--- /dev/null
+package org.apache.lucene.util;
+
+import java.util.Comparator;
+
+/**
+ * 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.
+ */
+
+/**
+ * Represents char[], as a slice (offset + length) into an existing char[].
+ * The {@link #chars} member should never be null; use
+ * {@link #EMPTY_ARRAY} if necessary.
+ * @lucene.internal
+ */
+public final class CharsRef implements Comparable<CharsRef>, CharSequence {
+ private static final char[] EMPTY_ARRAY = new char[0];
+ public char[] chars;
+ public int offset;
+ public int length;
+
+ /**
+ * Creates a new {@link CharsRef} initialized an empty array zero-length
+ */
+ public CharsRef() {
+ this(EMPTY_ARRAY, 0, 0);
+ }
+
+ /**
+ * Creates a new {@link CharsRef} initialized with an array of the given
+ * capacity
+ */
+ public CharsRef(int capacity) {
+ chars = new char[capacity];
+ }
+
+ /**
+ * Creates a new {@link CharsRef} initialized with the given array, offset and
+ * length
+ */
+ public CharsRef(char[] chars, int offset, int length) {
+ assert chars != null;
+ assert chars.length >= offset + length;
+ this.chars = chars;
+ this.offset = offset;
+ this.length = length;
+ }
+
+ /**
+ * Creates a new {@link CharsRef} initialized with the given Strings character
+ * array
+ */
+ public CharsRef(String string) {
+ this.chars = string.toCharArray();
+ this.offset = 0;
+ this.length = chars.length;
+ }
+
+ /**
+ * Creates a new {@link CharsRef} and copies the contents of the source into
+ * the new instance.
+ * @see #copy(CharsRef)
+ */
+ public CharsRef(CharsRef other) {
+ copy(other);
+ }
+
+ @Override
+ public Object clone() {
+ return new CharsRef(this);
+ }
+
+ @Override
+ public int hashCode() {
+ final int prime = 31;
+ int result = 0;
+ final int end = offset + length;
+ for (int i = offset; i < end; i++) {
+ result = prime * result + chars[i];
+ }
+ return result;
+ }
+
+ @Override
+ public boolean equals(Object other) {
+ if (this == other) {
+ return true;
+ }
+
+ if (other instanceof CharsRef) {
+ return charsEquals((CharsRef) other);
+ }
+
+ if (other instanceof CharSequence) {
+ final CharSequence seq = (CharSequence) other;
+ if (length == seq.length()) {
+ int n = length;
+ int i = offset;
+ int j = 0;
+ while (n-- != 0) {
+ if (chars[i++] != seq.charAt(j++))
+ return false;
+ }
+ return true;
+ }
+ }
+ return false;
+ }
+
+ public boolean charsEquals(CharsRef other) {
+ if (length == other.length) {
+ int otherUpto = other.offset;
+ final char[] otherChars = other.chars;
+ final int end = offset + length;
+ for (int upto = offset; upto < end; upto++, otherUpto++) {
+ if (chars[upto] != otherChars[otherUpto]) {
+ return false;
+ }
+ }
+ return true;
+ } else {
+ return false;
+ }
+ }
+
+ /** Signed int order comparison */
+ public int compareTo(CharsRef other) {
+ if (this == other)
+ return 0;
+
+ final char[] aChars = this.chars;
+ int aUpto = this.offset;
+ final char[] bChars = other.chars;
+ int bUpto = other.offset;
+
+ final int aStop = aUpto + Math.min(this.length, other.length);
+
+ while (aUpto < aStop) {
+ int aInt = aChars[aUpto++];
+ int bInt = bChars[bUpto++];
+ if (aInt > bInt) {
+ return 1;
+ } else if (aInt < bInt) {
+ return -1;
+ }
+ }
+
+ // One is a prefix of the other, or, they are equal:
+ return this.length - other.length;
+ }
+
+ /**
+ * Copies the given {@link CharsRef} referenced content into this instance
+ * starting at offset 0.
+ *
+ * @param other
+ * the {@link CharsRef} to copy
+ */
+ public void copy(CharsRef other) {
+ if (chars == null) {
+ chars = new char[other.length];
+ } else {
+ chars = ArrayUtil.grow(chars, other.length);
+ }
+ System.arraycopy(other.chars, other.offset, chars, 0, other.length);
+ length = other.length;
+ offset = 0;
+ }
+
+ public void grow(int newLength) {
+ if (chars.length < newLength) {
+ chars = ArrayUtil.grow(chars, newLength);
+ }
+ }
+
+ /**
+ * Copies the given array into this CharsRef starting at offset 0
+ */
+ public void copy(char[] otherChars, int otherOffset, int otherLength) {
+ grow(otherLength);
+ System.arraycopy(otherChars, otherOffset, this.chars, 0,
+ otherLength);
+ this.offset = 0;
+ this.length = otherLength;
+ }
+
+ /**
+ * Appends the given array to this CharsRef
+ */
+ public void append(char[] otherChars, int otherOffset, int otherLength) {
+ final int newLength = length + otherLength;
+ grow(this.offset + newLength);
+ System.arraycopy(otherChars, otherOffset, this.chars, this.offset+length,
+ otherLength);
+ this.length += otherLength;
+ }
+
+ @Override
+ public String toString() {
+ return new String(chars, offset, length);
+ }
+
+ public int length() {
+ return length;
+ }
+
+ public char charAt(int index) {
+ return chars[offset + index];
+ }
+
+ public CharSequence subSequence(int start, int end) {
+ return new CharsRef(chars, offset + start, offset + end - 1);
+ }
+
+ private final static Comparator<CharsRef> utf16SortedAsUTF8SortOrder = new UTF16SortedAsUTF8Comparator();
+
+ public static Comparator<CharsRef> getUTF16SortedAsUTF8Comparator() {
+ return utf16SortedAsUTF8SortOrder;
+ }
+
+ private static class UTF16SortedAsUTF8Comparator implements Comparator<CharsRef> {
+ // Only singleton
+ private UTF16SortedAsUTF8Comparator() {};
+
+ public int compare(CharsRef a, CharsRef b) {
+ if (a == b)
+ return 0;
+
+ final char[] aChars = a.chars;
+ int aUpto = a.offset;
+ final char[] bChars = b.chars;
+ int bUpto = b.offset;
+
+ final int aStop = aUpto + Math.min(a.length, b.length);
+
+ while (aUpto < aStop) {
+ char aChar = aChars[aUpto++];
+ char bChar = bChars[bUpto++];
+ if (aChar != bChar) {
+ // http://icu-project.org/docs/papers/utf16_code_point_order.html
+
+ /* aChar != bChar, fix up each one if they're both in or above the surrogate range, then compare them */
+ if (aChar >= 0xd800 && bChar >= 0xd800) {
+ if (aChar >= 0xe000) {
+ aChar -= 0x800;
+ } else {
+ aChar += 0x2000;
+ }
+
+ if (bChar >= 0xe000) {
+ bChar -= 0x800;
+ } else {
+ bChar += 0x2000;
+ }
+ }
+
+ /* now aChar and bChar are in code point order */
+ return (int)aChar - (int)bChar; /* int must be 32 bits wide */
+ }
+ }
+
+ // One is a prefix of the other, or, they are equal:
+ return a.length - b.length;
+ }
+ }
+}
\ No newline at end of file
fnp / pylucene.git / blobdiff