SERVER-35043, SERVER-22949: move geoNear implementation into aggregation

This commit removes the geoNear command and moves its implementation
into the aggregation framework. Users should use the aggregate command
with a $geoNear stage.

The implementation rewrite additionally removes the limit in the
$geoNear aggregation stage. To limit the number of results, use a $limit
stage.

1 files changed, 27 insertions, 35 deletions

diff --git a/jstests/libs/geo_near_random.js b/jstests/libs/geo_near_random.js
index 207ca1302d9..d5de7aa70a7 100644
--- a/jstests/libs/geo_near_random.js
+++ b/jstests/libs/geo_near_random.js
@@ -43,17 +43,17 @@ GeoNearRandomTest.prototype.insertPts = function(nPts, indexBounds, scale) {
         this.t.ensureIndex({loc: '2d'}, indexBounds);
 };
 
-GeoNearRandomTest.prototype.assertIsPrefix = function(short, long) {
+GeoNearRandomTest.prototype.assertIsPrefix = function(short, long, errmsg) {
     for (var i = 0; i < short.length; i++) {
-        var xS = short[i].obj ? short[i].obj.loc[0] : short[i].loc[0];
-        var yS = short[i].obj ? short[i].obj.loc[1] : short[i].loc[1];
-        var dS = short[i].obj ? short[i].dis : 1;
+        var xS = short[i] ? short[i].loc[0] : short[i].loc[0];
+        var yS = short[i] ? short[i].loc[1] : short[i].loc[1];
+        var dS = short[i] ? short[i].dis : 1;
 
-        var xL = long[i].obj ? long[i].obj.loc[0] : long[i].loc[0];
-        var yL = long[i].obj ? long[i].obj.loc[1] : long[i].loc[1];
-        var dL = long[i].obj ? long[i].dis : 1;
+        var xL = long[i] ? long[i].loc[0] : long[i].loc[0];
+        var yL = long[i] ? long[i].loc[1] : long[i].loc[1];
+        var dL = long[i] ? long[i].dis : 1;
 
-        assert.eq([xS, yS, dS], [xL, yL, dL]);
+        assert.eq([xS, yS, dS], [xL, yL, dL], errmsg);
     }
 };
 
@@ -66,37 +66,29 @@ GeoNearRandomTest.prototype.testPt = function(pt, opts) {
 
     print("testing point: " + tojson(pt) + " opts: " + tojson(opts));
 
-    var cmd = {geoNear: this.t.getName(), near: pt, num: 1, spherical: opts.sphere};
+    let query = {loc: {}};
+    query.loc[opts.sphere ? '$nearSphere' : '$near'] = pt;
+    const proj = {dis: {$meta: "geoNearDistance"}};
+    const runQuery = (limit) => this.t.find(query, proj).limit(opts.nToTest).toArray();
 
-    var last = this.db.runCommand(cmd).results;
+    let last = runQuery(1);
     for (var i = 2; i <= opts.nToTest; i++) {
-        // print(i); // uncomment to watch status
-        cmd.num = i;
-        var ret = this.db.runCommand(cmd).results;
-
-        try {
-            this.assertIsPrefix(last, ret);
-        } catch (e) {
-            print("*** failed while compairing " + (i - 1) + " and " + i);
-            printjson(cmd);
-            throw e;  // rethrow
-        }
-
-        // Make sure distances are in increasing order
-        assert.gte(ret[ret.length - 1].dis, last[last.length - 1].dis);
+        let ret = runQuery(i);
+        this.assertIsPrefix(last, ret, `Unexpected result when comparing ${i-1} and ${i}`);
 
+        // Make sure distances are in increasing order.
+        assert.gte(ret[ret.length - 1].dis, last[last.length - 1].dis);
         last = ret;
     }
 
-    last = last.map(function(x) {
-        return x.obj;
-    });
-
-    var query = {loc: {}};
-    query.loc[opts.sphere ? '$nearSphere' : '$near'] = pt;
-    var near = this.t.find(query).limit(opts.nToTest).toArray();
-
-    // Test that a query using $near/$nearSphere with a limit of 'nToTest' returns the same points
-    // (in order) as the geoNear command with num=nToTest.
-    assert.eq(last, near);
+    // Test that a query using $near or $nearSphere returns the same points in order as the $geoNear
+    // aggregation stage.
+    const queryResults = runQuery(opts.nToTest);
+    const aggResults = this.t
+                           .aggregate([
+                               {$geoNear: {near: pt, distanceField: "dis", spherical: opts.sphere}},
+                               {$limit: opts.nToTest}
+                           ])
+                           .toArray();
+    assert.eq(queryResults, aggResults);
 };