--- /dev/null
+package org.apache.lucene.analysis;
+
+/**
+ * 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.util.AttributeSource;
+import org.apache.lucene.util.NumericUtils;
+import org.apache.lucene.document.NumericField; // for javadocs
+import org.apache.lucene.search.NumericRangeQuery; // for javadocs
+import org.apache.lucene.search.NumericRangeFilter; // for javadocs
+import org.apache.lucene.analysis.tokenattributes.CharTermAttribute;
+import org.apache.lucene.analysis.tokenattributes.TypeAttribute;
+import org.apache.lucene.analysis.tokenattributes.PositionIncrementAttribute;
+
+/**
+ * <b>Expert:</b> This class provides a {@link TokenStream}
+ * for indexing numeric values that can be used by {@link
+ * NumericRangeQuery} or {@link NumericRangeFilter}.
+ *
+ * <p>Note that for simple usage, {@link NumericField} is
+ * recommended. {@link NumericField} disables norms and
+ * term freqs, as they are not usually needed during
+ * searching. If you need to change these settings, you
+ * should use this class.
+ *
+ * <p>See {@link NumericField} for capabilities of fields
+ * indexed numerically.</p>
+ *
+ * <p>Here's an example usage, for an <code>int</code> field:
+ *
+ * <pre>
+ * Field field = new Field(name, new NumericTokenStream(precisionStep).setIntValue(value));
+ * field.setOmitNorms(true);
+ * field.setIndexOptions(IndexOptions.DOCS_ONLY);
+ * document.add(field);
+ * </pre>
+ *
+ * <p>For optimal performance, re-use the TokenStream and Field instance
+ * for more than one document:
+ *
+ * <pre>
+ * NumericTokenStream stream = new NumericTokenStream(precisionStep);
+ * Field field = new Field(name, stream);
+ * field.setOmitNorms(true);
+ * field.setIndexOptions(IndexOptions.DOCS_ONLY);
+ * Document document = new Document();
+ * document.add(field);
+ *
+ * for(all documents) {
+ * stream.setIntValue(value)
+ * writer.addDocument(document);
+ * }
+ * </pre>
+ *
+ * <p>This stream is not intended to be used in analyzers;
+ * it's more for iterating the different precisions during
+ * indexing a specific numeric value.</p>
+
+ * <p><b>NOTE</b>: as token streams are only consumed once
+ * the document is added to the index, if you index more
+ * than one numeric field, use a separate <code>NumericTokenStream</code>
+ * instance for each.</p>
+ *
+ * <p>See {@link NumericRangeQuery} for more details on the
+ * <a
+ * href="../search/NumericRangeQuery.html#precisionStepDesc"><code>precisionStep</code></a>
+ * parameter as well as how numeric fields work under the hood.</p>
+ *
+ * @since 2.9
+ */
+public final class NumericTokenStream extends TokenStream {
+
+ /** The full precision token gets this token type assigned. */
+ public static final String TOKEN_TYPE_FULL_PREC = "fullPrecNumeric";
+
+ /** The lower precision tokens gets this token type assigned. */
+ public static final String TOKEN_TYPE_LOWER_PREC = "lowerPrecNumeric";
+
+ /**
+ * Creates a token stream for numeric values using the default <code>precisionStep</code>
+ * {@link NumericUtils#PRECISION_STEP_DEFAULT} (4). The stream is not yet initialized,
+ * before using set a value using the various set<em>???</em>Value() methods.
+ */
+ public NumericTokenStream() {
+ this(NumericUtils.PRECISION_STEP_DEFAULT);
+ }
+
+ /**
+ * Creates a token stream for numeric values with the specified
+ * <code>precisionStep</code>. The stream is not yet initialized,
+ * before using set a value using the various set<em>???</em>Value() methods.
+ */
+ public NumericTokenStream(final int precisionStep) {
+ super();
+ this.precisionStep = precisionStep;
+ if (precisionStep < 1)
+ throw new IllegalArgumentException("precisionStep must be >=1");
+ }
+
+ /**
+ * Expert: Creates a token stream for numeric values with the specified
+ * <code>precisionStep</code> using the given {@link AttributeSource}.
+ * The stream is not yet initialized,
+ * before using set a value using the various set<em>???</em>Value() methods.
+ */
+ public NumericTokenStream(AttributeSource source, final int precisionStep) {
+ super(source);
+ this.precisionStep = precisionStep;
+ if (precisionStep < 1)
+ throw new IllegalArgumentException("precisionStep must be >=1");
+ }
+
+ /**
+ * Expert: Creates a token stream for numeric values with the specified
+ * <code>precisionStep</code> using the given
+ * {@link org.apache.lucene.util.AttributeSource.AttributeFactory}.
+ * The stream is not yet initialized,
+ * before using set a value using the various set<em>???</em>Value() methods.
+ */
+ public NumericTokenStream(AttributeFactory factory, final int precisionStep) {
+ super(factory);
+ this.precisionStep = precisionStep;
+ if (precisionStep < 1)
+ throw new IllegalArgumentException("precisionStep must be >=1");
+ }
+
+ /**
+ * Initializes the token stream with the supplied <code>long</code> value.
+ * @param value the value, for which this TokenStream should enumerate tokens.
+ * @return this instance, because of this you can use it the following way:
+ * <code>new Field(name, new NumericTokenStream(precisionStep).setLongValue(value))</code>
+ */
+ public NumericTokenStream setLongValue(final long value) {
+ this.value = value;
+ valSize = 64;
+ shift = 0;
+ return this;
+ }
+
+ /**
+ * Initializes the token stream with the supplied <code>int</code> value.
+ * @param value the value, for which this TokenStream should enumerate tokens.
+ * @return this instance, because of this you can use it the following way:
+ * <code>new Field(name, new NumericTokenStream(precisionStep).setIntValue(value))</code>
+ */
+ public NumericTokenStream setIntValue(final int value) {
+ this.value = value;
+ valSize = 32;
+ shift = 0;
+ return this;
+ }
+
+ /**
+ * Initializes the token stream with the supplied <code>double</code> value.
+ * @param value the value, for which this TokenStream should enumerate tokens.
+ * @return this instance, because of this you can use it the following way:
+ * <code>new Field(name, new NumericTokenStream(precisionStep).setDoubleValue(value))</code>
+ */
+ public NumericTokenStream setDoubleValue(final double value) {
+ this.value = NumericUtils.doubleToSortableLong(value);
+ valSize = 64;
+ shift = 0;
+ return this;
+ }
+
+ /**
+ * Initializes the token stream with the supplied <code>float</code> value.
+ * @param value the value, for which this TokenStream should enumerate tokens.
+ * @return this instance, because of this you can use it the following way:
+ * <code>new Field(name, new NumericTokenStream(precisionStep).setFloatValue(value))</code>
+ */
+ public NumericTokenStream setFloatValue(final float value) {
+ this.value = NumericUtils.floatToSortableInt(value);
+ valSize = 32;
+ shift = 0;
+ return this;
+ }
+
+ @Override
+ public void reset() {
+ if (valSize == 0)
+ throw new IllegalStateException("call set???Value() before usage");
+ shift = 0;
+ }
+
+ @Override
+ public boolean incrementToken() {
+ if (valSize == 0)
+ throw new IllegalStateException("call set???Value() before usage");
+ if (shift >= valSize)
+ return false;
+
+ clearAttributes();
+ final char[] buffer;
+ switch (valSize) {
+ case 64:
+ buffer = termAtt.resizeBuffer(NumericUtils.BUF_SIZE_LONG);
+ termAtt.setLength(NumericUtils.longToPrefixCoded(value, shift, buffer));
+ break;
+
+ case 32:
+ buffer = termAtt.resizeBuffer(NumericUtils.BUF_SIZE_INT);
+ termAtt.setLength(NumericUtils.intToPrefixCoded((int) value, shift, buffer));
+ break;
+
+ default:
+ // should not happen
+ throw new IllegalArgumentException("valSize must be 32 or 64");
+ }
+
+ typeAtt.setType((shift == 0) ? TOKEN_TYPE_FULL_PREC : TOKEN_TYPE_LOWER_PREC);
+ posIncrAtt.setPositionIncrement((shift == 0) ? 1 : 0);
+ shift += precisionStep;
+ return true;
+ }
+
+ @Override
+ public String toString() {
+ final StringBuilder sb = new StringBuilder("(numeric,valSize=").append(valSize);
+ sb.append(",precisionStep=").append(precisionStep).append(')');
+ return sb.toString();
+ }
+
+ /** Returns the precision step. */
+ public int getPrecisionStep() {
+ return precisionStep;
+ }
+
+ // members
+ private final CharTermAttribute termAtt = addAttribute(CharTermAttribute.class);
+ private final TypeAttribute typeAtt = addAttribute(TypeAttribute.class);
+ private final PositionIncrementAttribute posIncrAtt = addAttribute(PositionIncrementAttribute.class);
+
+ private int shift = 0, valSize = 0; // valSize==0 means not initialized
+ private final int precisionStep;
+
+ private long value = 0L;
+}
fnp / pylucene.git / blobdiff