/***********************************************************************************************************************
* Copyright (C) 2010-2013 by the Stratosphere project (http://stratosphere.eu)
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
* an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
* specific language governing permissions and limitations under the License.
**********************************************************************************************************************/
package eu.stratosphere.test.recordJobs.sort.tsUtil;
import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import eu.stratosphere.types.Key;
/**
* An integer number according to the rules of Jim Gray's sorting benchmark has a length of 100 bytes. The first 10
* bytes represent the key for the sort process, the rest is the value. The final byte of a 100 byte integer is always
* the newline character.
* <p>
* This class is a wrapper for the key part of the integer number.
*
*/
public final class TeraKey implements Key<TeraKey> {
private static final long serialVersionUID = 1L;
/**
* The size of the key in bytes.
*/
public static final int KEY_SIZE = 10;
/**
* The buffer to store the key.
*/
private byte[] key;
/**
* The offset to the key byte sequence.
*/
private int offset;
/**
* Constructs a new key object. The key points to the subsequence in the given array, i.e. it
* is sharing the byte array.
*
* @param srcBuf The source buffer to read the key from.
* @param offset The offset in the byte array where the key subsequence starts.
*/
public TeraKey(final byte[] srcBuf, int offset) {
this.key = srcBuf;
this.offset = offset;
}
/**
* Default constructor required for serialization/deserialization.
*/
public TeraKey() {
this.key = new byte[KEY_SIZE];
}
/**
* Sets the value of this key object. This key will point to the subsequence in the given array, i.e. it
* is sharing the byte array.
*
* @param data The source buffer to read the key from.
* @param offset The offset in the byte array where the key subsequence starts.
*/
public void setValue(final byte[] data, int offset) {
this.key = data;
this.offset = offset;
}
@Override
public void write(DataOutput out) throws IOException
{
out.write(this.key, this.offset, KEY_SIZE);
}
@Override
public void read(DataInput in) throws IOException {
in.readFully(this.key, 0, KEY_SIZE);
this.offset = 0;
}
@Override
public int compareTo(TeraKey tsk) {
int diff = 0;
for (int i = 0; i < KEY_SIZE; ++i) {
diff = (this.key[i + this.offset] - tsk.key[i + tsk.offset]);
if (diff != 0) {
break;
}
}
return diff;
}
@Override
public int hashCode() {
int result = 1;
for (int i = 0; i < KEY_SIZE; i++) {
result = 31 * result + this.key[i + this.offset];
}
return result;
}
@Override
public boolean equals(Object obj) {
if (getClass() != obj.getClass()) {
return false;
}
final TeraKey other = (TeraKey) obj;
for (int i = 0, tx = this.offset, ox = other.offset; i < KEY_SIZE; i++, tx++, ox++) {
if (this.key[tx] != other.key[ox]) {
return false;
}
}
return true;
}
/**
* Copies the key to the given byte buffer.
*
* @param buf
* the buffer to copy the key to
*/
public void copyToBuffer(final byte[] buf) {
System.arraycopy(this.key, this.offset, buf, 0, KEY_SIZE);
}
@Override
public String toString() {
return new String(this.key, this.offset, KEY_SIZE);
}
}