/// <summary>the map function.</summary>
/// <remarks>
/// the map function. It iterates through the value aggregator descriptor
/// list to generate aggregation id/value pairs and emit them.
/// </remarks>
/// <exception cref="System.IO.IOException"/>
public override void Map(K1 key, V1 value, OutputCollector <Text, Text> output, Reporter
reporter)
{
IEnumerator iter = this.aggregatorDescriptorList.GetEnumerator();
while (iter.HasNext())
{
ValueAggregatorDescriptor ad = (ValueAggregatorDescriptor)iter.Next();
IEnumerator <KeyValuePair <Text, Text> > ens = ad.GenerateKeyValPairs(key, value).GetEnumerator
();
while (ens.HasNext())
{
KeyValuePair <Text, Text> en = ens.Next();
output.Collect(en.Key, en.Value);
}
}
}
private static AList <ValueAggregatorDescriptor> GetAggregatorDescriptors(JobConf
job)
{
string advn = "aggregator.descriptor";
int num = job.GetInt(advn + ".num", 0);
AList <ValueAggregatorDescriptor> retv = new AList <ValueAggregatorDescriptor>(num);
for (int i = 0; i < num; i++)
{
string spec = job.Get(advn + "." + i);
ValueAggregatorDescriptor ad = GetValueAggregatorDescriptor(spec, job);
if (ad != null)
{
retv.AddItem(ad);
}
}
return(retv);
}