flink-core/src/main/java/org/apache/flink/api/common/typeutils/base/ComparatorUtil.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 org.apache.flink.api.common.typeutils.base;

import org.apache.flink.annotation.Internal;
import org.apache.flink.api.common.typeutils.TypeComparator;
import org.apache.flink.core.memory.MemorySegment;

/**
 * Utilities related to {@link TypeComparator}.
 */
@Internal
public class ComparatorUtil {

	public static void putByteNormalizedKey(byte value, MemorySegment target, int offset, int numBytes) {
		if (numBytes == 1) {
			// default case, full normalized key. need to explicitly convert to int to
			// avoid false results due to implicit type conversion to int when subtracting
			// the min byte value
			int highByte = value & 0xff;
			highByte -= Byte.MIN_VALUE;
			target.put(offset, (byte) highByte);
		}
		else if (numBytes <= 0) {
		}
		else {
			int highByte = value & 0xff;
			highByte -= Byte.MIN_VALUE;
			target.put(offset, (byte) highByte);
			for (int i = 1; i < numBytes; i++) {
				target.put(offset + i, (byte) 0);
			}
		}
	}

	public static void putCharNormalizedKey(char value, MemorySegment target, int offset, int numBytes) {
		// note that the char is an unsigned data type in java and consequently needs
		// no code that transforms the signed representation to an offset representation
		// that is equivalent to unsigned, when compared byte by byte
		if (numBytes == 2) {
			// default case, full normalized key
			target.put(offset,     (byte) ((value >>> 8) & 0xff));
			target.put(offset + 1, (byte) ((value) & 0xff));
		}
		else if (numBytes <= 0) {
		}
		else if (numBytes == 1) {
			target.put(offset,     (byte) ((value >>> 8) & 0xff));
		}
		else {
			target.put(offset,     (byte) ((value >>> 8) & 0xff));
			target.put(offset + 1, (byte) ((value) & 0xff));
			for (int i = 2; i < numBytes; i++) {
				target.put(offset + i, (byte) 0);
			}
		}
	}

	public static void putBooleanNormalizedKey(boolean value, MemorySegment target, int offset, int numBytes) {
		if (numBytes > 0) {
			target.put(offset, (byte) (value ? 1 : 0));

			for (offset = offset + 1; numBytes > 1; numBytes--) {
				target.put(offset++, (byte) 0);
			}
		}
	}

	public static void putShortNormalizedKey(short value, MemorySegment target, int offset, int numBytes) {
		if (numBytes == 2) {
			// default case, full normalized key
			int highByte = ((value >>> 8) & 0xff);
			highByte -= Byte.MIN_VALUE;
			target.put(offset, (byte) highByte);
			target.put(offset + 1, (byte) ((value) & 0xff));
		}
		else if (numBytes <= 0) {
		}
		else if (numBytes == 1) {
			int highByte = ((value >>> 8) & 0xff);
			highByte -= Byte.MIN_VALUE;
			target.put(offset, (byte) highByte);
		}
		else {
			int highByte = ((value >>> 8) & 0xff);
			highByte -= Byte.MIN_VALUE;
			target.put(offset, (byte) highByte);
			target.put(offset + 1, (byte) ((value) & 0xff));
			for (int i = 2; i < numBytes; i++) {
				target.put(offset + i, (byte) 0);
			}
		}
	}

	public static void putIntNormalizedKey(int iValue, MemorySegment target, int offset, int numBytes) {
		putUnsignedIntegerNormalizedKey(iValue - Integer.MIN_VALUE, target, offset, numBytes);
	}

	public static void putUnsignedIntegerNormalizedKey(int value, MemorySegment target, int offset, int numBytes) {
		if (numBytes == 4) {
			// default case, full normalized key
			target.putIntBigEndian(offset, value);
		} else if (numBytes > 0) {
			if (numBytes < 4) {
				for (int i = 0; numBytes > 0; numBytes--, i++) {
					target.put(offset + i, (byte) (value >>> ((3 - i) << 3)));
				}
			} else {
				target.putIntBigEndian(offset, value);
				for (int i = 4; i < numBytes; i++) {
					target.put(offset + i, (byte) 0);
				}
			}
		}
	}

	public static void putLongNormalizedKey(long lValue, MemorySegment target, int offset, int numBytes) {
		putUnsignedLongNormalizedKey(lValue - Long.MIN_VALUE, target, offset, numBytes);
	}

	public static void putUnsignedLongNormalizedKey(long value, MemorySegment target, int offset, int numBytes) {
		if (numBytes == 8) {
			// default case, full normalized key
			target.putLongBigEndian(offset, value);
		} else if (numBytes > 0) {
			if (numBytes < 8) {
				for (int i = 0; numBytes > 0; numBytes--, i++) {
					target.put(offset + i, (byte) (value >>> ((7 - i) << 3)));
				}
			} else {
				target.putLongBigEndian(offset, value);
				for (int i = 8; i < numBytes; i++) {
					target.put(offset + i, (byte) 0);
				}
			}
		}
	}
}