AlphabeticIndex.java
// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
/*
*******************************************************************************
* Copyright (C) 2008-2016, Google Inc, International Business Machines Corporation
* and others. All Rights Reserved.
*******************************************************************************
*/
package com.ibm.icu.text;
import com.ibm.icu.lang.UCharacter;
import com.ibm.icu.text.AlphabeticIndex.Bucket;
import com.ibm.icu.text.AlphabeticIndex.Bucket.LabelType;
import com.ibm.icu.util.LocaleData;
import com.ibm.icu.util.ULocale;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.Iterator;
import java.util.List;
import java.util.Locale;
/**
* AlphabeticIndex supports the creation of a UI index appropriate for a given language. It can
* support either direct use, or use with a client that doesn't support localized collation. The
* following is an example of what an index might look like in a UI:
*
* <pre>
* <b>... A B C D E F G H I J K L M N O P Q R S T U V W X Y Z ...</b>
*
* <b>A</b>
* Addison
* Albertson
* Azensky
* <b>B</b>
* Baecker
* ...
* </pre>
*
* The class can generate a list of labels for use as a UI "index", that is, a list of clickable
* characters (or character sequences) that allow the user to see a segment (bucket) of a larger
* "target" list. That is, each label corresponds to a bucket in the target list, where everything
* in the bucket is greater than or equal to the character (according to the locale's collation).
* Strings can be added to the index; they will be in sorted order in the right bucket.
*
* <p>The class also supports having buckets for strings before the first (underflow), after the
* last (overflow), and between scripts (inflow). For example, if the index is constructed with
* labels for Russian and English, Greek characters would fall into an inflow bucket between the
* other two scripts.
*
* <p><em>Note:</em> If you expect to have a lot of ASCII or Latin characters as well as characters
* from the user's language, then it is a good idea to call addLabels(ULocale.English).
*
* <h2>Direct Use</h2>
*
* <p>The following shows an example of building an index directly. The "show..." methods below are
* just to illustrate usage.
*
* <pre>
* // Create a simple index where the values for the strings are Integers, and add the strings
*
* AlphabeticIndex<Integer> index = new AlphabeticIndex<Integer>(desiredLocale).addLabels(additionalLocale);
* int counter = 0;
* for (String item : test) {
* index.addRecord(item, counter++);
* }
* ...
* // Show index at top. We could skip or gray out empty buckets
*
* for (AlphabeticIndex.Bucket<Integer> bucket : index) {
* if (showAll || bucket.size() != 0) {
* showLabelAtTop(UI, bucket.getLabel());
* }
* }
* ...
* // Show the buckets with their contents, skipping empty buckets
*
* for (AlphabeticIndex.Bucket<Integer> bucket : index) {
* if (bucket.size() != 0) {
* showLabelInList(UI, bucket.getLabel());
* for (AlphabeticIndex.Record<Integer> item : bucket) {
* showIndexedItem(UI, item.getName(), item.getData());
* }
* </pre>
*
* The caller can build different UIs using this class. For example, an index character could be
* omitted or grayed-out if its bucket is empty. Small buckets could also be combined based on size,
* such as:
*
* <pre>
* <b>... A-F G-N O-Z ...</b>
* </pre>
*
* <h2>Client Support</h2>
*
* <p>Callers can also use the {@link AlphabeticIndex.ImmutableIndex}, or the AlphabeticIndex
* itself, to support sorting on a client that doesn't support AlphabeticIndex functionality.
*
* <p>The ImmutableIndex is both immutable and thread-safe. The corresponding AlphabeticIndex
* methods are not thread-safe because they "lazily" build the index buckets.
*
* <ul>
* <li>ImmutableIndex.getBucket(index) provides random access to all buckets and their labels and
* label types.
* <li>AlphabeticIndex.getBucketLabels() or the bucket iterator on either class can be used to get
* a list of the labels, such as "...", "A", "B",..., and send that list to the client.
* <li>When the client has a new name, it sends that name to the server. The server needs to call
* the following methods, and communicate the bucketIndex and collationKey back to the client.
* <pre>
* int bucketIndex = index.getBucketIndex(name);
* String label = immutableIndex.getBucket(bucketIndex).getLabel(); // optional
* RawCollationKey collationKey = collator.getRawCollationKey(name, null);
* </pre>
* <li>The client would put the name (and associated information) into its bucket for bucketIndex.
* The collationKey is a sequence of bytes that can be compared with a binary compare, and
* produce the right localized result.
* </ul>
*
* @author Mark Davis
* @stable ICU 4.8
*/
public final class AlphabeticIndex<V> implements Iterable<Bucket<V>> {
/**
* Prefix string for Chinese index buckets. See
* http://unicode.org/repos/cldr/trunk/specs/ldml/tr35-collation.html#Collation_Indexes
*/
private static final String BASE = "\uFDD0";
private static final char CGJ = '\u034F';
private static final Comparator<String> binaryCmp = new UTF16.StringComparator(true, false, 0);
private final RuleBasedCollator collatorOriginal;
private final RuleBasedCollator collatorPrimaryOnly;
private RuleBasedCollator collatorExternal;
// Comparator for records, so that the Record class can be static.
private final Comparator<Record<V>> recordComparator =
new Comparator<Record<V>>() {
@Override
public int compare(Record<V> o1, Record<V> o2) {
return collatorOriginal.compare(o1.name, o2.name);
}
};
private final List<String> firstCharsInScripts;
// We accumulate these as we build up the input parameters
private final UnicodeSet initialLabels = new UnicodeSet();
private List<Record<V>> inputList;
// Lazy evaluated: null means that we have not built yet.
private BucketList<V> buckets;
private String overflowLabel = "\u2026";
private String underflowLabel = "\u2026";
private String inflowLabel = "\u2026";
/**
* Immutable, thread-safe version of {@link AlphabeticIndex}. This class provides thread-safe
* methods for bucketing, and random access to buckets and their properties, but does not offer
* adding records to the index.
*
* @param <V> The Record value type is unused. It can be omitted for this class if it was
* omitted for the AlphabeticIndex that built it.
* @stable ICU 51
*/
public static final class ImmutableIndex<V> implements Iterable<Bucket<V>> {
private final BucketList<V> buckets;
private final Collator collatorPrimaryOnly;
private ImmutableIndex(BucketList<V> bucketList, Collator collatorPrimaryOnly) {
this.buckets = bucketList;
this.collatorPrimaryOnly = collatorPrimaryOnly;
}
/**
* Returns the number of index buckets and labels, including underflow/inflow/overflow.
*
* @return the number of index buckets
* @stable ICU 51
*/
public int getBucketCount() {
return buckets.getBucketCount();
}
/**
* Finds the index bucket for the given name and returns the number of that bucket. Use
* {@link #getBucket(int)} to get the bucket's properties.
*
* @param name the string to be sorted into an index bucket
* @return the bucket number for the name
* @stable ICU 51
*/
public int getBucketIndex(CharSequence name) {
return buckets.getBucketIndex(name, collatorPrimaryOnly);
}
/**
* Returns the index-th bucket. Returns null if the index is out of range.
*
* @param index bucket number
* @return the index-th bucket
* @stable ICU 51
*/
public Bucket<V> getBucket(int index) {
if (0 <= index && index < buckets.getBucketCount()) {
return buckets.immutableVisibleList.get(index);
} else {
return null;
}
}
/**
* {@inheritDoc}
*
* @stable ICU 51
*/
@Override
public Iterator<Bucket<V>> iterator() {
return buckets.iterator();
}
}
/**
* Create the index object.
*
* @param locale The locale for the index.
* @stable ICU 4.8
*/
public AlphabeticIndex(ULocale locale) {
this(locale, null);
}
/**
* Create the index object.
*
* @param locale The locale for the index.
* @stable ICU 4.8
*/
public AlphabeticIndex(Locale locale) {
this(ULocale.forLocale(locale), null);
}
/**
* Create an AlphabeticIndex that uses a specific collator.
*
* <p>The index will be created with no labels; the addLabels() function must be called after
* creation to add the desired labels to the index.
*
* <p>The index will work directly with the supplied collator. If the caller will need to
* continue working with the collator it should be cloned first, so that the collator provided
* to the AlphabeticIndex remains unchanged after creation of the index.
*
* @param collator The collator to use to order the contents of this index.
* @stable ICU 51
*/
public AlphabeticIndex(RuleBasedCollator collator) {
this(null, collator);
}
/** Internal constructor containing implementation used by public constructors. */
private AlphabeticIndex(ULocale locale, RuleBasedCollator collator) {
collatorOriginal =
collator != null ? collator : (RuleBasedCollator) Collator.getInstance(locale);
try {
collatorPrimaryOnly = collatorOriginal.cloneAsThawed();
} catch (Exception e) {
// should never happen
throw new IllegalStateException("Collator cannot be cloned", e);
}
collatorPrimaryOnly.setStrength(Collator.PRIMARY);
collatorPrimaryOnly.freeze();
firstCharsInScripts = getFirstCharactersInScripts();
Collections.sort(firstCharsInScripts, collatorPrimaryOnly);
// Guard against a degenerate collator where
// some script boundary strings are primary ignorable.
for (; ; ) {
if (firstCharsInScripts.isEmpty()) {
throw new IllegalArgumentException(
"AlphabeticIndex requires some non-ignorable script boundary strings");
}
if (collatorPrimaryOnly.compare(firstCharsInScripts.get(0), "") == 0) {
firstCharsInScripts.remove(0);
} else {
break;
}
}
// Chinese index characters, which are specific to each of the several Chinese tailorings,
// take precedence over the single locale data exemplar set per language.
if (!addChineseIndexCharacters() && locale != null) {
addIndexExemplars(locale);
}
}
/**
* Add more index characters (aside from what are in the locale)
*
* @param additions additional characters to add to the index, such as A-Z.
* @return this, for chaining
* @stable ICU 4.8
*/
public AlphabeticIndex<V> addLabels(UnicodeSet additions) {
initialLabels.addAll(additions);
buckets = null;
return this;
}
/**
* Add more index characters (aside from what are in the locale)
*
* @param additions additional characters to add to the index, such as those in Swedish.
* @return this, for chaining
* @stable ICU 4.8
*/
public AlphabeticIndex<V> addLabels(ULocale... additions) {
for (ULocale addition : additions) {
addIndexExemplars(addition);
}
buckets = null;
return this;
}
/**
* Add more index characters (aside from what are in the locale)
*
* @param additions additional characters to add to the index, such as those in Swedish.
* @return this, for chaining
* @stable ICU 4.8
*/
public AlphabeticIndex<V> addLabels(Locale... additions) {
for (Locale addition : additions) {
addIndexExemplars(ULocale.forLocale(addition));
}
buckets = null;
return this;
}
/**
* Set the overflow label
*
* @param overflowLabel see class description
* @return this, for chaining
* @stable ICU 4.8
*/
public AlphabeticIndex<V> setOverflowLabel(String overflowLabel) {
this.overflowLabel = overflowLabel;
buckets = null;
return this;
}
/**
* Get the default label used in the IndexCharacters' locale for underflow, eg the last item in:
* X Y Z ...
*
* @return underflow label
* @stable ICU 4.8
*/
public String getUnderflowLabel() {
return underflowLabel; // TODO get localized version
}
/**
* Set the underflowLabel label
*
* @param underflowLabel see class description
* @return this, for chaining
* @stable ICU 4.8
*/
public AlphabeticIndex<V> setUnderflowLabel(String underflowLabel) {
this.underflowLabel = underflowLabel;
buckets = null;
return this;
}
/**
* Get the default label used in the IndexCharacters' locale for overflow, eg the first item in:
* ... A B C
*
* @return overflow label
* @stable ICU 4.8
*/
public String getOverflowLabel() {
return overflowLabel; // TODO get localized version
}
/**
* Set the inflowLabel label
*
* @param inflowLabel see class description
* @return this, for chaining
* @stable ICU 4.8
*/
public AlphabeticIndex<V> setInflowLabel(String inflowLabel) {
this.inflowLabel = inflowLabel;
buckets = null;
return this;
}
/**
* Get the default label used for abbreviated buckets <i>between</i> other labels. For example,
* consider the labels for Latin and Greek are used: X Y Z ... Α Β Γ.
*
* @return inflow label
* @stable ICU 4.8
*/
public String getInflowLabel() {
return inflowLabel; // TODO get localized version
}
/**
* Get the limit on the number of labels in the index. The number of buckets can be slightly
* larger: see getBucketCount().
*
* @return maxLabelCount maximum number of labels.
* @stable ICU 4.8
*/
public int getMaxLabelCount() {
return maxLabelCount;
}
/**
* Set a limit on the number of labels in the index. The number of buckets can be slightly
* larger: see getBucketCount().
*
* @param maxLabelCount Set the maximum number of labels. Currently, if the number is exceeded,
* then every nth item is removed to bring the count down. A more sophisticated mechanism
* may be available in the future.
* @return this, for chaining
* @stable ICU 4.8
*/
public AlphabeticIndex<V> setMaxLabelCount(int maxLabelCount) {
this.maxLabelCount = maxLabelCount;
buckets = null;
return this;
}
/**
* Determine the best labels to use. This is based on the exemplars, but we also process to make
* sure that they are unique, and sort differently, and that the overall list is small enough.
*/
private List<String> initLabels() {
Normalizer2 nfkdNormalizer = Normalizer2.getNFKDInstance();
List<String> indexCharacters = new ArrayList<String>();
String firstScriptBoundary = firstCharsInScripts.get(0);
String overflowBoundary = firstCharsInScripts.get(firstCharsInScripts.size() - 1);
// We make a sorted array of elements.
// Some of the input may be redundant.
// That is, we might have c, ch, d, where "ch" sorts just like "c", "h".
// We filter out those cases.
for (String item : initialLabels) {
boolean checkDistinct;
if (!UTF16.hasMoreCodePointsThan(item, 1)) {
checkDistinct = false;
} else if (item.charAt(item.length() - 1) == '*'
&& item.charAt(item.length() - 2) != '*') {
// Use a label if it is marked with one trailing star,
// even if the label string sorts the same when all contractions are suppressed.
item = item.substring(0, item.length() - 1);
checkDistinct = false;
} else {
checkDistinct = true;
}
if (collatorPrimaryOnly.compare(item, firstScriptBoundary) < 0) {
// Ignore a primary-ignorable or non-alphabetic index character.
} else if (collatorPrimaryOnly.compare(item, overflowBoundary) >= 0) {
// Ignore an index character that will land in the overflow bucket.
} else if (checkDistinct && collatorPrimaryOnly.compare(item, separated(item)) == 0) {
// Ignore a multi-code point index character that does not sort distinctly
// from the sequence of its separate characters.
} else {
int insertionPoint =
Collections.binarySearch(indexCharacters, item, collatorPrimaryOnly);
if (insertionPoint < 0) {
indexCharacters.add(~insertionPoint, item);
} else {
String itemAlreadyIn = indexCharacters.get(insertionPoint);
if (isOneLabelBetterThanOther(nfkdNormalizer, item, itemAlreadyIn)) {
indexCharacters.set(insertionPoint, item);
}
}
}
}
// if the result is still too large, cut down to maxLabelCount elements, by removing every
// nth element
final int size = indexCharacters.size() - 1;
if (size > maxLabelCount) {
int count = 0;
int old = -1;
for (Iterator<String> it = indexCharacters.iterator(); it.hasNext(); ) {
++count;
it.next();
final int bump = count * maxLabelCount / size;
if (bump == old) {
it.remove();
} else {
old = bump;
}
}
}
return indexCharacters;
}
private static String fixLabel(String current) {
if (!current.startsWith(BASE)) {
return current;
}
int rest = current.charAt(BASE.length());
if (0x2800 < rest && rest <= 0x28FF) { // stroke count
return (rest - 0x2800) + "\u5283";
}
return current.substring(BASE.length());
}
/**
* This method is called to get the index exemplars. Normally these come from the locale
* directly, but if they aren't available, we have to synthesize them.
*/
private void addIndexExemplars(ULocale locale) {
UnicodeSet exemplars = LocaleData.getExemplarSet(locale, 0, LocaleData.ES_INDEX);
if (exemplars != null && !exemplars.isEmpty()) {
initialLabels.addAll(exemplars);
return;
}
// The locale data did not include explicit Index characters.
// Synthesize a set of them from the locale's standard exemplar characters.
exemplars = LocaleData.getExemplarSet(locale, 0, LocaleData.ES_STANDARD);
exemplars = exemplars.cloneAsThawed();
// question: should we add auxiliary exemplars?
if (exemplars.containsSome('a', 'z') || exemplars.isEmpty()) {
exemplars.addAll('a', 'z');
}
if (exemplars.containsSome(0xAC00, 0xD7A3)) { // Hangul syllables
// cut down to small list
exemplars
.remove(0xAC00, 0xD7A3)
.add(0xAC00)
.add(0xB098)
.add(0xB2E4)
.add(0xB77C)
.add(0xB9C8)
.add(0xBC14)
.add(0xC0AC)
.add(0xC544)
.add(0xC790)
.add(0xCC28)
.add(0xCE74)
.add(0xD0C0)
.add(0xD30C)
.add(0xD558);
}
if (exemplars.containsSome(0x1200, 0x137F)) { // Ethiopic block
// cut down to small list
// make use of the fact that Ethiopic is allocated in 8's, where
// the base is 0 mod 8.
UnicodeSet ethiopic = new UnicodeSet("[ሀለሐመሠረሰሸቀቈቐቘበቨተቸኀኈነኘአከኰኸዀወዐዘዠየደዸጀገጐጘጠጨጰጸፀፈፐፘ]");
ethiopic.retainAll(exemplars);
exemplars.remove('ሀ', 0x137F).addAll(ethiopic);
}
// Upper-case any that aren't already so.
// (We only do this for synthesized index characters.)
for (String item : exemplars) {
initialLabels.add(UCharacter.toUpperCase(locale, item));
}
}
/** Add Chinese index characters from the tailoring. */
private boolean addChineseIndexCharacters() {
UnicodeSet contractions = new UnicodeSet();
try {
collatorPrimaryOnly.internalAddContractions(BASE.charAt(0), contractions);
} catch (Exception e) {
return false;
}
if (contractions.isEmpty()) {
return false;
}
initialLabels.addAll(contractions);
for (String s : contractions) {
assert (s.startsWith(BASE));
char c = s.charAt(s.length() - 1);
if (0x41 <= c && c <= 0x5A) { // A-Z
// There are Pinyin labels, add ASCII A-Z labels as well.
initialLabels.add(0x41, 0x5A); // A-Z
break;
}
}
return true;
}
/**
* Return the string with interspersed CGJs. Input must have more than 2 codepoints.
*
* <p>This is used to test whether contractions sort differently from their components.
*/
private String separated(String item) {
StringBuilder result = new StringBuilder();
// add a CGJ except within surrogates
char last = item.charAt(0);
result.append(last);
for (int i = 1; i < item.length(); ++i) {
char ch = item.charAt(i);
if (!UCharacter.isHighSurrogate(last) || !UCharacter.isLowSurrogate(ch)) {
result.append(CGJ);
}
result.append(ch);
last = ch;
}
return result.toString();
}
/**
* Builds an immutable, thread-safe version of this instance, without data records.
*
* @return an immutable index instance
* @stable ICU 51
*/
public ImmutableIndex<V> buildImmutableIndex() {
// The current AlphabeticIndex Java code never modifies the bucket list once built.
// If it contains no records, we can use it.
// addRecord() sets buckets=null rather than inserting the new record into it.
BucketList<V> immutableBucketList;
if (inputList != null && !inputList.isEmpty()) {
// We need a bucket list with no records.
immutableBucketList = createBucketList();
} else {
if (buckets == null) {
buckets = createBucketList();
}
immutableBucketList = buckets;
}
return new ImmutableIndex<V>(immutableBucketList, collatorPrimaryOnly);
}
/**
* Get the labels.
*
* @return The list of bucket labels, after processing.
* @stable ICU 4.8
*/
public List<String> getBucketLabels() {
initBuckets();
ArrayList<String> result = new ArrayList<String>();
for (Bucket<V> bucket : buckets) {
result.add(bucket.getLabel());
}
return result;
}
/**
* Get a clone of the collator used internally. Note that for performance reasons, the clone is
* only done once, and then stored. The next time it is accessed, the same instance is returned.
*
* <p><b><i>Don't use this method across threads if you are changing the settings on the
* collator, at least not without synchronizing.</i></b>
*
* @return a clone of the collator used internally
* @stable ICU 4.8
*/
public RuleBasedCollator getCollator() {
if (collatorExternal == null) {
try {
collatorExternal = collatorOriginal.clone();
} catch (Exception e) {
// should never happen
throw new IllegalStateException("Collator cannot be cloned", e);
}
}
return collatorExternal;
}
/**
* Add a record (name and data) to the index. The name will be used to sort the items into
* buckets, and to sort within the bucket. Two records may have the same name. When they do, the
* sort order is according to the order added: the first added comes first.
*
* @param name Name, such as a name
* @param data Data, such as an address or link
* @return this, for chaining
* @stable ICU 4.8
*/
public AlphabeticIndex<V> addRecord(CharSequence name, V data) {
// TODO instead of invalidating, just add to unprocessed list.
buckets = null; // invalidate old bucketlist
if (inputList == null) {
inputList = new ArrayList<Record<V>>();
}
inputList.add(new Record<V>(name, data));
return this;
}
/**
* Get the bucket number for the given name. This routine permits callers to implement their own
* bucket handling mechanisms, including client-server handling. For example, when a new name is
* created on the client, it can ask the server for the bucket for that name, and the sortkey
* (using getCollator). Once the client has that information, it can put the name into the right
* bucket, and sort it within that bucket, without having access to the index or collator.
*
* <p>Note that the bucket number (and sort key) are only valid for the settings of the current
* AlphabeticIndex; if those are changed, then the bucket number and sort key must be
* regenerated.
*
* @param name Name, such as a name
* @return the bucket index for the name
* @stable ICU 4.8
*/
public int getBucketIndex(CharSequence name) {
initBuckets();
return buckets.getBucketIndex(name, collatorPrimaryOnly);
}
/**
* Clear the index.
*
* @return this, for chaining
* @stable ICU 4.8
*/
public AlphabeticIndex<V> clearRecords() {
if (inputList != null && !inputList.isEmpty()) {
inputList.clear();
buckets = null;
}
return this;
}
/**
* Return the number of buckets in the index. This will be the same as the number of labels,
* plus buckets for the underflow, overflow, and inflow(s).
*
* @return number of buckets
* @stable ICU 4.8
*/
public int getBucketCount() {
initBuckets();
return buckets.getBucketCount();
}
/**
* Return the number of records in the index: that is, the total number of distinct
* <name,data> pairs added with addRecord(...), over all the buckets.
*
* @return total number of records in buckets
* @stable ICU 4.8
*/
public int getRecordCount() {
return inputList != null ? inputList.size() : 0;
}
/**
* Return an iterator over the buckets.
*
* @return iterator over buckets.
* @stable ICU 4.8
*/
@Override
public Iterator<Bucket<V>> iterator() {
initBuckets();
return buckets.iterator();
}
/** Creates an index, and buckets and sorts the list of records into the index. */
private void initBuckets() {
if (buckets != null) {
return;
}
buckets = createBucketList();
if (inputList == null || inputList.isEmpty()) {
return;
}
// Sort the records by name.
// Stable sort preserves input order of collation duplicates.
Collections.sort(inputList, recordComparator);
// Now, we traverse all of the input, which is now sorted.
// If the item doesn't go in the current bucket, we find the next bucket that contains it.
// This makes the process order n*log(n), since we just sort the list and then do a linear
// process.
// However, if the user adds an item at a time and then gets the buckets, this isn't
// efficient, so
// we need to improve it for that case.
Iterator<Bucket<V>> bucketIterator = buckets.fullIterator();
Bucket<V> currentBucket = bucketIterator.next();
Bucket<V> nextBucket;
String upperBoundary;
if (bucketIterator.hasNext()) {
nextBucket = bucketIterator.next();
upperBoundary = nextBucket.lowerBoundary;
} else {
nextBucket = null;
upperBoundary = null;
}
for (Record<V> r : inputList) {
// if the current bucket isn't the right one, find the one that is
// We have a special flag for the last bucket so that we don't look any further
while (upperBoundary != null
&& collatorPrimaryOnly.compare(r.name, upperBoundary) >= 0) {
currentBucket = nextBucket;
// now reset the boundary that we compare against
if (bucketIterator.hasNext()) {
nextBucket = bucketIterator.next();
upperBoundary = nextBucket.lowerBoundary;
} else {
upperBoundary = null;
}
}
// now put the record into the bucket.
Bucket<V> bucket = currentBucket;
if (bucket.displayBucket != null) {
bucket = bucket.displayBucket;
}
if (bucket.records == null) {
bucket.records = new ArrayList<Record<V>>();
}
bucket.records.add(r);
}
}
private int maxLabelCount = 99;
/**
* Returns true if one index character string is "better" than the other. Shorter NFKD is
* better, and otherwise NFKD-binary-less-than is better, and otherwise binary-less-than is
* better.
*/
private static boolean isOneLabelBetterThanOther(
Normalizer2 nfkdNormalizer, String one, String other) {
// This is called with primary-equal strings, but never with one.equals(other).
String n1 = nfkdNormalizer.normalize(one);
String n2 = nfkdNormalizer.normalize(other);
int result = n1.codePointCount(0, n1.length()) - n2.codePointCount(0, n2.length());
if (result != 0) {
return result < 0;
}
result = binaryCmp.compare(n1, n2);
if (result != 0) {
return result < 0;
}
return binaryCmp.compare(one, other) < 0;
}
/**
* A (name, data) pair, to be sorted by name into one of the index buckets. The user data is not
* used by the index implementation.
*
* @stable ICU 4.8
*/
public static class Record<V> {
private final CharSequence name;
private final V data;
private Record(CharSequence name, V data) {
this.name = name;
this.data = data;
}
/**
* Get the name
*
* @return the name
* @stable ICU 4.8
*/
public CharSequence getName() {
return name;
}
/**
* Get the data
*
* @return the data
* @stable ICU 4.8
*/
public V getData() {
return data;
}
/**
* Standard toString()
*
* @stable ICU 4.8
*/
@Override
public String toString() {
return name + "=" + data;
}
}
/**
* An index "bucket" with a label string and type. It is referenced by {@link
* AlphabeticIndex#getBucketIndex(CharSequence)} and {@link
* AlphabeticIndex.ImmutableIndex#getBucketIndex(CharSequence)}, returned by {@link
* AlphabeticIndex.ImmutableIndex#getBucket(int)}, and {@link
* AlphabeticIndex#addRecord(CharSequence, Object)} adds a record into a bucket according to the
* record's name.
*
* @param <V> Data type
* @stable ICU 4.8
*/
public static class Bucket<V> implements Iterable<Record<V>> {
private final String label;
private final String lowerBoundary;
private final LabelType labelType;
private Bucket<V> displayBucket;
private int displayIndex;
private List<Record<V>> records;
/**
* Type of the label
*
* @stable ICU 4.8
*/
public enum LabelType {
/**
* Normal
*
* @stable ICU 4.8
*/
NORMAL,
/**
* Underflow (before the first)
*
* @stable ICU 4.8
*/
UNDERFLOW,
/**
* Inflow (between scripts)
*
* @stable ICU 4.8
*/
INFLOW,
/**
* Overflow (after the last)
*
* @stable ICU 4.8
*/
OVERFLOW
}
/**
* Set up the bucket.
*
* @param label label for the bucket
* @param labelType is an underflow, overflow, or inflow bucket
* @stable ICU 4.8
*/
private Bucket(String label, String lowerBoundary, LabelType labelType) {
this.label = label;
this.lowerBoundary = lowerBoundary;
this.labelType = labelType;
}
/**
* Get the label
*
* @return label for the bucket
* @stable ICU 4.8
*/
public String getLabel() {
return label;
}
/**
* Is a normal, underflow, overflow, or inflow bucket
*
* @return is an underflow, overflow, or inflow bucket
* @stable ICU 4.8
*/
public LabelType getLabelType() {
return labelType;
}
/**
* Get the number of records in the bucket.
*
* @return number of records in bucket
* @stable ICU 4.8
*/
public int size() {
return records == null ? 0 : records.size();
}
/**
* Iterator over the records in the bucket
*
* @stable ICU 4.8
*/
@Override
public Iterator<Record<V>> iterator() {
if (records == null) {
return Collections.<Record<V>>emptyList().iterator();
}
return records.iterator();
}
/**
* Standard toString()
*
* @stable ICU 4.8
*/
@Override
public String toString() {
return "{"
+ "labelType="
+ labelType
+ ", "
+ "lowerBoundary="
+ lowerBoundary
+ ", "
+ "label="
+ label
+ "}";
}
}
private BucketList<V> createBucketList() {
// Initialize indexCharacters.
List<String> indexCharacters = initLabels();
// Variables for hasMultiplePrimaryWeights().
long variableTop;
if (collatorPrimaryOnly.isAlternateHandlingShifted()) {
variableTop = collatorPrimaryOnly.getVariableTop() & 0xffffffffL;
} else {
variableTop = 0;
}
boolean hasInvisibleBuckets = false;
// Helper arrays for Chinese Pinyin collation.
@SuppressWarnings({"rawtypes", "unchecked"})
Bucket<V>[] asciiBuckets = new Bucket[26];
@SuppressWarnings({"rawtypes", "unchecked"})
Bucket<V>[] pinyinBuckets = new Bucket[26];
boolean hasPinyin = false;
ArrayList<Bucket<V>> bucketList = new ArrayList<Bucket<V>>();
// underflow bucket
bucketList.add(new Bucket<V>(getUnderflowLabel(), "", LabelType.UNDERFLOW));
// fix up the list, adding underflow, additions, overflow
// Insert inflow labels as needed.
int scriptIndex = -1;
String scriptUpperBoundary = "";
for (String current : indexCharacters) {
if (collatorPrimaryOnly.compare(current, scriptUpperBoundary) >= 0) {
// We crossed the script boundary into a new script.
String inflowBoundary = scriptUpperBoundary;
boolean skippedScript = false;
for (; ; ) {
scriptUpperBoundary = firstCharsInScripts.get(++scriptIndex);
if (collatorPrimaryOnly.compare(current, scriptUpperBoundary) < 0) {
break;
}
skippedScript = true;
}
if (skippedScript && bucketList.size() > 1) {
// We are skipping one or more scripts,
// and we are not just getting out of the underflow label.
bucketList.add(
new Bucket<V>(getInflowLabel(), inflowBoundary, LabelType.INFLOW));
}
}
// Add a bucket with the current label.
Bucket<V> bucket = new Bucket<V>(fixLabel(current), current, LabelType.NORMAL);
bucketList.add(bucket);
// Remember ASCII and Pinyin buckets for Pinyin redirects.
char c;
if (current.length() == 1 && 'A' <= (c = current.charAt(0)) && c <= 'Z') {
asciiBuckets[c - 'A'] = bucket;
} else if (current.length() == BASE.length() + 1
&& current.startsWith(BASE)
&& 'A' <= (c = current.charAt(BASE.length()))
&& c <= 'Z') {
pinyinBuckets[c - 'A'] = bucket;
hasPinyin = true;
}
// Check for multiple primary weights.
if (!current.startsWith(BASE)
&& hasMultiplePrimaryWeights(collatorPrimaryOnly, variableTop, current)
&& !current.endsWith("\uffff")) {
// "Æ" or "Sch" etc.
for (int i = bucketList.size() - 2; ; --i) {
Bucket<V> singleBucket = bucketList.get(i);
if (singleBucket.labelType != LabelType.NORMAL) {
// There is no single-character bucket since the last
// underflow or inflow label.
break;
}
if (singleBucket.displayBucket == null
&& !hasMultiplePrimaryWeights(
collatorPrimaryOnly, variableTop, singleBucket.lowerBoundary)) {
// Add an invisible bucket that redirects strings greater than the expansion
// to the previous single-character bucket.
// For example, after ... Q R S Sch we add Sch\uFFFF->S
// and after ... Q R S Sch Sch\uFFFF St we add St\uFFFF->S.
bucket = new Bucket<V>("", current + "\uFFFF", LabelType.NORMAL);
bucket.displayBucket = singleBucket;
bucketList.add(bucket);
hasInvisibleBuckets = true;
break;
}
}
}
}
if (bucketList.size() == 1) {
// No real labels, show only the underflow label.
return new BucketList<V>(bucketList, bucketList);
}
// overflow bucket
bucketList.add(
new Bucket<V>(
getOverflowLabel(), scriptUpperBoundary, LabelType.OVERFLOW)); // final
if (hasPinyin) {
// Redirect Pinyin buckets.
Bucket<V> asciiBucket = null;
for (int i = 0; i < 26; ++i) {
if (asciiBuckets[i] != null) {
asciiBucket = asciiBuckets[i];
}
if (pinyinBuckets[i] != null && asciiBucket != null) {
pinyinBuckets[i].displayBucket = asciiBucket;
hasInvisibleBuckets = true;
}
}
}
if (!hasInvisibleBuckets) {
return new BucketList<V>(bucketList, bucketList);
}
// Merge inflow buckets that are visually adjacent.
// Iterate backwards: Merge inflow into overflow rather than the other way around.
int i = bucketList.size() - 1;
Bucket<V> nextBucket = bucketList.get(i);
while (--i > 0) {
Bucket<V> bucket = bucketList.get(i);
if (bucket.displayBucket != null) {
continue; // skip invisible buckets
}
if (bucket.labelType == LabelType.INFLOW) {
if (nextBucket.labelType != LabelType.NORMAL) {
bucket.displayBucket = nextBucket;
continue;
}
}
nextBucket = bucket;
}
ArrayList<Bucket<V>> publicBucketList = new ArrayList<Bucket<V>>();
for (Bucket<V> bucket : bucketList) {
if (bucket.displayBucket == null) {
publicBucketList.add(bucket);
}
}
return new BucketList<V>(bucketList, publicBucketList);
}
private static class BucketList<V> implements Iterable<Bucket<V>> {
private final ArrayList<Bucket<V>> bucketList;
private final List<Bucket<V>> immutableVisibleList;
private BucketList(ArrayList<Bucket<V>> bucketList, ArrayList<Bucket<V>> publicBucketList) {
this.bucketList = bucketList;
int displayIndex = 0;
for (Bucket<V> bucket : publicBucketList) {
bucket.displayIndex = displayIndex++;
}
immutableVisibleList = Collections.unmodifiableList(publicBucketList);
}
private int getBucketCount() {
return immutableVisibleList.size();
}
private int getBucketIndex(CharSequence name, Collator collatorPrimaryOnly) {
// binary search
int start = 0;
int limit = bucketList.size();
while ((start + 1) < limit) {
int i = (start + limit) / 2;
Bucket<V> bucket = bucketList.get(i);
int nameVsBucket = collatorPrimaryOnly.compare(name, bucket.lowerBoundary);
if (nameVsBucket < 0) {
limit = i;
} else {
start = i;
}
}
Bucket<V> bucket = bucketList.get(start);
if (bucket.displayBucket != null) {
bucket = bucket.displayBucket;
}
return bucket.displayIndex;
}
/** Private iterator over all the buckets, visible and invisible */
private Iterator<Bucket<V>> fullIterator() {
return bucketList.iterator();
}
/** Iterator over just the visible buckets. */
@Override
public Iterator<Bucket<V>> iterator() {
return immutableVisibleList.iterator(); // use immutable list to prevent remove().
}
}
private static boolean hasMultiplePrimaryWeights(
RuleBasedCollator coll, long variableTop, String s) {
long[] ces = coll.internalGetCEs(s);
boolean seenPrimary = false;
for (int i = 0; i < ces.length; ++i) {
long ce = ces[i];
long p = ce >>> 32;
if (p > variableTop) {
// not primary ignorable
if (seenPrimary) {
return true;
}
seenPrimary = true;
}
}
return false;
}
// TODO: Surely we have at least a ticket for porting these mask values to UCharacter.java?!
private static final int GC_LU_MASK = 1 << UCharacter.UPPERCASE_LETTER;
private static final int GC_LL_MASK = 1 << UCharacter.LOWERCASE_LETTER;
private static final int GC_LT_MASK = 1 << UCharacter.TITLECASE_LETTER;
private static final int GC_LM_MASK = 1 << UCharacter.MODIFIER_LETTER;
private static final int GC_LO_MASK = 1 << UCharacter.OTHER_LETTER;
private static final int GC_L_MASK =
GC_LU_MASK | GC_LL_MASK | GC_LT_MASK | GC_LM_MASK | GC_LO_MASK;
private static final int GC_CN_MASK = 1 << UCharacter.GENERAL_OTHER_TYPES;
/**
* Return a list of the first character in each script. Only exposed for testing.
*
* @return list of first characters in each script
* @internal
* @deprecated This API is ICU internal, only for testing.
*/
@Deprecated
public List<String> getFirstCharactersInScripts() {
List<String> dest = new ArrayList<String>(200);
// Fetch the script-first-primary contractions which are defined in the root collator.
// They all start with U+FDD1.
UnicodeSet set = new UnicodeSet();
collatorPrimaryOnly.internalAddContractions(0xFDD1, set);
if (set.isEmpty()) {
throw new UnsupportedOperationException(
"AlphabeticIndex requires script-first-primary contractions");
}
for (String boundary : set) {
int gcMask = 1 << UCharacter.getType(boundary.codePointAt(1));
if ((gcMask & (GC_L_MASK | GC_CN_MASK)) == 0) {
// Ignore boundaries for the special reordering groups.
// Take only those for "real scripts" (where the sample character is a Letter,
// and the one for unassigned implicit weights (Cn).
continue;
}
dest.add(boundary);
}
return dest;
}
}