unit GroupMonitor;

interface

uses
  Windows, SysUtils, Classes, GroupWebSocket, GroupClient;

type
  TGroupHeartbeatThread = class;
  TGroupKeepAlive = class;
  
  TGroupMonitor = class
  private
    FLastTime: DWORD;
    FGroupHeartbeat: TGroupHeartbeatThread;
    FGroupKeepAlive: TGroupKeepAlive;
    FLock: TRTLCriticalSection;
    FClient: TGroupClient;
    FRunning: Boolean;
    FPingInterval: Integer;
    FPingTimeout: Integer;
    FKeepAlive: Boolean;
    procedure SetRunning(const Value: Boolean);
    procedure SetKeepAlive(const Value: Boolean);
    class function GetMonitor: TGroupMonitor;
  public
    constructor Create;
    destructor Destroy; override;   

    procedure Start(AClient: TGroupClient);
    procedure Stop;
    procedure ReflashLastTime;

    property Running: Boolean read FRunning write SetRunning;
    //"pingInterval":25000,"pingTimeout":60000
    property PingInterval: Integer read FPingInterval write FPingInterval;
    property PingTimeout: Integer read FPingTimeout write FPingTimeout;
    property KeepAlive: Boolean read FKeepAlive write SetKeepAlive;
  end;

  TGroupHeartbeatThread = class(TThread)
  private
    FGroupMonitor: TGroupMonitor;
  public
    constructor Create(AGroupMonitor: TGroupMonitor);
    procedure Execute; override;
  end;

  TGroupKeepAlive = class(TThread)
  private
    FGroupMonitor: TGroupMonitor;
  public
    constructor Create(AGroupMonitor: TGroupMonitor);
    procedure Execute; override;
  end;


{
  TGroupMonitor
  一、监控心跳
    1.管理TGroupClient的心跳（发送和接收心跳）；
    2.可以设置心跳间隔时间；
    3.设置心跳超时时间；
    4.超时重连机制；
  二、监控处理GroupClient异常断开
    1、异常重连
  三、同步与主服务的连接状态
}



implementation

uses
  LoggerImport, DateUtils;

//var
//  GrpMonitor: TGroupMonitor;

{ TGroupMonitor }

constructor TGroupMonitor.Create;
begin
  inherited;
  FPingInterval := 25000;
  FPingTimeout := 60000;
  InitializeCriticalSection(FLock);
  FRunning := False;
end;

destructor TGroupMonitor.Destroy;
begin
  Stop;
  DeleteCriticalSection(FLock);
  inherited;
end;

class function TGroupMonitor.GetMonitor: TGroupMonitor;
begin
//  if GrpMonitor = nil then
//    GrpMonitor := TGroupMonitor.Create;
//  Result := GrpMonitor;
end;

procedure TGroupMonitor.ReflashLastTime;
begin
  EnterCriticalSection(FLock);
  FLastTime := GetTickCount;
  LeaveCriticalSection(FLock);
end;

procedure TGroupMonitor.SetKeepAlive(const Value: Boolean);
begin
  if FKeepAlive = Value then
    Exit;
  FKeepAlive := Value;
  if FKeepAlive then
  begin
    if FGroupKeepAlive <> nil then
    begin
      FGroupKeepAlive.Terminate;
      FGroupKeepAlive.WaitFor;
      FGroupKeepAlive := nil;
    end;
    FGroupKeepAlive := TGroupKeepAlive.Create(Self);
    FGroupKeepAlive.Resume;
  end
  else
  begin
    if FGroupKeepAlive <> nil then
    begin
      FGroupKeepAlive.Terminate;
      FGroupKeepAlive.WaitFor;
      FGroupKeepAlive := nil;
    end;
  end;
end;

procedure TGroupMonitor.SetRunning(const Value: Boolean);
begin
  FRunning := Value;
end;

procedure TGroupMonitor.Start(AClient: TGroupClient);
begin
  ReflashLastTime;
  if AClient = nil then
    Exit;
  if FRunning then
    Exit;

  Stop;
  FClient := AClient;
  FGroupHeartbeat := TGroupHeartbeatThread.Create(Self);
  FRunning := True;
end;

procedure TGroupMonitor.Stop;
begin
  if not FRunning then
    Exit;
//  FClient := nil;
  if Assigned(FGroupHeartbeat) then
  begin
    FGroupHeartbeat.Terminate;
    try
      FGroupHeartbeat.WaitFor
    finally
      FGroupHeartbeat := nil;
    end;
  end;

  FRunning := False;
end;
//EnterCriticalSection(LastTimeLock);      {开始: 轮到我了其他线程走开}
//LeaveCriticalSection(LastTimeLock);      {结束: 其他线程可以来了}
{ TMonitorThread }

constructor TGroupHeartBeatThread.Create(AGroupMonitor: TGroupMonitor);
begin
  FGroupMonitor := AGroupMonitor;
  inherited Create(False);
end;

procedure TGroupHeartBeatThread.Execute;
var
  AIntervalTime: DWORD;
  iLoop: Integer;
begin
  while not Terminated do
  begin
    AIntervalTime := GetTickCount - FGroupMonitor.FLastTime;

    if AIntervalTime > FGroupMonitor.FPingTimeout then
    begin
      Error(IntToStr(FGroupMonitor.FPingTimeout div 1000) +
        '60秒内没有收到服务端消息，启动重联.', 'TGroupHeartBeatThread.Execute');
//      MainForm.TimerForreconnectgroup.Enabled := False;
//      MainForm.TimerForreconnectgroup.Enabled := True;
      Exit;
    end;

    if AIntervalTime > FGroupMonitor.FPingInterval then
    begin
      FGroupMonitor.FClient.Ping;
    end;

    for iLoop := 0 to 19 do
    begin
      if Terminated then
        Exit;
      Sleep(1000);
    end;
  end;
end;

{ TGroupKeepAlive }

constructor TGroupKeepAlive.Create(AGroupMonitor: TGroupMonitor);
begin
  FGroupMonitor := AGroupMonitor;
  inherited Create(True);
end;

procedure TGroupKeepAlive.Execute;
var
  AIntervalTime: DWORD;
  iLoop: Integer;
begin
  while not Terminated do
  begin
    AIntervalTime := Random(10) + 10;
    for iLoop := 0 to AIntervalTime - 1 do
    begin
      if Terminated then
        Exit;
      Sleep(1000);
    end;

    if not FGroupMonitor.FClient.Connected then
      FGroupMonitor.FClient.Connect;
  end;
end;

initialization

finalization

end.