#region License Information
/* HeuristicLab
* Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
*
* This file is part of HeuristicLab.
*
* HeuristicLab is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* HeuristicLab is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with HeuristicLab. If not, see .
*/
#endregion
using System;
using System.Collections.Generic;
using System.Linq;
using HeuristicLab.Services.Hive.DataTransfer;
namespace HeuristicLab.Services.Hive {
public class RoundRobinTaskScheduler : ITaskScheduler {
private IHiveDao dao {
get { return ServiceLocator.Instance.HiveDao; }
}
public IEnumerable Schedule(IEnumerable tasks, int count = 1) {
if (!tasks.Any()) return Enumerable.Empty();
var userPriorities = dao.GetUserPriorities(x => true).OrderBy(x => x.DateEnqueued).ToArray();
var jobs = new List();
foreach (var userPriority in userPriorities) {
jobs.AddRange(dao.GetJobInfoForScheduler(x => x.OwnerUserId == userPriority.Id));
}
var taskJobRelations = tasks.Join(jobs,
task => task.JobId,
job => job.Id,
(task, job) => new { Task = task, JobInfo = job })
.OrderByDescending(x => x.Task.Priority)
.ToList();
var scheduledTasks = new List();
int priorityIndex = 0;
if (count == 0 || count > taskJobRelations.Count) count = taskJobRelations.Count;
for (int i = 0; i < count; i++) {
var defaultEntry = taskJobRelations.First(); // search first task which is not included yet
var priorityEntries = taskJobRelations.Where(x => x.JobInfo.OwnerUserId == userPriorities[priorityIndex].Id).ToArray(); // search for tasks with desired user priority
while (!priorityEntries.Any() && priorityIndex < userPriorities.Length - 1) {
priorityIndex++;
priorityEntries = taskJobRelations.Where(x => x.JobInfo.OwnerUserId == userPriorities[priorityIndex].Id).ToArray();
}
if (priorityEntries.Any()) { // tasks with desired user priority found
var priorityEntry = priorityEntries.OrderByDescending(x => x.Task.Priority).ThenBy(x => x.JobInfo.DateCreated).First();
if (defaultEntry.Task.Priority <= priorityEntry.Task.Priority) {
taskJobRelations.Remove(priorityEntry);
scheduledTasks.Add(priorityEntry.Task);
UpdateUserPriority(userPriorities[priorityIndex]);
priorityIndex++;
} else { // there are other tasks with higher priorities
taskJobRelations.Remove(defaultEntry);
scheduledTasks.Add(defaultEntry.Task);
}
} else {
taskJobRelations.Remove(defaultEntry);
scheduledTasks.Add(defaultEntry.Task);
}
if (priorityIndex >= (userPriorities.Length - 1)) priorityIndex = 0;
}
return scheduledTasks;
}
private void UpdateUserPriority(UserPriority up) {
up.DateEnqueued = DateTime.Now;
dao.EnqueueUserPriority(up);
}
}
}