org.apache.sqoop.lib

Class LobRef<DATATYPE,CONTAINERTYPE,ACCESSORTYPE>

java.lang.Object

org.apache.sqoop.lib.LobRef<DATATYPE,CONTAINERTYPE,ACCESSORTYPE>

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable, org.apache.hadoop.io.Writable

Direct Known Subclasses:

BlobRef, ClobRef

public abstract class LobRef<DATATYPE,CONTAINERTYPE,ACCESSORTYPE>
extends java.lang.Object
implements java.io.Closeable, org.apache.hadoop.io.Writable

Abstract base class that holds a reference to a Blob or a Clob. DATATYPE is the type being held (e.g., a byte array). CONTAINERTYPE is the type used to hold this data (e.g., BytesWritable). ACCESSORTYPE is the type used to access this data in a streaming fashion (either an InputStream or a Reader).

Field Summary

Fields

Modifier and Type	Field and Description
protected static java.lang.ThreadLocal<java.util.regex.Matcher>	EXTERNAL_MATCHER
static org.apache.commons.logging.Log	LOG

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	LobRef()
protected	LobRef(CONTAINERTYPE container)
protected	LobRef(java.lang.String file, long offset, long length)

Method Summary

Modifier and Type	Method and Description
java.lang.Object	clone()
void	close()
protected abstract CONTAINERTYPE	deepCopyData(CONTAINERTYPE data) Make a copy of the materialized data.
protected void	finalize()
DATATYPE	getData()
protected CONTAINERTYPE	getDataObj() Internal API to retrieve the data object.
ACCESSORTYPE	getDataStream(org.apache.hadoop.conf.Configuration conf, org.apache.hadoop.fs.Path basePath) Get access to the LOB data itself.
ACCESSORTYPE	getDataStream(org.apache.hadoop.mapreduce.Mapper.Context mapContext) Convenience method to access #getDataStream(Configuration, Path) from within a map task that read this LobRef from a file-based InputSplit.
protected abstract ACCESSORTYPE	getExternalSource(org.apache.sqoop.io.LobFile.Reader reader) Using the LobFile reader, get an accessor InputStream or Reader to the underlying data.
protected abstract DATATYPE	getInternalData(CONTAINERTYPE data)
protected abstract ACCESSORTYPE	getInternalSource(CONTAINERTYPE data) Wrap the materialized data in an InputStream or Reader.
boolean	isExternal()
void	readFields(java.io.DataInput in)
protected abstract void	readFieldsInternal(java.io.DataInput in) Perform the readFields() operation on a fully-materializable record.
protected void	setDataObj(CONTAINERTYPE data) Internal API to set the data object.
java.lang.String	toString()
void	write(java.io.DataOutput out)
protected abstract void	writeInternal(java.io.DataOutput out) Perform the write() operation on a fully-materializable record.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

LOG

public static final org.apache.commons.logging.Log LOG

EXTERNAL_MATCHER

protected static final java.lang.ThreadLocal<java.util.regex.Matcher> EXTERNAL_MATCHER

Constructor Detail

LobRef

protected LobRef()

LobRef

protected LobRef(CONTAINERTYPE container)

LobRef

protected LobRef(java.lang.String file,
                 long offset,
                 long length)

Method Detail

getDataObj

protected CONTAINERTYPE getDataObj()

Internal API to retrieve the data object.

setDataObj

protected void setDataObj(CONTAINERTYPE data)

Internal API to set the data object.

clone

public java.lang.Object clone()
                       throws java.lang.CloneNotSupportedException

Overrides:

clone in class java.lang.Object

Throws:

java.lang.CloneNotSupportedException

finalize

protected void finalize()
                 throws java.lang.Throwable

Overrides:

finalize in class java.lang.Object

Throws:

java.lang.Throwable

close

public void close()
           throws java.io.IOException

Specified by:

close in interface java.io.Closeable

Specified by:

close in interface java.lang.AutoCloseable

Throws:

java.io.IOException

isExternal

public boolean isExternal()

Returns:

true if the LOB data is in an external file; false if it materialized inline.

getDataStream

public ACCESSORTYPE getDataStream(org.apache.hadoop.mapreduce.Mapper.Context mapContext)
                           throws java.io.IOException

Convenience method to access #getDataStream(Configuration, Path) from within a map task that read this LobRef from a file-based InputSplit.

Parameters:

mapContext - the Mapper.Context instance that encapsulates the current map task.

Returns:

an object that lazily streams the record to the client.

Throws:

java.lang.IllegalArgumentException - if it cannot find the source path for this LOB based on the MapContext.

java.io.IOException - if it could not read the LOB from external storage.

getDataStream

public ACCESSORTYPE getDataStream(org.apache.hadoop.conf.Configuration conf,
                                  org.apache.hadoop.fs.Path basePath)
                           throws java.io.IOException

Get access to the LOB data itself. This method returns a lazy reader of the LOB data, accessing the filesystem for external LOB storage as necessary.

Parameters:

conf - the Configuration used to access the filesystem

basePath - the base directory where the table records are stored.

Returns:

an object that lazily streams the record to the client.

Throws:

java.io.IOException - if it could not read the LOB from external storage.

getExternalSource

protected abstract ACCESSORTYPE getExternalSource(org.apache.sqoop.io.LobFile.Reader reader)
                                           throws java.io.IOException

Using the LobFile reader, get an accessor InputStream or Reader to the underlying data.

Throws:

java.io.IOException

getInternalSource

protected abstract ACCESSORTYPE getInternalSource(CONTAINERTYPE data)

Wrap the materialized data in an InputStream or Reader.

getInternalData

protected abstract DATATYPE getInternalData(CONTAINERTYPE data)

Returns:

the materialized data itself.

deepCopyData

protected abstract CONTAINERTYPE deepCopyData(CONTAINERTYPE data)

Make a copy of the materialized data.

getData

public DATATYPE getData()

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

readFields

public void readFields(java.io.DataInput in)
                throws java.io.IOException

Specified by:

readFields in interface org.apache.hadoop.io.Writable

Throws:

java.io.IOException

readFieldsInternal

protected abstract void readFieldsInternal(java.io.DataInput in)
                                    throws java.io.IOException

Perform the readFields() operation on a fully-materializable record.

Parameters:

in - the DataInput to deserialize from.

Throws:

java.io.IOException

write

public void write(java.io.DataOutput out)
           throws java.io.IOException

Specified by:

write in interface org.apache.hadoop.io.Writable

Throws:

java.io.IOException

writeInternal

protected abstract void writeInternal(java.io.DataOutput out)
                               throws java.io.IOException

Perform the write() operation on a fully-materializable record.

Parameters:

out - the DataOutput to deserialize to.

Throws:

java.io.IOException