+++ /dev/null
-package org.apache.lucene.search.function;
-
-/**
- * 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.
- */
-
-import org.apache.lucene.search.Explanation;
-
-/**
- * Expert: represents field values as different types.
- * Normally created via a
- * {@link org.apache.lucene.search.function.ValueSource ValueSuorce}
- * for a particular field and reader.
- *
- * @lucene.experimental
- *
- *
- */
-public abstract class DocValues {
- /*
- * DocValues is distinct from ValueSource because
- * there needs to be an object created at query evaluation time that
- * is not referenced by the query itself because:
- * - Query objects should be MT safe
- * - For caching, Query objects are often used as keys... you don't
- * want the Query carrying around big objects
- */
-
- /**
- * Return doc value as a float.
- * <P>Mandatory: every DocValues implementation must implement at least this method.
- * @param doc document whose float value is requested.
- */
- public abstract float floatVal(int doc);
-
- /**
- * Return doc value as an int.
- * <P>Optional: DocValues implementation can (but don't have to) override this method.
- * @param doc document whose int value is requested.
- */
- public int intVal(int doc) {
- return (int) floatVal(doc);
- }
-
- /**
- * Return doc value as a long.
- * <P>Optional: DocValues implementation can (but don't have to) override this method.
- * @param doc document whose long value is requested.
- */
- public long longVal(int doc) {
- return (long) floatVal(doc);
- }
-
- /**
- * Return doc value as a double.
- * <P>Optional: DocValues implementation can (but don't have to) override this method.
- * @param doc document whose double value is requested.
- */
- public double doubleVal(int doc) {
- return floatVal(doc);
- }
-
- /**
- * Return doc value as a string.
- * <P>Optional: DocValues implementation can (but don't have to) override this method.
- * @param doc document whose string value is requested.
- */
- public String strVal(int doc) {
- return Float.toString(floatVal(doc));
- }
-
- /**
- * Return a string representation of a doc value, as required for Explanations.
- */
- public abstract String toString(int doc);
-
- /**
- * Explain the scoring value for the input doc.
- */
- public Explanation explain(int doc) {
- return new Explanation(floatVal(doc), toString(doc));
- }
-
- /**
- * Expert: for test purposes only, return the inner array of values, or null if not applicable.
- * <p>
- * Allows tests to verify that loaded values are:
- * <ol>
- * <li>indeed cached/reused.</li>
- * <li>stored in the expected size/type (byte/short/int/float).</li>
- * </ol>
- * Note: implementations of DocValues must override this method for
- * these test elements to be tested, Otherwise the test would not fail, just
- * print a warning.
- */
- Object getInnerArray() {
- throw new UnsupportedOperationException("this optional method is for test purposes only");
- }
-
- // --- some simple statistics on values
- private float minVal = Float.NaN;
- private float maxVal = Float.NaN;
- private float avgVal = Float.NaN;
- private boolean computed=false;
- // compute optional values
- private void compute() {
- if (computed) {
- return;
- }
- float sum = 0;
- int n = 0;
- while (true) {
- float val;
- try {
- val = floatVal(n);
- } catch (ArrayIndexOutOfBoundsException e) {
- break;
- }
- sum += val;
- minVal = Float.isNaN(minVal) ? val : Math.min(minVal, val);
- maxVal = Float.isNaN(maxVal) ? val : Math.max(maxVal, val);
- ++n;
- }
-
- avgVal = n == 0 ? Float.NaN : sum / n;
- computed = true;
- }
-
- /**
- * Returns the minimum of all values or <code>Float.NaN</code> if this
- * DocValues instance does not contain any value.
- * <p>
- * This operation is optional
- * </p>
- *
- * @return the minimum of all values or <code>Float.NaN</code> if this
- * DocValues instance does not contain any value.
- */
- public float getMinValue() {
- compute();
- return minVal;
- }
-
- /**
- * Returns the maximum of all values or <code>Float.NaN</code> if this
- * DocValues instance does not contain any value.
- * <p>
- * This operation is optional
- * </p>
- *
- * @return the maximum of all values or <code>Float.NaN</code> if this
- * DocValues instance does not contain any value.
- */
- public float getMaxValue() {
- compute();
- return maxVal;
- }
-
- /**
- * Returns the average of all values or <code>Float.NaN</code> if this
- * DocValues instance does not contain any value. *
- * <p>
- * This operation is optional
- * </p>
- *
- * @return the average of all values or <code>Float.NaN</code> if this
- * DocValues instance does not contain any value
- */
- public float getAverageValue() {
- compute();
- return avgVal;
- }
-
-}
fnp / pylucene.git / blobdiff