Package org.apache.hadoop.mapred.join

Class WrappedRecordReader<K extends WritableComparable,U extends Writable>

java.lang.Object
org.apache.hadoop.mapred.join.WrappedRecordReader<K,U>
All Implemented Interfaces:
Closeable, AutoCloseable, Comparable<ComposableRecordReader<K,?>>, Configurable, ComposableRecordReader<K,U>, RecordReader<K,U>
@Public @Stable public class WrappedRecordReader<K extends WritableComparable,U extends Writable> extends Object implements ComposableRecordReader<K,U>, Configurable
Proxy class for a RecordReader participating in the join framework. This class keeps track of the "head" key-value pair for the provided RecordReader and keeps a store of values matching a key when this source is participating in a join.

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    accept(org.apache.hadoop.mapred.join.CompositeRecordReader.JoinCollector i, K key)
    Add an iterator to the collector at the position occupied by this RecordReader over the values in this stream paired with the key provided (ie register a stream of values from this source matching K with a collector).
    void
    close()
    Forward close request to proxied RR.
    int
    compareTo(ComposableRecordReader<K,?> other)
    Implement Comparable contract (compare key at head of proxied RR with that of another).
    K
    createKey()
    Request new key from proxied RR.
    U
    createValue()
    Request new value from proxied RR.
    boolean
    equals(Object other)
    Return true iff compareTo(other) retn true.
    Configuration
    getConf()
    Return the configuration used by this object.
    long
    getPos()
    Request position from proxied RR.
    float
    getProgress()
    Request progress from proxied RR.
    int
    hashCode()
     
    boolean
    hasNext()
    Return true if the RR- including the k,v pair stored in this object- is exhausted.
    int
    id()
    Return the position in the collector this class occupies.
    K
    key()
    Return the key at the head of this RR.
    void
    key(K qkey)
    Clone the key at the head of this RR into the object supplied.
    protected boolean
    next()
    Read the next k,v pair into the head of this object; return true iff the RR and this are exhausted.
    boolean
    next(K key, U value)
    Write key-value pair at the head of this stream to the objects provided; get next key-value pair from proxied RR.
    void
    setConf(Configuration conf)
    Set the configuration to be used by this object.
    void
    skip(K key)
    Skip key-value pairs with keys less than or equal to the key provided.

    Methods inherited from class java.lang.Object

    clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait