com.codetaco.funnel.orderby.KeyHelper Maven / Gradle / Ivy
package com.codetaco.funnel.orderby;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.codetaco.funnel.columns.ColumnHelper;
import com.codetaco.funnel.parameters.FunnelContext;
/**
*
* KeyHelper class.
*
*
* @author Chris DeGreef [email protected]
*/
public class KeyHelper
{
final private static Logger logger = LoggerFactory.getLogger(KeyHelper.class);
/** Constant MAX_KEY_SIZE=255 */
public static final int MAX_KEY_SIZE = 255;
final KeyContext context;
final int maxKeyBytes;
KeyPart formatter;
/**
*
* Constructor for KeyHelper.
*
*/
public KeyHelper()
{
this(MAX_KEY_SIZE);
}
/**
*
* Constructor for KeyHelper.
*
*
* @param maxsize a int.
*/
public KeyHelper(final int maxsize)
{
logger.debug("maximum string key length is " + MAX_KEY_SIZE);
maxKeyBytes = maxsize;
context = new KeyContext();
}
/**
* Add the key in sequence after all other keys that have already been
* defined. This is done through a linked list of keys. Use the column
* helper to find the definition of the key if a column name was specified.
*
* @param _formatter a {@link com.codetaco.funnel.orderby.KeyPart} object.
* @param columnHelper a {@link com.codetaco.funnel.columns.ColumnHelper}
* object.
*/
public void add(final KeyPart _formatter, final ColumnHelper columnHelper)
{
if (columnHelper != null && columnHelper.exists(_formatter.columnName))
{
final KeyPart colDef = columnHelper.get(_formatter.columnName);
_formatter.defineFrom(colDef);
}
if (this.formatter == null)
this.formatter = _formatter;
else
this.formatter.add(_formatter);
}
/**
* It is likely that the provided data is a reusable buffer of bytes. So we
* can't just store these bytes for later use.
*
* @param data an array of byte.
* @throws java.lang.Exception if any.
* @param recordNumber a long.
* @return a {@link com.codetaco.funnel.orderby.KeyContext} object.
*/
public KeyContext extractKey(final byte[] data, final long recordNumber) throws Exception
{
/*
* The extra byte is for a 0x00 character to be placed at the end of
* String keys. This is important in order to handle keys where the user
* specified the maximum length for a String key. Or took the default
* sort, which is the maximum key.
*/
context.key = new byte[maxKeyBytes + 1];
context.keyLength = 0;
context.rawRecordBytes = new byte[1][];
context.rawRecordBytes[0] = data;
context.recordNumber = recordNumber;
formatter.pack(context);
context.rawRecordBytes = null;
return context;
}
/**
* Call this method for csv files that break each row up into fields (byte
* arrays). [][].
*
* @param data an array of byte.
* @param recordNumber a long.
* @throws java.lang.Exception if any.
* @return a {@link com.codetaco.funnel.orderby.KeyContext} object.
*/
public KeyContext extractKey(final byte[][] data, final long recordNumber) throws Exception
{
/*
* The extra byte is for a 0x00 character to be placed at the end of
* String keys. This is important in order to handle keys where the user
* specified the maximum length for a String key. Or took the default
* sort, which is the maximum key.
*/
context.key = new byte[maxKeyBytes + 1];
context.keyLength = 0;
context.rawRecordBytes = data;
context.recordNumber = recordNumber;
formatter.pack(context);
context.rawRecordBytes = null;
return context;
}
/**
*
* extractKey.
*
*
* @param data a {@link java.lang.String} object.
* @param recordNumber a long.
* @return a {@link com.codetaco.funnel.orderby.KeyContext} object.
* @throws java.lang.Exception if any.
*/
public KeyContext extractKey(final String data, final long recordNumber) throws Exception
{
context.key = new byte[maxKeyBytes];
context.keyLength = 0;
context.rawRecordBytes = new byte[1][];
context.rawRecordBytes[0] = data.getBytes();
context.recordNumber = recordNumber;
formatter.pack(context);
context.rawRecordBytes = null;
return context;
}
/**
*
* setUpAsCopy.
*
*
* @param funnelContext a
* {@link com.codetaco.funnel.parameters.FunnelContext} object.
*/
public void setUpAsCopy(final FunnelContext funnelContext)
{
switch (funnelContext.getCopyOrder())
{
case ByKey:
AlphaKey ak;
if (funnelContext.getCsv() == null)
{
add(ak = new AlphaKey(), null);
ak.offset = 0;
ak.length = MAX_KEY_SIZE;
ak.direction = KeyDirection.ASC;
} else
{
add(ak = new AlphaKey(), null);
ak.csvFieldNumber = 0;
ak.offset = 0;
ak.length = MAX_KEY_SIZE;
ak.direction = KeyDirection.ASC;
}
break;
case Original:
add(new RecordNumberKey(KeyDirection.ASC, null), null);
break;
case Reverse:
add(new RecordNumberKey(KeyDirection.DESC, null), null);
break;
}
}
}