Optimize presets.match

Previous implementation was linear in the number of
presets. This should be near constant time.

js/id/presets.js

@@ -11,6 +11,37 @@ iD.presets = function() {
         other,
         other_area;
 
+    // Index of presets by (geometry, tag key).
+    var index = {
+        point: {},
+        vertex: {},
+        line: {},
+        area: {},
+        relation: {}
+    };
+
+    all.match = function(entity, resolver) {
+        var geometry = entity.geometry(resolver),
+            geometryMatches = index[geometry],
+            best = -1,
+            match = geometry === 'area' ? other_area : other;
+
+        for (var k in entity.tags) {
+            var keyMatches = geometryMatches[k];
+            if (!keyMatches) continue;
+
+            for (var i = 0; i < keyMatches.length; i++) {
+                var score = keyMatches[i].matchScore(entity);
+                if (score > best) {
+                    best = score;
+                    match = keyMatches[i];
+                }
+            }
+        }
+
+        return match;
+    };
+
     all.load = function(d) {
 
         if (d.fields) {
@@ -45,6 +76,18 @@ iD.presets = function() {
         other = all.item('other');
         other_area = all.item('other_area');
 
+        for (var i = 0; i < all.collection.length; i++) {
+            var preset = all.collection[i],
+                geometry = preset.geometry;
+
+            for (var j = 0; j < geometry.length; j++) {
+                var g = index[geometry[j]];
+                for (var k in preset.tags) {
+                    (g[k] = g[k] || []).push(preset);
+                }
+            }
+        }
+
         return all;
     };
 

js/id/presets/collection.js

@@ -10,32 +10,12 @@ iD.presets.Collection = function(collection) {
             });
         },
 
-        match: function(entity, resolver) {
-            return presets.matchGeometry(entity.geometry(resolver)).matchTags(entity);
-        },
-
         matchGeometry: function(geometry) {
             return iD.presets.Collection(collection.filter(function(d) {
                 return d.matchGeometry(geometry);
             }));
         },
 
-        matchTags: function(entity) {
-
-            var best = -1,
-                match;
-
-            for (var i = 0; i < collection.length; i++) {
-                var score = collection[i].matchScore(entity);
-                if (score > best) {
-                    best = score;
-                    match = collection[i];
-                }
-            }
-
-            return match;
-        },
-
         search: function(value) {
             if (!value) return this;
 

test/index.html

@@ -246,6 +246,7 @@
 
     <script src="spec/modes/add_point.js"></script>
 
+    <script src="spec/presets.js"></script>
     <script src="spec/presets/preset.js"></script>
     <script src="spec/presets/collection.js"></script>
     <script src="spec/presets/category.js"></script>

test/index_packaged.html

@@ -87,6 +87,7 @@
 
     <script src="spec/modes/add_point.js"></script>
 
+    <script src="spec/presets.js"></script>
     <script src="spec/presets/preset.js"></script>
     <script src="spec/presets/collection.js"></script>
     <script src="spec/presets/category.js"></script>

test/spec/presets.js

@@ -0,0 +1,38 @@
+describe("iD.presets", function() {
+    var p = {
+        other: {
+            tags: {},
+            geometry: ['point', 'vertex', 'line', 'area']
+        },
+        residential: {
+            tags: {
+                highway: 'residential'
+            },
+            geometry: ['line']
+        },
+        park: {
+            tags: {
+                leisure: 'park'
+            },
+            geometry: ['point', 'area']
+        }
+    };
+
+    var c = iD.presets().load({presets: p}),
+        w = iD.Way({tags: { highway: 'residential'}}),
+        g = iD.Graph().replace(w);
+
+    describe("#match", function() {
+        it("returns a collection containing presets matching a geometry and tags", function() {
+            var way = iD.Way({tags: { highway: 'residential'}}),
+                graph = iD.Graph([way]);
+            expect(c.match(way, graph).id).to.eql('residential');
+        });
+
+        it("returns an other preset when no tags match", function() {
+            var way = iD.Way({tags: {foo: 'bar'}}),
+                graph = iD.Graph([way]);
+            expect(c.match(way, graph).id).to.eql('other');
+        });
+    });
+});

test/spec/presets/collection.js

@@ -36,12 +36,6 @@ describe("iD.presets.Collection", function() {
         });
     });
 
-    describe("#matchTags", function() {
-        it("returns a new collection only containing presets matching an entity's tags", function() {
-            expect(c.matchTags(w, g)).to.eql(p.residential);
-        });
-    });
-
     describe("#search", function() {
         it("filters presets by name", function() {
             expect(c.search("resid").collection.indexOf(p.residential) >= 0).to.eql(true);