You can now specify either "_sum" or "_count" as the source code for 2 built-in Erlang reduce functions. The framework is ready for YOU to add more built in reductions. The short list includes: _avg, _stddev, _min, and _max. We could also have one function that does all that in a single function, but it might not be as fun to use.

git-svn-id: https://svn.apache.org/repos/asf/couchdb/trunk@774101 13f79535-47bb-0310-9956-ffa450edef68

2 files changed, 120 insertions, 0 deletions

diff --git a/share/www/script/couch_tests.js b/share/www/script/couch_tests.js
index 62e877d8..6528835d 100644
--- a/share/www/script/couch_tests.js
+++ b/share/www/script/couch_tests.js
@@ -37,6 +37,7 @@ loadTest("bulk_docs.js");
 loadTest("lots_of_docs.js");
 loadTest("reduce.js");
 loadTest("reduce_false.js");
+loadTest("reduce_builtin.js");
 loadTest("design_options.js");
 loadTest("multiple_rows.js");
 loadTest("large_docs.js");
diff --git a/share/www/script/test/reduce_builtin.js b/share/www/script/test/reduce_builtin.js
new file mode 100644
index 00000000..c3d00339
--- /dev/null
+++ b/share/www/script/test/reduce_builtin.js
@@ -0,0 +1,119 @@
+// Licensed under the Apache License, Version 2.0 (the "License"); you may not
+// use this file except in compliance with the License.  You may obtain a copy
+// of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+// License for the specific language governing permissions and limitations under
+// the License.
+
+couchTests.reduce_builtin = function(debug) {
+  var db = new CouchDB("test_suite_db");
+  db.deleteDb();
+  db.createDb();
+  if (debug) debugger;
+  
+  var numDocs = 500
+  var docs = makeDocs(1,numDocs + 1);
+  db.bulkSave(docs);
+  
+  var summate = function(N) {return (N+1)*N/2;};
+
+  // this is the same test as the reduce.js test
+  // only we'll let CouchDB run reduce in Erlang
+  var map = function (doc) {
+      emit(doc.integer, doc.integer);
+      emit(doc.integer, doc.integer)};
+
+  var result = db.query(map, "_sum");
+  T(result.rows[0].value == 2*summate(numDocs));
+  result = db.query(map, "_count");
+  T(result.rows[0].value == 1000);
+
+  result = db.query(map, "_sum", {startkey: 4, endkey: 4});
+  T(result.rows[0].value == 8);
+  result = db.query(map, "_count", {startkey: 4, endkey: 4});
+  T(result.rows[0].value == 2);
+
+  result = db.query(map, "_sum", {startkey: 4, endkey: 5});
+  T(result.rows[0].value == 18);
+  result = db.query(map, "_count", {startkey: 4, endkey: 5});
+  T(result.rows[0].value == 4);
+  
+  result = db.query(map, "_sum", {startkey: 4, endkey: 6});
+  T(result.rows[0].value == 30);
+  result = db.query(map, "_count", {startkey: 4, endkey: 6});
+  T(result.rows[0].value == 6);
+
+  result = db.query(map, "_sum", {group:true, limit:3});
+  T(result.rows[0].value == 2);
+  T(result.rows[1].value == 4);
+  T(result.rows[2].value == 6);
+
+  for(var i=1; i<numDocs/2; i+=30) {
+    result = db.query(map, "_sum", {startkey: i, endkey: numDocs - i});
+    T(result.rows[0].value == 2*(summate(numDocs-i) - summate(i-1)));
+  }
+  
+  db.deleteDb();
+  db.createDb();
+
+  for(var i=1; i <= 5; i++) {
+
+    for(var j=0; j < 10; j++) {
+      // these docs are in the order of the keys collation, for clarity
+      var docs = [];
+      docs.push({keys:["a"]});
+      docs.push({keys:["a"]});
+      docs.push({keys:["a", "b"]});
+      docs.push({keys:["a", "b"]});
+      docs.push({keys:["a", "b", "c"]});
+      docs.push({keys:["a", "b", "d"]});
+      docs.push({keys:["a", "c", "d"]});
+      docs.push({keys:["d"]});
+      docs.push({keys:["d", "a"]});
+      docs.push({keys:["d", "b"]});
+      docs.push({keys:["d", "c"]});
+      db.bulkSave(docs);
+      T(db.info().doc_count == ((i - 1) * 10 * 11) + ((j + 1) * 11));
+    }
+
+    map = function (doc) {emit(doc.keys, 1)};
+    // with emitted values being 1, count should be the same as sum
+    var builtins = ["_sum", "_count"];
+
+    for (var b=0; b < builtins.length; b++) {
+      var fun = builtins[b];
+      var results = db.query(map, fun, {group:true});
+      
+      //group by exact key match
+      T(equals(results.rows[0], {key:["a"],value:20*i}));
+      T(equals(results.rows[1], {key:["a","b"],value:20*i}));
+      T(equals(results.rows[2], {key:["a", "b", "c"],value:10*i}));
+      T(equals(results.rows[3], {key:["a", "b", "d"],value:10*i}));
+
+      // test to make sure group reduce and limit params provide valid json
+      var results = db.query(map, fun, {group: true, limit: 2});
+      T(equals(results.rows[0], {key: ["a"], value: 20*i}));
+      T(equals(results.rows.length, 2));
+
+      //group by the first element in the key array
+      var results = db.query(map, fun, {group_level:1});
+      T(equals(results.rows[0], {key:["a"],value:70*i}));
+      T(equals(results.rows[1], {key:["d"],value:40*i}));
+
+      //group by the first 2 elements in the key array
+      var results = db.query(map, fun, {group_level:2});
+      T(equals(results.rows[0], {key:["a"],value:20*i}));
+      T(equals(results.rows[1], {key:["a","b"],value:40*i}));
+      T(equals(results.rows[2], {key:["a","c"],value:10*i}));
+      T(equals(results.rows[3], {key:["d"],value:10*i}));
+      T(equals(results.rows[4], {key:["d","a"],value:10*i}));
+      T(equals(results.rows[5], {key:["d","b"],value:10*i}));
+      T(equals(results.rows[6], {key:["d","c"],value:10*i}));
+    };    
+  }
+}
\ No newline at end of file