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MapReduce >> mail # user >> Two questions about FSDataInputStream


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Re: Two questions about FSDataInputStream
For #1, I see the following in output of javap:

  public synchronized void seek(long) throws java.io.IOException;

which is described here:
http://hadoop.apache.org/docs/current/api/org/apache/hadoop/fs/FSDataInputStream.html#seek(long)
On Tue, Nov 12, 2013 at 3:08 PM, John Lilley <[EMAIL PROTECTED]>wrote:

>  First, this documentation:
> http://hadoop.apache.org/docs/current/api/org/apache/hadoop/fs/FSDataInputStream.html
>
> claims that FSDataInputStream has a seek() method, but javap doesn’t show
> one:
>
> $ javap -classpath [haddoopjars]  org.apache.hadoop.fs.FSDataInputStream
>
> Compiled from "FSDataInputStream.java"
>
> public class org.apache.hadoop.fs.FSDataInputStream extends
> java.io.DataInputStream implements org.apache.hadoop.fs.Seek
>
>
> able,org.apache.hadoop.fs.PositionedReadable,java.io.Closeable,org.apache.hadoop.fs.ByteBufferReadable,org.apache.hadoop
>
> .fs.HasFileDescriptor,org.apache.hadoop.fs.CanSetDropBehind,org.apache.hadoop.fs.CanSetReadahead
> {
>
>   public org.apache.hadoop.fs.FSDataInputStream(java.io.InputStream)
> throws java.io.IOException;
>
>   public synchronized void seek(long) throws java.io.IOException;
>
>   public long getPos() throws java.io.IOException;
>
>   public int read(long, byte[], int, int) throws java.io.IOException;
>
>   public void readFully(long, byte[], int, int) throws java.io.IOException;
>
>   public void readFully(long, byte[]) throws java.io.IOException;
>
>   public boolean seekToNewSource(long) throws java.io.IOException;
>
>   public java.io.InputStream getWrappedStream();
>
>   public int read(java.nio.ByteBuffer) throws java.io.IOException;
>
>   public java.io.FileDescriptor getFileDescriptor() throws
> java.io.IOException;
>
>   public void setReadahead(java.lang.Long) throws java.io.IOException,
> java.lang.UnsupportedOperationException;
>
>   public void setDropBehind(java.lang.Boolean) throws java.io.IOException,
> java.lang.UnsupportedOperationException;
>
> }
>
>
>
> Second, after every call to inputStream.read(position, byteArray, 0,
> size), the getPos() call returns the same answer.  Should it change?
>
>
>
> Given the lack of all these things, how is one supposed to call
> read(ByteBuffer) for random I/O?
>
>
>
> john
>
>
>
NEW: Monitor These Apps!
elasticsearch, apache solr, apache hbase, hadoop, redis, casssandra, amazon cloudwatch, mysql, memcached, apache kafka, apache zookeeper, apache storm, ubuntu, centOS, red hat, debian, puppet labs, java, senseiDB