Delphi雪花算法 生成随机数

//  新建unit单元

unit untSnowflake;

interface

uses
SysUtils, SyncObjs, DateUtils;

type
TSnowflake = class
private
FOrgID: Integer; //机构号
FMachineID: integer; //机器号
FLocker: TCriticalSection;
fTime: Int64; //时间戳
fsn: int64; //序列
public
constructor Create;
destructor Destroy; override;
property MachineID: Integer read FMachineID write FMachineID;
property OrgID: Integer read FOrgID write FOrgID;
function Generate: Int64;
end;

implementation

const
Epoch: int64 = 1602262728000; //北京时间2018-10-15号 curtime := DateTimeToUnix(Now) * 1000;
OrgBits: Byte = 5; //机构号 0..31
MachineBits: Byte = 5; //机器号 0..31
snBits: Byte = 12; //序列号12位
timeShift: Byte = 22; //时间戳左移位数=序列号位数+机器号位数+机构号位数
orgShift: Byte = 17; //机构号左移位数=序列号位数+机器号位数
machineShift: Byte = 12; //工作站左移位数=序列号位数
snMask: Word = 4095; //12位的计数序列号支持每个节点每毫秒产生4096个ID序号

{ TSnowflake }

constructor TSnowflake.Create;
begin
FLocker := TCriticalSection.Create;
end;

destructor TSnowflake.Destroy;
begin
FLocker.Free;
inherited;
end;

function TSnowflake.Generate: Int64;
var
curtime: Int64;
begin
FLocker.Acquire;
try
curtime := DateTimeToUnix(Now) * 1000;
if curtime = fTime then
begin
fsn := (fsn + 1) and snMask;
if fsn = 0 then
begin
while curtime <= fTime do
curtime := DateTimeToUnix(Now) * 1000;
end;
end
else
fsn := 0;
fTime := curtime;
Result := (curtime - Epoch) shl timeShift
or FOrgID shl orgShift
or FMachineID shl machineShift
or fsn;
finally
FLocker.Release;
end;
end;

initialization


end.

 

 

 

// 方法调用

var
s: TSnowflake;
i: Integer;
begin
s := TSnowflake.Create;
s.OrgID := 8;
s.MachineID := 10;
for i := 1 to StrToInt(cxTextEdit1.Text) do
begin
cxMemo1.Lines.Add(IntToStr(s.Generate));
Application.ProcessMessages;
end;
s.Free;
end;