public ITask[] Acquire(AcquireModel model)
{
var job = model.Job?.Trim();
if (job.IsNullOrEmpty())
{
return(new TaskModel[0]);
}
var app = _App;
if (app == null)
{
return(new TaskModel[0]);
}
// 应用停止发放作业
app = App.FindByID(app.ID) ?? app;
if (!app.Enable)
{
return(new TaskModel[0]);
}
var jb = app.Jobs.FirstOrDefault(e => e.Name == job);
// 全局锁，确保单个作业只有一个线程在分配作业
using var ck = Cache.AcquireLock($"Job:{jb.ID}", 15_000);
// 找到作业。为了确保能够快速拿到新的作业参数，这里做二次查询
if (jb != null)
{
jb = Job.Find(Job._.ID == jb.ID);
}
else
{
jb = Job.FindByAppIDAndName(app.ID, job);
}
if (jb == null)
{
throw new XException($"应用[{app.ID}/{app.Name}]下未找到作业[{job}]");
}
if (jb.Step == 0 || jb.Start.Year <= 2000)
{
throw new XException("作业[{0}/{1}]未设置开始时间或步进", jb.ID, jb.Name);
}
var online = GetOnline(app, _Net);
var list = new List <JobTask>();
// 每分钟检查一下错误任务和中断任务
CheckErrorTask(app, jb, model.Count, list);
// 错误项不够时，增加切片
if (list.Count < model.Count)
{
//var ps = ControllerContext.Current.Parameters;
var server = online.Name;
var pid = online.ProcessId;
//var topic = ps["topic"] + "";
var ip = _Net.Remote.Host;
switch (jb.Mode)
{
case JobModes.Message:
list.AddRange(jb.AcquireMessage(model.Topic, server, ip, pid, model.Count - list.Count, Cache));
break;
case JobModes.Data:
case JobModes.Alarm:
//case JobModes.CSharp:
//case JobModes.Sql:
default:
{
// 如果能够切片，则查询数据库后进入，避免缓存导致重复
if (jb.TrySplit(jb.Start, jb.Step, out var end))
{
// 申请任务前，不能再查数据库，那样子会导致多线程脏读，从而出现多客户端分到相同任务的情况
//jb = Job.FindByKey(jb.ID);
list.AddRange(jb.Acquire(server, ip, pid, model.Count - list.Count, Cache));
}
}
break;
}
}
// 记录状态
online.Tasks += list.Count;
online.SaveAsync();
return(list.Select(e => e.ToModel()).ToArray());
}