperties>> BaseMetadataTable::NewUpdateProperties() {
+  return NotSupported("Cannot create an update properties for a metadata table");
+}
+
+Result<std::shared_ptr<UpdateSchema>> BaseMetadataTable::NewUpdateSchema() {
+  return NotSupported("Cannot create an update schema for a metadata table");
+}
+
+Result<std::shared_ptr<UpdateLocation>> BaseMetadataTable::NewUpdateLocation() {
+  return NotSupported("Cannot create an update location for a metadata table");
+}
+
+Result<std::shared_ptr<UpdatePartitionSpec>> BaseMetadataTable::NewUpdatePartitionSpec() {
+  return NotSupported("Cannot create an update partition spec for a metadata table");
+}
+
+Result<std::shared_ptr<UpdateSortOrder>> BaseMetadataTable::NewUpdateSortOrder() {
+  return NotSupported("Cannot create an update sort order for a metadata table");
+}
+
+Result<std::shared_ptr<ExpireSnapshots>> BaseMetadataTable::NewExpireSnapshots() {
+  return NotSupported("Cannot create an expire snapshots for a metadata table");
+}
+
+}  // namespace iceberg