/* * 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; /** * 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(Bound.BOTTOM, Bound.TOP) { @Override public boolean selects(ClusteringComparator comparator, Clustering 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 Bound start; private final Bound end; private Slice(Bound start, Bound end) { assert start.isStart() && end.isEnd(); this.start = start; this.end = end; } public static Slice make(Bound start, Bound end) { if (start == Bound.BOTTOM && end == Bound.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(Bound.inclusiveStartOf(values), Bound.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(Bound.inclusiveStartOf(startValues), Bound.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 Bound start() { return start; } public Bound end() { return end; } public Bound open(boolean reversed) { return reversed ? end : start; } public Bound 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, Slice.Bound start, Slice.Bound end) { assert start.isStart() && end.isEnd(); return comparator.compare(end, start) < 0; } /** * Returns whether a given clustering is selected by this slice. * * @param comparator the comparator for the table this is a slice of. * @param clustering the clustering to test inclusion of. * * @return whether {@code clustering} is selected by this slice. */ public boolean selects(ClusteringComparator comparator, Clustering clustering) { return comparator.compare(start, clustering) <= 0 && comparator.compare(clustering, end) <= 0; } /** * Returns whether a given 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, Bound 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 ? Bound.inclusiveEndOf(values) : Bound.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 ? Bound.inclusiveStartOf(values) : Bound.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 start after max or end before min, it can't intersect if (start.compareTo(comparator, maxClusteringValues) > 0 || end.compareTo(comparator, minClusteringValues) < 0) return false; // We could safely return true here, but there's a minor optimization: if the first component // of the slice is restricted to a single value (typically the slice is [4:5, 4:7]), we can // check that the second component falls within the min/max for that component (and repeat for // all components). for (int j = 0; j < minClusteringValues.size() && j < maxClusteringValues.size(); j++) { ByteBuffer s = j < start.size() ? start.get(j) : null; ByteBuffer f = j < end.size() ? end.get(j) : null; // we already know the first component falls within its min/max range (otherwise we wouldn't get here) if (j > 0 && (j < end.size() && comparator.compareComponent(j, f, minClusteringValues.get(j)) < 0 || j < start.size() && comparator.compareComponent(j, s, maxClusteringValues.get(j)) > 0)) return false; // if this component isn't equal in the start and finish, we don't need to check any more if (j >= start.size() || j >= end.size() || comparator.compareComponent(j, s, f) != 0) break; } return true; } 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 { Bound.serializer.serialize(slice.start, out, version, types); Bound.serializer.serialize(slice.end, out, version, types); } public long serializedSize(Slice slice, int version, List<AbstractType<?>> types) { return Bound.serializer.serializedSize(slice.start, version, types) + Bound.serializer.serializedSize(slice.end, version, types); } public Slice deserialize(DataInputPlus in, int version, List<AbstractType<?>> types) throws IOException { Bound start = Bound.serializer.deserialize(in, version, types); Bound end = Bound.serializer.deserialize(in, version, types); return new Slice(start, end); } } /** * The bound of a slice. * <p> * This can be either a start or an end bound, and this can be either inclusive or exclusive. */ public static class Bound extends AbstractClusteringPrefix { public static final Serializer serializer = new Serializer(); /** * The smallest and biggest bound. Note that as range tomstone bounds are (special case) of slice bounds, * we want the BOTTOM and TOP to be the same object, but we alias them here because it's cleaner when dealing * with slices to refer to Slice.Bound.BOTTOM and Slice.Bound.TOP. */ public static final Bound BOTTOM = RangeTombstone.Bound.BOTTOM; public static final Bound TOP = RangeTombstone.Bound.TOP; protected Bound(Kind kind, ByteBuffer[] values) { super(kind, values); } public static Bound create(Kind kind, ByteBuffer[] values) { assert !kind.isBoundary(); return new Bound(kind, values); } public static Kind boundKind(boolean isStart, boolean isInclusive) { return isStart ? (isInclusive ? Kind.INCL_START_BOUND : Kind.EXCL_START_BOUND) : (isInclusive ? Kind.INCL_END_BOUND : Kind.EXCL_END_BOUND); } public static Bound inclusiveStartOf(ByteBuffer... values) { return create(Kind.INCL_START_BOUND, values); } public static Bound inclusiveEndOf(ByteBuffer... values) { return create(Kind.INCL_END_BOUND, values); } public static Bound exclusiveStartOf(ByteBuffer... values) { return create(Kind.EXCL_START_BOUND, values); } public static Bound exclusiveEndOf(ByteBuffer... values) { return create(Kind.EXCL_END_BOUND, values); } public static Bound inclusiveStartOf(ClusteringPrefix prefix) { ByteBuffer[] values = new ByteBuffer[prefix.size()]; for (int i = 0; i < prefix.size(); i++) values[i] = prefix.get(i); return inclusiveStartOf(values); } public static Bound exclusiveStartOf(ClusteringPrefix prefix) { ByteBuffer[] values = new ByteBuffer[prefix.size()]; for (int i = 0; i < prefix.size(); i++) values[i] = prefix.get(i); return exclusiveStartOf(values); } public static Bound inclusiveEndOf(ClusteringPrefix prefix) { ByteBuffer[] values = new ByteBuffer[prefix.size()]; for (int i = 0; i < prefix.size(); i++) values[i] = prefix.get(i); return inclusiveEndOf(values); } public static Bound create(ClusteringComparator comparator, boolean isStart, boolean isInclusive, Object... values) { CBuilder builder = CBuilder.create(comparator); for (Object val : values) { if (val instanceof ByteBuffer) builder.add((ByteBuffer) val); else builder.add(val); } return builder.buildBound(isStart, isInclusive); } public Bound withNewKind(Kind kind) { assert !kind.isBoundary(); return new Bound(kind, values); } public boolean isStart() { return kind().isStart(); } public boolean isEnd() { return !isStart(); } public boolean isInclusive() { return kind == Kind.INCL_START_BOUND || kind == Kind.INCL_END_BOUND; } public boolean isExclusive() { return kind == Kind.EXCL_START_BOUND || kind == Kind.EXCL_END_BOUND; } /** * Returns the inverse of the current bound. * <p> * This invert both start into end (and vice-versa) and inclusive into exclusive (and vice-versa). * * @return the invert of this bound. For instance, if this bound is an exlusive start, this return * an inclusive end with the same values. */ public Slice.Bound invert() { return withNewKind(kind().invert()); } // For use by intersects, it's called with the sstable bound opposite to the slice bound // (so if the slice bound is a start, it's call with the max sstable bound) private int compareTo(ClusteringComparator comparator, List<ByteBuffer> sstableBound) { for (int i = 0; i < sstableBound.size(); i++) { // Say the slice bound is a start. It means we're in the case where the max // sstable bound is say (1:5) while the slice start is (1). So the start // does start before the sstable end bound (and intersect it). It's the exact // inverse with a end slice bound. if (i >= size()) return isStart() ? -1 : 1; int cmp = comparator.compareComponent(i, get(i), sstableBound.get(i)); if (cmp != 0) return cmp; } // Say the slice bound is a start. I means we're in the case where the max // sstable bound is say (1), while the slice start is (1:5). This again means // that the slice start before the end bound. if (size() > sstableBound.size()) return isStart() ? -1 : 1; // The slice bound is equal to the sstable bound. Results depends on whether the slice is inclusive or not return isInclusive() ? 0 : (isStart() ? 1 : -1); } public String toString(CFMetaData metadata) { return toString(metadata.comparator); } public String toString(ClusteringComparator comparator) { StringBuilder sb = new StringBuilder(); sb.append(kind()).append('('); for (int i = 0; i < size(); i++) { if (i > 0) sb.append(", "); sb.append(comparator.subtype(i).getString(get(i))); } return sb.append(')').toString(); } /** * Serializer for slice bounds. * <p> * Contrarily to {@code Clustering}, a slice bound can be a true prefix of the full clustering, so we actually record * its size. */ public static class Serializer { public void serialize(Slice.Bound bound, DataOutputPlus out, int version, List<AbstractType<?>> types) throws IOException { out.writeByte(bound.kind().ordinal()); out.writeShort(bound.size()); ClusteringPrefix.serializer.serializeValuesWithoutSize(bound, out, version, types); } public long serializedSize(Slice.Bound bound, int version, List<AbstractType<?>> types) { return 1 // kind ordinal + TypeSizes.sizeof((short)bound.size()) + ClusteringPrefix.serializer.valuesWithoutSizeSerializedSize(bound, version, types); } public Slice.Bound deserialize(DataInputPlus in, int version, List<AbstractType<?>> types) throws IOException { Kind kind = Kind.values()[in.readByte()]; return deserializeValues(in, kind, version, types); } public Slice.Bound deserializeValues(DataInputPlus in, Kind kind, int version, List<AbstractType<?>> types) throws IOException { int size = in.readUnsignedShort(); if (size == 0) return kind.isStart() ? BOTTOM : TOP; ByteBuffer[] values = ClusteringPrefix.serializer.deserializeValuesWithoutSize(in, size, version, types); return Slice.Bound.create(kind, values); } } } }