001    // License: GPL. For details, see LICENSE file.
002    package org.openstreetmap.josm.io;
003    
004    import static org.openstreetmap.josm.tools.I18n.tr;
005    import static org.openstreetmap.josm.tools.I18n.trn;
006    
007    import java.io.InputStream;
008    import java.net.HttpURLConnection;
009    import java.util.ArrayList;
010    import java.util.Collection;
011    import java.util.HashSet;
012    import java.util.Iterator;
013    import java.util.LinkedHashSet;
014    import java.util.List;
015    import java.util.NoSuchElementException;
016    import java.util.Set;
017    import java.util.concurrent.Callable;
018    import java.util.concurrent.CompletionService;
019    import java.util.concurrent.ExecutionException;
020    import java.util.concurrent.Executor;
021    import java.util.concurrent.ExecutorCompletionService;
022    import java.util.concurrent.Executors;
023    import java.util.concurrent.Future;
024    
025    import org.openstreetmap.josm.Main;
026    import org.openstreetmap.josm.data.osm.DataSet;
027    import org.openstreetmap.josm.data.osm.DataSetMerger;
028    import org.openstreetmap.josm.data.osm.Node;
029    import org.openstreetmap.josm.data.osm.OsmPrimitive;
030    import org.openstreetmap.josm.data.osm.OsmPrimitiveType;
031    import org.openstreetmap.josm.data.osm.PrimitiveId;
032    import org.openstreetmap.josm.data.osm.Relation;
033    import org.openstreetmap.josm.data.osm.RelationMember;
034    import org.openstreetmap.josm.data.osm.SimplePrimitiveId;
035    import org.openstreetmap.josm.data.osm.Way;
036    import org.openstreetmap.josm.gui.progress.NullProgressMonitor;
037    import org.openstreetmap.josm.gui.progress.ProgressMonitor;
038    import org.openstreetmap.josm.tools.CheckParameterUtil;
039    
040    /**
041     * Retrieves a set of {@link OsmPrimitive}s from an OSM server using the so called
042     * Multi Fetch API.
043     *
044     * Usage:
045     * <pre>
046     *    MultiFetchServerObjectReader reader = MultiFetchServerObjectReader()
047     *         .append(2345,2334,4444)
048     *         .append(new Node(72343));
049     *    reader.parseOsm();
050     *    if (!reader.getMissingPrimitives().isEmpty()) {
051     *        System.out.println("There are missing primitives: " + reader.getMissingPrimitives());
052     *    }
053     *    if (!reader.getSkippedWays().isEmpty()) {
054     *       System.out.println("There are skipped ways: " + reader.getMissingPrimitives());
055     *    }
056     * </pre>
057     */
058    public class MultiFetchServerObjectReader extends OsmServerReader{
059        /**
060         * the max. number of primitives retrieved in one step. Assuming IDs with 7 digits,
061         * this leads to a max. request URL of ~ 1600 Bytes ((7 digits +  1 Separator) * 200),
062         * which should be safe according to the
063         * <a href="http://www.boutell.com/newfaq/misc/urllength.html">WWW FAQ</a>.
064         */
065        static private int MAX_IDS_PER_REQUEST = 200;
066    
067        private Set<Long> nodes;
068        private Set<Long> ways;
069        private Set<Long> relations;
070        private Set<PrimitiveId> missingPrimitives;
071        private DataSet outputDataSet;
072    
073        /**
074         * Constructs a {@code MultiFetchServerObjectReader}.
075         */
076        public MultiFetchServerObjectReader() {
077            nodes = new LinkedHashSet<Long>();
078            ways = new LinkedHashSet<Long>();
079            relations = new LinkedHashSet<Long>();
080            this.outputDataSet = new DataSet();
081            this.missingPrimitives = new LinkedHashSet<PrimitiveId>();
082        }
083    
084        /**
085         * Remembers an {@link OsmPrimitive}'s id. The id will
086         * later be fetched as part of a Multi Get request.
087         *
088         * Ignore the id if it represents a new primitives.
089         *
090         * @param id  the id
091         */
092        protected void remember(PrimitiveId id) {
093            if (id.isNew()) return;
094            switch(id.getType()) {
095            case NODE: nodes.add(id.getUniqueId()); break;
096            case WAY: ways.add(id.getUniqueId()); break;
097            case RELATION: relations.add(id.getUniqueId()); break;
098            }
099        }
100    
101        /**
102         * remembers an {@link OsmPrimitive}'s id. <code>ds</code> must include
103         * an {@link OsmPrimitive} with id=<code>id</code>. The id will
104         * later we fetched as part of a Multi Get request.
105         *
106         * Ignore the id if it id <= 0.
107         *
108         * @param ds  the dataset (must not be null)
109         * @param id  the primitive id
110         * @param type The primitive type. Must be one of {@link OsmPrimitiveType#NODE NODE}, {@link OsmPrimitiveType#WAY WAY}, {@link OsmPrimitiveType#RELATION RELATION}
111         * @throws IllegalArgumentException if ds is null
112         * @throws NoSuchElementException if ds does not include an {@link OsmPrimitive} with id=<code>id</code>
113         */
114        protected void remember(DataSet ds, long id, OsmPrimitiveType type) throws IllegalArgumentException, NoSuchElementException{
115            CheckParameterUtil.ensureParameterNotNull(ds, "ds");
116            if (id <= 0) return;
117            OsmPrimitive primitive = ds.getPrimitiveById(id, type);
118            if (primitive == null)
119                throw new NoSuchElementException(tr("No primitive with id {0} in local dataset. Cannot infer primitive type.", id));
120            remember(primitive.getPrimitiveId());
121            return;
122        }
123    
124        /**
125         * appends a {@link OsmPrimitive} id to the list of ids which will be fetched from the server.
126         * 
127         * @param ds the {@link DataSet} to which the primitive belongs
128         * @param id the primitive id
129         * @param type The primitive type. Must be one of {@link OsmPrimitiveType#NODE NODE}, {@link OsmPrimitiveType#WAY WAY}, {@link OsmPrimitiveType#RELATION RELATION}
130         * @return this
131         */
132        public MultiFetchServerObjectReader append(DataSet ds, long id, OsmPrimitiveType type) {
133            OsmPrimitive p = ds.getPrimitiveById(id,type);
134            switch(type) {
135            case NODE:
136                return appendNode((Node)p);
137            case WAY:
138                return appendWay((Way)p);
139            case RELATION:
140                return appendRelation((Relation)p);
141            }
142            return this;
143        }
144    
145        /**
146         * appends a {@link Node} id to the list of ids which will be fetched from the server.
147         *
148         * @param node  the node (ignored, if null)
149         * @return this
150         */
151        public MultiFetchServerObjectReader appendNode(Node node) {
152            if (node == null) return this;
153            remember(node.getPrimitiveId());
154            return this;
155        }
156    
157        /**
158         * appends a {@link Way} id and the list of ids of nodes the way refers to the list of ids which will be fetched from the server.
159         *
160         * @param way the way (ignored, if null)
161         * @return this
162         */
163        public MultiFetchServerObjectReader appendWay(Way way) {
164            if (way == null) return this;
165            if (way.isNew()) return this;
166            for (Node node: way.getNodes()) {
167                if (!node.isNew()) {
168                    remember(node.getPrimitiveId());
169                }
170            }
171            remember(way.getPrimitiveId());
172            return this;
173        }
174    
175        /**
176         * appends a {@link Relation} id to the list of ids which will be fetched from the server.
177         *
178         * @param relation  the relation (ignored, if null)
179         * @return this
180         */
181        protected MultiFetchServerObjectReader appendRelation(Relation relation) {
182            if (relation == null) return this;
183            if (relation.isNew()) return this;
184            remember(relation.getPrimitiveId());
185            for (RelationMember member : relation.getMembers()) {
186                if (OsmPrimitiveType.from(member.getMember()).equals(OsmPrimitiveType.RELATION)) {
187                    // avoid infinite recursion in case of cyclic dependencies in relations
188                    //
189                    if (relations.contains(member.getMember().getId())) {
190                        continue;
191                    }
192                }
193                if (!member.getMember().isIncomplete()) {
194                    append(member.getMember());
195                }
196            }
197            return this;
198        }
199    
200        /**
201         * appends an {@link OsmPrimitive} to the list of ids which will be fetched from the server.
202         * @param primitive the primitive
203         * @return this
204         */
205        public MultiFetchServerObjectReader append(OsmPrimitive primitive) {
206            if (primitive != null) {
207                switch (OsmPrimitiveType.from(primitive)) {
208                    case NODE: return appendNode((Node)primitive);
209                    case WAY: return appendWay((Way)primitive);
210                    case RELATION: return appendRelation((Relation)primitive);
211                }
212            }
213            return this;
214        }
215    
216        /**
217         * appends a list of {@link OsmPrimitive} to the list of ids which will be fetched from the server.
218         *
219         * @param primitives  the list of primitives (ignored, if null)
220         * @return this
221         *
222         * @see #append(OsmPrimitive)
223         */
224        public MultiFetchServerObjectReader append(Collection<? extends OsmPrimitive> primitives) {
225            if (primitives == null) return this;
226            for (OsmPrimitive primitive : primitives) {
227                append(primitive);
228            }
229            return this;
230        }
231    
232        /**
233         * extracts a subset of max {@link #MAX_IDS_PER_REQUEST} ids from <code>ids</code> and
234         * replies the subset. The extracted subset is removed from <code>ids</code>.
235         *
236         * @param ids a set of ids
237         * @return the subset of ids
238         */
239        protected Set<Long> extractIdPackage(Set<Long> ids) {
240            HashSet<Long> pkg = new HashSet<Long>();
241            if (ids.isEmpty())
242                return pkg;
243            if (ids.size() > MAX_IDS_PER_REQUEST) {
244                Iterator<Long> it = ids.iterator();
245                for (int i=0; i<MAX_IDS_PER_REQUEST; i++) {
246                    pkg.add(it.next());
247                }
248                ids.removeAll(pkg);
249            } else {
250                pkg.addAll(ids);
251                ids.clear();
252            }
253            return pkg;
254        }
255    
256        /**
257         * builds the Multi Get request string for a set of ids and a given
258         * {@link OsmPrimitiveType}.
259         *
260         * @param type The primitive type. Must be one of {@link OsmPrimitiveType#NODE NODE}, {@link OsmPrimitiveType#WAY WAY}, {@link OsmPrimitiveType#RELATION RELATION}
261         * @param idPackage  the package of ids
262         * @return the request string
263         */
264        protected static String buildRequestString(OsmPrimitiveType type, Set<Long> idPackage) {
265            StringBuilder sb = new StringBuilder();
266            sb.append(type.getAPIName()).append("s?")
267            .append(type.getAPIName()).append("s=");
268    
269            Iterator<Long> it = idPackage.iterator();
270            for (int i=0; i<idPackage.size(); i++) {
271                sb.append(it.next());
272                if (i < idPackage.size()-1) {
273                    sb.append(",");
274                }
275            }
276            return sb.toString();
277        }
278    
279        /**
280         * builds the Multi Get request string for a single id and a given
281         * {@link OsmPrimitiveType}.
282         *
283         * @param type The primitive type. Must be one of {@link OsmPrimitiveType#NODE NODE}, {@link OsmPrimitiveType#WAY WAY}, {@link OsmPrimitiveType#RELATION RELATION}
284         * @param id the id
285         * @return the request string
286         */
287        protected static String buildRequestString(OsmPrimitiveType type, long id) {
288            StringBuilder sb = new StringBuilder();
289            sb.append(type.getAPIName()).append("s?")
290            .append(type.getAPIName()).append("s=")
291            .append(id);
292            return sb.toString();
293        }
294    
295        protected void rememberNodesOfIncompleteWaysToLoad(DataSet from) {
296            for (Way w: from.getWays()) {
297                if (w.hasIncompleteNodes()) {
298                    for (Node n: w.getNodes()) {
299                        if (n.isIncomplete()) {
300                            nodes.add(n.getId());
301                        }
302                    }
303                }
304            }
305        }
306    
307        /**
308         * merges the dataset <code>from</code> to {@link #outputDataSet}.
309         *
310         * @param from the other dataset
311         */
312        protected void merge(DataSet from) {
313            final DataSetMerger visitor = new DataSetMerger(outputDataSet,from);
314            visitor.merge();
315        }
316    
317        /**
318         * fetches a set of ids of a given {@link OsmPrimitiveType} from the server
319         *
320         * @param ids the set of ids
321         * @param type The primitive type. Must be one of {@link OsmPrimitiveType#NODE NODE}, {@link OsmPrimitiveType#WAY WAY}, {@link OsmPrimitiveType#RELATION RELATION}
322         * @throws OsmTransferException if an error occurs while communicating with the API server
323         */
324        protected void fetchPrimitives(Set<Long> ids, OsmPrimitiveType type, ProgressMonitor progressMonitor) throws OsmTransferException {
325            String msg = "";
326            String baseUrl = OsmApi.getOsmApi().getBaseUrl();
327            switch (type) {
328                case NODE:     msg = tr("Fetching a package of nodes from ''{0}''",     baseUrl); break;
329                case WAY:      msg = tr("Fetching a package of ways from ''{0}''",      baseUrl); break;
330                case RELATION: msg = tr("Fetching a package of relations from ''{0}''", baseUrl); break;
331            }
332            progressMonitor.setTicksCount(ids.size());
333            progressMonitor.setTicks(0);
334            // The complete set containg all primitives to fetch
335            Set<Long> toFetch = new HashSet<Long>(ids);
336            // Build a list of fetchers that will  download smaller sets containing only MAX_IDS_PER_REQUEST (200) primitives each.
337            // we will run up to MAX_DOWNLOAD_THREADS concurrent fetchers.
338            int threadsNumber = Main.pref.getInteger("osm.download.threads", OsmApi.MAX_DOWNLOAD_THREADS);
339            threadsNumber = Math.min(Math.max(threadsNumber, 1), OsmApi.MAX_DOWNLOAD_THREADS);
340            Executor exec = Executors.newFixedThreadPool(threadsNumber);
341            CompletionService<FetchResult> ecs = new ExecutorCompletionService<FetchResult>(exec);
342            List<Future<FetchResult>> jobs = new ArrayList<Future<FetchResult>>();
343            while (!toFetch.isEmpty()) {
344                jobs.add(ecs.submit(new Fetcher(type, extractIdPackage(toFetch), progressMonitor)));
345            }
346            // Run the fetchers
347            for (int i = 0; i < jobs.size() && !isCanceled(); i++) {
348                progressMonitor.subTask(msg + "... " + progressMonitor.getTicks() + "/" + progressMonitor.getTicksCount());
349                try {
350                    FetchResult result = ecs.take().get();
351                    if (result.missingPrimitives != null) {
352                        missingPrimitives.addAll(result.missingPrimitives);
353                    }
354                    if (result.dataSet != null && !isCanceled()) {
355                        rememberNodesOfIncompleteWaysToLoad(result.dataSet);
356                        merge(result.dataSet);
357                    }
358                } catch (InterruptedException e) {
359                    e.printStackTrace();
360                } catch (ExecutionException e) {
361                    e.printStackTrace();
362                }
363            }
364            // Cancel requests if the user choosed to
365            if (isCanceled()) {
366                for (Future<FetchResult> job : jobs) {
367                    job.cancel(true);
368                }
369            }
370        }
371    
372        /**
373         * invokes one or more Multi Gets to fetch the {@link OsmPrimitive}s and replies
374         * the dataset of retrieved primitives. Note that the dataset includes non visible primitives too!
375         * In contrast to a simple Get for a node, a way, or a relation, a Multi Get always replies
376         * the latest version of the primitive (if any), even if the primitive is not visible (i.e. if
377         * visible==false).
378         *
379         * Invoke {@link #getMissingPrimitives()} to get a list of primitives which have not been
380         * found on  the server (the server response code was 404)
381         *
382         * @return the parsed data
383         * @throws OsmTransferException if an error occurs while communicating with the API server
384         * @see #getMissingPrimitives()
385         *
386         */
387        @Override
388        public DataSet parseOsm(ProgressMonitor progressMonitor) throws OsmTransferException {
389            int n = nodes.size() + ways.size() + relations.size();
390            progressMonitor.beginTask(trn("Downloading {0} object from ''{1}''", "Downloading {0} objects from ''{1}''", n, n, OsmApi.getOsmApi().getBaseUrl()));
391            try {
392                missingPrimitives = new HashSet<PrimitiveId>();
393                if (isCanceled()) return null;
394                fetchPrimitives(ways,OsmPrimitiveType.WAY, progressMonitor);
395                if (isCanceled()) return null;
396                fetchPrimitives(nodes,OsmPrimitiveType.NODE, progressMonitor);
397                if (isCanceled()) return null;
398                fetchPrimitives(relations,OsmPrimitiveType.RELATION, progressMonitor);
399                if (outputDataSet != null) {
400                    outputDataSet.deleteInvisible();
401                }
402                return outputDataSet;
403            } finally {
404                progressMonitor.finishTask();
405            }
406        }
407    
408        /**
409         * replies the set of ids of all primitives for which a fetch request to the
410         * server was submitted but which are not available from the server (the server
411         * replied a return code of 404)
412         *
413         * @return the set of ids of missing primitives
414         */
415        public Set<PrimitiveId> getMissingPrimitives() {
416            return missingPrimitives;
417        }
418        
419        /**
420         * The class holding the results given by {@link Fetcher}. 
421         * It is only a wrapper of the resulting {@link DataSet} and the collection of {@link PrimitiveId} that could not have been loaded.
422         */
423        protected static class FetchResult {
424            
425            /**
426             * The resulting data set
427             */
428            public final DataSet dataSet;
429            
430            /**
431             * The collection of primitive ids that could not have been loaded
432             */
433            public final Set<PrimitiveId> missingPrimitives;
434            
435            /**
436             * Constructs a {@code FetchResult}
437             * @param dataSet The resulting data set
438             * @param missingPrimitives The collection of primitive ids that could not have been loaded
439             */
440            public FetchResult(DataSet dataSet, Set<PrimitiveId> missingPrimitives) {
441                this.dataSet = dataSet;
442                this.missingPrimitives = missingPrimitives;
443            }
444        }
445        
446        /**
447         * The class that actually download data from OSM API. Several instances of this class are used by {@link MultiFetchServerObjectReader} (one per set of primitives to fetch).
448         * The inheritance of {@link OsmServerReader} is only explained by the need to have a distinct OSM connection by {@code Fetcher} instance.
449         * @see FetchResult
450         */
451        protected static class Fetcher extends OsmServerReader implements Callable<FetchResult> {
452    
453            private final Set<Long> pkg;
454            private final OsmPrimitiveType type;
455            private final ProgressMonitor progressMonitor;
456    
457            /**
458             * Constructs a {@code Fetcher}
459             * @param type The primitive type. Must be one of {@link OsmPrimitiveType#NODE NODE}, {@link OsmPrimitiveType#WAY WAY}, {@link OsmPrimitiveType#RELATION RELATION}
460             * @param idsPackage The set of primitives ids to fetch
461             * @param progressMonitor The progress monitor
462             */
463            public Fetcher(OsmPrimitiveType type, Set<Long> idsPackage, ProgressMonitor progressMonitor) {
464                this.pkg = idsPackage;
465                this.type = type;
466                this.progressMonitor = progressMonitor;
467            }
468    
469            @Override
470            public DataSet parseOsm(ProgressMonitor progressMonitor) throws OsmTransferException {
471                // This method is implemented because of the OsmServerReader inheritance, but not used, as the main target of this class is the call() method.
472                return fetch(progressMonitor).dataSet;
473            }
474            
475            @Override
476            public FetchResult call() throws Exception {
477                return fetch(progressMonitor);
478            }
479            
480            /**
481             * fetches the requested primitives and updates the specified progress monitor.
482             * @param progressMonitor the progress monitor
483             * @return the {@link FetchResult} of this operation
484             * @throws OsmTransferException if an error occurs while communicating with the API server
485             */
486            protected FetchResult fetch(ProgressMonitor progressMonitor) throws OsmTransferException {
487                try {
488                    return multiGetIdPackage(type, pkg, progressMonitor);
489                } catch (OsmApiException e) {
490                    if (e.getResponseCode() == HttpURLConnection.HTTP_NOT_FOUND) {
491                        System.out.println(tr("Server replied with response code 404, retrying with an individual request for each object."));
492                        return singleGetIdPackage(type, pkg, progressMonitor);
493                    } else {
494                        throw e;
495                    }
496                }
497            }
498            
499            /**
500             * invokes a Multi Get for a set of ids and a given {@link OsmPrimitiveType}.
501             * The retrieved primitives are merged to {@link #outputDataSet}.
502             *
503             * @param type The primitive type. Must be one of {@link OsmPrimitiveType#NODE NODE}, {@link OsmPrimitiveType#WAY WAY}, {@link OsmPrimitiveType#RELATION RELATION}
504             * @param pkg the package of ids
505             * @return the {@link FetchResult} of this operation
506             * @throws OsmTransferException if an error occurs while communicating with the API server
507             */
508            protected FetchResult multiGetIdPackage(OsmPrimitiveType type, Set<Long> pkg, ProgressMonitor progressMonitor) throws OsmTransferException {
509                String request = buildRequestString(type, pkg);
510                final InputStream in = getInputStream(request, NullProgressMonitor.INSTANCE);
511                if (in == null) return null;
512                progressMonitor.subTask(tr("Downloading OSM data..."));
513                try {
514                    return new FetchResult(OsmReader.parseDataSet(in, progressMonitor.createSubTaskMonitor(pkg.size(), false)), null);
515                } catch (Exception e) {
516                    throw new OsmTransferException(e);
517                }
518            }
519    
520            /**
521             * invokes a Multi Get for a single id and a given {@link OsmPrimitiveType}.
522             * The retrieved primitive is merged to {@link #outputDataSet}.
523             *
524             * @param type The primitive type. Must be one of {@link OsmPrimitiveType#NODE NODE}, {@link OsmPrimitiveType#WAY WAY}, {@link OsmPrimitiveType#RELATION RELATION}
525             * @param id the id
526             * @return the {@link DataSet} resulting of this operation
527             * @throws OsmTransferException if an error occurs while communicating with the API server
528             */
529            protected DataSet singleGetId(OsmPrimitiveType type, long id, ProgressMonitor progressMonitor) throws OsmTransferException {
530                String request = buildRequestString(type, id);
531                final InputStream in = getInputStream(request, NullProgressMonitor.INSTANCE);
532                if (in == null) return null;
533                progressMonitor.subTask(tr("Downloading OSM data..."));
534                try {
535                    return OsmReader.parseDataSet(in, progressMonitor.createSubTaskMonitor(1, false));
536                } catch (Exception e) {
537                    throw new OsmTransferException(e);
538                }
539            }
540    
541            /**
542             * invokes a sequence of Multi Gets for individual ids in a set of ids and a given {@link OsmPrimitiveType}.
543             * The retrieved primitives are merged to {@link #outputDataSet}.
544             *
545             * This method is used if one of the ids in pkg doesn't exist (the server replies with return code 404).
546             * If the set is fetched with this method it is possible to find out which of the ids doesn't exist.
547             * Unfortunately, the server does not provide an error header or an error body for a 404 reply.
548             *
549             * @param type The primitive type. Must be one of {@link OsmPrimitiveType#NODE NODE}, {@link OsmPrimitiveType#WAY WAY}, {@link OsmPrimitiveType#RELATION RELATION}
550             * @param pkg the set of ids
551             * @return the {@link FetchResult} of this operation
552             * @throws OsmTransferException if an error occurs while communicating with the API server
553             */
554            protected FetchResult singleGetIdPackage(OsmPrimitiveType type, Set<Long> pkg, ProgressMonitor progressMonitor) throws OsmTransferException {
555                FetchResult result = new FetchResult(new DataSet(), new HashSet<PrimitiveId>());
556                String baseUrl = OsmApi.getOsmApi().getBaseUrl();
557                for (long id : pkg) {
558                    try {
559                        String msg = "";
560                        switch (type) {
561                            case NODE:     msg = tr("Fetching node with id {0} from ''{1}''",     id, baseUrl); break;
562                            case WAY:      msg = tr("Fetching way with id {0} from ''{1}''",      id, baseUrl); break;
563                            case RELATION: msg = tr("Fetching relation with id {0} from ''{1}''", id, baseUrl); break;
564                        }
565                        progressMonitor.setCustomText(msg);
566                        result.dataSet.mergeFrom(singleGetId(type, id, progressMonitor));
567                    } catch (OsmApiException e) {
568                        if (e.getResponseCode() == HttpURLConnection.HTTP_NOT_FOUND) {
569                            System.out.println(tr("Server replied with response code 404 for id {0}. Skipping.", Long.toString(id)));
570                            result.missingPrimitives.add(new SimplePrimitiveId(id, type));
571                        } else {
572                            throw e;
573                        }
574                    }
575                }
576                return result;
577            }
578        }
579    }