--- /dev/null
+package org.apache.lucene.store.instantiated;
+
+/**
+ * Copyright 2006 The Apache Software Foundation
+ *
+ * Licensed 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.
+ */
+
+import java.io.Serializable;
+import java.util.Comparator;
+
+import org.apache.lucene.index.Term;
+
+/**
+ * A term in the inverted index, coupled to the documents it occurs in.
+ *
+ * @see org.apache.lucene.index.Term
+ */
+public class InstantiatedTerm
+ implements Serializable {
+
+ private static final long serialVersionUID = 1l;
+
+ public static final Comparator<InstantiatedTerm> comparator = new Comparator<InstantiatedTerm>() {
+ public int compare(InstantiatedTerm instantiatedTerm, InstantiatedTerm instantiatedTerm1) {
+ return instantiatedTerm.getTerm().compareTo(instantiatedTerm1.getTerm());
+ }
+ };
+
+ public static final Comparator<Object> termComparator = new Comparator<Object>() {
+ public int compare(Object o, Object o1) {
+ return ((InstantiatedTerm)o).getTerm().compareTo((Term)o1);
+ }
+ };
+
+ private Term term;
+
+ /**
+ * index of term in InstantiatedIndex
+ * @see org.apache.lucene.store.instantiated.InstantiatedIndex#getOrderedTerms() */
+ private int termIndex;
+
+ /**
+ * @return Term associated with this entry of the index object graph
+ */
+ public Term getTerm() {
+ return term;
+ }
+
+ InstantiatedTerm(String field, String text) {
+ this.term = new Term(field, text);
+ }
+
+// this could speed up TermDocs.skipTo even more
+// private Map</** document number*/Integer, /** index in associatedDocuments */Integer> associatedDocumentIndexByDocumentNumber = new HashMap<Integer, Integer>();
+//
+// public Map</** document number*/Integer, /** index in associatedDocuments */Integer> getAssociatedDocumentIndexByDocumentNumber() {
+// return associatedDocumentIndexByDocumentNumber;
+// }
+
+ /** Ordered by document number */
+ private InstantiatedTermDocumentInformation[] associatedDocuments;
+
+ /**
+ * Meta data per document in which this term is occurring.
+ * Ordered by document number.
+ *
+ * @return Meta data per document in which this term is occurring.
+ */
+ public InstantiatedTermDocumentInformation[] getAssociatedDocuments() {
+ return associatedDocuments;
+ }
+
+
+ /**
+ * Meta data per document in which this term is occurring.
+ * Ordered by document number.
+ *
+ * @param associatedDocuments meta data per document in which this term is occurring, ordered by document number
+ */
+ void setAssociatedDocuments(InstantiatedTermDocumentInformation[] associatedDocuments) {
+ this.associatedDocuments = associatedDocuments;
+ }
+
+ /**
+ * Finds index to the first beyond the current whose document number is
+ * greater than or equal to <i>target</i>, -1 if there is no such element.
+ *
+ * @param target the document number to match
+ * @return -1 if there is no such element
+ */
+ public int seekCeilingDocumentInformationIndex(int target) {
+ return seekCeilingDocumentInformationIndex(target, 0, getAssociatedDocuments().length);
+ }
+
+ /**
+ * Finds index to the first beyond the current whose document number is
+ * greater than or equal to <i>target</i>, -1 if there is no such element.
+ *
+ * @param target the document number to match
+ * @param startOffset associated documents index start offset
+ * @return -1 if there is no such element
+ */
+ public int seekCeilingDocumentInformationIndex(int target, int startOffset) {
+ return seekCeilingDocumentInformationIndex(target, startOffset, getAssociatedDocuments().length);
+ }
+
+ /**
+ * Finds index to the first beyond the current whose document number is
+ * greater than or equal to <i>target</i>, -1 if there is no such element.
+ *
+ * @param target the document number to match
+ * @param startOffset associated documents index start offset
+ * @param endPosition associated documents index end position
+ * @return -1 if there is no such element
+ */
+ public int seekCeilingDocumentInformationIndex(int target, int startOffset, int endPosition) {
+
+ int pos = binarySearchAssociatedDocuments(target, startOffset, endPosition - startOffset);
+
+// int pos = Arrays.binarySearch(getAssociatedDocuments(), target, InstantiatedTermDocumentInformation.doumentNumberIntegerComparator);
+
+ if (pos < 0) {
+ pos = -1 - pos;
+ }
+ if (getAssociatedDocuments().length <= pos) {
+ return -1;
+ } else {
+ return pos;
+ }
+ }
+
+ public int binarySearchAssociatedDocuments(int target) {
+ return binarySearchAssociatedDocuments(target, 0);
+ }
+
+ public int binarySearchAssociatedDocuments(int target, int offset) {
+ return binarySearchAssociatedDocuments(target, offset, associatedDocuments.length - offset);
+ }
+
+ /**
+ * @param target value to search for in the array
+ * @param offset index of the first valid value in the array
+ * @param length number of valid values in the array
+ * @return index of an occurrence of key in array, or -(insertionIndex + 1) if key is not contained in array (<i>insertionIndex</i> is then the index at which key could be inserted).
+ */
+ public int binarySearchAssociatedDocuments(int target, int offset, int length) {
+
+ // implementation originally from http://ochafik.free.fr/blog/?p=106
+
+ if (length == 0) {
+ return -1 - offset;
+ }
+ int min = offset, max = offset + length - 1;
+ int minVal = getAssociatedDocuments()[min].getDocument().getDocumentNumber();
+ int maxVal = getAssociatedDocuments()[max].getDocument().getDocumentNumber();
+
+
+ int nPreviousSteps = 0;
+
+ for (; ;) {
+
+ // be careful not to compute key - minVal, for there might be an integer overflow.
+ if (target <= minVal) return target == minVal ? min : -1 - min;
+ if (target >= maxVal) return target == maxVal ? max : -2 - max;
+
+ assert min != max;
+
+ int pivot;
+ // A typical binarySearch algorithm uses pivot = (min + max) / 2.
+ // The pivot we use here tries to be smarter and to choose a pivot close to the expectable location of the key.
+ // This reduces dramatically the number of steps needed to get to the key.
+ // However, it does not work well with a logarithmic distribution of values, for instance.
+ // When the key is not found quickly the smart way, we switch to the standard pivot.
+ if (nPreviousSteps > 2) {
+ pivot = (min + max) >> 1;
+ // stop increasing nPreviousSteps from now on
+ } else {
+ // NOTE: We cannot do the following operations in int precision, because there might be overflows.
+ // long operations are slower than float operations with the hardware this was tested on (intel core duo 2, JVM 1.6.0).
+ // Overall, using float proved to be the safest and fastest approach.
+ pivot = min + (int) ((target - (float) minVal) / (maxVal - (float) minVal) * (max - min));
+ nPreviousSteps++;
+ }
+
+ int pivotVal = getAssociatedDocuments()[pivot].getDocument().getDocumentNumber();
+
+ // NOTE: do not store key - pivotVal because of overflows
+ if (target > pivotVal) {
+ min = pivot + 1;
+ max--;
+ } else if (target == pivotVal) {
+ return pivot;
+ } else {
+ min++;
+ max = pivot - 1;
+ }
+ maxVal = getAssociatedDocuments()[max].getDocument().getDocumentNumber();
+ minVal = getAssociatedDocuments()[min].getDocument().getDocumentNumber();
+ }
+ }
+
+
+ /**
+ * Navigates to the view of this occurrences of this term in a specific document.
+ *
+ * This method is only used by InstantiatedIndex(IndexReader) and
+ * should not be optimized for less CPU at the cost of more RAM.
+ *
+ * @param documentNumber the n:th document in the index
+ * @return view of this term from specified document
+ */
+ public InstantiatedTermDocumentInformation getAssociatedDocument(int documentNumber) {
+ int pos = binarySearchAssociatedDocuments(documentNumber);
+ return pos < 0 ? null : getAssociatedDocuments()[pos];
+ }
+
+ public final String field() {
+ return term.field();
+ }
+
+ public final String text() {
+ return term.text();
+ }
+
+ @Override
+ public String toString() {
+ return term.toString();
+ }
+
+
+ public int getTermIndex() {
+ return termIndex;
+ }
+
+ public void setTermIndex(int termIndex) {
+ this.termIndex = termIndex;
+ }
+}
fnp / pylucene.git / blobdiff