feat: convert iceberg schema to arrow schema

cmake_modules/IcebergThirdpartyToolchain.cmake

@@ -23,9 +23,9 @@ set(ICEBERG_ARROW_INSTALL_INTERFACE_LIBS)
 # ----------------------------------------------------------------------
 # Versions and URLs for toolchain builds
 
-set(ICEBERG_ARROW_BUILD_VERSION "18.1.0")
+set(ICEBERG_ARROW_BUILD_VERSION "19.0.1")
 set(ICEBERG_ARROW_BUILD_SHA256_CHECKSUM
-    "2dc8da5f8796afe213ecc5e5aba85bb82d91520eff3cf315784a52d0fa61d7fc")
+    "acb76266e8b0c2fbb7eb15d542fbb462a73b3fd1e32b80fad6c2fafd95a51160")
 
 if(DEFINED ENV{ICEBERG_ARROW_URL})
   set(ARROW_SOURCE_URL "$ENV{ICEBERG_ARROW_URL}")

src/iceberg/CMakeLists.txt

@@ -22,6 +22,7 @@ set(ICEBERG_SOURCES
     demo.cc
     schema.cc
     schema_field.cc
+    schema_internal.cc
     type.cc)
 
 set(ICEBERG_STATIC_BUILD_INTERFACE_LIBS)

src/iceberg/arrow_c_data.h

@@ -29,10 +29,15 @@
 
 #include <cstdint>
 
+extern "C" {
+
 #ifndef ARROW_C_DATA_INTERFACE
 #  define ARROW_C_DATA_INTERFACE
 
-extern "C" {
+#  define ARROW_FLAG_DICTIONARY_ORDERED 1
+#  define ARROW_FLAG_NULLABLE 2
+#  define ARROW_FLAG_MAP_KEYS_SORTED 4
+
 struct ArrowSchema {
   // Array type description
   const char* format;
@@ -66,6 +71,6 @@ struct ArrowArray {
   void* private_data;
 };
 
-}  // extern "C"
-
 #endif  // ARROW_C_DATA_INTERFACE
+
+}  // extern "C"

src/iceberg/error.h

@@ -32,6 +32,8 @@ enum class ErrorKind {
   kAlreadyExists,
   kNoSuchTable,
   kCommitStateUnknown,
+  kInvalidSchema,
+  kInvalidArgument,
 };
 
 /// \brief Error with a kind and a message.

src/iceberg/schema_field.h

@@ -64,7 +64,7 @@ class ICEBERG_EXPORT SchemaField : public iceberg::util::Formattable {
   /// \brief Get whether the field is optional.
   [[nodiscard]] bool optional() const;
 
-  [[nodiscard]] std::string ToString() const;
+  [[nodiscard]] std::string ToString() const override;
 
   friend bool operator==(const SchemaField& lhs, const SchemaField& rhs) {
     return lhs.Equals(rhs);

src/iceberg/schema_internal.cc

@@ -0,0 +1,193 @@
+/*
+ * 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/schema_internal.h"
+
+#include <format>
+#include <optional>
+#include <string>
+
+#include "iceberg/expected.h"
+#include "iceberg/schema.h"
+
+namespace iceberg {
+
+namespace {
+
+constexpr const char* kArrowExtensionName = "ARROW:extension:name";
+constexpr const char* kArrowExtensionMetadata = "ARROW:extension:metadata";
+
+// Convert an Iceberg type to Arrow schema. Return value is Nanoarrow error code.
+ArrowErrorCode ToArrowSchema(const Type& type, bool optional, std::string_view name,
+                             std::optional<int32_t> field_id, ArrowSchema* schema) {
+  ArrowBuffer metadata_buffer;
+  NANOARROW_RETURN_NOT_OK(ArrowMetadataBuilderInit(&metadata_buffer, nullptr));
+  if (field_id.has_value()) {
+    NANOARROW_RETURN_NOT_OK(ArrowMetadataBuilderAppend(
+        &metadata_buffer, ArrowCharView(std::string(kFieldIdKey).c_str()),
+        ArrowCharView(std::to_string(field_id.value()).c_str())));
+  }
+
+  switch (type.type_id()) {
+    case TypeId::kStruct: {
+      NANOARROW_RETURN_NOT_OK(ArrowSchemaInitFromType(schema, NANOARROW_TYPE_STRUCT));
+
+      const auto& struct_type = static_cast<const StructType&>(type);
+      const auto& fields = struct_type.fields();
+      NANOARROW_RETURN_NOT_OK(ArrowSchemaAllocateChildren(schema, fields.size()));
+
+      for (size_t i = 0; i < fields.size(); i++) {
+        const auto& field = fields[i];
+        NANOARROW_RETURN_NOT_OK(ToArrowSchema(*field.type(), field.optional(),
+                                              field.name(), field.field_id(),
+                                              schema->children[i]));
+      }
+    } break;
+    case TypeId::kList: {
+      NANOARROW_RETURN_NOT_OK(ArrowSchemaInitFromType(schema, NANOARROW_TYPE_LIST));
+
+      const auto& list_type = static_cast<const ListType&>(type);
+      const auto& elem_field = list_type.fields()[0];
+      NANOARROW_RETURN_NOT_OK(ToArrowSchema(*elem_field.type(), elem_field.optional(),
+                                            elem_field.name(), elem_field.field_id(),
+                                            schema->children[0]));
+    } break;
+    case TypeId::kMap: {
+      NANOARROW_RETURN_NOT_OK(ArrowSchemaInitFromType(schema, NANOARROW_TYPE_MAP));
+
+      const auto& map_type = static_cast<const MapType&>(type);
+      const auto& key_field = map_type.key();
+      const auto& value_field = map_type.value();
+      NANOARROW_RETURN_NOT_OK(ToArrowSchema(*key_field.type(), key_field.optional(),
+                                            key_field.name(), key_field.field_id(),
+                                            schema->children[0]->children[0]));
+      NANOARROW_RETURN_NOT_OK(ToArrowSchema(*value_field.type(), value_field.optional(),
+                                            value_field.name(), value_field.field_id(),
+                                            schema->children[0]->children[1]));
+    } break;
+    case TypeId::kBoolean:
+      NANOARROW_RETURN_NOT_OK(ArrowSchemaInitFromType(schema, NANOARROW_TYPE_BOOL));
+      break;
+    case TypeId::kInt:
+      NANOARROW_RETURN_NOT_OK(ArrowSchemaInitFromType(schema, NANOARROW_TYPE_INT32));
+      break;
+    case TypeId::kLong:
+      NANOARROW_RETURN_NOT_OK(ArrowSchemaInitFromType(schema, NANOARROW_TYPE_INT64));
+      break;
+    case TypeId::kFloat:
+      NANOARROW_RETURN_NOT_OK(ArrowSchemaInitFromType(schema, NANOARROW_TYPE_FLOAT));
+      break;
+    case TypeId::kDouble:
+      NANOARROW_RETURN_NOT_OK(ArrowSchemaInitFromType(schema, NANOARROW_TYPE_DOUBLE));
+      break;
+    case TypeId::kDecimal: {
+      ArrowSchemaInit(schema);
+      const auto& decimal_type = static_cast<const DecimalType&>(type);
+      NANOARROW_RETURN_NOT_OK(ArrowSchemaSetTypeDecimal(schema, NANOARROW_TYPE_DECIMAL128,
+                                                        decimal_type.precision(),
+                                                        decimal_type.scale()));
+    } break;
+    case TypeId::kDate:
+      NANOARROW_RETURN_NOT_OK(ArrowSchemaInitFromType(schema, NANOARROW_TYPE_DATE32));
+      break;
+    case TypeId::kTime: {
+      ArrowSchemaInit(schema);
+      NANOARROW_RETURN_NOT_OK(ArrowSchemaSetTypeDateTime(schema, NANOARROW_TYPE_TIME64,
+                                                         NANOARROW_TIME_UNIT_MICRO,
+                                                         /*timezone=*/nullptr));
+    } break;
+    case TypeId::kTimestamp: {
+      ArrowSchemaInit(schema);
+      NANOARROW_RETURN_NOT_OK(ArrowSchemaSetTypeDateTime(schema, NANOARROW_TYPE_TIMESTAMP,
+                                                         NANOARROW_TIME_UNIT_MICRO,
+                                                         /*timezone=*/nullptr));
+    } break;
+    case TypeId::kTimestampTz: {
+      ArrowSchemaInit(schema);
+      NANOARROW_RETURN_NOT_OK(ArrowSchemaSetTypeDateTime(
+          schema, NANOARROW_TYPE_TIMESTAMP, NANOARROW_TIME_UNIT_MICRO, "UTC"));
+    } break;
+    case TypeId::kString:
+      NANOARROW_RETURN_NOT_OK(ArrowSchemaInitFromType(schema, NANOARROW_TYPE_STRING));
+      break;
+    case TypeId::kBinary:
+      NANOARROW_RETURN_NOT_OK(ArrowSchemaInitFromType(schema, NANOARROW_TYPE_BINARY));
+      break;
+    case TypeId::kFixed: {
+      ArrowSchemaInit(schema);
+      const auto& fixed_type = static_cast<const FixedType&>(type);
+      NANOARROW_RETURN_NOT_OK(ArrowSchemaSetTypeFixedSize(
+          schema, NANOARROW_TYPE_FIXED_SIZE_BINARY, fixed_type.length()));
+    } break;
+    case TypeId::kUuid: {
+      ArrowSchemaInit(schema);
+      NANOARROW_RETURN_NOT_OK(ArrowSchemaSetTypeFixedSize(
+          schema, NANOARROW_TYPE_FIXED_SIZE_BINARY, /*fixed_size=*/16));
+      NANOARROW_RETURN_NOT_OK(
+          ArrowMetadataBuilderAppend(&metadata_buffer, ArrowCharView(kArrowExtensionName),
+                                     ArrowCharView("arrow.uuid")));
+    } break;
+  }
+
+  if (!name.empty()) {
+    NANOARROW_RETURN_NOT_OK(ArrowSchemaSetName(schema, std::string(name).c_str()));
+  }
+
+  NANOARROW_RETURN_NOT_OK(ArrowSchemaSetMetadata(
+      schema, reinterpret_cast<const char*>(metadata_buffer.data)));
+  ArrowBufferReset(&metadata_buffer);
+
+  if (optional) {
+    schema->flags |= ARROW_FLAG_NULLABLE;
+  } else {
+    schema->flags &= ~ARROW_FLAG_NULLABLE;
+  }
+
+  return NANOARROW_OK;
+}
+
+}  // namespace
+
+expected<void, Error> ToArrowSchema(const Schema& schema, ArrowSchema* out) {
+  if (out == nullptr) [[unlikely]] {
+    return unexpected<Error>{{.kind = ErrorKind::kInvalidArgument,
+                              .message = "Output Arrow schema cannot be null"}};
+  }
+
+  if (ArrowErrorCode errorCode = ToArrowSchema(schema, /*optional=*/false, /*name=*/"",
+                                               /*field_id=*/std::nullopt, out);
+      errorCode != NANOARROW_OK) {
+    return unexpected<Error>{
+        {.kind = ErrorKind::kInvalidSchema,
+         .message = std::format(
+             "Failed to convert Iceberg schema to Arrow schema, error code: {}",
+             errorCode)}};
+  }
+
+  return {};
+}
+
+expected<std::unique_ptr<Schema>, Error> FromArrowSchema(const ArrowSchema& schema,
+                                                         int32_t schema_id) {
+  // TODO(wgtmac): Implement this
+  return unexpected<Error>{
+      {.kind = ErrorKind::kInvalidSchema, .message = "Not implemented yet"}};
+}
+
+}  // namespace iceberg

src/iceberg/schema_internal.h

@@ -0,0 +1,52 @@
+/*
+ * 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 <nanoarrow/nanoarrow.h>
+
+#include "iceberg/error.h"
+#include "iceberg/expected.h"
+#include "iceberg/type_fwd.h"
+
+namespace iceberg {
+
+// Apache Arrow C++ uses "PARQUET:field_id" to store field IDs for Parquet.
+// Here we follow a similar convention for Iceberg but we might also add
+// "PARQUET:field_id" in the future once we implement a Parquet writer.
+constexpr std::string_view kFieldIdKey = "ICEBERG:field_id";
+
+/// \brief Convert an Iceberg schema to an Arrow schema.
+///
+/// \param[in] schema The Iceberg schema to convert.
+/// \param[out] out The Arrow schema to convert to.
+/// \return An error if the conversion fails.
+expected<void, Error> ToArrowSchema(const Schema& schema, ArrowSchema* out);
+
+/// \brief Convert an Arrow schema to an Iceberg schema.
+///
+/// \param[in] schema The Arrow schema to convert.
+/// \param[in] schema_id The schema ID of the Iceberg schema.
+/// \return The Iceberg schema or an error if the conversion fails.
+expected<std::unique_ptr<Schema>, Error> FromArrowSchema(const ArrowSchema& schema,
+                                                         int32_t schema_id);
+
+}  // namespace iceberg

test/CMakeLists.txt

@@ -30,18 +30,19 @@ add_test(NAME schema_test COMMAND schema_test)
 
 add_executable(expected_test)
 target_sources(expected_test PRIVATE expected_test.cc)
-target_link_libraries(expected_test PRIVATE iceberg_static GTest::gtest_main)
+target_link_libraries(expected_test PRIVATE iceberg_static GTest::gtest_main GTest::gmock)
 add_test(NAME expected_test COMMAND expected_test)
 
 if(ICEBERG_BUILD_BUNDLE)
   add_executable(avro_test)
   target_sources(avro_test PRIVATE avro_test.cc)
-  target_link_libraries(avro_test PRIVATE iceberg_bundle_static GTest::gtest_main)
+  target_link_libraries(avro_test PRIVATE iceberg_bundle_static GTest::gtest_main
+                                          GTest::gmock)
   add_test(NAME avro_test COMMAND avro_test)
 
   add_executable(arrow_test)
   target_sources(arrow_test PRIVATE arrow_test.cc)
   target_link_libraries(arrow_test PRIVATE iceberg_bundle_static Arrow::arrow_static
-                                           GTest::gtest_main)
+                                           GTest::gtest_main GTest::gmock)
   add_test(NAME arrow_test COMMAND arrow_test)
 endif()