yifan-c commented on code in PR #1739: URL: https://github.com/apache/cassandra/pull/1739#discussion_r931271260
########## src/java/org/apache/cassandra/serializers/SetIndexedCollectionSerializer.java: ########## @@ -0,0 +1,209 @@ +/* + * 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.cassandra.serializers; + +import java.nio.BufferUnderflowException; +import java.nio.ByteBuffer; + +import com.google.common.collect.Range; + +import org.apache.cassandra.db.marshal.AbstractType; +import org.apache.cassandra.db.marshal.ByteBufferAccessor; +import org.apache.cassandra.transport.ProtocolVersion; +import org.apache.cassandra.utils.ByteBufferUtil; + +/** + * Common superclass for {@link SetSerializer} and {@link MapSerializer}, considering a set as a map without values. + */ +abstract class SetIndexedCollectionSerializer<T> extends CollectionSerializer<T> +{ + private final boolean hasValues; + private final String name; + + protected SetIndexedCollectionSerializer(boolean hasValues) + { + this.hasValues = hasValues; + name = hasValues ? "map" : "set"; + } + + @Override + public ByteBuffer getSliceFromSerialized(ByteBuffer collection, + ByteBuffer from, + ByteBuffer to, + AbstractType<?> comparator, + boolean frozen) + { + if (from == ByteBufferUtil.UNSET_BYTE_BUFFER && to == ByteBufferUtil.UNSET_BYTE_BUFFER) + return collection; + + try + { + ByteBuffer input = collection.duplicate(); + int n = readCollectionSize(input, ByteBufferAccessor.instance, ProtocolVersion.V3); + input.position(input.position() + sizeOfCollectionSize(n, ProtocolVersion.V3)); + int startPos = input.position(); + int count = 0; + boolean inSlice = from == ByteBufferUtil.UNSET_BYTE_BUFFER; + + for (int i = 0; i < n; i++) + { + int pos = input.position(); + ByteBuffer key = readValue(input, ByteBufferAccessor.instance, 0, ProtocolVersion.V3); // key + input.position(input.position() + sizeOfValue(key, ByteBufferAccessor.instance, ProtocolVersion.V3)); + + // If we haven't passed the start already, check if we have now + if (!inSlice) + { + int comparison = comparator.compareForCQL(from, key); + if (comparison <= 0) + { + // We're now within the slice + inSlice = true; + startPos = pos; + } + else + { + // We're before the slice, so we know we don't care about this element + if (hasValues) + skipValue(input, ProtocolVersion.V3); + continue; + } + } + + // Now check if we're done + int comparison = to == ByteBufferUtil.UNSET_BYTE_BUFFER ? -1 : comparator.compareForCQL(key, to); + if (comparison > 0) + { + // We're done and shouldn't include the key we just read + input.position(pos); + break; + } + + // Otherwise, we'll include that element + if (hasValues) + skipValue(input, ProtocolVersion.V3); // value + ++count; + + // But if we know it was the last of the slice, we break early + if (comparison == 0) + break; + } + + if (count == 0 && !frozen) + return null; + + return copyAsNewCollection(collection, count, startPos, input.position(), ProtocolVersion.V3); + } + catch (BufferUnderflowException | IndexOutOfBoundsException e) + { + throw new MarshalException("Not enough bytes to read a " + name); + } + } + + @Override + public int getIndexFromSerialized(ByteBuffer collection, ByteBuffer key, AbstractType<?> comparator) + { + try + { + ByteBuffer input = collection.duplicate(); + int n = readCollectionSize(input, ByteBufferAccessor.instance, ProtocolVersion.V3); + int offset = sizeOfCollectionSize(n, ProtocolVersion.V3); + for (int i = 0; i < n; i++) + { + ByteBuffer kbb = readValue(input, ByteBufferAccessor.instance, offset, ProtocolVersion.V3); + offset += sizeOfValue(kbb, ByteBufferAccessor.instance, ProtocolVersion.V3); + int comparison = comparator.compareForCQL(kbb, key); + + if (comparison == 0) + return i; + + if (comparison > 0) + // since the set is in sorted order, we know we've gone too far and the element doesn't exist + return -1; + + // comparison < 0 + if (hasValues) + offset += skipValue(input, ByteBufferAccessor.instance, offset, ProtocolVersion.V3); + } + return -1; + } + catch (BufferUnderflowException e) + { + throw new MarshalException("Not enough bytes to read a " + name); + } + } + + @Override + public Range<Integer> getIndexesRangeFromSerialized(ByteBuffer collection, + ByteBuffer from, + ByteBuffer to, + AbstractType<?> comparator) + { + if (from == ByteBufferUtil.UNSET_BYTE_BUFFER && to == ByteBufferUtil.UNSET_BYTE_BUFFER) + return Range.closed(0, Integer.MAX_VALUE); + + try + { + ByteBuffer input = collection.duplicate(); + int n = readCollectionSize(input, ByteBufferAccessor.instance, ProtocolVersion.V3); + input.position(input.position() + sizeOfCollectionSize(n, ProtocolVersion.V3)); + int start = from == ByteBufferUtil.UNSET_BYTE_BUFFER ? 0 : -1; + int end = to == ByteBufferUtil.UNSET_BYTE_BUFFER ? n : -1; + + for (int i = 0; i < n; i++) + { + if (start >= 0 && end >= 0) + break; + else if (hasValues && i > 0) + skipValue(input, ProtocolVersion.V3); Review Comment: Super weak nit: ```java private void skipMapValue(ByteBuffer input, ProtocolVersion version) { if (hasValues) skipValue(input, version); } ``` -- This is an automated message from the Apache Git Service. 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