source: josm/trunk/src/org/openstreetmap/josm/command/PurgeCommand.java@ 10804

Last change on this file since 10804 was 10378, checked in by Don-vip, 8 years ago

Checkstyle 6.19: enable SingleSpaceSeparator and fix violations
  • Property svn:eol-style set to native
File size: 10.6 KB
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1// License: GPL. For details, see LICENSE file.
2package org.openstreetmap.josm.command;
3
4import static org.openstreetmap.josm.tools.I18n.trn;
5
6import java.util.ArrayList;
7import java.util.Collection;
8import java.util.HashMap;
9import java.util.HashSet;
10import java.util.Iterator;
11import java.util.List;
12import java.util.Map;
13import java.util.Objects;
14import java.util.Set;
15
16import javax.swing.Icon;
17
18import org.openstreetmap.josm.data.conflict.Conflict;
19import org.openstreetmap.josm.data.conflict.ConflictCollection;
20import org.openstreetmap.josm.data.osm.DataSet;
21import org.openstreetmap.josm.data.osm.Node;
22import org.openstreetmap.josm.data.osm.NodeData;
23import org.openstreetmap.josm.data.osm.OsmPrimitive;
24import org.openstreetmap.josm.data.osm.PrimitiveData;
25import org.openstreetmap.josm.data.osm.PrimitiveId;
26import org.openstreetmap.josm.data.osm.Relation;
27import org.openstreetmap.josm.data.osm.RelationData;
28import org.openstreetmap.josm.data.osm.Storage;
29import org.openstreetmap.josm.data.osm.Way;
30import org.openstreetmap.josm.data.osm.WayData;
31import org.openstreetmap.josm.gui.layer.OsmDataLayer;
32import org.openstreetmap.josm.tools.ImageProvider;
33
34/**
35 * Command, to purge a list of primitives.
36 */
37public class PurgeCommand extends Command {
38 protected List<OsmPrimitive> toPurge;
39 protected Storage<PrimitiveData> makeIncompleteData;
40
41 protected Map<PrimitiveId, PrimitiveData> makeIncompleteDataByPrimId;
42
43 protected final ConflictCollection purgedConflicts = new ConflictCollection();
44
45 protected final DataSet ds;
46
47 /**
48 * This command relies on a number of consistency conditions:
49 * - makeIncomplete must be a subset of toPurge.
50 * - Each primitive, that is in toPurge but not in makeIncomplete, must
51 * have all its referrers in toPurge.
52 * - Each element of makeIncomplete must not be new and must have only
53 * referrers that are either a relation or included in toPurge.
54 * @param layer OSM data layer
55 * @param toPurge primitives to purge
56 * @param makeIncomplete primitives to make incomplete
57 */
58 public PurgeCommand(OsmDataLayer layer, Collection<OsmPrimitive> toPurge, Collection<OsmPrimitive> makeIncomplete) {
59 super(layer);
60 this.ds = layer.data;
61 /**
62 * The topological sort is to avoid missing way nodes and missing
63 * relation members when adding primitives back to the dataset on undo.
64 *
65 * The same should hold for normal execution, but at time of writing
66 * there seem to be no such consistency checks when removing primitives.
67 * (It is done in a save manner, anyway.)
68 */
69 this.toPurge = topoSort(toPurge);
70 saveIncomplete(makeIncomplete);
71 }
72
73 protected final void saveIncomplete(Collection<OsmPrimitive> makeIncomplete) {
74 makeIncompleteData = new Storage<>(new Storage.PrimitiveIdHash());
75 makeIncompleteDataByPrimId = makeIncompleteData.foreignKey(new Storage.PrimitiveIdHash());
76
77 for (OsmPrimitive osm : makeIncomplete) {
78 makeIncompleteData.add(osm.save());
79 }
80 }
81
82 @Override
83 public boolean executeCommand() {
84 ds.beginUpdate();
85 try {
86 purgedConflicts.get().clear();
87 /**
88 * Loop from back to front to keep referential integrity.
89 */
90 for (int i = toPurge.size()-1; i >= 0; --i) {
91 OsmPrimitive osm = toPurge.get(i);
92 if (makeIncompleteDataByPrimId.containsKey(osm)) {
93 // we could simply set the incomplete flag
94 // but that would not free memory in case the
95 // user clears undo/redo buffer after purge
96 PrimitiveData empty;
97 switch(osm.getType()) {
98 case NODE: empty = new NodeData(); break;
99 case WAY: empty = new WayData(); break;
100 case RELATION: empty = new RelationData(); break;
101 default: throw new AssertionError();
102 }
103 empty.setId(osm.getUniqueId());
104 empty.setIncomplete(true);
105 osm.load(empty);
106 } else {
107 ds.removePrimitive(osm);
108 Conflict<?> conflict = getLayer().getConflicts().getConflictForMy(osm);
109 if (conflict != null) {
110 purgedConflicts.add(conflict);
111 getLayer().getConflicts().remove(conflict);
112 }
113 }
114 }
115 } finally {
116 ds.endUpdate();
117 }
118 return true;
119 }
120
121 @Override
122 public void undoCommand() {
123 if (ds == null)
124 return;
125
126 for (OsmPrimitive osm : toPurge) {
127 PrimitiveData data = makeIncompleteDataByPrimId.get(osm);
128 if (data != null) {
129 if (ds.getPrimitiveById(osm) != osm)
130 throw new AssertionError(
131 String.format("Primitive %s has been made incomplete when purging, but it cannot be found on undo.", osm));
132 osm.load(data);
133 } else {
134 if (ds.getPrimitiveById(osm) != null)
135 throw new AssertionError(String.format("Primitive %s was removed when purging, but is still there on undo", osm));
136 ds.addPrimitive(osm);
137 }
138 }
139
140 for (Conflict<?> conflict : purgedConflicts) {
141 getLayer().getConflicts().add(conflict);
142 }
143 }
144
145 /**
146 * Sorts a collection of primitives such that for each object
147 * its referrers come later in the sorted collection.
148 * @param sel collection of primitives to sort
149 * @return sorted list
150 */
151 public static List<OsmPrimitive> topoSort(Collection<OsmPrimitive> sel) {
152 Set<OsmPrimitive> in = new HashSet<>(sel);
153
154 List<OsmPrimitive> out = new ArrayList<>(in.size());
155
156 // Nodes not deleted in the first pass
157 Set<OsmPrimitive> remainingNodes = new HashSet<>(in.size());
158
159 /**
160 * First add nodes that have no way referrer.
161 */
162 outer:
163 for (Iterator<OsmPrimitive> it = in.iterator(); it.hasNext();) {
164 OsmPrimitive u = it.next();
165 if (u instanceof Node) {
166 Node n = (Node) u;
167 for (OsmPrimitive ref : n.getReferrers()) {
168 if (ref instanceof Way && in.contains(ref)) {
169 it.remove();
170 remainingNodes.add(n);
171 continue outer;
172 }
173 }
174 it.remove();
175 out.add(n);
176 }
177 }
178
179 /**
180 * Then add all ways, each preceded by its (remaining) nodes.
181 */
182 for (Iterator<OsmPrimitive> it = in.iterator(); it.hasNext();) {
183 OsmPrimitive u = it.next();
184 if (u instanceof Way) {
185 Way w = (Way) u;
186 it.remove();
187 for (Node n : w.getNodes()) {
188 if (remainingNodes.contains(n)) {
189 remainingNodes.remove(n);
190 out.add(n);
191 }
192 }
193 out.add(w);
194 }
195 }
196
197 if (!remainingNodes.isEmpty())
198 throw new AssertionError("topo sort algorithm failed (nodes remaining)");
199
200 /**
201 * Rest are relations. Do topological sorting on a DAG where each
202 * arrow points from child to parent. (Because it is faster to
203 * loop over getReferrers() than getMembers().)
204 */
205 @SuppressWarnings({ "unchecked", "rawtypes" })
206 Set<Relation> inR = (Set) in;
207
208 Map<Relation, Integer> numChilds = new HashMap<>();
209
210 // calculate initial number of childs
211 for (Relation r : inR) {
212 numChilds.put(r, 0);
213 }
214 for (Relation r : inR) {
215 for (OsmPrimitive parent : r.getReferrers()) {
216 if (!(parent instanceof Relation))
217 throw new AssertionError();
218 Integer i = numChilds.get(parent);
219 if (i != null) {
220 numChilds.put((Relation) parent, i+1);
221 }
222 }
223 }
224 Set<Relation> childlessR = new HashSet<>();
225 for (Relation r : inR) {
226 if (numChilds.get(r).equals(0)) {
227 childlessR.add(r);
228 }
229 }
230
231 List<Relation> outR = new ArrayList<>(inR.size());
232 while (!childlessR.isEmpty()) {
233 // Identify one childless Relation and let it virtually die. This makes other relations childless.
234 Iterator<Relation> it = childlessR.iterator();
235 Relation next = it.next();
236 it.remove();
237 outR.add(next);
238
239 for (OsmPrimitive parentPrim : next.getReferrers()) {
240 Relation parent = (Relation) parentPrim;
241 Integer i = numChilds.get(parent);
242 if (i != null) {
243 numChilds.put(parent, i-1);
244 if (i-1 == 0) {
245 childlessR.add(parent);
246 }
247 }
248 }
249 }
250
251 if (outR.size() != inR.size())
252 throw new AssertionError("topo sort algorithm failed");
253
254 out.addAll(outR);
255
256 return out;
257 }
258
259 @Override
260 public String getDescriptionText() {
261 return trn("Purged {0} object", "Purged {0} objects", toPurge.size(), toPurge.size());
262 }
263
264 @Override
265 public Icon getDescriptionIcon() {
266 return ImageProvider.get("data", "purge");
267 }
268
269 @Override
270 public Collection<? extends OsmPrimitive> getParticipatingPrimitives() {
271 return toPurge;
272 }
273
274 @Override
275 public void fillModifiedData(Collection<OsmPrimitive> modified, Collection<OsmPrimitive> deleted, Collection<OsmPrimitive> added) {
276 // Do nothing
277 }
278
279 @Override
280 public int hashCode() {
281 return Objects.hash(super.hashCode(), toPurge, makeIncompleteData, makeIncompleteDataByPrimId, purgedConflicts, ds);
282 }
283
284 @Override
285 public boolean equals(Object obj) {
286 if (this == obj) return true;
287 if (obj == null || getClass() != obj.getClass()) return false;
288 if (!super.equals(obj)) return false;
289 PurgeCommand that = (PurgeCommand) obj;
290 return Objects.equals(toPurge, that.toPurge) &&
291 Objects.equals(makeIncompleteData, that.makeIncompleteData) &&
292 Objects.equals(makeIncompleteDataByPrimId, that.makeIncompleteDataByPrimId) &&
293 Objects.equals(purgedConflicts, that.purgedConflicts) &&
294 Objects.equals(ds, that.ds);
295 }
296}
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