internal ChainRecordWriter(Type keyClass, Type valueClass, Chain.ChainBlockingQueue
<Chain.KeyValuePair <KEYOUT, VALUEOUT> > output, Configuration conf)
{
// constructor to write to blocking queue
this.keyClass = keyClass;
this.valueClass = valueClass;
this.outputQueue = output;
this.conf = conf;
}
internal ChainRecordReader(Type keyClass, Type valueClass, Chain.ChainBlockingQueue
<Chain.KeyValuePair <KEYIN, VALUEIN> > inputQueue, Configuration conf)
{
// ChainRecordReader either reads from blocking queue or task context.
// constructor to read from a blocking queue
this.keyClass = keyClass;
this.valueClass = valueClass;
this.inputQueue = inputQueue;
this.conf = conf;
}
/// <summary>
/// Add mapper(the last mapper) that reads input from
/// queue and writes output to the output context
/// </summary>
/// <exception cref="System.IO.IOException"/>
/// <exception cref="System.Exception"/>
internal virtual void AddMapper(Chain.ChainBlockingQueue <Chain.KeyValuePair <object
, object> > input, TaskInputOutputContext outputContext, int index)
{
Configuration conf = GetConf(index);
Type keyClass = conf.GetClass(MapperInputKeyClass, typeof(object));
Type valueClass = conf.GetClass(MapperInputValueClass, typeof(object));
RecordReader rr = new Chain.ChainRecordReader(keyClass, valueClass, input, conf);
RecordWriter rw = new Chain.ChainRecordWriter(outputContext);
Chain.MapRunner runner = new Chain.MapRunner(this, mappers[index], CreateMapContext
(rr, rw, outputContext, GetConf(index)), rr, rw);
threads.AddItem(runner);
}
/// <summary>Add reducer that reads from context and writes to a queue</summary>
/// <exception cref="System.IO.IOException"/>
/// <exception cref="System.Exception"/>
internal virtual void AddReducer(TaskInputOutputContext inputContext, Chain.ChainBlockingQueue
<Chain.KeyValuePair <object, object> > outputQueue)
{
Type keyOutClass = rConf.GetClass(ReducerOutputKeyClass, typeof(object));
Type valueOutClass = rConf.GetClass(ReducerOutputValueClass, typeof(object));
RecordWriter rw = new Chain.ChainRecordWriter(keyOutClass, valueOutClass, outputQueue
, rConf);
Reducer.Context reducerContext = CreateReduceContext(rw, (ReduceContext)inputContext
, rConf);
Chain.ReduceRunner runner = new Chain.ReduceRunner(this, reducerContext, reducer,
rw);
threads.AddItem(runner);
}
