Java tutorial
/* * 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.document; import org.apache.lucene.document.RangeFieldQuery.QueryType; import org.apache.lucene.search.Query; import org.apache.lucene.util.BytesRef; import org.apache.lucene.util.FutureObjects; import org.apache.lucene.util.NumericUtils; /** * An indexed Long Range field. * <p> * This field indexes dimensional ranges defined as min/max pairs. It supports * up to a maximum of 4 dimensions (indexed as 8 numeric values). With 1 dimension representing a single long range, * 2 dimensions representing a bounding box, 3 dimensions a bounding cube, and 4 dimensions a tesseract. * <p> * Multiple values for the same field in one document is supported, and open ended ranges can be defined using * {@code Long.MIN_VALUE} and {@code Long.MAX_VALUE}. * * <p> * This field defines the following static factory methods for common search operations over long ranges: * <ul> * <li>{@link #newIntersectsQuery newIntersectsQuery()} matches ranges that intersect the defined search range. * <li>{@link #newWithinQuery newWithinQuery()} matches ranges that are within the defined search range. * <li>{@link #newContainsQuery newContainsQuery()} matches ranges that contain the defined search range. * </ul> */ public class LongRange extends Field { /** stores long values so number of bytes is 8 */ public static final int BYTES = Long.BYTES; /** * Create a new LongRange type, from min/max parallel arrays * * @param name field name. must not be null. * @param min range min values; each entry is the min value for the dimension * @param max range max values; each entry is the max value for the dimension */ public LongRange(String name, final long[] min, final long[] max) { super(name, getType(min.length)); setRangeValues(min, max); } /** set the field type */ private static FieldType getType(int dimensions) { if (dimensions > 4) { throw new IllegalArgumentException("LongRange does not support greater than 4 dimensions"); } FieldType ft = new FieldType(); // dimensions is set as 2*dimension size (min/max per dimension) ft.setDimensions(dimensions * 2, BYTES); ft.freeze(); return ft; } /** * Changes the values of the field. * @param min array of min values. (accepts {@code Long.MIN_VALUE}) * @param max array of max values. (accepts {@code Long.MAX_VALUE}) * @throws IllegalArgumentException if {@code min} or {@code max} is invalid */ public void setRangeValues(long[] min, long[] max) { checkArgs(min, max); if (min.length * 2 != type.pointDataDimensionCount() || max.length * 2 != type.pointDataDimensionCount()) { throw new IllegalArgumentException( "field (name=" + name + ") uses " + type.pointDataDimensionCount() / 2 + " dimensions; cannot change to (incoming) " + min.length + " dimensions"); } final byte[] bytes; if (fieldsData == null) { bytes = new byte[BYTES * 2 * min.length]; fieldsData = new BytesRef(bytes); } else { bytes = ((BytesRef) fieldsData).bytes; } verifyAndEncode(min, max, bytes); } /** validate the arguments */ private static void checkArgs(final long[] min, final long[] max) { if (min == null || max == null || min.length == 0 || max.length == 0) { throw new IllegalArgumentException("min/max range values cannot be null or empty"); } if (min.length != max.length) { throw new IllegalArgumentException("min/max ranges must agree"); } if (min.length > 4) { throw new IllegalArgumentException("LongRange does not support greater than 4 dimensions"); } } /** Encodes the min, max ranges into a byte array */ static byte[] encode(long[] min, long[] max) { checkArgs(min, max); byte[] b = new byte[BYTES * 2 * min.length]; verifyAndEncode(min, max, b); return b; } /** * encode the ranges into a sortable byte array ({@code Double.NaN} not allowed) * <p> * example for 4 dimensions (8 bytes per dimension value): * minD1 ... minD4 | maxD1 ... maxD4 */ static void verifyAndEncode(long[] min, long[] max, byte[] bytes) { for (int d = 0, i = 0, j = min.length * BYTES; d < min.length; ++d, i += BYTES, j += BYTES) { if (Double.isNaN(min[d])) { throw new IllegalArgumentException("invalid min value (" + Double.NaN + ")" + " in LongRange"); } if (Double.isNaN(max[d])) { throw new IllegalArgumentException("invalid max value (" + Double.NaN + ")" + " in LongRange"); } if (min[d] > max[d]) { throw new IllegalArgumentException( "min value (" + min[d] + ") is greater than max value (" + max[d] + ")"); } encode(min[d], bytes, i); encode(max[d], bytes, j); } } /** encode the given value into the byte array at the defined offset */ private static void encode(long val, byte[] bytes, int offset) { NumericUtils.longToSortableBytes(val, bytes, offset); } /** * Get the min value for the given dimension * @param dimension the dimension, always positive * @return the decoded min value */ public long getMin(int dimension) { FutureObjects.checkIndex(dimension, type.pointDataDimensionCount() / 2); return decodeMin(((BytesRef) fieldsData).bytes, dimension); } /** * Get the max value for the given dimension * @param dimension the dimension, always positive * @return the decoded max value */ public long getMax(int dimension) { FutureObjects.checkIndex(dimension, type.pointDataDimensionCount() / 2); return decodeMax(((BytesRef) fieldsData).bytes, dimension); } /** decodes the min value (for the defined dimension) from the encoded input byte array */ static long decodeMin(byte[] b, int dimension) { int offset = dimension * BYTES; return NumericUtils.sortableBytesToLong(b, offset); } /** decodes the max value (for the defined dimension) from the encoded input byte array */ static long decodeMax(byte[] b, int dimension) { int offset = b.length / 2 + dimension * BYTES; return NumericUtils.sortableBytesToLong(b, offset); } /** * Create a query for matching indexed ranges that intersect the defined range. * @param field field name. must not be null. * @param min array of min values. (accepts {@code Long.MIN_VALUE}) * @param max array of max values. (accepts {@code Long.MAX_VALUE}) * @return query for matching intersecting ranges (overlap, within, or contains) * @throws IllegalArgumentException if {@code field} is null, {@code min} or {@code max} is invalid */ public static Query newIntersectsQuery(String field, final long[] min, final long[] max) { return newRelationQuery(field, min, max, QueryType.INTERSECTS); } /** * Create a query for matching indexed ranges that contain the defined range. * @param field field name. must not be null. * @param min array of min values. (accepts {@code Long.MIN_VALUE}) * @param max array of max values. (accepts {@code Long.MAX_VALUE}) * @return query for matching ranges that contain the defined range * @throws IllegalArgumentException if {@code field} is null, {@code min} or {@code max} is invalid */ public static Query newContainsQuery(String field, final long[] min, final long[] max) { return newRelationQuery(field, min, max, QueryType.CONTAINS); } /** * Create a query for matching indexed ranges that are within the defined range. * @param field field name. must not be null. * @param min array of min values. (accepts {@code Long.MIN_VALUE}) * @param max array of max values. (accepts {@code Long.MAX_VALUE}) * @return query for matching ranges within the defined range * @throws IllegalArgumentException if {@code field} is null, {@code min} or {@code max} is invalid */ public static Query newWithinQuery(String field, final long[] min, final long[] max) { return newRelationQuery(field, min, max, QueryType.WITHIN); } /** * Create a query for matching indexed ranges that cross the defined range. * A CROSSES is defined as any set of ranges that are not disjoint and not wholly contained by * the query. Effectively, its the complement of union(WITHIN, DISJOINT). * @param field field name. must not be null. * @param min array of min values. (accepts {@code Long.MIN_VALUE}) * @param max array of max values. (accepts {@code Long.MAX_VALUE}) * @return query for matching ranges within the defined range * @throws IllegalArgumentException if {@code field} is null, {@code min} or {@code max} is invalid */ public static Query newCrossesQuery(String field, final long[] min, final long[] max) { return newRelationQuery(field, min, max, QueryType.CROSSES); } /** helper method for creating the desired relational query */ private static Query newRelationQuery(String field, final long[] min, final long[] max, QueryType relation) { checkArgs(min, max); return new RangeFieldQuery(field, encode(min, max), min.length, relation) { @Override protected String toString(byte[] ranges, int dimension) { return LongRange.toString(ranges, dimension); } }; } @Override public String toString() { StringBuilder sb = new StringBuilder(); sb.append(getClass().getSimpleName()); sb.append(" <"); sb.append(name); sb.append(':'); byte[] b = ((BytesRef) fieldsData).bytes; toString(b, 0); for (int d = 0; d < type.pointDataDimensionCount() / 2; ++d) { sb.append(' '); sb.append(toString(b, d)); } sb.append('>'); return sb.toString(); } /** * Returns the String representation for the range at the given dimension * @param ranges the encoded ranges, never null * @param dimension the dimension of interest * @return The string representation for the range at the provided dimension */ private static String toString(byte[] ranges, int dimension) { return "[" + Long.toString(decodeMin(ranges, dimension)) + " : " + Long.toString(decodeMax(ranges, dimension)) + "]"; } }