conveyal/modeify#163 limit profile router responses by access mode

src/main/java/org/opentripplanner/api/resource/ProfileResource.java

@@ -65,7 +65,7 @@ public Response profileRoute (
             @QueryParam("minCarTime")   @DefaultValue("1")     int minCarTime,
             @QueryParam("minBikeTime")  @DefaultValue("1")     int minBikeTime,
             @QueryParam("orderBy")      @DefaultValue("AVG")   Option.SortOrder orderBy,
-            @QueryParam("limit")        @DefaultValue("10")    int limit,
+            @QueryParam("limit")        @DefaultValue("10")    int limit,       // max options to return PER ACCESS MODE
             @QueryParam("suboptimal")   @DefaultValue("5")     int suboptimalMinutes,
             @QueryParam("accessModes")  @DefaultValue("WALK,BICYCLE") TraverseModeSet accessModes,
             @QueryParam("egressModes")  @DefaultValue("WALK")         TraverseModeSet egressModes,

src/main/java/org/opentripplanner/profile/ProfileRequest.java

@@ -37,7 +37,7 @@ public class ProfileRequest implements Serializable {
 
     public LocalDate date;
     public Option.SortOrder orderBy;
-    public int limit;
+    public int limit; // the maximum number of options presented PER ACCESS MODE
     public TraverseModeSet accessModes, egressModes, directModes, transitModes;
     public boolean analyst = false; // if true, propagate travel times out to street network
 

src/main/java/org/opentripplanner/profile/ProfileResponse.java

@@ -1,11 +1,12 @@
 package org.opentripplanner.profile;
 
-import java.util.Collection;
-import java.util.Collections;
-import java.util.Comparator;
-import java.util.List;
+import java.util.*;
 
+import com.beust.jcommander.internal.Sets;
+import com.google.common.collect.ArrayListMultimap;
+import com.google.common.collect.ListMultimap;
 import com.google.common.collect.Lists;
+import org.opentripplanner.routing.core.TraverseMode;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -14,23 +15,23 @@ public class ProfileResponse {
 
     private static final Logger LOG = LoggerFactory.getLogger(ProfileResponse.class);
 
-    public List<Option> options = Lists.newArrayList();
+    public Set<Option> options = Sets.newHashSet();
 
     /**
      * The constructed response will include all the options that do not use transit,
-     * as well as the top N options that do use transit.
+     * as well as the top N options that do use transit for each access mode.
      *
      * @param orderBy specifies how the top N transit options will be chosen
-     * @param limit the maximum number of transit options to include in the response.
+     * @param limit the maximum number of transit options to include in the response. zero or negative means no limit.
      */
     public ProfileResponse (Collection<Option> options, Option.SortOrder orderBy, int limit) {
         List<Option> transitOptions = Lists.newArrayList();
-        // Always include non-transit options
+        // Always return all non-transit options
         for (Option option : options) {
             if (option.transit == null || option.transit.isEmpty()) this.options.add(option);
             else transitOptions.add(option);
         }
-        // Then choose the top N transit options
+        // Order all transit options by the specified method
         Comparator<Option> c;
         switch (orderBy) {
             case MAX:
@@ -44,10 +45,23 @@ public ProfileResponse (Collection<Option> options, Option.SortOrder orderBy, in
                 c = new Option.MinComparator();
         }
         Collections.sort(transitOptions, c);
-        if (limit > 0 && limit <= transitOptions.size()) {
-            transitOptions = transitOptions.subList(0, limit);
+        // Group options by access mode, retaining ordering.
+        // ListMultimap can hold duplicate key-value pairs and maintains the insertion ordering of values for a given key.
+        // TODO update this to also use the egress mode in the key
+        ListMultimap<TraverseMode, Option> transitOptionsByAccessMode = ArrayListMultimap.create();
+        for (Option option : transitOptions) {
+            for (StreetSegment segment : option.access) {
+                transitOptionsByAccessMode.put(segment.mode, option);
+            }
+        }
+        // Retain the top N transit options for each access mode. Duplicates may be present, but options is a Set.
+        for (Collection<Option> singleModeOptions : transitOptionsByAccessMode.asMap().values()) {
+            int n = 0;
+            for (Option option : singleModeOptions) {
+                options.add(option);
+                if (limit > 0 && ++n >= limit) break;
+            }
         }
-        this.options.addAll(transitOptions);
         for (Option option : this.options) {
             LOG.info("{} {}", option.stats, option.summary);
         }