| /* |
| * 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.datasketches.hll; |
| |
| /** |
| * @author Lee Rhodes |
| */ |
| abstract class PairIterator { |
| |
| /** |
| * Gets the header string for a list of pairs |
| * @return the header string for a list of pairs |
| */ |
| String getHeader() { |
| return String.format("%10s%10s%10s%6s", "Index", "Key", "Slot", "Value"); |
| } |
| |
| /** |
| * In LIST and SET modes, this gets the iterating index into the integer array of HLL key/value |
| * pairs. |
| * In HLL mode, this is the iterating index into the hypothetical array of HLL values, which may |
| * be physically contructed differently based on the compaction scheme (HLL_4, HLL_6, HLL_8). |
| * @return the index. |
| */ |
| abstract int getIndex(); |
| |
| /** |
| * Gets the key, the low 26 bits of an pair, and can be up to 26 bits in length. |
| * @return the key |
| */ |
| abstract int getKey(); |
| |
| /** |
| * Gets the key, value pair as a single int where the key is the lower 26 bits |
| * and the value is in the upper 6 bits. |
| * @return the key, value pair. |
| */ |
| abstract int getPair(); |
| |
| /** |
| * Gets the target or actual HLL slot number, which is derived from the key and LgConfigK. |
| * The slot number is the index into a hypothetical array of length K and has LgConfigK bits. |
| * If in LIST or SET mode this is the index into the hypothetical target HLL array of size K. |
| * In HLL mode, this will be the actual index into the hypothetical target HLL array of size K. |
| * @return the target or actual HLL slot number. |
| */ |
| abstract int getSlot(); |
| |
| /** |
| * Gets the current pair as a string |
| * @return the current pair as a string |
| */ |
| String getString() { |
| final int index = getIndex(); |
| final int key = getKey(); |
| final int slot = getSlot(); |
| final int value = getValue(); |
| return String.format("%10d%10d%10d%6d", index, key, slot, value); |
| } |
| |
| /** |
| * Gets the HLL value of a particular slot or pair. |
| * @return the HLL value of a particular slot or pair. |
| */ |
| abstract int getValue(); |
| |
| /** |
| * Returns true at the next pair in sequence. |
| * If false, the iteration is done. |
| * @return true at the next pair in sequence. |
| */ |
| abstract boolean nextAll(); |
| |
| /** |
| * Returns true at the next pair where getKey() and getValue() are valid. |
| * If false, the iteration is done. |
| * @return true at the next pair where getKey() and getValue() are valid. |
| */ |
| abstract boolean nextValid(); |
| |
| } |