feat(inspect): expand MetadataTable framework for all 16 metadata table types

src/iceberg/inspect/metadata_table.cc

@@ -35,6 +35,13 @@ MetadataTable::MetadataTable(std::shared_ptr<Table> source_table,
 
 MetadataTable::~MetadataTable() = default;
 
+bool MetadataTable::supports_time_travel() const noexcept { return false; }
+
+Result<ArrowArray> MetadataTable::Scan(
+    std::optional<SnapshotSelection> /* snapshot_selection */) {
+  return NotSupported("Scan is not supported for this metadata table type");
+}
+
 Result<std::unique_ptr<MetadataTable>> MetadataTable::Make(std::shared_ptr<Table> table,
                                                            Kind kind) {
   if (table == nullptr) [[unlikely]] {
@@ -46,9 +53,24 @@ Result<std::unique_ptr<MetadataTable>> MetadataTable::Make(std::shared_ptr<Table
       return SnapshotsTable::Make(table);
     case Kind::kHistory:
       return HistoryTable::Make(table);
+    case Kind::kEntries:
+    case Kind::kFiles:
+    case Kind::kDataFiles:
+    case Kind::kDeleteFiles:
+    case Kind::kMetadataLogEntries:
+    case Kind::kRefs:
+    case Kind::kManifests:
+    case Kind::kPartitions:
+    case Kind::kAllDataFiles:
+    case Kind::kAllDeleteFiles:
+    case Kind::kAllFiles:
+    case Kind::kAllManifests:
+    case Kind::kAllEntries:
+    case Kind::kPositionDeletes:
+      return NotSupported("Metadata table type not yet implemented");
   }
 
-  return NotSupported("Unsupported metadata table type");
+  return NotSupported("Unknown metadata table type");
 }
 
 }  // namespace iceberg

src/iceberg/inspect/metadata_table.h

@@ -20,20 +20,48 @@
 #pragma once
 
 #include <memory>
+#include <optional>
+#include <string>
 
+#include "iceberg/arrow_c_data.h"
 #include "iceberg/iceberg_export.h"
 #include "iceberg/result.h"
 #include "iceberg/table_identifier.h"
 #include "iceberg/type_fwd.h"
+#include "iceberg/util/timepoint.h"
 
 namespace iceberg {
 
+/// \brief Parameters for snapshot selection (time travel).
+struct SnapshotSelection {
+  /// \brief The snapshot ID to read.
+  std::optional<int64_t> snapshot_id;
+  /// \brief Read the snapshot that was current at this timestamp.
+  std::optional<TimePointMs> as_of_timestamp;
+  /// \brief Read the snapshot referenced by this named ref (branch or tag).
+  std::optional<std::string> ref_name;
+};
+
 /// \brief Base class for Iceberg metadata tables.
 class ICEBERG_EXPORT MetadataTable {
  public:
   enum class Kind {
-    kSnapshots,
+    kEntries,
+    kFiles,
+    kDataFiles,
+    kDeleteFiles,
     kHistory,
+    kMetadataLogEntries,
+    kSnapshots,
+    kRefs,
+    kManifests,
+    kPartitions,
+    kAllDataFiles,
+    kAllDeleteFiles,
+    kAllFiles,
+    kAllManifests,
+    kAllEntries,
+    kPositionDeletes,
   };
 
   static Result<std::unique_ptr<MetadataTable>> Make(std::shared_ptr<Table> table,
@@ -43,6 +71,24 @@ class ICEBERG_EXPORT MetadataTable {
 
   virtual Kind kind() const noexcept = 0;
 
+  /// \brief Whether this metadata table supports time-travel queries.
+  ///
+  /// The default implementation returns false. Subclasses that support
+  /// reading historical snapshots should override to return true.
+  virtual bool supports_time_travel() const noexcept;
+
+  /// \brief Scan the metadata table and return all rows as an Arrow struct array.
+  ///
+  /// The returned ArrowArray is a struct array where each element is one row.
+  /// The caller takes ownership and must call ArrowArrayRelease when done.
+  ///
+  /// \param snapshot_selection optional snapshot selection for time travel.
+  ///        Pass std::nullopt to use the current snapshot.
+  ///
+  /// The default implementation returns NotSupported. Subclasses override this
+  /// to materialize their data.
+  virtual Result<ArrowArray> Scan(std::optional<SnapshotSelection> snapshot_selection);
+
   const TableIdentifier& name() const { return identifier_; }
 
   const std::shared_ptr<Schema>& schema() const { return schema_; }

src/iceberg/test/metadata_table_test.cc

@@ -19,6 +19,8 @@
 
 #include "iceberg/inspect/metadata_table.h"
 
+#include <vector>
+
 #include <gmock/gmock.h>
 #include <gtest/gtest.h>
 
@@ -117,4 +119,61 @@ TEST_F(MetadataTableTest, FactoryRejectsNullSourceTable) {
   EXPECT_THAT(result, HasErrorMessage("Table cannot be null"));
 }
 
+TEST_F(MetadataTableTest, AllKindEnumValues) {
+  // Verify all 16 Kind enum values are present and distinct.
+  EXPECT_EQ(static_cast<int>(MetadataTable::Kind::kEntries), 0);
+  EXPECT_EQ(static_cast<int>(MetadataTable::Kind::kFiles), 1);
+  EXPECT_EQ(static_cast<int>(MetadataTable::Kind::kDataFiles), 2);
+  EXPECT_EQ(static_cast<int>(MetadataTable::Kind::kDeleteFiles), 3);
+  EXPECT_EQ(static_cast<int>(MetadataTable::Kind::kHistory), 4);
+  EXPECT_EQ(static_cast<int>(MetadataTable::Kind::kMetadataLogEntries), 5);
+  EXPECT_EQ(static_cast<int>(MetadataTable::Kind::kSnapshots), 6);
+  EXPECT_EQ(static_cast<int>(MetadataTable::Kind::kRefs), 7);
+  EXPECT_EQ(static_cast<int>(MetadataTable::Kind::kManifests), 8);
+  EXPECT_EQ(static_cast<int>(MetadataTable::Kind::kPartitions), 9);
+  EXPECT_EQ(static_cast<int>(MetadataTable::Kind::kAllDataFiles), 10);
+  EXPECT_EQ(static_cast<int>(MetadataTable::Kind::kAllDeleteFiles), 11);
+  EXPECT_EQ(static_cast<int>(MetadataTable::Kind::kAllFiles), 12);
+  EXPECT_EQ(static_cast<int>(MetadataTable::Kind::kAllManifests), 13);
+  EXPECT_EQ(static_cast<int>(MetadataTable::Kind::kAllEntries), 14);
+  EXPECT_EQ(static_cast<int>(MetadataTable::Kind::kPositionDeletes), 15);
+}
+
+TEST_F(MetadataTableTest, UnimplementedKindsReturnNotSupported) {
+  // All new (not-yet-implemented) kinds should return NotSupported from the factory.
+  std::vector<MetadataTable::Kind> unimplemented = {
+      MetadataTable::Kind::kEntries,
+      MetadataTable::Kind::kFiles,
+      MetadataTable::Kind::kDataFiles,
+      MetadataTable::Kind::kDeleteFiles,
+      MetadataTable::Kind::kMetadataLogEntries,
+      MetadataTable::Kind::kRefs,
+      MetadataTable::Kind::kManifests,
+      MetadataTable::Kind::kPartitions,
+      MetadataTable::Kind::kAllDataFiles,
+      MetadataTable::Kind::kAllDeleteFiles,
+      MetadataTable::Kind::kAllFiles,
+      MetadataTable::Kind::kAllManifests,
+      MetadataTable::Kind::kAllEntries,
+      MetadataTable::Kind::kPositionDeletes,
+  };
+
+  for (auto kind : unimplemented) {
+    auto result = MetadataTable::Make(source_table_, kind);
+    EXPECT_THAT(result, IsError(ErrorKind::kNotSupported))
+        << "Kind " << static_cast<int>(kind) << " should return NotSupported";
+  }
+}
+
+TEST_F(MetadataTableTest, DefaultSupportsTimeTravelReturnsFalse) {
+  // The base class default implementation should return false.
+  EXPECT_FALSE(snapshots_table_->supports_time_travel());
+}
+
+TEST_F(MetadataTableTest, DefaultScanReturnsNotSupported) {
+  // The base class default Scan() should return NotSupported.
+  auto result = snapshots_table_->Scan(std::nullopt);
+  EXPECT_THAT(result, IsError(ErrorKind::kNotSupported));
+}
+
 }  // namespace iceberg