separate logic between polyline compression algorithm and JSON formatting.

fixes and closes #1245

Algorithms/polyline_compressor.cpp

@@ -25,16 +25,16 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 */
 
-#include "PolylineCompressor.h"
+#include "polyline_compressor.hpp"
 #include "../DataStructures/SegmentInformation.h"
 
 #include <osrm/Coordinate.h>
 
-void PolylineCompressor::encodeVectorSignedNumber(std::vector<int> &numbers,
+std::string PolylineCompressor::encode_vector(std::vector<int> &numbers) const
-                                                  std::string &output) const
 {
-    const unsigned end = static_cast<unsigned>(numbers.size());
+    std::string output;
-    for (unsigned i = 0; i < end; ++i)
+    const auto end = numbers.size();
+    for (std::size_t i = 0; i < end; ++i)
     {
         numbers[i] <<= 1;
         if (numbers[i] < 0)
@@ -44,12 +44,14 @@ void PolylineCompressor::encodeVectorSignedNumber(std::vector<int> &numbers,
     }
     for (const int number : numbers)
     {
-        encodeNumber(number, output);
+        output += encode_number(number);
     }
+    return output;
 }
 
-void PolylineCompressor::encodeNumber(int number_to_encode, std::string &output) const
+std::string PolylineCompressor::encode_number(int number_to_encode) const
 {
+    std::string output;
     while (number_to_encode >= 0x20)
     {
         const int next_value = (0x20 | (number_to_encode & 0x1f)) + 63;
@@ -67,46 +69,29 @@ void PolylineCompressor::encodeNumber(int number_to_encode, std::string &output)
     {
         output += static_cast<char>(number_to_encode);
     }
+    return output;
 }
 
-JSON::String
+std::string
-PolylineCompressor::printEncodedString(const std::vector<SegmentInformation> &polyline) const
+PolylineCompressor::get_encoded_string(const std::vector<SegmentInformation> &polyline) const
 {
     std::string output;
     std::vector<int> delta_numbers;
-    if (!polyline.empty())
+    if (polyline.empty())
     {
-        FixedPointCoordinate last_coordinate = {0, 0};
+        return {};
-        for (const auto &segment : polyline)
-        {
-            if (segment.necessary)
-            {
-                const int lat_diff = segment.location.lat - last_coordinate.lat;
-                const int lon_diff = segment.location.lon - last_coordinate.lon;
-                delta_numbers.emplace_back(lat_diff);
-                delta_numbers.emplace_back(lon_diff);
-                last_coordinate = segment.location;
-            }
-        }
-        encodeVectorSignedNumber(delta_numbers, output);
     }
-    JSON::String return_value(output);
+    FixedPointCoordinate previous_coordinate = {0, 0};
-    return return_value;
-}
-
-JSON::Array
-PolylineCompressor::printUnencodedString(const std::vector<SegmentInformation> &polyline) const
-{
-    JSON::Array json_geometry_array;
     for (const auto &segment : polyline)
     {
         if (segment.necessary)
         {
-            JSON::Array json_coordinate;
+            const int lat_diff = segment.location.lat - previous_coordinate.lat;
-            json_coordinate.values.push_back(segment.location.lat / COORDINATE_PRECISION);
+            const int lon_diff = segment.location.lon - previous_coordinate.lon;
-            json_coordinate.values.push_back(segment.location.lon / COORDINATE_PRECISION);
+            delta_numbers.emplace_back(lat_diff);
-            json_geometry_array.values.push_back(json_coordinate);
+            delta_numbers.emplace_back(lon_diff);
+            previous_coordinate = segment.location;
         }
     }
-    return json_geometry_array;
+    return encode_vector(delta_numbers);
 }

Algorithms/polyline_compressor.hpp

@@ -0,0 +1,47 @@
+/*
+
+Copyright (c) 2013, Project OSRM, Dennis Luxen, others
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without modification,
+are permitted provided that the following conditions are met:
+
+Redistributions of source code must retain the above copyright notice, this list
+of conditions and the following disclaimer.
+Redistributions in binary form must reproduce the above copyright notice, this
+list of conditions and the following disclaimer in the documentation and/or
+other materials provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
+ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+*/
+
+#ifndef POLYLINECOMPRESSOR_H_
+#define POLYLINECOMPRESSOR_H_
+
+struct SegmentInformation;
+
+#include <string>
+#include <vector>
+
+class PolylineCompressor
+{
+  private:
+    std::string encode_vector(std::vector<int> &numbers) const;
+
+    std::string encode_number(const int number_to_encode) const;
+
+  public:
+    std::string get_encoded_string(const std::vector<SegmentInformation> &polyline) const;
+};
+
+#endif /* POLYLINECOMPRESSOR_H_ */

Algorithms/polyline_formatter.cpp

@@ -0,0 +1,56 @@
+/*
+
+Copyright (c) 2013, Project OSRM, Dennis Luxen, others
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without modification,
+are permitted provided that the following conditions are met:
+
+Redistributions of source code must retain the above copyright notice, this list
+of conditions and the following disclaimer.
+Redistributions in binary form must reproduce the above copyright notice, this
+list of conditions and the following disclaimer in the documentation and/or
+other materials provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
+ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+*/
+
+#include "polyline_formatter.hpp"
+
+#include "polyline_compressor.hpp"
+#include "../DataStructures/SegmentInformation.h"
+
+#include <osrm/Coordinate.h>
+
+JSON::String
+PolylineFormatter::printEncodedString(const std::vector<SegmentInformation> &polyline) const
+{
+    return JSON::String(PolylineCompressor().get_encoded_string(polyline));
+}
+
+JSON::Array
+PolylineFormatter::printUnencodedString(const std::vector<SegmentInformation> &polyline) const
+{
+    JSON::Array json_geometry_array;
+    for (const auto &segment : polyline)
+    {
+        if (segment.necessary)
+        {
+            JSON::Array json_coordinate;
+            json_coordinate.values.push_back(segment.location.lat / COORDINATE_PRECISION);
+            json_coordinate.values.push_back(segment.location.lon / COORDINATE_PRECISION);
+            json_geometry_array.values.push_back(json_coordinate);
+        }
+    }
+    return json_geometry_array;
+}

Algorithms/polyline_formatter.hpp

@@ -25,8 +25,8 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 */
 
-#ifndef POLYLINECOMPRESSOR_H_
+#ifndef POLYLINE_FORMATTER_H_
-#define POLYLINECOMPRESSOR_H_
+#define POLYLINE_FORMATTER_H_
 
 struct SegmentInformation;
 
@@ -35,17 +35,11 @@ struct SegmentInformation;
 #include <string>
 #include <vector>
 
-class PolylineCompressor
+struct PolylineFormatter
 {
-  private:
-    void encodeVectorSignedNumber(std::vector<int> &numbers, std::string &output) const;
-
-    void encodeNumber(int number_to_encode, std::string &output) const;
-
-  public:
     JSON::String printEncodedString(const std::vector<SegmentInformation> &polyline) const;
 
     JSON::Array printUnencodedString(const std::vector<SegmentInformation> &polyline) const;
 };
 
-#endif /* POLYLINECOMPRESSOR_H_ */
+#endif /* POLYLINE_FORMATTER_H_ */

Descriptors/DescriptionFactory.cpp

@@ -30,7 +30,7 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include <osrm/Coordinate.h>
 
 #include "../typedefs.h"
-#include "../Algorithms/PolylineCompressor.h"
+#include "../Algorithms/polyline_formatter.hpp"
 #include "../DataStructures/RawRouteData.h"
 #include "../DataStructures/SegmentInformation.h"
 #include "../DataStructures/TurnInstructions.h"
@@ -112,9 +112,9 @@ JSON::Value DescriptionFactory::AppendGeometryString(const bool return_encoded)
 {
     if (return_encoded)
     {
-        return polyline_compressor.printEncodedString(path_description);
+        return PolylineFormatter().printEncodedString(path_description);
     }
-    return polyline_compressor.printUnencodedString(path_description);
+    return PolylineFormatter().printUnencodedString(path_description);
 }
 
 void DescriptionFactory::BuildRouteSummary(const double distance, const unsigned time)

Descriptors/DescriptionFactory.h

@@ -29,8 +29,8 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #define DESCRIPTIONFACTORY_H_
 
 #include "../Algorithms/DouglasPeucker.h"
-#include "../Algorithms/PolylineCompressor.h"
 #include "../DataStructures/phantom_node.hpp"
+#include "../DataStructures/JSONContainer.h"
 #include "../DataStructures/SegmentInformation.h"
 #include "../DataStructures/TurnInstructions.h"
 #include "../typedefs.h"
@@ -47,7 +47,6 @@ struct PathData;
 class DescriptionFactory
 {
     DouglasPeucker polyline_generalizer;
-    PolylineCompressor polyline_compressor;
     PhantomNode start_phantom, target_phantom;
 
     double DegreeToRadian(const double degree) const;