org.apache.hadoop.filecache
Class TaskDistributedCacheManager

java.lang.Object
  extended by org.apache.hadoop.filecache.TaskDistributedCacheManager

public class TaskDistributedCacheManager
extends Object

Helper class of TrackerDistributedCacheManager that represents the cached files of a single job. This class is internal to Hadoop, and should not be treated as a public interface.


Method Summary
 List<String> getClassPaths()
          Retrieves class paths (as local references) to add.
 ClassLoader makeClassLoader(ClassLoader parent)
          Creates a class loader that includes the designated files and archives.
 void release()
          Releases the cached files/archives, so that space can be reclaimed by the TrackerDistributedCacheManager.
 void setSizes(long[] sizes)
           
 void setupCache(Configuration taskConf, String publicCacheSubdir, String privateCacheSubdir)
          Retrieve public distributed cache files into the local cache and updates the task configuration (which has been passed in via the constructor).
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Method Detail

setupCache

public void setupCache(Configuration taskConf,
                       String publicCacheSubdir,
                       String privateCacheSubdir)
                throws IOException
Retrieve public distributed cache files into the local cache and updates the task configuration (which has been passed in via the constructor). The private distributed cache is just looked at and the paths where the files/archives should go to is decided here. The actual localization is done by JobLocalizer. It is the caller's responsibility to re-write the task configuration XML file, if necessary.

Throws:
IOException

getClassPaths

public List<String> getClassPaths()
                           throws IOException
Retrieves class paths (as local references) to add. Should be called after setup().

Throws:
IOException

release

public void release()
             throws IOException
Releases the cached files/archives, so that space can be reclaimed by the TrackerDistributedCacheManager.

Throws:
IOException

setSizes

public void setSizes(long[] sizes)
              throws IOException
Throws:
IOException

makeClassLoader

public ClassLoader makeClassLoader(ClassLoader parent)
                            throws MalformedURLException
Creates a class loader that includes the designated files and archives.

Throws:
MalformedURLException


Copyright © 2009 The Apache Software Foundation