de.blizzy.documentr.search.TagFinder.java Source code

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Here is the source code for de.blizzy.documentr.search.TagFinder.java

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/*
documentr - Edit, maintain, and present software documentation on the web.
Copyright (C) 2012-2013 Maik Schreiber
    
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
    
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.
    
You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/
package de.blizzy.documentr.search;

import java.io.IOException;
import java.util.Set;
import java.util.concurrent.TimeoutException;

import org.apache.lucene.index.DocsEnum;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.MultiFields;
import org.apache.lucene.index.Terms;
import org.apache.lucene.index.TermsEnum;
import org.apache.lucene.search.DocIdSetIterator;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.SearcherManager;
import org.apache.lucene.util.Bits;
import org.apache.lucene.util.BytesRef;
import org.springframework.security.core.Authentication;

import com.google.common.collect.Sets;
import com.google.common.util.concurrent.ListeningExecutorService;

import de.blizzy.documentr.access.DocumentrPermissionEvaluator;
import de.blizzy.documentr.access.UserStore;

class TagFinder {
    private SearcherManager searcherManager;
    private ListeningExecutorService taskExecutor;
    private UserStore userStore;
    private DocumentrPermissionEvaluator permissionEvaluator;

    TagFinder(SearcherManager searcherManager, ListeningExecutorService taskExecutor, UserStore userStore,
            DocumentrPermissionEvaluator permissionEvaluator) {

        this.searcherManager = searcherManager;
        this.taskExecutor = taskExecutor;
        this.userStore = userStore;
        this.permissionEvaluator = permissionEvaluator;

    }

    public Set<String> getAllTags(Authentication authentication) throws IOException, TimeoutException {
        IndexReader reader = null;
        IndexSearcher searcher = null;
        try {
            searcher = searcherManager.acquire();

            // no point in running the task asynchronously here
            GetVisibleDocIdsTask visibleDocIdsTask = new GetVisibleDocIdsTask(searcher, authentication, userStore,
                    permissionEvaluator, taskExecutor);
            Bits visibleDocIds = visibleDocIdsTask.call();

            Set<String> tags = Sets.newHashSet();
            if (visibleDocIds.length() > 0) {
                reader = searcher.getIndexReader();
                Terms terms = MultiFields.getTerms(reader, PageIndex.TAG);
                if (terms != null) {
                    TermsEnum termsEnum = terms.iterator(null);
                    BytesRef ref;
                    while ((ref = termsEnum.next()) != null) {
                        DocsEnum docsEnum = termsEnum.docs(visibleDocIds, null, 0);
                        if (docsEnum.nextDoc() != DocIdSetIterator.NO_MORE_DOCS) {
                            tags.add(ref.utf8ToString());
                        }
                    }
                }
            }
            return tags;
        } finally {
            if (searcher != null) {
                searcherManager.release(searcher);
            }
        }
    }
}