rash67 commented on code in PR #12879: URL: https://github.com/apache/druid/pull/12879#discussion_r957627745
########## processing/src/main/java/org/apache/druid/query/aggregation/SerializablePairLongStringDeltaEncodedStagedSerde.java: ########## @@ -0,0 +1,131 @@ +/* + * 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.druid.query.aggregation; + +import com.google.common.base.Preconditions; +import com.google.common.primitives.Ints; +import org.apache.druid.java.util.common.StringUtils; +import org.apache.druid.segment.serde.cell.StagedSerde; +import org.apache.druid.segment.serde.cell.StorableBuffer; + +import javax.annotation.Nullable; +import java.nio.ByteBuffer; +import java.nio.ByteOrder; + +/** + * serializes a Long/String pair in the context of a column/segment. Uses the minValue to perform delta + * encoding/decoding and if the range of the segment fits in an integer (useIntegerDelta), the format is + * Integer:Integer:bytes + * + * otherwise + * Long:Integer:bytes + */ +public class SerializablePairLongStringDeltaEncodedStagedSerde implements StagedSerde<SerializablePairLongString> +{ + private static final byte[] EMPTY_BYTES = new byte[0]; + + private final long minValue; + private final boolean useIntegerDelta; + + public SerializablePairLongStringDeltaEncodedStagedSerde(long minValue, boolean useIntegerDelta) + { + this.minValue = minValue; + this.useIntegerDelta = useIntegerDelta; + } + + @Override + public StorableBuffer serializeDelayed(@Nullable SerializablePairLongString value) + { + if (value == null) { + return StorableBuffer.EMPTY; + } + + String rhsString = value.rhs; + byte[] rhsBytes = stringToUtf8Bytes(rhsString); + + return new StorableBuffer() + { + @Override + public void store(ByteBuffer byteBuffer) + { + Preconditions.checkNotNull(value.lhs, "Long in SerializablePairLongString must be non-null"); + + long delta = value.lhs - minValue; + + Preconditions.checkState(delta >= 0 || delta == value.lhs); + + if (useIntegerDelta) { + byteBuffer.putInt(Ints.checkedCast(delta)); + } else { + byteBuffer.putLong(delta); + } + + byteBuffer.putInt(rhsBytes.length); + + if (rhsBytes.length > 0) { + byteBuffer.put(rhsBytes); + } + } + + @Override + public int getSerializedSize() + { + return (useIntegerDelta ? Integer.BYTES : Long.BYTES) + Integer.BYTES + rhsBytes.length; + } + }; + } + + @Nullable + @Override + public SerializablePairLongString deserialize(ByteBuffer byteBuffer) + { + if (byteBuffer.remaining() == 0) { + return null; + } + + ByteBuffer readOnlyBuffer = byteBuffer.asReadOnlyBuffer().order(ByteOrder.nativeOrder()); + long lhs; + + if (useIntegerDelta) { + lhs = readOnlyBuffer.getInt(); + } else { + lhs = readOnlyBuffer.getLong(); + } + + lhs += minValue; + + int stringSize = readOnlyBuffer.getInt(); + String lastString = null; + + if (stringSize > 0) { + byte[] stringBytes = new byte[stringSize]; + + readOnlyBuffer.get(stringBytes, 0, stringSize); + lastString = StringUtils.fromUtf8(stringBytes); + } + + return new SerializablePairLongString(lhs, lastString); + } + + private static byte[] stringToUtf8Bytes(@Nullable String value) + { + return value == null ? EMPTY_BYTES : StringUtils.toUtf8Nullable(value); Review Comment: it's the other one you suggested, that is toUtf8WithEmpty or something -- 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]
