com.adgear.anoa.read.ThriftDecoders Maven / Gradle / Ivy

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package com.adgear.anoa.read;

import com.adgear.anoa.Anoa;
import com.adgear.anoa.AnoaHandler;
import com.fasterxml.jackson.core.JsonParser;

import org.apache.thrift.TBase;
import org.apache.thrift.protocol.TBinaryProtocol;
import org.apache.thrift.protocol.TCompactProtocol;
import org.apache.thrift.protocol.TJSONProtocol;
import org.apache.thrift.protocol.TProtocol;
import org.apache.thrift.transport.TMemoryInputTransport;
import org.apache.thrift.transport.TTransport;

import java.util.function.Function;
import java.util.function.Supplier;

/**
 * Utility class for generating functions for deserializing Thrift records. Unless specified
 * otherwise, the functions should not be deemed thread-safe.
 */
final public class ThriftDecoders {

  private ThriftDecoders() {
  }

  /**
   * @param supplier provides the returned Thrift record instances
   * @param       Thrift record type
   * @return A function which deserializes a Thrift record from its compact binary encoding
   */
  static public  Function compact(
      Supplier supplier) {
    return fn(supplier, TCompactProtocol::new);
  }

  /**
   * @param anoaHandler {@code AnoaHandler} instance to use for exception handling
   * @param supplier    provides the returned Thrift record instances
   * @param          Thrift record type
   * @param          Metadata type
   * @return A function which deserializes a Thrift record from its compact binary encoding
   */
  static public 
  Function, Anoa> compact(
      AnoaHandler anoaHandler,
      Supplier supplier) {
    return fn(anoaHandler, supplier, TCompactProtocol::new);
  }

  /**
   * @param supplier provides the returned Thrift record instances
   * @param       Thrift record type
   * @return A function which deserializes a Thrift record from its standard binary encoding
   */
  static public  Function binary(
      Supplier supplier) {
    return fn(supplier, TBinaryProtocol::new);
  }

  /**
   * @param anoaHandler {@code AnoaHandler} instance to use for exception handling
   * @param supplier    provides the returned Thrift record instances
   * @param          Thrift record type
   * @param          Metadata type
   * @return A function which deserializes a Thrift record from its standard binary encoding
   */
  static public 
  Function, Anoa> binary(
      AnoaHandler anoaHandler,
      Supplier supplier) {
    return fn(anoaHandler, supplier, TBinaryProtocol::new);
  }

  /**
   * @param supplier provides the returned Thrift record instances
   * @param       Thrift record type
   * @return A function which deserializes a Thrift record from its Thrift JSON encoding
   */
  static public  Function json(
      Supplier supplier) {
    return fn(supplier, TJSONProtocol::new);
  }

  /**
   * @param anoaHandler {@code AnoaHandler} instance to use for exception handling
   * @param supplier    provides the returned Thrift record instances
   * @param          Thrift record type
   * @param          Metadata type
   * @return A function which deserializes a Thrift record from its Thrift JSON encoding
   */
  static public 
  Function, Anoa> json(
      AnoaHandler anoaHandler,
      Supplier supplier) {
    return fn(anoaHandler, supplier, TJSONProtocol::new);
  }

  static  Function fn(
      Supplier supplier,
      Function protocolFactory) {
    final TMemoryInputTransport tTransport = new TMemoryInputTransport();
    final TProtocol tProtocol = protocolFactory.apply(tTransport);
    final LookAheadIterator lookAheadIterator =
        LookAheadIteratorFactory.thrift(tProtocol, supplier);
    return (byte[] bytes) -> {
      lookAheadIterator.reset(null);
      tTransport.reset(bytes);
      return lookAheadIterator.next();
    };
  }

  static  Function, Anoa> fn(
      AnoaHandler anoaHandler,
      Supplier supplier,
      Function protocolFactory) {
    final TMemoryInputTransport tTransport = new TMemoryInputTransport();
    final TProtocol tProtocol = protocolFactory.apply(tTransport);
    final LookAheadIterator> lookAheadIterator =
        LookAheadIteratorFactory.thrift(anoaHandler, tProtocol, supplier);
    return (Anoa bytesWrapped) -> bytesWrapped.flatMap(bytes -> {
      lookAheadIterator.reset(null);
      tTransport.reset(bytesWrapped.get());
      return lookAheadIterator.next();
    });
  }

  /**
   * @param recordClass Thrift record class object
   * @param          Jackson JsonParser type
   * @param          Thrift record type
   * @return A function which reads a Thrift record from a JsonParser, in its 'natural' encoding.
   */
  static public 

  Function jackson(
      Class recordClass) {
    return new ThriftReader<>(recordClass).decoder();
  }

  /**
   * @param recordClass Thrift record class object
   * @param 
         Jackson JsonParser type
   * @param          Thrift record type
   * @return A function which reads a Thrift record from a JsonParser, in its 'natural' encoding,
   * with stricter type checking.
   */
  static public 

  Function jacksonStrict(
      Class recordClass) {
    return new ThriftReader<>(recordClass).decoderStrict();
  }

  /**
   * @param anoaHandler {@code AnoaHandler} instance to use for exception handling
   * @param recordClass Thrift record class object
   * @param 
         Jackson JsonParser type
   * @param          Thrift record type
   * @param          Metadata type
   * @return A function which reads a Thrift record from a JsonParser, in its 'natural' encoding.
   */
  static public 

  Function, Anoa> jackson(
      AnoaHandler anoaHandler,
      Class recordClass) {
    return new ThriftReader<>(recordClass).decoder(anoaHandler);
  }

  /**
   * @param anoaHandler {@code AnoaHandler} instance to use for exception handling
   * @param recordClass Thrift record class object
   * @param 
         Jackson JsonParser type
   * @param          Thrift record type
   * @param          Metadata type
   * @return A function which reads a Thrift record from a JsonParser, in its 'natural' encoding,
   * with stricter type checking.
   */
  static public 
  Function, Anoa> jacksonStrict(
      AnoaHandler anoaHandler,
      Class recordClass) {
    return new ThriftReader<>(recordClass).decoderStrict(anoaHandler);
  }
}