v0.2.54..v0.2.55 changeset ElementHashVisitor.h

diff --git a/hoot-core/src/main/cpp/hoot/core/visitors/ElementHashVisitor.h b/hoot-core/src/main/cpp/hoot/core/visitors/ElementHashVisitor.h
new file mode 100644
index 0000000..acc348e
--- /dev/null
+++ b/hoot-core/src/main/cpp/hoot/core/visitors/ElementHashVisitor.h
@@ -0,0 +1,104 @@
+/*
+ * This file is part of Hootenanny.
+ *
+ * Hootenanny 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/>.
+ *
+ * --------------------------------------------------------------------
+ *
+ * The following copyright notices are generated automatically. If you
+ * have a new notice to add, please use the format:
+ * " * @copyright Copyright ..."
+ * This will properly maintain the copyright information. DigitalGlobe
+ * copyrights will be updated automatically.
+ *
+ * @copyright Copyright (C) 2017, 2018, 2019, 2020 DigitalGlobe (http://www.digitalglobe.com/)
+ */
+#ifndef ELEMENT_HASH_VISITOR_H
+#define ELEMENT_HASH_VISITOR_H
+
+// hoot
+#include <hoot/core/visitors/ElementOsmMapVisitor.h>
+#include <hoot/core/elements/Node.h>
+#include <hoot/core/elements/Way.h>
+#include <hoot/core/elements/Relation.h>
+
+namespace hoot
+{
+
+/**
+ * Calculates a hash for each element and optionally stores the hash in the MetadataTags::HootHash()
+ * tag and or collects it for later use. Any existing hash tag value will be overwritten.
+ *
+ * See this for details: https://github.com/ngageoint/hootenanny/issues/1663
+ *
+ * We want to keep ID's out of this, so not using GeoJsonWriter. Although, possibly we could add
+ * a switch to GeoJsonWriter to not write ID's and use it at some point instead of this.
+ *
+ * @todo implement OperationStatusInfo
+ */
+class ElementHashVisitor : public ElementOsmMapVisitor
+{
+public:
+
+  static std::string className() { return "hoot::ElementHashVisitor"; }
+
+  ElementHashVisitor();
+
+  virtual void visit(const ElementPtr &e);
+
+  QString toJson(const ConstElementPtr& e) const;
+  virtual QString toJson(const Tags& tags, const double ce = -1.0) const;
+
+  QByteArray toHash(const ConstElementPtr& e) const;
+  QByteArray toHash(const Tags& tags, const double ce = -1.0) const;
+  QString toHashString(const ConstElementPtr& e) const;
+  QString toHashString(const Tags& tags, const double ce = -1.0) const;
+
+  virtual QString getDescription() const { return "Calculates unique hash values for elements"; }
+
+  virtual std::string getClassName() const { return className(); }
+
+  void setIncludeCircularError(bool include) { _includeCe = include; }
+  void setWriteHashes(bool write) { _writeHashes = write; }
+  void setCollectHashes(bool collect) { _collectHashes = collect; }
+
+  QMap<QString, ElementId> getHashes() const { return _hashesToElementIds; }
+  QSet<std::pair<ElementId, ElementId>> getDuplicates() const { return _duplicates; }
+  void clearHashes() { _hashesToElementIds.clear(); }
+
+protected:
+
+  virtual QString _toJson(const ConstNodePtr& node) const;
+  virtual QString _toJson(const ConstWayPtr& way) const;
+  virtual QString _toJson(const ConstRelationPtr& relation) const;
+
+private:
+
+  // determines if element circular error will be used in computation of the hash
+  bool _includeCe;
+  // allows for ignoring info tag keys on a case by case basis
+  QStringList _nonMetadataIgnoreKeys;
+  // determines whether hashes are written to an element's tags
+  bool _writeHashes;
+  // determines if hash values should be collected for post-processing purposes
+  bool _collectHashes;
+  // collected hash values mapped to element IDs
+  QMap<QString, ElementId> _hashesToElementIds;
+  // pairings of all duplicate elements found
+  QSet<std::pair<ElementId, ElementId>> _duplicates;
+};
+
+}
+
+#endif // ELEMENT_HASH_VISITOR_H