package net.yacy.data;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.ConcurrentModificationException;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.SortedSet;
import java.util.TreeSet;
import org.apache.solr.client.solrj.SolrQuery;
import org.apache.solr.client.solrj.response.QueryResponse;
import org.apache.solr.common.SolrException;
import net.yacy.cora.sorting.ClusteredScoreMap;
import net.yacy.cora.sorting.OrderedScoreMap;
import net.yacy.cora.sorting.ReversibleScoreMap;
import net.yacy.cora.util.ConcurrentLog;
import net.yacy.cora.util.StringBuilderComparator;
import net.yacy.document.LibraryProvider;
import net.yacy.search.index.Segment;
import net.yacy.search.schema.CollectionSchema;
/**
* People make mistakes when they type words.
* The most common mistakes are the four categories listed below:
* <ol>
* <li>Changing one letter: bat / cat;</li>
* <li>Adding one letter: bat / boat;</li>
* <li>Deleting one letter: frog / fog; or</li>
* <li>Reversing two consecutive letters: two / tow.</li>
* </ol>
* DidYouMean provides producer threads, that feed a blocking queue with word variations according to
* the above mentioned four categories. Consumer threads check then the generated word variations against a term index.
* Only words contained in the term index are return by the getSuggestion method.<p/>
* @author apfelmaennchen
* @author orbiter (extensions for multi-language support + multi-word suggestions)
*/
public class DidYouMean {
private static final int MinimumInputWordLength = 2;
private static final int MinimumOutputWordLength = 4;
private static final char[] ALPHABET_LATIN = {
'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',
'\u00df',
'\u00e0','\u00e1','\u00e2','\u00e3','\u00e4','\u00e5','\u00e6','\u00e7',
'\u00e8','\u00e9','\u00ea','\u00eb','\u00ec','\u00ed','\u00ee','\u00ef',
'\u00f0','\u00f1','\u00f2','\u00f3','\u00f4','\u00f5','\u00f6',
'\u00f8','\u00f9','\u00fa','\u00fb','\u00fc','\u00fd','\u00fe','\u00ff'};
private static final char[] ALPHABET_KANJI = new char[512]; // \u3400-\u34ff + \u4e00-\u4eff
private static final char[] ALPHABET_HIRAGANA = new char[96]; // \u3040-\u309F
private static final char[] ALPHABET_KATAKANA = new char[96]; // \u30A0-\u30FF
private static final char[] ALPHABET_CJK_UNIFIED_IDEOGRAPHS_Part1 = new char[5376]; // \u4E00-\u62FF
private static final char[] ALPHABET_CJK_UNIFIED_IDEOGRAPHS_Part2 = new char[5376]; // \u6300-\u77FF
private static final char[] ALPHABET_CJK_UNIFIED_IDEOGRAPHS_Part3 = new char[5376]; // \u7800-\u8CFF
private static final char[] ALPHABET_CJK_UNIFIED_IDEOGRAPHS_Part4 = new char[4864]; // \u8D00-\u9FFF
static {
// this is very experimental: a very small subset of Kanji
for (char a = '\u3400'; a <= '\u34ff'; a++) ALPHABET_KANJI[0xff & (a - '\u3400')] = a;
for (char a = '\u4e00'; a <= '\u4eff'; a++) ALPHABET_KANJI[0xff & (a - '\u4e00') + 256] = a;
for (char a = '\u3040'; a <= '\u309F'; a++) ALPHABET_HIRAGANA[0xff & (a - '\u3040')] = a;
for (char a = '\u30A0'; a <= '\u30FF'; a++) ALPHABET_KATAKANA[0xff & (a - '\u30A0')] = a;
for (char a = '\u4E00'; a <= '\u62FF'; a++) ALPHABET_CJK_UNIFIED_IDEOGRAPHS_Part1[0xff & (a - '\u4E00')] = a;
for (char a = '\u6300'; a <= '\u77FF'; a++) ALPHABET_CJK_UNIFIED_IDEOGRAPHS_Part2[0xff & (a - '\u6300')] = a;
for (char a = '\u7800'; a <= '\u8CFF'; a++) ALPHABET_CJK_UNIFIED_IDEOGRAPHS_Part3[0xff & (a - '\u7800')] = a;
for (char a = '\u8D00'; a <= '\u9FFF'; a++) ALPHABET_CJK_UNIFIED_IDEOGRAPHS_Part4[0xff & (a - '\u8D00')] = a;
}
private static final char[][] ALPHABETS = {
ALPHABET_LATIN, ALPHABET_KANJI, ALPHABET_HIRAGANA, ALPHABET_KATAKANA,
ALPHABET_CJK_UNIFIED_IDEOGRAPHS_Part1, ALPHABET_CJK_UNIFIED_IDEOGRAPHS_Part2, ALPHABET_CJK_UNIFIED_IDEOGRAPHS_Part3, ALPHABET_CJK_UNIFIED_IDEOGRAPHS_Part4};
public static final int AVAILABLE_CPU = Runtime.getRuntime().availableProcessors();
private static final wordLengthComparator WORD_LENGTH_COMPARATOR = new wordLengthComparator();
private final Segment segment;
private final StringBuilder word;
private final int wordLen;
private long timeLimit;
private final SortedSet<StringBuilder> resultSet;
private char[] alphabet;
private boolean more;
/**
* @param index a termIndex - most likely retrieved from a switchboard object.
* @param sort true/false - sorts the resulting TreeSet by index.count(); <b>Warning:</b> this causes heavy i/o.
*/
public DidYouMean(final Segment segment, final StringBuilder word0) {
this.resultSet = Collections.synchronizedSortedSet(new TreeSet<StringBuilder>(new headMatchingComparator(word0, WORD_LENGTH_COMPARATOR)));
this.word = word0;
this.wordLen = this.word.length();
this.segment = segment;
this.more = segment.connectedRWI() && segment.RWICount() > 0; // with RWIs connected the guessing is super-fast
// identify language
if (this.word.length() > 0) {
final char testchar = this.word.charAt(0);
boolean alphafound = false;
alphatest: for (final char[] alpha: ALPHABETS) {
if (isAlphabet(alpha, testchar)) {
this.alphabet = new char[alpha.length];
System.arraycopy(alpha, 0, this.alphabet, 0, alpha.length);
alphafound = true;
break alphatest;
}
}
if (!alphafound && testchar < 'A') {
this.alphabet = new char[ALPHABET_LATIN.length];
System.arraycopy(ALPHABET_LATIN, 0, this.alphabet, 0, ALPHABET_LATIN.length);
alphafound = true;
}
if (!alphafound) {
// generate generic alphabet using simply a character block of 256 characters
final int firstchar = (0xff & (testchar / 256)) * 256;
final int lastchar = firstchar + 255;
this.alphabet = new char[256];
// test this with /suggest.json?q=%EF%BD%84
for (int a = firstchar; a <= lastchar; a++) {
this.alphabet[0xff & (a - firstchar)] = (char) a;
}
}
}
}
private static final boolean isAlphabet(final char[] alpha, final char testchar) {
for (final char a: alpha) {
if (a == testchar) {
return true;
}
}
return false;
}
public void reset() {
this.resultSet.clear();
}
/**
* get suggestions for a given word. The result is first ordered using a term size ordering,
* and a subset of the result is sorted again with a IO-intensive order based on the index size
* @param word0
* @param timeout
* @param preSortSelection the number of words that participate in the IO-intensive sort
* @return
*/
public Collection<StringBuilder> getSuggestions(final long timeout, final int preSortSelection) {
if (this.word.length() < MinimumInputWordLength) {
return this.resultSet; // return nothing if input is too short
}
final long startTime = System.currentTimeMillis();
final long timelimit = startTime + timeout;
int lastIndexOfSpace = this.word.lastIndexOf(" ");
if (lastIndexOfSpace > 0) {
// recursion over several words
return getSuggestions(this.word.substring(0, lastIndexOfSpace), this.word.substring(lastIndexOfSpace + 1), timeout, preSortSelection, this.segment);
}
final SortedSet<StringBuilder> preSorted = getSuggestions(timeout);
final ReversibleScoreMap<StringBuilder> scored = new ClusteredScoreMap<StringBuilder>(StringBuilderComparator.CASE_INSENSITIVE_ORDER);
Collection<StringBuilder> countSorted = new ArrayList<StringBuilder>();
if (this.more) {
final int wc = this.segment.getWordCountGuess(this.word.toString()); // all counts must be greater than this
try {
for (final StringBuilder s: preSorted) {
if (System.currentTimeMillis() > timelimit) break;
if (!(scored.sizeSmaller(2 * preSortSelection))) break;
String s0 = s.toString();
int wcg = s0.indexOf(' ') > 0 ? s0.length() * 100 : this.segment.getWordCountGuess(s0);
if (wcg > wc) scored.inc(s, wcg);
}
} catch (final ConcurrentModificationException e) {
}
Iterator<StringBuilder> i = scored.keys(false);
while (i.hasNext()) countSorted.add(i.next());
} else {
try {
for (final StringBuilder s: preSorted) {
if (StringBuilderComparator.CASE_INSENSITIVE_ORDER.startsWith(s, this.word) ||
StringBuilderComparator.CASE_INSENSITIVE_ORDER.endsWith(this.word, s)) countSorted.add(s);
}
} catch (final ConcurrentModificationException e) {
}
}
// finished
ConcurrentLog.info("DidYouMean", "found " + preSorted.size() + " unsorted terms, returned " + countSorted.size() + " sorted suggestions; execution time: "
+ (System.currentTimeMillis() - startTime) + "ms");
return countSorted;
}
/**
* return a string that is a suggestion list for the list of given words
* @param head - the sequence of words before the last space in the sequence
* @param tail - the word after the last space, possibly empty
* @param timeout
* @param preSortSelection
* @return
*/
private static Collection<StringBuilder> getSuggestions(final String head, final String tail, final long timeout, final int preSortSelection, final Segment segment) {
final SortedSet<StringBuilder> result = new TreeSet<StringBuilder>(StringBuilderComparator.CASE_INSENSITIVE_ORDER);
int count = 30;
final SolrQuery solrQuery = new SolrQuery();
solrQuery.setParam("defType", "edismax");
solrQuery.setFacet(false);
solrQuery.setQuery(CollectionSchema.title.getSolrFieldName() + ":\"" + head + "\"^10 OR " + CollectionSchema.text_t.getSolrFieldName() + ":\"" + head + "\"" + (tail.length() == 0 ? "" : CollectionSchema.text_t.getSolrFieldName() + ":\"" + head + " " + tail + "\""));
solrQuery.setStart(0);
solrQuery.setRows(count);
solrQuery.setHighlight(true);
solrQuery.setHighlightFragsize(head.length() + tail.length() + 80);
solrQuery.setHighlightSimplePre("<b>");
solrQuery.setHighlightSimplePost("</b>");
solrQuery.setHighlightSnippets(1);
solrQuery.addHighlightField(CollectionSchema.title.getSolrFieldName());
solrQuery.addHighlightField(CollectionSchema.text_t.getSolrFieldName());
solrQuery.setFields(); // no fields wanted! only snippets
OrderedScoreMap<String> snippets = new OrderedScoreMap<String>(null);
try {
QueryResponse response = segment.fulltext().getDefaultConnector().getResponseByParams(solrQuery);
Map<String, Map<String, List<String>>> rawsnippets = response.getHighlighting(); // a map from the urlhash to a map with key=field and value = list of snippets
if (rawsnippets != null) {
for (Map<String, List<String>> re: rawsnippets.values()) {
for (List<String> sl: re.values()) {
for (String s: sl) {
s = s.replaceAll("</b> <b>", " ");
int sp = s.indexOf("</b>");
if (sp >= 0) {
if (tail.length() > 0) {
if (sp - tail.length() < 0 || !s.substring(sp - tail.length(), sp).equals(tail)) continue;
s = tail + s.substring(sp + 4);
} else {
s = s.substring(sp + 4);
}
for (int i = 0; i < s.length(); i++) {
char c = s.charAt(i);
if (c < 'A') s = s.replace(c, ' ');
}
s = s.trim();
sp = s.indexOf(" ");
if (sp >= 0) s = s.substring(0, sp);
sp = s.indexOf("<b>");
if (sp >= 0) s = s.substring(0, sp).trim();
String[] sx = s.split(" ");
StringBuilder sb = new StringBuilder(s.length());
for (String x: sx) if (x.length() > 1 && sb.length() < 28) sb.append(x).append(' '); else break;
s = sb.toString().trim();
int score = count;
if (s.length() > 2) {
boolean store = true;
for (String a: snippets) {
if (a.startsWith(s)) {
snippets.inc(a, count);
store = false; // s becomes superfluous
}
if (s.startsWith(a)) {
snippets.dec(a, count); // a becomes superfluous
score += count;
}
}
if (store) snippets.inc(s, score);
}
count--;
}
}
}
}
}
} catch (SolrException e) {
} catch (IOException e) {
}
Iterator<String> si = snippets.keys(false);
while (si.hasNext() && result.size() < 10) {
String s = si.next();
StringBuilder sb = new StringBuilder(head.length() + s.length() + 1);
sb.append(head).append(' ').append(s);
result.add(sb);
}
return result;
}
/**
* This method triggers the producer and consumer threads of the DidYouMean object.
* @param word a String with a single word
* @param timeout execution time in ms.
* @return a Set<String> with word variations contained in term index.
*/
private SortedSet<StringBuilder> getSuggestions(final long timeout) {
final long startTime = System.currentTimeMillis();
this.timeLimit = startTime + timeout;
Thread[] producers = null;
if (this.more) {
// create and start producers
// the CPU load to create the guessed words is very low, but the testing
// against the library may be CPU intensive. Since it is possible to test
// words in the library concurrently, it is a good idea to start separate threads
producers = new Thread[4];
producers[0] = new ChangingOneLetter();
producers[1] = new AddingOneLetter();
producers[2] = new DeletingOneLetter();
producers[3] = new ReversingTwoConsecutiveLetters();
for (final Thread t: producers) {
t.start();
}
}
test(this.word);
this.resultSet.addAll(getSuggestions(this.word.toString(), "", timeout, 10, this.segment));
if (this.more) {
// finish the producer
for (final Thread t: producers) {
long wait = this.timeLimit - System.currentTimeMillis();
if (wait > 0) try {
t.join(wait);
} catch (final InterruptedException e) {}
}
}
// we don't want the given word in the result
this.resultSet.remove(this.word);
return this.resultSet;
}
private void test(final StringBuilder s) {
final Set<StringBuilder> libr = LibraryProvider.dymLib.recommend(s);
libr.addAll(LibraryProvider.geoLoc.recommend(s));
for (final StringBuilder t: libr) {
if (t.length() >= MinimumOutputWordLength) this.resultSet.add(t);
}
if (s.length() >= MinimumOutputWordLength) this.resultSet.add(s);
}
/**
* DidYouMean's producer thread that changes one letter (e.g. bat/cat) for a given term
* based on the given alphabet and puts it on the blocking queue, to be 'consumed' by a consumer thread.<p/>
* <b>Note:</b> the loop runs (alphabet.length * len) tests.
*/
public class ChangingOneLetter extends Thread {
@Override
public void run() {
char m;
for (int i = 0; i < DidYouMean.this.wordLen; i++) {
m = DidYouMean.this.word.charAt(i);
for (final char c: DidYouMean.this.alphabet) {
if (m != c) {
final StringBuilder ts = new StringBuilder(DidYouMean.this.word.length() + 1).append(DidYouMean.this.word.substring(0, i)).append(c).append(DidYouMean.this.word.substring(i + 1));
test(ts);
}
if (System.currentTimeMillis() > DidYouMean.this.timeLimit) return;
}
}
}
}
/**
* DidYouMean's producer thread that deletes extra letters (e.g. frog/fog) for a given term
* and puts it on the blocking queue, to be 'consumed' by a consumer thread.<p/>
* <b>Note:</b> the loop runs (len) tests.
*/
private class DeletingOneLetter extends Thread {
@Override
public void run() {
for (int i = 0; i < DidYouMean.this.wordLen; i++) {
final StringBuilder ts = new StringBuilder(DidYouMean.this.word.length() + 1).append(DidYouMean.this.word.substring(0, i)).append(DidYouMean.this.word.substring(i + 1));
test(ts);
if (System.currentTimeMillis() > DidYouMean.this.timeLimit) return;
}
}
}
/**
* DidYouMean's producer thread that adds missing letters (e.g. bat/boat) for a given term
* based on the given alphabet and puts it on the blocking queue, to be 'consumed' by a consumer thread.<p/>
* <b>Note:</b> the loop runs (alphabet.length * len) tests.
*/
private class AddingOneLetter extends Thread {
@Override
public void run() {
for (int i = 0; i <= DidYouMean.this.wordLen; i++) {
for (final char c: DidYouMean.this.alphabet) {
final StringBuilder ts = new StringBuilder(DidYouMean.this.word.length() + 1).append(DidYouMean.this.word.substring(0, i)).append(c).append(DidYouMean.this.word.substring(i));
test(ts);
if (System.currentTimeMillis() > DidYouMean.this.timeLimit) return;
}
}
}
}
/**
* DidYouMean's producer thread that reverses any two consecutive letters (e.g. two/tow) for a given term
* and puts it on the blocking queue, to be 'consumed' by a consumer thread.<p/>
* <b>Note:</b> the loop runs (len-1) tests.
*/
private class ReversingTwoConsecutiveLetters extends Thread {
@Override
public void run() {
for (int i = 0; i < DidYouMean.this.wordLen - 1; i++) {
final StringBuilder ts = new StringBuilder(DidYouMean.this.word.length() + 1).append(DidYouMean.this.word.substring(0, i)).append(DidYouMean.this.word.charAt(i + 1)).append(DidYouMean.this.word.charAt(i)).append(DidYouMean.this.word.substring(i + 2));
test(ts);
if (System.currentTimeMillis() > DidYouMean.this.timeLimit) return;
}
}
}
/**
* wordLengthComparator is used by DidYouMean to order terms by the term length
* This is the default order if the indexSizeComparator is not used
*/
private static class wordLengthComparator implements Comparator<StringBuilder> {
@Override
public int compare(final StringBuilder o1, final StringBuilder o2) {
final int i1 = o1.length();
final int i2 = o2.length();
if (i1 == i2) {
return StringBuilderComparator.CASE_INSENSITIVE_ORDER.compare(o1, o2);
}
return (i1 < i2) ? 1 : -1; // '<' is correct, because the longest word shall be first
}
}
/**
* headMatchingComparator is used to sort results in such a way that words that match with the given words are sorted first
*/
private static class headMatchingComparator implements Comparator<StringBuilder> {
private final StringBuilder head;
private final Comparator<StringBuilder> secondaryComparator;
public headMatchingComparator(final StringBuilder head, final Comparator<StringBuilder> secondaryComparator) {
this.head = head;
this.secondaryComparator = secondaryComparator;
}
@Override
public int compare(final StringBuilder o1, final StringBuilder o2) {
final boolean o1m = StringBuilderComparator.CASE_INSENSITIVE_ORDER.startsWith(o1, this.head);
final boolean o2m = StringBuilderComparator.CASE_INSENSITIVE_ORDER.startsWith(o2, this.head);
if ((o1m && o2m) || (!o1m && !o2m)) {
return this.secondaryComparator.compare(o1, o2);
}
return o1m ? -1 : 1;
}
}
}