/*
* Copyright 2016 IBM Corp.
*
* Licensed 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.
*/
module.exports = function(kernelP) {
return (function() {
var Utils = require('../utils.js');
var gKernelP = kernelP;
/**
* @classdesc
* :: Experimental ::
* Used to convert a JVM object of type `T` to and from the internal Spark SQL representation.
*
* == Scala ==
* Encoders are generally created automatically through implicits from a `SparkSession`, or can be
* explicitly created by calling static methods on {@link Encoders}.
*
* @example
* import spark.implicits._
*
* val ds = Seq(1, 2, 3).toDS() // implicitly provided (spark.implicits.newIntEncoder)
*
*
* == Java ==
* Encoders are specified by calling static methods on {@link Encoders}.
*
* @example
* List<String> data = Arrays.asList("abc", "abc", "xyz");
* Dataset<String> ds = context.createDataset(data, Encoders.STRING());
*
*
* Encoders can be composed into tuples:
*
* @example
* Encoder<Tuple2<Integer, String>> encoder2 = Encoders.tuple(Encoders.INT(), Encoders.STRING());
* List<Tuple2<Integer, String>> data2 = Arrays.asList(new scala.Tuple2(1, "a");
* Dataset<Tuple2<Integer, String>> ds2 = context.createDataset(data2, encoder2);
*
*
* Or constructed from Java Beans:
*
* @example
* Encoders.bean(MyClass.class);
*
*
* == Implementation ==
* - Encoders are not required to be thread-safe and thus they do not need to use locks to guard
* against concurrent access if they reuse internal buffers to improve performance.
*
* @since EclairJS 0.7 Spark 1.6.0
* @class
* @memberof module:eclairjs/sql
*/
function Encoder() {
Utils.handleConstructor(this, arguments, gKernelP);
}
/**
* Returns the schema of encoding this type of object as a Row.
* @returns {StructType}
*/
Encoder.prototype.schema = function() {
var StructType = require('types/StructType');
var args = {
target: this,
method: 'schema',
returnType: StructType
};
return Utils.generate(args);
};
/**
* A ClassTag that can be used to construct and Array to contain a collection of `T`.
* @returns {ClassTag}
*/
Encoder.prototype.clsTag = function() {
throw "not implemented by ElairJS";
};
return Encoder;
})();
};