| /* |
| * 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.db; |
| |
| import java.io.IOException; |
| import java.nio.ByteBuffer; |
| import java.util.*; |
| |
| import org.apache.cassandra.config.CFMetaData; |
| import org.apache.cassandra.db.marshal.AbstractType; |
| import org.apache.cassandra.io.util.DataInputPlus; |
| import org.apache.cassandra.io.util.DataOutputPlus; |
| import org.apache.cassandra.utils.ByteBufferUtil; |
| |
| /** |
| * A slice represents the selection of a range of rows. |
| * <p> |
| * A slice has a start and an end bound that are both (potentially full) clustering prefixes. |
| * A slice selects every rows whose clustering is bigger than the slice start prefix but smaller |
| * than the end prefix. Both start and end can be either inclusive or exclusive. |
| */ |
| public class Slice |
| { |
| public static final Serializer serializer = new Serializer(); |
| |
| /** The slice selecting all rows (of a given partition) */ |
| public static final Slice ALL = new Slice(ClusteringBound.BOTTOM, ClusteringBound.TOP) |
| { |
| @Override |
| public boolean includes(ClusteringComparator comparator, ClusteringPrefix clustering) |
| { |
| return true; |
| } |
| |
| @Override |
| public boolean intersects(ClusteringComparator comparator, List<ByteBuffer> minClusteringValues, List<ByteBuffer> maxClusteringValues) |
| { |
| return true; |
| } |
| |
| @Override |
| public String toString(ClusteringComparator comparator) |
| { |
| return "ALL"; |
| } |
| }; |
| |
| private final ClusteringBound start; |
| private final ClusteringBound end; |
| |
| private Slice(ClusteringBound start, ClusteringBound end) |
| { |
| assert start.isStart() && end.isEnd(); |
| this.start = start; |
| this.end = end; |
| } |
| |
| public static Slice make(ClusteringBound start, ClusteringBound end) |
| { |
| if (start == ClusteringBound.BOTTOM && end == ClusteringBound.TOP) |
| return ALL; |
| |
| return new Slice(start, end); |
| } |
| |
| public static Slice make(ClusteringComparator comparator, Object... values) |
| { |
| CBuilder builder = CBuilder.create(comparator); |
| for (Object val : values) |
| { |
| if (val instanceof ByteBuffer) |
| builder.add((ByteBuffer) val); |
| else |
| builder.add(val); |
| } |
| return new Slice(builder.buildBound(true, true), builder.buildBound(false, true)); |
| } |
| |
| public static Slice make(Clustering clustering) |
| { |
| // This doesn't give us what we want with the clustering prefix |
| assert clustering != Clustering.STATIC_CLUSTERING; |
| ByteBuffer[] values = extractValues(clustering); |
| return new Slice(ClusteringBound.inclusiveStartOf(values), ClusteringBound.inclusiveEndOf(values)); |
| } |
| |
| public static Slice make(Clustering start, Clustering end) |
| { |
| // This doesn't give us what we want with the clustering prefix |
| assert start != Clustering.STATIC_CLUSTERING && end != Clustering.STATIC_CLUSTERING; |
| |
| ByteBuffer[] startValues = extractValues(start); |
| ByteBuffer[] endValues = extractValues(end); |
| |
| return new Slice(ClusteringBound.inclusiveStartOf(startValues), ClusteringBound.inclusiveEndOf(endValues)); |
| } |
| |
| private static ByteBuffer[] extractValues(ClusteringPrefix clustering) |
| { |
| ByteBuffer[] values = new ByteBuffer[clustering.size()]; |
| for (int i = 0; i < clustering.size(); i++) |
| values[i] = clustering.get(i); |
| return values; |
| } |
| |
| public ClusteringBound start() |
| { |
| return start; |
| } |
| |
| public ClusteringBound end() |
| { |
| return end; |
| } |
| |
| public ClusteringBound open(boolean reversed) |
| { |
| return reversed ? end : start; |
| } |
| |
| public ClusteringBound close(boolean reversed) |
| { |
| return reversed ? start : end; |
| } |
| |
| /** |
| * Return whether the slice is empty. |
| * |
| * @param comparator the comparator to compare the bounds. |
| * @return whether the slice formed is empty or not. |
| */ |
| public boolean isEmpty(ClusteringComparator comparator) |
| { |
| return isEmpty(comparator, start(), end()); |
| } |
| |
| /** |
| * Return whether the slice formed by the two provided bound is empty or not. |
| * |
| * @param comparator the comparator to compare the bounds. |
| * @param start the start for the slice to consider. This must be a start bound. |
| * @param end the end for the slice to consider. This must be an end bound. |
| * @return whether the slice formed by {@code start} and {@code end} is |
| * empty or not. |
| */ |
| public static boolean isEmpty(ClusteringComparator comparator, ClusteringBound start, ClusteringBound end) |
| { |
| assert start.isStart() && end.isEnd(); |
| return comparator.compare(end, start) <= 0; |
| } |
| |
| /** |
| * Returns whether a given clustering or bound is included in this slice. |
| * |
| * @param comparator the comparator for the table this is a slice of. |
| * @param bound the bound to test inclusion of. |
| * |
| * @return whether {@code bound} is within the bounds of this slice. |
| */ |
| public boolean includes(ClusteringComparator comparator, ClusteringPrefix bound) |
| { |
| return comparator.compare(start, bound) <= 0 && comparator.compare(bound, end) <= 0; |
| } |
| |
| /** |
| * Returns a slice for continuing paging from the last returned clustering prefix. |
| * |
| * @param comparator the comparator for the table this is a filter for. |
| * @param lastReturned the last clustering that was returned for the query we are paging for. The |
| * resulting slices will be such that only results coming stricly after {@code lastReturned} are returned |
| * (where coming after means "greater than" if {@code !reversed} and "lesser than" otherwise). |
| * @param inclusive whether or not we want to include the {@code lastReturned} in the newly returned page of results. |
| * @param reversed whether the query we're paging for is reversed or not. |
| * |
| * @return a new slice that selects results coming after {@code lastReturned}, or {@code null} if paging |
| * the resulting slice selects nothing (i.e. if it originally selects nothing coming after {@code lastReturned}). |
| */ |
| public Slice forPaging(ClusteringComparator comparator, Clustering lastReturned, boolean inclusive, boolean reversed) |
| { |
| if (lastReturned == null) |
| return this; |
| |
| if (reversed) |
| { |
| int cmp = comparator.compare(lastReturned, start); |
| if (cmp < 0 || (!inclusive && cmp == 0)) |
| return null; |
| |
| cmp = comparator.compare(end, lastReturned); |
| if (cmp < 0 || (inclusive && cmp == 0)) |
| return this; |
| |
| ByteBuffer[] values = extractValues(lastReturned); |
| return new Slice(start, inclusive ? ClusteringBound.inclusiveEndOf(values) : ClusteringBound.exclusiveEndOf(values)); |
| } |
| else |
| { |
| int cmp = comparator.compare(end, lastReturned); |
| if (cmp < 0 || (!inclusive && cmp == 0)) |
| return null; |
| |
| cmp = comparator.compare(lastReturned, start); |
| if (cmp < 0 || (inclusive && cmp == 0)) |
| return this; |
| |
| ByteBuffer[] values = extractValues(lastReturned); |
| return new Slice(inclusive ? ClusteringBound.inclusiveStartOf(values) : ClusteringBound.exclusiveStartOf(values), end); |
| } |
| } |
| |
| /** |
| * Given the per-clustering column minimum and maximum value a sstable contains, whether or not this slice potentially |
| * intersects that sstable or not. |
| * |
| * @param comparator the comparator for the table this is a slice of. |
| * @param minClusteringValues the smallest values for each clustering column that a sstable contains. |
| * @param maxClusteringValues the biggest values for each clustering column that a sstable contains. |
| * |
| * @return whether the slice might intersects with the sstable having {@code minClusteringValues} and |
| * {@code maxClusteringValues}. |
| */ |
| public boolean intersects(ClusteringComparator comparator, List<ByteBuffer> minClusteringValues, List<ByteBuffer> maxClusteringValues) |
| { |
| // If this slice starts after max clustering or ends before min clustering, it can't intersect |
| return start.compareTo(comparator, maxClusteringValues) <= 0 && end.compareTo(comparator, minClusteringValues) >= 0; |
| } |
| |
| public String toString(CFMetaData metadata) |
| { |
| return toString(metadata.comparator); |
| } |
| |
| public String toString(ClusteringComparator comparator) |
| { |
| StringBuilder sb = new StringBuilder(); |
| sb.append(start.isInclusive() ? "[" : "("); |
| for (int i = 0; i < start.size(); i++) |
| { |
| if (i > 0) |
| sb.append(':'); |
| sb.append(comparator.subtype(i).getString(start.get(i))); |
| } |
| sb.append(", "); |
| for (int i = 0; i < end.size(); i++) |
| { |
| if (i > 0) |
| sb.append(':'); |
| sb.append(comparator.subtype(i).getString(end.get(i))); |
| } |
| sb.append(end.isInclusive() ? "]" : ")"); |
| return sb.toString(); |
| } |
| |
| @Override |
| public boolean equals(Object other) |
| { |
| if(!(other instanceof Slice)) |
| return false; |
| |
| Slice that = (Slice)other; |
| return this.start().equals(that.start()) |
| && this.end().equals(that.end()); |
| } |
| |
| @Override |
| public int hashCode() |
| { |
| return Objects.hash(start(), end()); |
| } |
| |
| public static class Serializer |
| { |
| public void serialize(Slice slice, DataOutputPlus out, int version, List<AbstractType<?>> types) throws IOException |
| { |
| ClusteringBound.serializer.serialize(slice.start, out, version, types); |
| ClusteringBound.serializer.serialize(slice.end, out, version, types); |
| } |
| |
| public long serializedSize(Slice slice, int version, List<AbstractType<?>> types) |
| { |
| return ClusteringBound.serializer.serializedSize(slice.start, version, types) |
| + ClusteringBound.serializer.serializedSize(slice.end, version, types); |
| } |
| |
| public Slice deserialize(DataInputPlus in, int version, List<AbstractType<?>> types) throws IOException |
| { |
| ClusteringBound start = (ClusteringBound) ClusteringBound.serializer.deserialize(in, version, types); |
| ClusteringBound end = (ClusteringBound) ClusteringBound.serializer.deserialize(in, version, types); |
| return new Slice(start, end); |
| } |
| } |
| } |