added getMappedGroup4 and createGroup

node/db/GroupManager.js

@@ -18,4 +18,100 @@
  * limitations under the License.
  */
  
+var db = require("./DB").db;
+var async = require("async");
+ 
+exports.doesGroupExist = function(groupID, callback)
+{
+  //try to get the group entry
+  db.get("group:" + groupID, function (err, group)
+  {
+    callback(err, group != null);
+  });
+}
+
+exports.createGroup = function(callback)
+{
+  //search for non existing groupID
+  var groupID;
+  var foundNonExistingGroupID = false;
+  async.whilst(
+    function () { return !foundNonExistingGroupID; },
+    function (callback) 
+    {
+       //generate a random 10 digit groupID
+       groupID = "";
+       for(var i=0;i<10;i++)
+       {
+         groupID+=Math.floor(Math.random()*10);
+       }
+       
+       //check if this groupID already exisits
+       exports.doesGroupExist(groupID, function(err, exists)
+       {
+         foundNonExistingGroupID = !exists;
+         callback(err);
+       })
+    },
+    //we found a non existing groupID or an error happend
+    function (err) 
+    {
+      //check for errors
+      if(err)
+      {
+        callback(err);
+        return;
+      }
+      
+      //create the group
+      db.set("group:" + groupID, {pads: {}});
+      callback(null, {groupID: groupID});
+    }
+  );
+}
+
+exports.getMappedGroup4 = function(groupMapper, callback)
+{
+  //ensure mapper is optional
+  if(typeof groupMapper != "string")
+  {
+    callback({stop: "groupMapper is no string"});
+    return;
+  }
+  
+  //try to get a group for this mapper
+  db.get("mapper2group:"+groupMapper, function(err, groupID)
+  {
+     if(err)
+     {
+       callback(err);
+       return;
+     }
+     
+     //there is no group for this mapper, let's create a group
+     if(groupID == null)
+     {
+       exports.createGroup(function(err, responseObj)
+       {
+         //check for errors
+         if(err)
+         {
+           callback(err);
+           return;
+         }
+         
+         //create the mapper entry for this group
+         db.set("mapper2group:"+groupMapper, responseObj.groupID);
+         callback(null, responseObj);
+       });
+     }
+     //there is a group for this mapper, let's return it
+     else
+     {
+       callback(err, {groupID: groupID});
+     }
+  });
+}
+
+