| /* |
| * 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.table.api.window; |
| |
| import org.apache.flink.api.common.typeutils.base.TypeSerializerSingleton; |
| import org.apache.flink.core.memory.DataInputView; |
| import org.apache.flink.core.memory.DataOutputView; |
| |
| import java.io.IOException; |
| |
| /** |
| * A {@link Window} that represents a time interval from {@code start} (inclusive) to |
| * {@code end} (exclusive). |
| */ |
| public class TimeWindow extends Window { |
| |
| private final long start; |
| private final long end; |
| |
| public TimeWindow(long start, long end) { |
| this.start = start; |
| this.end = end; |
| } |
| |
| /** |
| * Gets the starting timestamp of the window. This is the first timestamp that belongs |
| * to this window. |
| * |
| * @return The starting timestamp of this window. |
| */ |
| public long getStart() { |
| return start; |
| } |
| |
| /** |
| * Gets the end timestamp of this window. The end timestamp is exclusive, meaning it |
| * is the first timestamp that does not belong to this window any more. |
| * |
| * @return The exclusive end timestamp of this window. |
| */ |
| public long getEnd() { |
| return end; |
| } |
| |
| /** |
| * Gets the largest timestamp that still belongs to this window. |
| * |
| * <p>This timestamp is identical to {@code getEnd() - 1}. |
| * |
| * @return The largest timestamp that still belongs to this window. |
| * @see #getEnd() |
| */ |
| @Override |
| public long maxTimestamp() { |
| return end - 1; |
| } |
| |
| @Override |
| public boolean equals(Object o) { |
| if (this == o) { |
| return true; |
| } |
| if (o == null || getClass() != o.getClass()) { |
| return false; |
| } |
| |
| TimeWindow window = (TimeWindow) o; |
| |
| return end == window.end && start == window.start; |
| } |
| |
| @Override |
| public int hashCode() { |
| // inspired from Apache BEAM |
| // The end values are themselves likely to be arithmetic sequence, which |
| // is a poor distribution to use for a hashtable, so we |
| // add a highly non-linear transformation. |
| return (int) (start + modInverse((int) (end << 1) + 1)); |
| } |
| |
| /** |
| * Compute the inverse of (odd) x mod 2^32. |
| */ |
| private int modInverse(int x) { |
| // Cube gives inverse mod 2^4, as x^4 == 1 (mod 2^4) for all odd x. |
| int inverse = x * x * x; |
| // Newton iteration doubles correct bits at each step. |
| inverse *= 2 - x * inverse; |
| inverse *= 2 - x * inverse; |
| inverse *= 2 - x * inverse; |
| return inverse; |
| } |
| |
| @Override |
| public String toString() { |
| return "TimeWindow{" + |
| "start=" + start + |
| ", end=" + end + |
| '}'; |
| } |
| |
| /** |
| * Returns {@code true} if this window intersects the given window. |
| */ |
| public boolean intersects(TimeWindow other) { |
| return this.start <= other.end && this.end >= other.start; |
| } |
| |
| /** |
| * Returns the minimal window covers both this window and the given window. |
| */ |
| public TimeWindow cover(TimeWindow other) { |
| return new TimeWindow(Math.min(start, other.start), Math.max(end, other.end)); |
| } |
| |
| @Override |
| public int compareTo(Window o) { |
| TimeWindow that = (TimeWindow) o; |
| if (this.start == that.start) { |
| return Long.compare(this.end, that.end); |
| } else { |
| return Long.compare(this.start, that.start); |
| } |
| } |
| |
| |
| // ------------------------------------------------------------------------ |
| // Serializer |
| // ------------------------------------------------------------------------ |
| |
| /** |
| * The serializer used to write the TimeWindow type. |
| */ |
| public static class Serializer extends TypeSerializerSingleton<TimeWindow> { |
| private static final long serialVersionUID = 1L; |
| |
| @Override |
| public boolean isImmutableType() { |
| return true; |
| } |
| |
| @Override |
| public TimeWindow createInstance() { |
| return null; |
| } |
| |
| @Override |
| public TimeWindow copy(TimeWindow from) { |
| return from; |
| } |
| |
| @Override |
| public TimeWindow copy(TimeWindow from, TimeWindow reuse) { |
| return from; |
| } |
| |
| @Override |
| public int getLength() { |
| return 0; |
| } |
| |
| @Override |
| public void serialize(TimeWindow record, DataOutputView target) throws IOException { |
| target.writeLong(record.start); |
| target.writeLong(record.end); |
| } |
| |
| @Override |
| public TimeWindow deserialize(DataInputView source) throws IOException { |
| long start = source.readLong(); |
| long end = source.readLong(); |
| return new TimeWindow(start, end); |
| } |
| |
| @Override |
| public TimeWindow deserialize(TimeWindow reuse, DataInputView source) throws IOException { |
| return deserialize(source); |
| } |
| |
| @Override |
| public void copy(DataInputView source, DataOutputView target) throws IOException { |
| target.writeLong(source.readLong()); |
| target.writeLong(source.readLong()); |
| } |
| |
| @Override |
| public boolean canEqual(Object obj) { |
| return obj instanceof TimeWindow.Serializer; |
| } |
| } |
| |
| // ------------------------------------------------------------------------ |
| // Utilities |
| // ------------------------------------------------------------------------ |
| |
| /** |
| * Method to get the window start for a timestamp. |
| * |
| * @param timestamp epoch millisecond to get the window start. |
| * @param offset The offset which window start would be shifted by. |
| * @param windowSize The size of the generated windows. |
| * @return window start |
| */ |
| public static long getWindowStartWithOffset(long timestamp, long offset, long windowSize) { |
| return timestamp - (timestamp - offset + windowSize) % windowSize; |
| } |
| |
| public static TimeWindow of(long start, long end) { |
| return new TimeWindow(start, end); |
| } |
| } |