cpp/examples/parquet/low_level_api/encryption_reader_writer.cc - arrow - Git at Google

 // 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 <arrow/util/secure_string.h>
 #include <reader_writer.h>

 #include <cassert>
 #include <fstream>
 #include <iostream>
 #include <memory>

 /*
  * This file contains sample for writing and reading encrypted Parquet file with
  * basic encryption configuration.
  *
  * A detailed description of the Parquet Modular Encryption specification can be found
  * here:
  * https://github.com/apache/parquet-format/blob/encryption/Encryption.md
  *
  * The write sample creates a file with eight columns where two of the columns and the
  * footer are encrypted.
  *
  * The read sample decrypts using key retriever that holds the keys of two encrypted
  * columns and the footer key.
  */

 constexpr int NUM_ROWS_PER_ROW_GROUP = 500;
 const char* PARQUET_FILENAME = "parquet_cpp_example.parquet.encrypted";
 const arrow::util::SecureString kFooterEncryptionKey("0123456789012345");
 const arrow::util::SecureString kColumnEncryptionKey1("1234567890123450");
 const arrow::util::SecureString kColumnEncryptionKey2("1234567890123451");

 int main(int argc, char** argv) {
   /**********************************************************************************
                              PARQUET ENCRYPTION WRITER EXAMPLE
   **********************************************************************************/

   try {
     // Create a local file output stream instance.
     using FileClass = ::arrow::io::FileOutputStream;
     std::shared_ptr<FileClass> out_file;
     PARQUET_ASSIGN_OR_THROW(out_file, FileClass::Open(PARQUET_FILENAME));

     // Setup the parquet schema
     std::shared_ptr<GroupNode> schema = SetupSchema();

     // Add encryption properties
     // Encryption configuration: Encrypt two columns and the footer.
     std::map<std::string, std::shared_ptr<parquet::ColumnEncryptionProperties>>
         encryption_cols;

     parquet::SchemaDescriptor schema_desc;
     schema_desc.Init(schema);
     auto column_path1 = schema_desc.Column(5)->path()->ToDotString();
     auto column_path2 = schema_desc.Column(4)->path()->ToDotString();

     encryption_cols[column_path1] =
         parquet::ColumnEncryptionProperties::WithColumnKey(kColumnEncryptionKey1, "kc1");
     encryption_cols[column_path2] =
         parquet::ColumnEncryptionProperties::WithColumnKey(kColumnEncryptionKey2, "kc2");

     parquet::FileEncryptionProperties::Builder file_encryption_builder(
         kFooterEncryptionKey);

     parquet::WriterProperties::Builder builder;
     // Add the current encryption configuration to WriterProperties.
     builder.encryption(file_encryption_builder.footer_key_metadata("kf")
                            ->encrypted_columns(std::move(encryption_cols))
                            ->build());

     // Add other writer properties
     builder.compression(parquet::Compression::SNAPPY);

     std::shared_ptr<parquet::WriterProperties> props = builder.build();

     // Create a ParquetFileWriter instance
     std::shared_ptr<parquet::ParquetFileWriter> file_writer =
         parquet::ParquetFileWriter::Open(out_file, schema, props);

     // Append a RowGroup with a specific number of rows.
     parquet::RowGroupWriter* rg_writer = file_writer->AppendRowGroup();

     // Write the Bool column
     parquet::BoolWriter* bool_writer =
         static_cast<parquet::BoolWriter*>(rg_writer->NextColumn());
     for (int i = 0; i < NUM_ROWS_PER_ROW_GROUP; i++) {
       bool value = ((i % 2) == 0) ? true : false;
       bool_writer->WriteBatch(1, nullptr, nullptr, &value);
     }

     // Write the Int32 column
     parquet::Int32Writer* int32_writer =
         static_cast<parquet::Int32Writer*>(rg_writer->NextColumn());
     for (int i = 0; i < NUM_ROWS_PER_ROW_GROUP; i++) {
       int32_t value = i;
       int32_writer->WriteBatch(1, nullptr, nullptr, &value);
     }

     // Write the Int64 column. Each row has repeats twice.
     parquet::Int64Writer* int64_writer =
         static_cast<parquet::Int64Writer*>(rg_writer->NextColumn());
     for (int i = 0; i < 2 * NUM_ROWS_PER_ROW_GROUP; i++) {
       int64_t value = i * 1000 * 1000;
       value *= 1000 * 1000;
       int16_t definition_level = 1;
       int16_t repetition_level = 0;
       if ((i % 2) == 0) {
         repetition_level = 1;  // start of a new record
       }
       int64_writer->WriteBatch(1, &definition_level, &repetition_level, &value);
     }

     // Write the INT96 column.
     parquet::Int96Writer* int96_writer =
         static_cast<parquet::Int96Writer*>(rg_writer->NextColumn());
     for (int i = 0; i < NUM_ROWS_PER_ROW_GROUP; i++) {
       parquet::Int96 value;
       value.value[0] = i;
       value.value[1] = i + 1;
       value.value[2] = i + 2;
       int96_writer->WriteBatch(1, nullptr, nullptr, &value);
     }

     // Write the Float column
     parquet::FloatWriter* float_writer =
         static_cast<parquet::FloatWriter*>(rg_writer->NextColumn());
     for (int i = 0; i < NUM_ROWS_PER_ROW_GROUP; i++) {
       float value = static_cast<float>(i) * 1.1f;
       float_writer->WriteBatch(1, nullptr, nullptr, &value);
     }

     // Write the Double column
     parquet::DoubleWriter* double_writer =
         static_cast<parquet::DoubleWriter*>(rg_writer->NextColumn());
     for (int i = 0; i < NUM_ROWS_PER_ROW_GROUP; i++) {
       double value = i * 1.1111111;
       double_writer->WriteBatch(1, nullptr, nullptr, &value);
     }

     // Write the ByteArray column. Make every alternate values NULL
     parquet::ByteArrayWriter* ba_writer =
         static_cast<parquet::ByteArrayWriter*>(rg_writer->NextColumn());
     for (int i = 0; i < NUM_ROWS_PER_ROW_GROUP; i++) {
       parquet::ByteArray value;
       char hello[FIXED_LENGTH] = "parquet";
       hello[7] = static_cast<char>(static_cast<int>('0') + i / 100);
       hello[8] = static_cast<char>(static_cast<int>('0') + (i / 10) % 10);
       hello[9] = static_cast<char>(static_cast<int>('0') + i % 10);
       if (i % 2 == 0) {
         int16_t definition_level = 1;
         value.ptr = reinterpret_cast<const uint8_t*>(&hello[0]);
         value.len = FIXED_LENGTH;
         ba_writer->WriteBatch(1, &definition_level, nullptr, &value);
       } else {
         int16_t definition_level = 0;
         ba_writer->WriteBatch(1, &definition_level, nullptr, nullptr);
       }
     }

     // Write the FixedLengthByteArray column
     parquet::FixedLenByteArrayWriter* flba_writer =
         static_cast<parquet::FixedLenByteArrayWriter*>(rg_writer->NextColumn());
     for (int i = 0; i < NUM_ROWS_PER_ROW_GROUP; i++) {
       parquet::FixedLenByteArray value;
       char v = static_cast<char>(i);
       char flba[FIXED_LENGTH] = {v, v, v, v, v, v, v, v, v, v};
       value.ptr = reinterpret_cast<const uint8_t*>(&flba[0]);

       flba_writer->WriteBatch(1, nullptr, nullptr, &value);
     }

     // Close the ParquetFileWriter
     file_writer->Close();

     // Write the bytes to file
     ARROW_DCHECK(out_file->Close().ok());
   } catch (const std::exception& e) {
     std::cerr << "Parquet write error: " << e.what() << std::endl;
     return -1;
   }

   /**********************************************************************************
                              PARQUET ENCRYPTION READER EXAMPLE
   **********************************************************************************/

   // Decryption configuration: Decrypt using key retriever callback that holds the keys
   // of two encrypted columns and the footer key.
   std::shared_ptr<parquet::StringKeyIdRetriever> string_kr1 =
       std::make_shared<parquet::StringKeyIdRetriever>();
   string_kr1->PutKey("kf", kFooterEncryptionKey);
   string_kr1->PutKey("kc1", kColumnEncryptionKey1);
   string_kr1->PutKey("kc2", kColumnEncryptionKey2);
   std::shared_ptr<parquet::DecryptionKeyRetriever> kr1 =
       std::static_pointer_cast<parquet::StringKeyIdRetriever>(string_kr1);

   parquet::FileDecryptionProperties::Builder file_decryption_builder;

   try {
     parquet::ReaderProperties reader_properties = parquet::default_reader_properties();

     // Add the current decryption configuration to ReaderProperties.
     reader_properties.file_decryption_properties(
         file_decryption_builder.key_retriever(std::move(kr1))->build());

     // Create a ParquetReader instance
     std::unique_ptr<parquet::ParquetFileReader> parquet_reader =
         parquet::ParquetFileReader::OpenFile(PARQUET_FILENAME, false, reader_properties);

     // Get the File MetaData
     std::shared_ptr<parquet::FileMetaData> file_metadata = parquet_reader->metadata();

     // Get the number of RowGroups
     int num_row_groups = file_metadata->num_row_groups();
     assert(num_row_groups == 1);

     // Get the number of Columns
     int num_columns = file_metadata->num_columns();
     assert(num_columns == 8);

     // Iterate over all the RowGroups in the file
     for (int r = 0; r < num_row_groups; ++r) {
       // Get the RowGroup Reader
       std::shared_ptr<parquet::RowGroupReader> row_group_reader =
           parquet_reader->RowGroup(r);

       int64_t values_read = 0;
       int64_t rows_read = 0;
       int16_t definition_level;
       int16_t repetition_level;
       int i;
       std::shared_ptr<parquet::ColumnReader> column_reader;

       // Get the Column Reader for the boolean column
       column_reader = row_group_reader->Column(0);
       parquet::BoolReader* bool_reader =
           static_cast<parquet::BoolReader*>(column_reader.get());

       // Read all the rows in the column
       i = 0;
       while (bool_reader->HasNext()) {
         bool value;
         // Read one value at a time. The number of rows read is returned. values_read
         // contains the number of non-null rows
         rows_read = bool_reader->ReadBatch(1, nullptr, nullptr, &value, &values_read);
         // Ensure only one value is read
         assert(rows_read == 1);
         // There are no NULL values in the rows written
         assert(values_read == 1);
         // Verify the value written
         bool expected_value = ((i % 2) == 0) ? true : false;
         assert(value == expected_value);
         i++;
       }

       // Get the Column Reader for the Int32 column
       column_reader = row_group_reader->Column(1);
       parquet::Int32Reader* int32_reader =
           static_cast<parquet::Int32Reader*>(column_reader.get());
       // Read all the rows in the column
       i = 0;
       while (int32_reader->HasNext()) {
         int32_t value;
         // Read one value at a time. The number of rows read is returned. values_read
         // contains the number of non-null rows
         rows_read = int32_reader->ReadBatch(1, nullptr, nullptr, &value, &values_read);
         // Ensure only one value is read
         assert(rows_read == 1);
         // There are no NULL values in the rows written
         assert(values_read == 1);
         // Verify the value written
         assert(value == i);
         i++;
       }

       // Get the Column Reader for the Int64 column
       column_reader = row_group_reader->Column(2);
       parquet::Int64Reader* int64_reader =
           static_cast<parquet::Int64Reader*>(column_reader.get());
       // Read all the rows in the column
       i = 0;
       while (int64_reader->HasNext()) {
         int64_t value;
         // Read one value at a time. The number of rows read is returned. values_read
         // contains the number of non-null rows
         rows_read = int64_reader->ReadBatch(1, &definition_level, &repetition_level,
                                             &value, &values_read);
         // Ensure only one value is read
         assert(rows_read == 1);
         // There are no NULL values in the rows written
         assert(values_read == 1);
         // Verify the value written
         int64_t expected_value = i * 1000 * 1000;
         expected_value *= 1000 * 1000;
         assert(value == expected_value);
         if ((i % 2) == 0) {
           assert(repetition_level == 1);
         } else {
           assert(repetition_level == 0);
         }
         i++;
       }

       // Get the Column Reader for the Int96 column
       column_reader = row_group_reader->Column(3);
       parquet::Int96Reader* int96_reader =
           static_cast<parquet::Int96Reader*>(column_reader.get());
       // Read all the rows in the column
       i = 0;
       while (int96_reader->HasNext()) {
         parquet::Int96 value;
         // Read one value at a time. The number of rows read is returned. values_read
         // contains the number of non-null rows
         rows_read = int96_reader->ReadBatch(1, nullptr, nullptr, &value, &values_read);
         // Ensure only one value is read
         assert(rows_read == 1);
         // There are no NULL values in the rows written
         assert(values_read == 1);
         // Verify the value written
         parquet::Int96 expected_value;
         expected_value.value[0] = i;
         expected_value.value[1] = i + 1;
         expected_value.value[2] = i + 2;
         for (int j = 0; j < 3; j++) {
           assert(value.value[j] == expected_value.value[j]);
         }
         ARROW_UNUSED(expected_value);  // suppress compiler warning in release builds
         i++;
       }

       // Get the Column Reader for the Float column
       column_reader = row_group_reader->Column(4);
       parquet::FloatReader* float_reader =
           static_cast<parquet::FloatReader*>(column_reader.get());
       // Read all the rows in the column
       i = 0;
       while (float_reader->HasNext()) {
         float value;
         // Read one value at a time. The number of rows read is returned. values_read
         // contains the number of non-null rows
         rows_read = float_reader->ReadBatch(1, nullptr, nullptr, &value, &values_read);
         // Ensure only one value is read
         assert(rows_read == 1);
         // There are no NULL values in the rows written
         assert(values_read == 1);
         // Verify the value written
         float expected_value = static_cast<float>(i) * 1.1f;
         assert(value == expected_value);
         i++;
       }

       // Get the Column Reader for the Double column
       column_reader = row_group_reader->Column(5);
       parquet::DoubleReader* double_reader =
           static_cast<parquet::DoubleReader*>(column_reader.get());
       // Read all the rows in the column
       i = 0;
       while (double_reader->HasNext()) {
         double value;
         // Read one value at a time. The number of rows read is returned. values_read
         // contains the number of non-null rows
         rows_read = double_reader->ReadBatch(1, nullptr, nullptr, &value, &values_read);
         // Ensure only one value is read
         assert(rows_read == 1);
         // There are no NULL values in the rows written
         assert(values_read == 1);
         // Verify the value written
         double expected_value = i * 1.1111111;
         assert(value == expected_value);
         i++;
       }

       // Get the Column Reader for the ByteArray column
       column_reader = row_group_reader->Column(6);
       parquet::ByteArrayReader* ba_reader =
           static_cast<parquet::ByteArrayReader*>(column_reader.get());
       // Read all the rows in the column
       i = 0;
       while (ba_reader->HasNext()) {
         parquet::ByteArray value;
         // Read one value at a time. The number of rows read is returned. values_read
         // contains the number of non-null rows
         rows_read =
             ba_reader->ReadBatch(1, &definition_level, nullptr, &value, &values_read);
         // Ensure only one value is read
         assert(rows_read == 1);
         ARROW_UNUSED(rows_read);  // suppress compiler warning in release builds
         // Verify the value written
         char expected_value[FIXED_LENGTH] = "parquet";
         expected_value[7] = static_cast<char>('0' + i / 100);
         expected_value[8] = static_cast<char>('0' + (i / 10) % 10);
         expected_value[9] = static_cast<char>('0' + i % 10);
         if (i % 2 == 0) {  // only alternate values exist
           // There are no NULL values in the rows written
           assert(values_read == 1);
           assert(value.len == FIXED_LENGTH);
           assert(memcmp(value.ptr, &expected_value[0], FIXED_LENGTH) == 0);
           assert(definition_level == 1);
         } else {
           // There are NULL values in the rows written
           assert(values_read == 0);
           assert(definition_level == 0);
         }
         ARROW_UNUSED(expected_value);  // suppress compiler warning in release builds
         i++;
       }

       // Get the Column Reader for the FixedLengthByteArray column
       column_reader = row_group_reader->Column(7);
       parquet::FixedLenByteArrayReader* flba_reader =
           static_cast<parquet::FixedLenByteArrayReader*>(column_reader.get());
       // Read all the rows in the column
       i = 0;
       while (flba_reader->HasNext()) {
         parquet::FixedLenByteArray value;
         // Read one value at a time. The number of rows read is returned. values_read
         // contains the number of non-null rows
         rows_read = flba_reader->ReadBatch(1, nullptr, nullptr, &value, &values_read);
         // Ensure only one value is read
         assert(rows_read == 1);
         // There are no NULL values in the rows written
         assert(values_read == 1);
         // Verify the value written
         char v = static_cast<char>(i);
         char expected_value[FIXED_LENGTH] = {v, v, v, v, v, v, v, v, v, v};
         assert(memcmp(value.ptr, &expected_value[0], FIXED_LENGTH) == 0);
         i++;
       }
     }
   } catch (const std::exception& e) {
     std::cerr << "Parquet read error: " << e.what() << std::endl;
   }

   std::cout << "Parquet Writing and Reading Complete" << std::endl;
   return 0;
 }
	// 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 <arrow/util/secure_string.h>
	#include <reader_writer.h>

	#include <cassert>
	#include <fstream>
	#include <iostream>
	#include <memory>

	/*
	* This file contains sample for writing and reading encrypted Parquet file with
	* basic encryption configuration.
	*
	* A detailed description of the Parquet Modular Encryption specification can be found
	* here:
	* https://github.com/apache/parquet-format/blob/encryption/Encryption.md
	*
	* The write sample creates a file with eight columns where two of the columns and the
	* footer are encrypted.
	*
	* The read sample decrypts using key retriever that holds the keys of two encrypted
	* columns and the footer key.
	*/

	constexpr int NUM_ROWS_PER_ROW_GROUP = 500;
	const char* PARQUET_FILENAME = "parquet_cpp_example.parquet.encrypted";
	const arrow::util::SecureString kFooterEncryptionKey("0123456789012345");
	const arrow::util::SecureString kColumnEncryptionKey1("1234567890123450");
	const arrow::util::SecureString kColumnEncryptionKey2("1234567890123451");

	int main(int argc, char** argv) {
	/**********************************************************************************
	PARQUET ENCRYPTION WRITER EXAMPLE
	**********************************************************************************/

	try {
	// Create a local file output stream instance.
	using FileClass = ::arrow::io::FileOutputStream;
	std::shared_ptr<FileClass> out_file;
	PARQUET_ASSIGN_OR_THROW(out_file, FileClass::Open(PARQUET_FILENAME));

	// Setup the parquet schema
	std::shared_ptr<GroupNode> schema = SetupSchema();

	// Add encryption properties
	// Encryption configuration: Encrypt two columns and the footer.
	std::map<std::string, std::shared_ptr<parquet::ColumnEncryptionProperties>>
	encryption_cols;

	parquet::SchemaDescriptor schema_desc;
	schema_desc.Init(schema);
	auto column_path1 = schema_desc.Column(5)->path()->ToDotString();
	auto column_path2 = schema_desc.Column(4)->path()->ToDotString();

	encryption_cols[column_path1] =
	parquet::ColumnEncryptionProperties::WithColumnKey(kColumnEncryptionKey1, "kc1");
	encryption_cols[column_path2] =
	parquet::ColumnEncryptionProperties::WithColumnKey(kColumnEncryptionKey2, "kc2");

	parquet::FileEncryptionProperties::Builder file_encryption_builder(
	kFooterEncryptionKey);

	parquet::WriterProperties::Builder builder;
	// Add the current encryption configuration to WriterProperties.
	builder.encryption(file_encryption_builder.footer_key_metadata("kf")
	->encrypted_columns(std::move(encryption_cols))
	->build());

	// Add other writer properties
	builder.compression(parquet::Compression::SNAPPY);

	std::shared_ptr<parquet::WriterProperties> props = builder.build();

	// Create a ParquetFileWriter instance
	std::shared_ptr<parquet::ParquetFileWriter> file_writer =
	parquet::ParquetFileWriter::Open(out_file, schema, props);

	// Append a RowGroup with a specific number of rows.
	parquet::RowGroupWriter* rg_writer = file_writer->AppendRowGroup();

	// Write the Bool column
	parquet::BoolWriter* bool_writer =
	static_cast<parquet::BoolWriter*>(rg_writer->NextColumn());
	for (int i = 0; i < NUM_ROWS_PER_ROW_GROUP; i++) {
	bool value = ((i % 2) == 0) ? true : false;
	bool_writer->WriteBatch(1, nullptr, nullptr, &value);
	}

	// Write the Int32 column
	parquet::Int32Writer* int32_writer =
	static_cast<parquet::Int32Writer*>(rg_writer->NextColumn());
	for (int i = 0; i < NUM_ROWS_PER_ROW_GROUP; i++) {
	int32_t value = i;
	int32_writer->WriteBatch(1, nullptr, nullptr, &value);
	}

	// Write the Int64 column. Each row has repeats twice.
	parquet::Int64Writer* int64_writer =
	static_cast<parquet::Int64Writer*>(rg_writer->NextColumn());
	for (int i = 0; i < 2 * NUM_ROWS_PER_ROW_GROUP; i++) {
	int64_t value = i * 1000 * 1000;
	value = 1000 1000;
	int16_t definition_level = 1;
	int16_t repetition_level = 0;
	if ((i % 2) == 0) {
	repetition_level = 1; // start of a new record
	}
	int64_writer->WriteBatch(1, &definition_level, &repetition_level, &value);
	}

	// Write the INT96 column.
	parquet::Int96Writer* int96_writer =
	static_cast<parquet::Int96Writer*>(rg_writer->NextColumn());
	for (int i = 0; i < NUM_ROWS_PER_ROW_GROUP; i++) {
	parquet::Int96 value;
	value.value[0] = i;
	value.value[1] = i + 1;
	value.value[2] = i + 2;
	int96_writer->WriteBatch(1, nullptr, nullptr, &value);
	}

	// Write the Float column
	parquet::FloatWriter* float_writer =
	static_cast<parquet::FloatWriter*>(rg_writer->NextColumn());
	for (int i = 0; i < NUM_ROWS_PER_ROW_GROUP; i++) {
	float value = static_cast<float>(i) * 1.1f;
	float_writer->WriteBatch(1, nullptr, nullptr, &value);
	}

	// Write the Double column
	parquet::DoubleWriter* double_writer =
	static_cast<parquet::DoubleWriter*>(rg_writer->NextColumn());
	for (int i = 0; i < NUM_ROWS_PER_ROW_GROUP; i++) {
	double value = i * 1.1111111;
	double_writer->WriteBatch(1, nullptr, nullptr, &value);
	}

	// Write the ByteArray column. Make every alternate values NULL
	parquet::ByteArrayWriter* ba_writer =
	static_cast<parquet::ByteArrayWriter*>(rg_writer->NextColumn());
	for (int i = 0; i < NUM_ROWS_PER_ROW_GROUP; i++) {
	parquet::ByteArray value;
	char hello[FIXED_LENGTH] = "parquet";
	hello[7] = static_cast<char>(static_cast<int>('0') + i / 100);
	hello[8] = static_cast<char>(static_cast<int>('0') + (i / 10) % 10);
	hello[9] = static_cast<char>(static_cast<int>('0') + i % 10);
	if (i % 2 == 0) {
	int16_t definition_level = 1;
	value.ptr = reinterpret_cast<const uint8_t*>(&hello[0]);
	value.len = FIXED_LENGTH;
	ba_writer->WriteBatch(1, &definition_level, nullptr, &value);
	} else {
	int16_t definition_level = 0;
	ba_writer->WriteBatch(1, &definition_level, nullptr, nullptr);
	}
	}

	// Write the FixedLengthByteArray column
	parquet::FixedLenByteArrayWriter* flba_writer =
	static_cast<parquet::FixedLenByteArrayWriter*>(rg_writer->NextColumn());
	for (int i = 0; i < NUM_ROWS_PER_ROW_GROUP; i++) {
	parquet::FixedLenByteArray value;
	char v = static_cast<char>(i);
	char flba[FIXED_LENGTH] = {v, v, v, v, v, v, v, v, v, v};
	value.ptr = reinterpret_cast<const uint8_t*>(&flba[0]);

	flba_writer->WriteBatch(1, nullptr, nullptr, &value);
	}

	// Close the ParquetFileWriter
	file_writer->Close();

	// Write the bytes to file
	ARROW_DCHECK(out_file->Close().ok());
	} catch (const std::exception& e) {
	std::cerr << "Parquet write error: " << e.what() << std::endl;
	return -1;
	}

	/**********************************************************************************
	PARQUET ENCRYPTION READER EXAMPLE
	**********************************************************************************/

	// Decryption configuration: Decrypt using key retriever callback that holds the keys
	// of two encrypted columns and the footer key.
	std::shared_ptr<parquet::StringKeyIdRetriever> string_kr1 =
	std::make_shared<parquet::StringKeyIdRetriever>();
	string_kr1->PutKey("kf", kFooterEncryptionKey);
	string_kr1->PutKey("kc1", kColumnEncryptionKey1);
	string_kr1->PutKey("kc2", kColumnEncryptionKey2);
	std::shared_ptr<parquet::DecryptionKeyRetriever> kr1 =
	std::static_pointer_cast<parquet::StringKeyIdRetriever>(string_kr1);

	parquet::FileDecryptionProperties::Builder file_decryption_builder;

	try {
	parquet::ReaderProperties reader_properties = parquet::default_reader_properties();

	// Add the current decryption configuration to ReaderProperties.
	reader_properties.file_decryption_properties(
	file_decryption_builder.key_retriever(std::move(kr1))->build());

	// Create a ParquetReader instance
	std::unique_ptr<parquet::ParquetFileReader> parquet_reader =
	parquet::ParquetFileReader::OpenFile(PARQUET_FILENAME, false, reader_properties);

	// Get the File MetaData
	std::shared_ptr<parquet::FileMetaData> file_metadata = parquet_reader->metadata();

	// Get the number of RowGroups
	int num_row_groups = file_metadata->num_row_groups();
	assert(num_row_groups == 1);

	// Get the number of Columns
	int num_columns = file_metadata->num_columns();
	assert(num_columns == 8);

	// Iterate over all the RowGroups in the file
	for (int r = 0; r < num_row_groups; ++r) {
	// Get the RowGroup Reader
	std::shared_ptr<parquet::RowGroupReader> row_group_reader =
	parquet_reader->RowGroup(r);

	int64_t values_read = 0;
	int64_t rows_read = 0;
	int16_t definition_level;
	int16_t repetition_level;
	int i;
	std::shared_ptr<parquet::ColumnReader> column_reader;

	// Get the Column Reader for the boolean column
	column_reader = row_group_reader->Column(0);
	parquet::BoolReader* bool_reader =
	static_cast<parquet::BoolReader*>(column_reader.get());

	// Read all the rows in the column
	i = 0;
	while (bool_reader->HasNext()) {
	bool value;
	// Read one value at a time. The number of rows read is returned. values_read
	// contains the number of non-null rows
	rows_read = bool_reader->ReadBatch(1, nullptr, nullptr, &value, &values_read);
	// Ensure only one value is read
	assert(rows_read == 1);
	// There are no NULL values in the rows written
	assert(values_read == 1);
	// Verify the value written
	bool expected_value = ((i % 2) == 0) ? true : false;
	assert(value == expected_value);
	i++;
	}

	// Get the Column Reader for the Int32 column
	column_reader = row_group_reader->Column(1);
	parquet::Int32Reader* int32_reader =
	static_cast<parquet::Int32Reader*>(column_reader.get());
	// Read all the rows in the column
	i = 0;
	while (int32_reader->HasNext()) {
	int32_t value;
	// Read one value at a time. The number of rows read is returned. values_read
	// contains the number of non-null rows
	rows_read = int32_reader->ReadBatch(1, nullptr, nullptr, &value, &values_read);
	// Ensure only one value is read
	assert(rows_read == 1);
	// There are no NULL values in the rows written
	assert(values_read == 1);
	// Verify the value written
	assert(value == i);
	i++;
	}

	// Get the Column Reader for the Int64 column
	column_reader = row_group_reader->Column(2);
	parquet::Int64Reader* int64_reader =
	static_cast<parquet::Int64Reader*>(column_reader.get());
	// Read all the rows in the column
	i = 0;
	while (int64_reader->HasNext()) {
	int64_t value;
	// Read one value at a time. The number of rows read is returned. values_read
	// contains the number of non-null rows
	rows_read = int64_reader->ReadBatch(1, &definition_level, &repetition_level,
	&value, &values_read);
	// Ensure only one value is read
	assert(rows_read == 1);
	// There are no NULL values in the rows written
	assert(values_read == 1);
	// Verify the value written
	int64_t expected_value = i * 1000 * 1000;
	expected_value = 1000 1000;
	assert(value == expected_value);
	if ((i % 2) == 0) {
	assert(repetition_level == 1);
	} else {
	assert(repetition_level == 0);
	}
	i++;
	}

	// Get the Column Reader for the Int96 column
	column_reader = row_group_reader->Column(3);
	parquet::Int96Reader* int96_reader =
	static_cast<parquet::Int96Reader*>(column_reader.get());
	// Read all the rows in the column
	i = 0;
	while (int96_reader->HasNext()) {
	parquet::Int96 value;
	// Read one value at a time. The number of rows read is returned. values_read
	// contains the number of non-null rows
	rows_read = int96_reader->ReadBatch(1, nullptr, nullptr, &value, &values_read);
	// Ensure only one value is read
	assert(rows_read == 1);
	// There are no NULL values in the rows written
	assert(values_read == 1);
	// Verify the value written
	parquet::Int96 expected_value;
	expected_value.value[0] = i;
	expected_value.value[1] = i + 1;
	expected_value.value[2] = i + 2;
	for (int j = 0; j < 3; j++) {
	assert(value.value[j] == expected_value.value[j]);
	}
	ARROW_UNUSED(expected_value); // suppress compiler warning in release builds
	i++;
	}

	// Get the Column Reader for the Float column
	column_reader = row_group_reader->Column(4);
	parquet::FloatReader* float_reader =
	static_cast<parquet::FloatReader*>(column_reader.get());
	// Read all the rows in the column
	i = 0;
	while (float_reader->HasNext()) {
	float value;
	// Read one value at a time. The number of rows read is returned. values_read
	// contains the number of non-null rows
	rows_read = float_reader->ReadBatch(1, nullptr, nullptr, &value, &values_read);
	// Ensure only one value is read
	assert(rows_read == 1);
	// There are no NULL values in the rows written
	assert(values_read == 1);
	// Verify the value written
	float expected_value = static_cast<float>(i) * 1.1f;
	assert(value == expected_value);
	i++;
	}

	// Get the Column Reader for the Double column
	column_reader = row_group_reader->Column(5);
	parquet::DoubleReader* double_reader =
	static_cast<parquet::DoubleReader*>(column_reader.get());
	// Read all the rows in the column
	i = 0;
	while (double_reader->HasNext()) {
	double value;
	// Read one value at a time. The number of rows read is returned. values_read
	// contains the number of non-null rows
	rows_read = double_reader->ReadBatch(1, nullptr, nullptr, &value, &values_read);
	// Ensure only one value is read
	assert(rows_read == 1);
	// There are no NULL values in the rows written
	assert(values_read == 1);
	// Verify the value written
	double expected_value = i * 1.1111111;
	assert(value == expected_value);
	i++;
	}

	// Get the Column Reader for the ByteArray column
	column_reader = row_group_reader->Column(6);
	parquet::ByteArrayReader* ba_reader =
	static_cast<parquet::ByteArrayReader*>(column_reader.get());
	// Read all the rows in the column
	i = 0;
	while (ba_reader->HasNext()) {
	parquet::ByteArray value;
	// Read one value at a time. The number of rows read is returned. values_read
	// contains the number of non-null rows
	rows_read =
	ba_reader->ReadBatch(1, &definition_level, nullptr, &value, &values_read);
	// Ensure only one value is read
	assert(rows_read == 1);
	ARROW_UNUSED(rows_read); // suppress compiler warning in release builds
	// Verify the value written
	char expected_value[FIXED_LENGTH] = "parquet";
	expected_value[7] = static_cast<char>('0' + i / 100);
	expected_value[8] = static_cast<char>('0' + (i / 10) % 10);
	expected_value[9] = static_cast<char>('0' + i % 10);
	if (i % 2 == 0) { // only alternate values exist
	// There are no NULL values in the rows written
	assert(values_read == 1);
	assert(value.len == FIXED_LENGTH);
	assert(memcmp(value.ptr, &expected_value[0], FIXED_LENGTH) == 0);
	assert(definition_level == 1);
	} else {
	// There are NULL values in the rows written
	assert(values_read == 0);
	assert(definition_level == 0);
	}
	ARROW_UNUSED(expected_value); // suppress compiler warning in release builds
	i++;
	}

	// Get the Column Reader for the FixedLengthByteArray column
	column_reader = row_group_reader->Column(7);
	parquet::FixedLenByteArrayReader* flba_reader =
	static_cast<parquet::FixedLenByteArrayReader*>(column_reader.get());
	// Read all the rows in the column
	i = 0;
	while (flba_reader->HasNext()) {
	parquet::FixedLenByteArray value;
	// Read one value at a time. The number of rows read is returned. values_read
	// contains the number of non-null rows
	rows_read = flba_reader->ReadBatch(1, nullptr, nullptr, &value, &values_read);
	// Ensure only one value is read
	assert(rows_read == 1);
	// There are no NULL values in the rows written
	assert(values_read == 1);
	// Verify the value written
	char v = static_cast<char>(i);
	char expected_value[FIXED_LENGTH] = {v, v, v, v, v, v, v, v, v, v};
	assert(memcmp(value.ptr, &expected_value[0], FIXED_LENGTH) == 0);
	i++;
	}
	}
	} catch (const std::exception& e) {
	std::cerr << "Parquet read error: " << e.what() << std::endl;
	}

	std::cout << "Parquet Writing and Reading Complete" << std::endl;
	return 0;
	}