Java Code Examples for org.apache.parquet.hadoop.api.ReadSupport#ReadContext

public void initialize(FileMetaData parquetFileMetadata,
                       Path file, List<BlockMetaData> blocks, Configuration configuration)
    throws IOException {
  // initialize a ReadContext for this file
  Map<String, String> fileMetadata = parquetFileMetadata.getKeyValueMetaData();
  ReadSupport.ReadContext readContext = readSupport.init(new InitContext(
      configuration, toSetMultiMap(fileMetadata), fileSchema));
  this.columnIOFactory = new ColumnIOFactory(parquetFileMetadata.getCreatedBy());
  this.requestedSchema = readContext.getRequestedSchema();
  this.fileSchema = parquetFileMetadata.getSchema();
  this.file = file;
  this.columnCount = requestedSchema.getPaths().size();
  this.recordConverter = readSupport.prepareForRead(
      configuration, fileMetadata, fileSchema, readContext);
  this.strictTypeChecking = configuration.getBoolean(STRICT_TYPE_CHECKING, true);
  List<ColumnDescriptor> columns = requestedSchema.getColumns();
  reader = new ParquetFileReader(configuration, parquetFileMetadata, file, blocks, columns);
  for (BlockMetaData block : blocks) {
    total += block.getRowCount();
  }
  this.unmaterializableRecordCounter = new UnmaterializableRecordCounter(configuration, total);
  LOG.info("RecordReader initialized will read a total of " + total + " records.");
}
 

public void initialize(ParquetFileReader reader, Configuration configuration)
    throws IOException {
  // initialize a ReadContext for this file
  this.reader = reader;
  FileMetaData parquetFileMetadata = reader.getFooter().getFileMetaData();
  this.fileSchema = parquetFileMetadata.getSchema();
  Map<String, String> fileMetadata = parquetFileMetadata.getKeyValueMetaData();
  ReadSupport.ReadContext readContext = readSupport.init(new InitContext(
      configuration, toSetMultiMap(fileMetadata), fileSchema));
  this.columnIOFactory = new ColumnIOFactory(parquetFileMetadata.getCreatedBy());
  this.requestedSchema = readContext.getRequestedSchema();
  this.columnCount = requestedSchema.getPaths().size();
  // Setting the projection schema before running any filtering (e.g. getting filtered record count)
  // because projection impacts filtering
  reader.setRequestedSchema(requestedSchema);
  this.recordConverter = readSupport.prepareForRead(
      configuration, fileMetadata, fileSchema, readContext);
  this.strictTypeChecking = configuration.getBoolean(STRICT_TYPE_CHECKING, true);
  this.total = reader.getFilteredRecordCount();
  this.unmaterializableRecordCounter = new UnmaterializableRecordCounter(configuration, total);
  this.filterRecords = configuration.getBoolean(RECORD_FILTERING_ENABLED, true);
  LOG.info("RecordReader initialized will read a total of {} records.", total);
}
 

public void initialize(ParquetFileReader reader, Configuration configuration) {
	this.reader = reader;
	FileMetaData parquetFileMetadata = reader.getFooter().getFileMetaData();
	// real schema of parquet file
	this.fileSchema = parquetFileMetadata.getSchema();
	Map<String, String> fileMetadata = parquetFileMetadata.getKeyValueMetaData();
	ReadSupport.ReadContext readContext = readSupport.init(new InitContext(
		configuration, toSetMultiMap(fileMetadata), readSchema));

	this.columnIOFactory = new ColumnIOFactory(parquetFileMetadata.getCreatedBy());
	this.recordMaterializer = readSupport.prepareForRead(
		configuration, fileMetadata, readSchema, readContext);
	this.numTotalRecords = reader.getRecordCount();
}
 

/**
 * Initializes the ReadSupport.
 *
 * @param context The InitContext.
 * @return A ReadContext that defines how to read the file.
 */
@Override
public ReadSupport.ReadContext init(InitContext context) {
  if (requestedSchema == null) {
    throw new RuntimeException("requestedSchema is null.");
  }
  MessageType requestedParquetSchema =
    new TajoSchemaConverter().convert(requestedSchema);
  LOG.debug("Reading data with projection:\n" + requestedParquetSchema);
  return new ReadContext(requestedParquetSchema);
}
 

public void initialize(ParquetFileReader reader, Configuration configuration) {
	this.reader = reader;
	FileMetaData parquetFileMetadata = reader.getFooter().getFileMetaData();
	// real schema of parquet file
	this.fileSchema = parquetFileMetadata.getSchema();
	Map<String, String> fileMetadata = parquetFileMetadata.getKeyValueMetaData();
	ReadSupport.ReadContext readContext = readSupport.init(new InitContext(
		configuration, toSetMultiMap(fileMetadata), readSchema));

	this.columnIOFactory = new ColumnIOFactory(parquetFileMetadata.getCreatedBy());
	this.recordMaterializer = readSupport.prepareForRead(
		configuration, fileMetadata, readSchema, readContext);
	this.numTotalRecords = reader.getRecordCount();
}
 

public void initialize(ParquetFileReader reader, ParquetReadOptions options) {
  // copy custom configuration to the Configuration passed to the ReadSupport
  Configuration conf = new Configuration();
  if (options instanceof HadoopReadOptions) {
    conf = ((HadoopReadOptions) options).getConf();
  }
  for (String property : options.getPropertyNames()) {
    conf.set(property, options.getProperty(property));
  }

  // initialize a ReadContext for this file
  this.reader = reader;
  FileMetaData parquetFileMetadata = reader.getFooter().getFileMetaData();
  this.fileSchema = parquetFileMetadata.getSchema();
  Map<String, String> fileMetadata = parquetFileMetadata.getKeyValueMetaData();
  ReadSupport.ReadContext readContext = readSupport.init(new InitContext(conf, toSetMultiMap(fileMetadata), fileSchema));
  this.columnIOFactory = new ColumnIOFactory(parquetFileMetadata.getCreatedBy());
  this.requestedSchema = readContext.getRequestedSchema();
  this.columnCount = requestedSchema.getPaths().size();
  // Setting the projection schema before running any filtering (e.g. getting filtered record count)
  // because projection impacts filtering
  reader.setRequestedSchema(requestedSchema);
  this.recordConverter = readSupport.prepareForRead(conf, fileMetadata, fileSchema, readContext);
  this.strictTypeChecking = options.isEnabled(STRICT_TYPE_CHECKING, true);
  this.total = reader.getFilteredRecordCount();
  this.unmaterializableRecordCounter = new UnmaterializableRecordCounter(options, total);
  this.filterRecords = options.useRecordFilter();
  LOG.info("RecordReader initialized will read a total of {} records.", total);
}
 

@Test
public void testInitWithoutSpecifyingRequestSchema() throws Exception {
  GroupReadSupport s = new GroupReadSupport();
  Configuration configuration = new Configuration();
  Map<String, String> keyValueMetaData = new HashMap<String, String>();
  MessageType fileSchema = MessageTypeParser.parseMessageType(fullSchemaStr);

  ReadSupport.ReadContext context = s.init(configuration, keyValueMetaData, fileSchema);
  assertEquals(context.getRequestedSchema(), fileSchema);
}
 

@Test
public void testInitWithPartialSchema() {
  GroupReadSupport s = new GroupReadSupport();
  Configuration configuration = new Configuration();
  Map<String, String> keyValueMetaData = new HashMap<String, String>();
  MessageType fileSchema = MessageTypeParser.parseMessageType(fullSchemaStr);
  MessageType partialSchema = MessageTypeParser.parseMessageType(partialSchemaStr);
  configuration.set(ReadSupport.PARQUET_READ_SCHEMA, partialSchemaStr);

  ReadSupport.ReadContext context = s.init(configuration, keyValueMetaData, fileSchema);
  assertEquals(context.getRequestedSchema(), partialSchema);
}