| /* |
| * 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.io.IOException; |
| |
| import org.apache.lucene.util.BytesRef; |
| import org.apache.lucene.util.automaton.CompiledAutomaton; |
| |
| /** |
| * A per-document byte[] with presorted values. This is fundamentally an |
| * iterator over the int ord values per document, with random access APIs |
| * to resolve an int ord to BytesRef. |
| * <p> |
| * Per-Document values in a SortedDocValues are deduplicated, dereferenced, |
| * and sorted into a dictionary of unique values. A pointer to the |
| * dictionary value (ordinal) can be retrieved for each document. Ordinals |
| * are dense and in increasing sorted order. |
| */ |
| |
| public abstract class SortedDocValues extends BinaryDocValues { |
| |
| /** Sole constructor. (For invocation by subclass |
| * constructors, typically implicit.) */ |
| protected SortedDocValues() {} |
| |
| /** |
| * Returns the ordinal for the current docID. |
| * It is illegal to call this method after {@link #advanceExact(int)} |
| * returned {@code false}. |
| * @return ordinal for the document: this is dense, starts at 0, then |
| * increments by 1 for the next value in sorted order. |
| */ |
| public abstract int ordValue() throws IOException; |
| |
| /** Retrieves the value for the specified ordinal. The returned |
| * {@link BytesRef} may be re-used across calls to {@link #lookupOrd(int)} |
| * so make sure to {@link BytesRef#deepCopyOf(BytesRef) copy it} if you want |
| * to keep it around. |
| * @param ord ordinal to lookup (must be >= 0 and < {@link #getValueCount()}) |
| * @see #ordValue() |
| */ |
| public abstract BytesRef lookupOrd(int ord) throws IOException; |
| |
| private final BytesRef empty = new BytesRef(); |
| |
| @Override |
| public BytesRef binaryValue() throws IOException { |
| int ord = ordValue(); |
| if (ord == -1) { |
| return empty; |
| } else { |
| return lookupOrd(ord); |
| } |
| } |
| |
| /** |
| * Returns the number of unique values. |
| * @return number of unique values in this SortedDocValues. This is |
| * also equivalent to one plus the maximum ordinal. |
| */ |
| public abstract int getValueCount(); |
| |
| /** If {@code key} exists, returns its ordinal, else |
| * returns {@code -insertionPoint-1}, like {@code |
| * Arrays.binarySearch}. |
| * |
| * @param key Key to look up |
| **/ |
| public int lookupTerm(BytesRef key) throws IOException { |
| int low = 0; |
| int high = getValueCount()-1; |
| |
| while (low <= high) { |
| int mid = (low + high) >>> 1; |
| final BytesRef term = lookupOrd(mid); |
| int cmp = term.compareTo(key); |
| |
| if (cmp < 0) { |
| low = mid + 1; |
| } else if (cmp > 0) { |
| high = mid - 1; |
| } else { |
| return mid; // key found |
| } |
| } |
| |
| return -(low + 1); // key not found. |
| } |
| |
| /** |
| * Returns a {@link TermsEnum} over the values. |
| * The enum supports {@link TermsEnum#ord()} and {@link TermsEnum#seekExact(long)}. |
| */ |
| public TermsEnum termsEnum() throws IOException { |
| return new SortedDocValuesTermsEnum(this); |
| } |
| |
| /** |
| * Returns a {@link TermsEnum} over the values, filtered by a {@link CompiledAutomaton} |
| * The enum supports {@link TermsEnum#ord()}. |
| */ |
| public TermsEnum intersect(CompiledAutomaton automaton) throws IOException { |
| TermsEnum in = termsEnum(); |
| switch (automaton.type) { |
| case NONE: |
| return TermsEnum.EMPTY; |
| case ALL: |
| return in; |
| case SINGLE: |
| return new SingleTermsEnum(in, automaton.term); |
| case NORMAL: |
| return new AutomatonTermsEnum(in, automaton); |
| default: |
| // unreachable |
| throw new RuntimeException("unhandled case"); |
| } |
| } |
| |
| } |