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// 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 = function(debug) {
var db = new CouchDB("test_suite_db", {"X-Couch-Full-Commit":"false"});
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;};
var map = function (doc) {
emit(doc.integer, doc.integer);
emit(doc.integer, doc.integer);
};
var reduce = function (keys, values) { return sum(values); };
var result = db.query(map, reduce);
T(result.rows[0].value == 2*summate(numDocs));
result = db.query(map, reduce, {startkey: 4, endkey: 4});
T(result.rows[0].value == 8);
result = db.query(map, reduce, {startkey: 4, endkey: 5});
T(result.rows[0].value == 18);
result = db.query(map, reduce, {startkey: 4, endkey: 6});
T(result.rows[0].value == 30);
result = db.query(map, reduce, {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, reduce, {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); };
reduce = function (keys, values) { return sum(values); };
var results = db.query(map, reduce, {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, reduce, {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, reduce, {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, reduce, {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}));
}
// now test out more complex reductions that need to use the combine option.
db.deleteDb();
db.createDb();
var map = function (doc) { emit(doc.val, doc.val); };
var reduceCombine = function (keys, values, rereduce) {
// This computes the standard deviation of the mapped results
var stdDeviation=0.0;
var count=0;
var total=0.0;
var sqrTotal=0.0;
if (!rereduce) {
// This is the reduce phase, we are reducing over emitted values from
// the map functions.
for(var i in values) {
total = total + values[i];
sqrTotal = sqrTotal + (values[i] * values[i]);
}
count = values.length;
}
else {
// This is the rereduce phase, we are re-reducing previosuly
// reduced values.
for(var i in values) {
count = count + values[i].count;
total = total + values[i].total;
sqrTotal = sqrTotal + values[i].sqrTotal;
}
}
var variance = (sqrTotal - ((total * total)/count)) / count;
stdDeviation = Math.sqrt(variance);
// the reduce result. It contains enough information to be rereduced
// with other reduce results.
return {"stdDeviation":stdDeviation,"count":count,
"total":total,"sqrTotal":sqrTotal};
};
// Save a bunch a docs.
for(var i=0; i < 10; i++) {
var docs = [];
docs.push({val:10});
docs.push({val:20});
docs.push({val:30});
docs.push({val:40});
docs.push({val:50});
docs.push({val:60});
docs.push({val:70});
docs.push({val:80});
docs.push({val:90});
docs.push({val:100});
db.bulkSave(docs);
}
var results = db.query(map, reduceCombine);
var difference = results.rows[0].value.stdDeviation - 28.722813232690143;
// account for floating point rounding error
T(Math.abs(difference) < 0.0000000001);
};
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