Change getAll to the more relevant unions.

Author: GabeIsman

lib/backend.js

@@ -39,12 +39,12 @@ var Backend = {
   },
 
   /**
-     Gets the contents of the specified keys and returns them in the same order
-     passed.
+     Gets the union of contents of the specified keys in each of the specified buckets and returns
+     a mapping of bucket to union.
   */
-  getAll : function(bucket, keys, cb){
+  unions : function(bucket, keys, cb){
     contract(arguments)
-        .params('string', 'array', 'function')
+        .params('array', 'array', 'function')
         .end();
   },
 

lib/memory-backend.js

@@ -60,18 +60,25 @@ MemoryBackend.prototype = {
   },
 
   /**
-     Gets the contents at the bucket's keys.
+     Gets the union of the keys in each of the specified buckets
   */
-  getAll : function(bucket, keys, cb){
+  unions : function(buckets, keys, cb){
     contract(arguments)
-        .params('string', 'array', 'function')
+        .params('array', 'array', 'function')
         .end();
 
-    if(this._buckets[bucket]){
-      cb(null, _.pick(this._buckets[bucket], keys));
-    }else{
-      cb(null, {});
-    }
+    var self = this;
+    var results = {};
+
+    buckets.forEach(function(bucket) {
+      if(self._buckets[bucket]){
+        results[bucket] = _.uniq(_.flatten(_.values(_.pick(self._buckets[bucket], keys))));
+      }else{
+        results[bucket] = [];
+      }
+    });
+
+    cb(null, results);
   },
 
   /**

lib/redis-backend.js

@@ -61,23 +61,23 @@ RedisBackend.prototype = {
   },
 
   /**
-    Gets an array of the contents of the specified keys.
+    Gets an object mapping each passed bucket to the union of the specified keys inside that bucket.
   */
-  getAll : function(bucket, keys, cb){
+  unions : function(buckets, keys, cb){
     contract(arguments)
-      .params('string', 'array', 'function')
+      .params('array', 'array', 'function')
       .end();
 
-    var redisKeys = this.bucketKey(bucket, keys);
+    var redisKeys = {};
     var batch = this.redis.batch();
     var self = this;
-
-    redisKeys.map(function(key) {
-      batch.smembers(key, self.redis.print);
+    buckets.forEach(function(bucket) {
+      redisKeys[bucket] = self.bucketKey(bucket, keys);
+      batch.sunion(redisKeys[bucket], noop);
     });
 
     batch.exec(function(err, replies) {
-      var result = Array.isArray(replies) ? _.zipObject(keys, replies) : replies;
+      var result = Array.isArray(replies) ? _.zipObject(buckets, replies) : {};
       cb(err, result);
     });
   },

test/backendtests.js

@@ -5,23 +5,25 @@ var _ = require('lodash');
 
 var testData = {
   key1: ["1", "2", "3"],
-  key2: ["4", "5", "6"],
-  key3: ["7", "8", "9"]
+  key2: ["3", "2", "4"],
+  key3: ["3", "4", "5"]
 };
-var bucket = 'test-bucket';
+var buckets = ['bucket1', 'bucket2'];
 
-exports.getAll = function() {
-  describe('getAll', function() {
+exports.unions = function() {
+  describe('unions', function() {
     before(function(done) {
       var backend = this.backend;
-      if (!backend.getAll) {
+      if (!backend.unions) {
         this.skip();
       }
 
       backend.clean(function() {
         var transaction = backend.begin();
         Object.keys(testData).forEach(function(key) {
-          backend.add(transaction, bucket, key, testData[key]);
+          buckets.forEach(function(bucket) {
+            backend.add(transaction, bucket, key, testData[key]);
+          });
         });
         backend.end(transaction, done);
       });
@@ -32,25 +34,36 @@ exports.getAll = function() {
     });
 
     it('should respond with an appropriate map', function(done) {
-      this.backend.getAll(bucket, Object.keys(testData), function(err, result) {
+      var expected = {
+        'bucket1': ["1", "2", "3", "4", "5"],
+        'bucket2': ["1", "2", "3", "4", "5"]
+      };
+      this.backend.unions(buckets, Object.keys(testData), function(err, result) {
         expect(err).to.be.null;
-        expect(result).to.be.eql(testData);
+        expect(result).to.be.eql(expected);
         done();
       });
     });
 
     it('should get only the specified keys', function(done) {
-      this.backend.getAll(bucket, ['key1'], function(err, result) {
+      var expected = {
+        'bucket1': ['1', '2', '3'],
+        'bucket2': ['1', '2', '3']
+      }
+      this.backend.unions(buckets, ['key1'], function(err, result) {
         expect(err).to.be.null;
-        expect(result).to.be.eql(_.pick(testData, 'key1'));
+        expect(result).to.be.eql(expected);
         done();
       });
     });
 
-    it('should be order-independent', function(done) {
-      this.backend.getAll(bucket, Object.keys(testData).reverse(), function(err, result) {
+    it('should only get the specified buckets', function(done) {
+      var expected = {
+        'bucket1': ['1', '2', '3']
+      };
+      this.backend.unions(['bucket1'], ['key1'], function(err, result) {
         expect(err).to.be.null;
-        expect(result).to.be.eql(testData);
+        expect(result).to.be.eql(expected);
         done();
       });
     });