| /* |
| * 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.lucene.index; |
| |
| import java.util.List; |
| |
| import org.apache.lucene.util.Bits; |
| |
| |
| /** |
| * Concatenates multiple Bits together, on every lookup. |
| * |
| * <p><b>NOTE</b>: This is very costly, as every lookup must |
| * do a binary search to locate the right sub-reader. |
| * |
| * @lucene.experimental |
| */ |
| public final class MultiBits implements Bits { |
| private final Bits[] subs; |
| |
| // length is 1+subs.length (the last entry has the maxDoc): |
| private final int[] starts; |
| |
| private final boolean defaultValue; |
| |
| private MultiBits(Bits[] subs, int[] starts, boolean defaultValue) { |
| assert starts.length == 1+subs.length; |
| this.subs = subs; |
| this.starts = starts; |
| this.defaultValue = defaultValue; |
| } |
| |
| /** Returns a single {@link Bits} instance for this |
| * reader, merging live Documents on the |
| * fly. This method will return null if the reader |
| * has no deletions. |
| * |
| * <p><b>NOTE</b>: this is a very slow way to access live docs. |
| * For example, each Bits access will require a binary search. |
| * It's better to get the sub-readers and iterate through them |
| * yourself. */ |
| public static Bits getLiveDocs(IndexReader reader) { |
| if (reader.hasDeletions()) { |
| final List<LeafReaderContext> leaves = reader.leaves(); |
| final int size = leaves.size(); |
| assert size > 0 : "A reader with deletions must have at least one leave"; |
| if (size == 1) { |
| return leaves.get(0).reader().getLiveDocs(); |
| } |
| final Bits[] liveDocs = new Bits[size]; |
| final int[] starts = new int[size + 1]; |
| for (int i = 0; i < size; i++) { |
| // record all liveDocs, even if they are null |
| final LeafReaderContext ctx = leaves.get(i); |
| liveDocs[i] = ctx.reader().getLiveDocs(); |
| starts[i] = ctx.docBase; |
| } |
| starts[size] = reader.maxDoc(); |
| return new MultiBits(liveDocs, starts, true); |
| } else { |
| return null; |
| } |
| } |
| |
| private boolean checkLength(int reader, int doc) { |
| final int length = starts[1+reader]-starts[reader]; |
| assert doc - starts[reader] < length: "doc=" + doc + " reader=" + reader + " starts[reader]=" + starts[reader] + " length=" + length; |
| return true; |
| } |
| |
| @Override |
| public boolean get(int doc) { |
| final int reader = ReaderUtil.subIndex(doc, starts); |
| assert reader != -1; |
| final Bits bits = subs[reader]; |
| if (bits == null) { |
| return defaultValue; |
| } else { |
| assert checkLength(reader, doc); |
| return bits.get(doc-starts[reader]); |
| } |
| } |
| |
| @Override |
| public String toString() { |
| StringBuilder b = new StringBuilder(); |
| b.append(subs.length).append(" subs: "); |
| for(int i=0;i<subs.length;i++) { |
| if (i != 0) { |
| b.append("; "); |
| } |
| if (subs[i] == null) { |
| b.append("s=").append(starts[i]).append(" l=null"); |
| } else { |
| b.append("s=").append(starts[i]).append(" l=").append(subs[i].length()).append(" b=").append(subs[i]); |
| } |
| } |
| b.append(" end=").append(starts[subs.length]); |
| return b.toString(); |
| } |
| |
| @Override |
| public int length() { |
| return starts[starts.length-1]; |
| } |
| } |