leerho commented on code in PR #447: URL: https://github.com/apache/datasketches-java/pull/447#discussion_r1289370146
########## src/main/java/org/apache/datasketches/kll/KllDirectCompactItemsSketch.java: ########## @@ -0,0 +1,307 @@ +/* + * 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.kll; + +import static org.apache.datasketches.kll.KllPreambleUtil.DATA_START_ADR; +import static org.apache.datasketches.kll.KllPreambleUtil.DATA_START_ADR_SINGLE_ITEM; +import static org.apache.datasketches.kll.KllPreambleUtil.getMemoryK; +import static org.apache.datasketches.kll.KllPreambleUtil.getMemoryLevelZeroSortedFlag; +import static org.apache.datasketches.kll.KllPreambleUtil.getMemoryM; +import static org.apache.datasketches.kll.KllPreambleUtil.getMemoryMinK; +import static org.apache.datasketches.kll.KllPreambleUtil.getMemoryN; +import static org.apache.datasketches.kll.KllSketch.SketchStructure.COMPACT_EMPTY; +import static org.apache.datasketches.kll.KllSketch.SketchStructure.COMPACT_SINGLE; + +import java.lang.reflect.Array; +import java.util.Comparator; + +import org.apache.datasketches.common.ArrayOfItemsSerDe; +import org.apache.datasketches.common.SketchesArgumentException; +import org.apache.datasketches.memory.Memory; +import org.apache.datasketches.memory.MemoryRequestServer; +import org.apache.datasketches.memory.WritableMemory; + +/** + * This class implements an off-heap, read-only KllItemsSketch using WritableMemory. + * + * <p>Please refer to the documentation in the package-info:<br> + * {@link org.apache.datasketches.kll}</p> + * + * @author Lee Rhodes, Kevin Lang + */ +@SuppressWarnings("unchecked") +final class KllDirectCompactItemsSketch<T> extends KllItemsSketch<T> { + private Memory mem; + + /** + * Internal implementation of the wrapped Memory KllSketch. + * @param memVal the MemoryValadate object + * @param comparator to compare items + * @param serDe Serializer / deserializer for items of type <i>T</i> and <i>T[]</i>. + */ + KllDirectCompactItemsSketch( //called below and KllItemsSketch + final KllMemoryValidate memVal, + final Comparator<? super T> comparator, + final ArrayOfItemsSerDe<T> serDe) { + super(memVal.sketchStructure, comparator, serDe); + this.mem = memVal.srcMem; + readOnly = true; + levelsArr = memVal.levelsArr; //always converted to writable form. + } + + @Override + public int getK() { + return getMemoryK(mem); + } + + @Override + public T getMaxItem() { + if (sketchStructure == COMPACT_EMPTY || isEmpty()) { + throw new SketchesArgumentException(EMPTY_MSG); + } + if (sketchStructure == COMPACT_SINGLE) { + return serDe.deserializeFromMemory(mem, DATA_START_ADR_SINGLE_ITEM, 1)[0]; + } + //sketchStructure == COMPACT_FULL + final int offset = DATA_START_ADR + getNumLevels() * Integer.BYTES; + return serDe.deserializeFromMemory(mem, offset, 2)[1]; + } + + @Override + public T getMinItem() { + if (sketchStructure == COMPACT_EMPTY || isEmpty()) { + throw new SketchesArgumentException(EMPTY_MSG); + } + if (sketchStructure == COMPACT_SINGLE) { + return serDe.deserializeFromMemory(mem, DATA_START_ADR_SINGLE_ITEM, 1)[0]; + } + //sketchStructure == COMPACT_FULL + final int offset = DATA_START_ADR + getNumLevels() * Integer.BYTES; + return serDe.deserializeFromMemory(mem, offset, 1)[0]; + } + + @Override + public long getN() { + if (sketchStructure == COMPACT_EMPTY) { return 0; } + if (sketchStructure == COMPACT_SINGLE) { return 1; } + return getMemoryN(mem); + } + + //restricted + + private int getCompactDataOffset() { //Sketch cannot be empty + return sketchStructure == COMPACT_SINGLE + ? DATA_START_ADR_SINGLE_ITEM + : DATA_START_ADR + getNumLevels() * Integer.BYTES + getMinMaxSizeBytes(); + } + + @Override + int getM() { + return getMemoryM(mem); + } + + @Override + MemoryRequestServer getMemoryRequestServer() { + return null; // not used. Must return null. + } + + @Override + int getMinK() { + if (sketchStructure == COMPACT_EMPTY || sketchStructure == COMPACT_SINGLE) { return getMemoryK(mem); } + return getMemoryMinK(mem); + } + + @Override + byte[] getMinMaxByteArr() { + if (sketchStructure == COMPACT_EMPTY || getN() == 0) { return new byte[0]; } + if (sketchStructure == COMPACT_SINGLE) { + final int bytesSingle = serDe.sizeOf(mem, DATA_START_ADR_SINGLE_ITEM, 1); + final byte[] byteArr = new byte[2 * bytesSingle]; + mem.getByteArray(DATA_START_ADR_SINGLE_ITEM, byteArr, 0, bytesSingle); + mem.getByteArray(DATA_START_ADR_SINGLE_ITEM, byteArr, bytesSingle, bytesSingle); + } + //sketchStructure == COMPACT_FULL + final int offset = DATA_START_ADR + getNumLevels() * Integer.BYTES; + final int bytesMinMax = serDe.sizeOf(mem, offset, 2); + final byte[] byteArr = new byte[bytesMinMax]; + mem.getByteArray(offset, byteArr, 0, bytesMinMax); + return byteArr; + } + + @Override + int getMinMaxSizeBytes() { + if (sketchStructure == COMPACT_EMPTY || getN() == 0) { return 0; } + if (sketchStructure == COMPACT_SINGLE) { + return serDe.sizeOf(mem, DATA_START_ADR_SINGLE_ITEM, 1) * 2; + } + //sketchStructure == COMPACT_FULL + final int offset = DATA_START_ADR + getNumLevels() * Integer.BYTES; + return serDe.sizeOf(mem, offset, 2); + } + + @Override + T[] getRetainedItemsArray() { + final int numRet = getNumRetained(); + final T[] outArr = (T[]) Array.newInstance(serDe.getClassOfT(), numRet); + if (sketchStructure == COMPACT_EMPTY) { return outArr; } + if (sketchStructure == COMPACT_SINGLE) { + outArr[0] = getSingleItem(); + return outArr; + } + final int offset = getCompactDataOffset(); //both single & full Review Comment: This actually works because `getSingleItem(`) does the work. However, this method would be easier to read if I had removed the COMPACT_SINGLE case like I did with `getRetainedItemsByteArr()` and `getRetainedItemsSizeBytes()`, because the `getCompactDataOffset()` computes the correct offset for both Compact Single and Full cases. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
