source: SRUAggregator/trunk/src/main/java/eu/clarin/sru/fcs/aggregator/app/Aggregator.java @ 5919

package eu.clarin.sru.fcs.aggregator.app;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.optimaize.langdetect.LanguageDetector;
import com.optimaize.langdetect.LanguageDetectorBuilder;
import com.optimaize.langdetect.ngram.NgramExtractors;
import com.optimaize.langdetect.profiles.LanguageProfile;
import com.optimaize.langdetect.profiles.LanguageProfileReader;
import com.optimaize.langdetect.text.*;
import eu.clarin.sru.fcs.aggregator.search.Search;
import eu.clarin.sru.fcs.aggregator.scan.ScanCrawlTask;
import eu.clarin.sru.fcs.aggregator.scan.Corpora;
import eu.clarin.sru.client.SRUVersion;
import eu.clarin.sru.client.fcs.ClarinFCSClientBuilder;
import eu.clarin.sru.fcs.aggregator.client.ThrottledClient;
import eu.clarin.sru.fcs.aggregator.scan.Corpus;
import eu.clarin.sru.fcs.aggregator.rest.RestService;
import eu.clarin.sru.fcs.aggregator.scan.Statistics;
import eu.clarin.sru.fcs.aggregator.lang.LanguagesISO693_3;
import io.dropwizard.Application;
import io.dropwizard.assets.AssetsBundle;
import io.dropwizard.setup.Bootstrap;
import io.dropwizard.setup.Environment;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.atomic.AtomicReference;
import opennlp.tools.tokenize.TokenizerModel;
import org.slf4j.LoggerFactory;

/**
 * Main component of the Aggregator application intended to provide users access
 * to CLARIN-FCS resources.
 *
 * The webapp base URL corresponds to the default behavior of displaying the
 * main aggregator page, where the user can enter query, select the resources of
 * CQL endpoints (as specified in the Clarin center registry), and search in
 * these resources. The endpoints/resources selection is optional, by default
 * all the endpoints root resources are selected.
 *
 * If invoked with 'x-aggregation-context' and 'query' parameter, the aggregator
 * will pre-select provided resources and fill in the query field. This
 * mechanism is currently used by VLO. Example: POST
 * http://weblicht.sfs.uni-tuebingen.de/Aggregator HTTP/1.1 operation =
 * searchRetrieve & version = 1.2 & query = bellen & x-aggregation-context =
 * {"http://fedora.clarin-d.uni-saarland.de/sru/":["hdl:11858/00-246C-0000-0008-5F2A-0"]}
 *
 *
 * Additionally, if run with the a URL query string parameter 'mode', the
 * special behavior of the aggregator is triggered:
 *
 * /?mode=testing corresponds to the mode where the CQL endpoints are taken not
 * from Clarin center repository, but from a hard-coded endpoints list; this
 * functionality is useful for testing the development instances of endpoints,
 * before they are moved to production. Was done to meet the request from MPI.
 *
 * /?mode=search corresponds to the mode where the aggregator page is requested
 * with the already known query and (optionally) resources to search in, and if
 * the immediate search is desired. In this case the aggregator search results
 * page is displayed and search results of the provided query start to fill it
 * in immediately (i.e. users don't need to click 'search' in the aggregator
 * page). Was done to meet the request from CLARIN ERIC (Martin Wynne contacted
 * us).
 *
 * /?mode=live corresponds to the mode where the information about corpora are
 * taken not from the scan cache (crawled in advance), but loaded live, starting
 * from the request to center registry and then performing scan operation
 * requests on each CQL endpoint listed there. It takes time to get the
 * corresponding responses from the endpoints, therefore the Aggregator page
 * loads very slow in this mode. But this mode is useful for testing of the
 * newly added or changed corpora without waiting for the next crawl.
 *
 *
 * Adds Application initialization and clean up: only one SRU threaded client is
 * used in the application, it has to be shut down when the application stops.
 * One Languages object instance is used within the application.
 *
 * @author Yana Panchenko
 * @author edima
 *
 * TODO: try to refine results by language using a language library, with UI
 * element
 *
 * TODO: condensed list of corpora
 *
 * TODO: group the list of corpora by institution?
 *
 * TODO: fix ordering of corpora in corpora view
 *
 * TODO: corpora search should not indicate the ones that don't match
 *
 * TODO: Collections view: home link (make a single consistent text for it)
 *
 * TODO: tri-state for parent collections; search + message implications
 *
 * TODO: version page: credits, open source, see vcr/version page
 *
 * TODO: statistics page liked from version page
 *
 * TODO: 1. support new spec-compatible centres, see Oliver's mail
 * (use SRUClient's extraResponseData POJOs)
 *
 * TODO: 2. zoom into the results from a corpus, allow functionality only for
 * the view (search for next set of results)
 *
 * TODO: disable popups easily
 *
 * TODO: Fix activeSearch memory leak (gc searches older than...)
 *
 * TODO: Use weblicht with results
 *
 * TODO: Export to personal workspace as csv, excel, tcf, plain text
 *
 * TODO: Download to personal workspace as csv, excel, tcf, plain text
 *
 * TODO: websockets
 *
 * TODO: atomic replace of cached corpora (file)
 *
 * TODO: show multiple hits on the same result in multiple rows, linked visually
 *
 * TODO: optimise page load
 *
 * TODO: improve help page text
 *
 */
public class Aggregator extends Application<AggregatorConfiguration> {

        private static final org.slf4j.Logger log = LoggerFactory.getLogger(Aggregator.class);

        public static final String DE_TOK_MODEL = "tokenizer/de-tuebadz-8.0-token.bin";

        private static final ScheduledExecutorService scheduler = Executors.newScheduledThreadPool(1);
        private static Aggregator instance;
        private AggregatorConfiguration.Params params;

        private AtomicReference<Corpora> scanCacheAtom = new AtomicReference<Corpora>(new Corpora());
        private AtomicReference<Statistics> scanStatsAtom = new AtomicReference<Statistics>(new Statistics());
        private AtomicReference<Statistics> searchStatsAtom = new AtomicReference<Statistics>(new Statistics());

        private TokenizerModel tokenizerModel;
        private LanguageDetector languageDetector;
        private TextObjectFactory textObjectFactory;

        private ThrottledClient sruScanClient = null;
        private ThrottledClient sruSearchClient = null;
        private Map<Long, Search> activeSearches = Collections.synchronizedMap(new HashMap<Long, Search>());

        public static void main(String[] args) throws Exception {
                new Aggregator().run(args);
        }

        @Override
        public String getName() {
                return "FCS Aggregator";
        }

        @Override
        public void initialize(Bootstrap<AggregatorConfiguration> bootstrap) {
                bootstrap.addBundle(new AssetsBundle("/assets", "/", "index.html"));
        }

        @Override
        public void run(AggregatorConfiguration config, Environment environment) throws Exception {
                params = config.aggregatorParams;
                instance = this;

                System.out.println("Using parameters: ");
                try {
                        System.out.println(new ObjectMapper().writerWithDefaultPrettyPrinter().
                                        writeValueAsString(config.aggregatorParams));
                } catch (IOException xc) {
                }

                environment.jersey().setUrlPattern("/rest/*");
                environment.jersey().register(new RestService());

                try {
                        init();
                } catch (Exception ex) {
                        log.error("INIT EXCEPTION", ex);
                        throw ex; // force exit
                }
        }

        public static Aggregator getInstance() {
                return instance;
        }

        public AggregatorConfiguration.Params getParams() {
                return params;
        }

        public Corpora getCorpora() {
                return scanCacheAtom.get();
        }

        public Statistics getScanStatistics() {
                return scanStatsAtom.get();
        }

        public Statistics getSearchStatistics() {
                return searchStatsAtom.get();
        }

        public void init() throws IOException {
                log.info("Aggregator initialization started.");
                sruScanClient = new ThrottledClient(
                                new ClarinFCSClientBuilder()
                                .setConnectTimeout(params.ENDPOINTS_SCAN_TIMEOUT_MS)
                                .setSocketTimeout(params.ENDPOINTS_SCAN_TIMEOUT_MS)
                                .addDefaultDataViewParsers()
                                .enableLegacySupport()
                                .buildThreadedClient(),
                                params.SCAN_MAX_CONCURRENT_REQUESTS_PER_ENDPOINT,
                                params.SEARCH_MAX_CONCURRENT_REQUESTS_PER_ENDPOINT
                );
                sruSearchClient = new ThrottledClient(
                                new ClarinFCSClientBuilder()
                                .setConnectTimeout(params.ENDPOINTS_SEARCH_TIMEOUT_MS)
                                .setSocketTimeout(params.ENDPOINTS_SEARCH_TIMEOUT_MS)
                                .addDefaultDataViewParsers()
                                .enableLegacySupport()
                                .buildThreadedClient(),
                                params.SCAN_MAX_CONCURRENT_REQUESTS_PER_ENDPOINT,
                                params.SEARCH_MAX_CONCURRENT_REQUESTS_PER_ENDPOINT
                );

                File corporaCacheFile = new File(params.AGGREGATOR_FILE_PATH);
                try {
                        Corpora corpora = new ObjectMapper().readValue(corporaCacheFile, Corpora.class);
                        scanCacheAtom.set(corpora);
                        log.info("corpus list read from file; number of root corpora: " + scanCacheAtom.get().getCorpora().size());
                } catch (Exception e) {
                        log.error("Error while reading cached corpora:", e);
                }

                LanguagesISO693_3.getInstance(); // force init
                initTokenizer();
                initLanguageDetector();

                ScanCrawlTask task = new ScanCrawlTask(sruScanClient,
                                params.CENTER_REGISTRY_URL, params.SCAN_MAX_DEPTH,
                                null, scanCacheAtom, corporaCacheFile, scanStatsAtom);
                scheduler.scheduleAtFixedRate(task, params.SCAN_TASK_INITIAL_DELAY,
                                params.SCAN_TASK_INTERVAL, params.getScanTaskTimeUnit());

                log.info("Aggregator initialization finished.");
        }

        public void shutdown(AggregatorConfiguration config) {
                log.info("Aggregator is shutting down.");
                for (Search search : activeSearches.values()) {
                        search.shutdown();
                }
                shutdownAndAwaitTermination(config.aggregatorParams, sruScanClient, scheduler);
                shutdownAndAwaitTermination(config.aggregatorParams, sruSearchClient, scheduler);
                log.info("Aggregator shutdown complete.");
        }

        // this function should be thread-safe
        public Search startSearch(SRUVersion version, List<Corpus> corpora, String searchString, String searchLang, int maxRecords) throws Exception {
                if (corpora.isEmpty()) {
                        // No corpora
                        return null;
                } else if (searchString.isEmpty()) {
                        // No query
                        return null;
                } else {
                        Search sr = new Search(sruSearchClient, version, searchStatsAtom.get(),
                                        corpora, searchString, searchLang, 1, maxRecords);
                        activeSearches.put(sr.getId(), sr);
                        return sr;
                }
        }

        public Search getSearchById(Long id) {
                return activeSearches.get(id);
        }

        private static void shutdownAndAwaitTermination(AggregatorConfiguration.Params params,
                        ThrottledClient sruClient, ExecutorService scheduler) {
                try {
                        sruClient.shutdown();
                        scheduler.shutdown();
                        Thread.sleep(params.EXECUTOR_SHUTDOWN_TIMEOUT_MS);
                        sruClient.shutdownNow();
                        scheduler.shutdownNow();
                        Thread.sleep(params.EXECUTOR_SHUTDOWN_TIMEOUT_MS);
                } catch (InterruptedException ie) {
                        sruClient.shutdownNow();
                        scheduler.shutdownNow();
                        Thread.currentThread().interrupt();
                }
        }

        private void initTokenizer() {
                TokenizerModel model = null;
                try {
                        try (InputStream tokenizerModelDeAsIS = Thread.currentThread().getContextClassLoader().getResourceAsStream(DE_TOK_MODEL)) {
                                model = new TokenizerModel(tokenizerModelDeAsIS);
                        }
                } catch (IOException ex) {
                        log.error("Failed to load tokenizer model", ex);
                }
                tokenizerModel = model;
        }

        public void initLanguageDetector() throws IOException {
                List<LanguageProfile> languageProfiles = new LanguageProfileReader().readAll();
                languageDetector = LanguageDetectorBuilder
                                .create(NgramExtractors.standard())
                                .withProfiles(languageProfiles)
                                .build();

                textObjectFactory = CommonTextObjectFactories.forDetectingOnLargeText();
        }

        public String detectLanguage(String text) {
                return languageDetector.detect(textObjectFactory.forText(text)).orNull();
        }
}