C# 顺序Guid生成器
是否有任何方法可以获得Sql Server 2005+顺序Guid生成器的功能，而无需插入记录以在往返过程中读取它或调用本机win dll调用？我看到有人用一种使用rpcrt4.dll的方法回答了这个问题，但我不确定这是否能够在我的托管生产环境中工作 编辑：使用@John Boker的答案，我试图将其转换为更多的GuidComb生成器，而不是依赖于最后生成的Guid，而不是重新开始。而不是以Guid.Empty开头C# 顺序Guid生成器,c#,guid,sequence,C#,Guid,Sequence,是否有任何方法可以获得Sql Server 2005+顺序Guid生成器的功能，而无需插入记录以在往返过程中读取它或调用本机win dll调用？我看到有人用一种使用rpcrt4.dll的方法回答了这个问题，但我不确定这是否能够在我的托管生产环境中工作 编辑：使用@John Boker的答案，我试图将其转换为更多的GuidComb生成器，而不是依赖于最后生成的Guid，而不是重新开始。而不是以Guid.Empty开头 public SequentialGuid() { var tempGu
public SequentialGuid()
{
var tempGuid = Guid.NewGuid();
var bytes = tempGuid.ToByteArray();
var time = DateTime.Now;
bytes[3] = (byte) time.Year;
bytes[2] = (byte) time.Month;
bytes[1] = (byte) time.Day;
bytes[0] = (byte) time.Hour;
bytes[5] = (byte) time.Minute;
bytes[4] = (byte) time.Second;
CurrentGuid = new Guid(bytes);
}
// 3 - the least significant byte in Guid ByteArray
[for SQL Server ORDER BY clause]
// 10 - the most significant byte in Guid ByteArray
[for SQL Server ORDERY BY clause]
SqlOrderMap = new[] {3, 2, 1, 0, 5, 4, 7, 6, 9, 8, 15, 14, 13, 12, 11, 10};
这看起来像是我想要用DateTime为guid添加种子的方式，还是像是我应该从SqlOrderMap索引的末尾开始反向操作？我不太担心它们在创建初始guid的任何时候都会成为分页中断，因为它只会在应用程序回收期间出现。这个人想出了一些方法来创建顺序guid，下面是一个链接 相关代码：
public class SequentialGuid {
Guid _CurrentGuid;
public Guid CurrentGuid {
get {
return _CurrentGuid;
}
}
public SequentialGuid() {
_CurrentGuid = Guid.NewGuid();
}
public SequentialGuid(Guid previousGuid) {
_CurrentGuid = previousGuid;
}
public static SequentialGuid operator++(SequentialGuid sequentialGuid) {
byte[] bytes = sequentialGuid._CurrentGuid.ToByteArray();
for (int mapIndex = 0; mapIndex < 16; mapIndex++) {
int bytesIndex = SqlOrderMap[mapIndex];
bytes[bytesIndex]++;
if (bytes[bytesIndex] != 0) {
break; // No need to increment more significant bytes
}
}
sequentialGuid._CurrentGuid = new Guid(bytes);
return sequentialGuid;
}
private static int[] _SqlOrderMap = null;
private static int[] SqlOrderMap {
get {
if (_SqlOrderMap == null) {
_SqlOrderMap = new int[16] {
3, 2, 1, 0, 5, 4, 7, 6, 9, 8, 15, 14, 13, 12, 11, 10
};
// 3 - the least significant byte in Guid ByteArray [for SQL Server ORDER BY clause]
// 10 - the most significant byte in Guid ByteArray [for SQL Server ORDERY BY clause]
}
return _SqlOrderMap;
}
}
}
公共类顺序GUID{
Guid _CurrentGuid；
公共Guid当前Guid{
得到{
返回_CurrentGuid；
}
}
公共顺序GUID（）{
_CurrentGuid=Guid.NewGuid（）；
}
公共顺序Guid（Guid previousGuid）{
_CurrentGuid=previousGuid；
}
公共静态SequentialGuid运算符++（SequentialGuid SequentialGuid）{
byte[]bytes=sequentialGuid.\u CurrentGuid.ToByteArray（）；
对于（int-mapIndex=0；mapIndex<16；mapIndex++）{
int bytesIndex=SqlOrderMap[mapIndex]；
字节[字节索引]+；
if（字节[字节索引]！=0）{
break；//无需增加更多有效字节
}
}
顺序Guid.\u CurrentGuid=新Guid（字节）；
返回顺序GUID；
}
私有静态int[]_SqlOrderMap=null；
私有静态int[]SqlOrderMap{
得到{
if（_SqlOrderMap==null）{
_SqlOrderMap=newint[16]{
3, 2, 1, 0, 5, 4, 7, 6, 9, 8, 15, 14, 13, 12, 11, 10
};
//3-Guid ByteArray中的最低有效字节[对于SQL Server ORDER BY子句]
//10-Guid ByteArray中的最高有效字节[对于SQL Server ORDERY BY子句]
}
返回_SqlOrderMap；
}
}
}
微软的
UuidCreateSequential
：（6字节）-计算机的MAC地址节点
：（7字节）-自1582年10月15日00:00:00.00（公历改为基督教日历的日期）起的100 ns间隔数时间戳
（2字节）-计数器，以防生成速度超过100ns的guid，或更改mac地址clockSequenceNumber
节点时间戳时钟序列号节点时间戳- a） 如果保存的状态不可用或已损坏，或者mac地址已更改，则生成随机的
clockSequenceNumber - b） 如果状态可用，但当前的
与保存的时间戳相同或更早，则增加时间戳时钟序列号
节点时间戳时钟序列号guid = new Guid(
timestamp & 0xFFFFFFFF, //timestamp low
(timestamp >> 32) & 0xFFFF, //timestamp mid
((timestamp >> 40) & 0x0FFF), | (1 << 12) //timestamp high and version (version 1)
(clockSequenceNumber & 0x3F) | (0x80), //clock sequence number and reserved
node[0], node[1], node[2], node[3], node[4], node[5], node[6]);
guid=新的guid(
时间戳&0xFFFFFFFF，//时间戳低
（时间戳>>32）&0xFFFF，//时间戳mid
（（timestamp>>40）&0x0FFF），|（1我的解决方案（在VB中，但易于转换）。它将GUID的最重要（用于SQL Server排序）前8个字节更改为DateTime.UtcNow.Ticks，并且还有额外的代码，可以帮助您在调用新GUID比系统时钟更新快的情况下多次获取相同的Ticks
Private ReadOnly _toSeqGuidLock As New Object()
''' <summary>
''' Replaces the most significant eight bytes of the GUID (according to SQL Server ordering) with the current UTC-timestamp.
''' </summary>
''' <remarks>Thread-Safe</remarks>
<System.Runtime.CompilerServices.Extension()> _
Public Function ToSeqGuid(ByVal guid As Guid) As Guid
Static lastTicks As Int64 = -1
Dim ticks = DateTime.UtcNow.Ticks
SyncLock _toSeqGuidLock
If ticks <= lastTicks Then
ticks = lastTicks + 1
End If
lastTicks = ticks
End SyncLock
Dim ticksBytes = BitConverter.GetBytes(ticks)
Array.Reverse(ticksBytes)
Dim guidBytes = guid.ToByteArray()
Array.Copy(ticksBytes, 0, guidBytes, 10, 6)
Array.Copy(ticksBytes, 6, guidBytes, 8, 2)
Return New Guid(guidBytes)
End Function
Private ReadOnly\u将guidlock设置为新对象（）
'''
''将GUID最重要的八个字节（根据SQL Server顺序）替换为当前UTC时间戳。
'''
“线程安全”
_
公共函数将seqguid（ByVal guid作为guid）作为guid
静态lastTicks为Int64=-1
Dim ticks=DateTime.UtcNow.ticks
同步锁
如果勾号C#版本
公共静态Guid到eqguid（）
{
Int64 lastTicks=-1；
长刻度=System.DateTime.UtcNow.ticks；
如果（勾号可以找到经常更新（至少每毫秒3次）的顺序guid。它是用常规C代码创建的（无本机代码调用）。是NHibernate实现guid的方式。Comb算法：
private Guid GenerateComb()
{
byte[] guidArray = Guid.NewGuid().ToByteArray();
DateTime baseDate = new DateTime(1900, 1, 1);
DateTime now = DateTime.UtcNow;
// Get the days and milliseconds which will be used to build the byte string
TimeSpan days = new TimeSpan(now.Ticks - baseDate.Ticks);
TimeSpan msecs = now.TimeOfDay;
// Convert to a byte array
// Note that SQL Server is accurate to 1/300th of a millisecond so we divide by 3.333333
byte[] daysArray = BitConverter.GetBytes(days.Days);
byte[] msecsArray = BitConverter.GetBytes((long) (msecs.TotalMilliseconds / 3.333333));
// Reverse the bytes to match SQL Servers ordering
Array.Reverse(daysArray);
Array.Reverse(msecsArray);
// Copy the bytes into the guid
Array.Copy(daysArray, daysArray.Length - 2, guidArray, guidArray.Length - 6, 2);
Array.Copy(msecsArray, msecsArray.Length - 4, guidArray, guidArray.Length - 4, 4);
return new Guid(guidArray);
}
与其他建议进行比较可能很有趣：
EntityFramework核心还实现了一个sequentialGuidValueGenerator。
它们为每个值生成随机GUID，并且仅根据时间戳和线程安全增量更改最重要的字节，以便在SQL Server中进行排序
这将导致所有值都非常不同，但具有可排序的时间戳。不是专门的guid，但我现在通常使用雪花样式的顺序id生成器
Private ReadOnly _toSeqGuidLock As New Object()
''' <summary>
''' Replaces the most significant eight bytes of the GUID (according to SQL Server ordering) with the current UTC-timestamp.
''' </summary>
''' <remarks>Thread-Safe</remarks>
<System.Runtime.CompilerServices.Extension()> _
Public Function ToSeqGuid(ByVal guid As Guid) As Guid
Static lastTicks As Int64 = -1
Dim ticks = DateTime.UtcNow.Ticks
SyncLock _toSeqGuidLock
If ticks <= lastTicks Then
ticks = lastTicks + 1
End If
lastTicks = ticks
End SyncLock
Dim ticksBytes = BitConverter.GetBytes(ticks)
Array.Reverse(ticksBytes)
Dim guidBytes = guid.ToByteArray()
Array.Copy(ticksBytes, 0, guidBytes, 10, 6)
Array.Copy(ticksBytes, 6, guidBytes, 8, 2)
Return New Guid(guidBytes)
End Function
public static Guid ToSeqGuid()
{
Int64 lastTicks = -1;
long ticks = System.DateTime.UtcNow.Ticks;
if (ticks <= lastTicks)
{
ticks = lastTicks + 1;
}
lastTicks = ticks;
byte[] ticksBytes = BitConverter.GetBytes(ticks);
Array.Reverse(ticksBytes);
Guid myGuid = new Guid();
byte[] guidBytes = myGuid.ToByteArray();
Array.Copy(ticksBytes, 0, guidBytes, 10, 6);
Array.Copy(ticksBytes, 6, guidBytes, 8, 2);
Guid newGuid = new Guid(guidBytes);
string filepath = @"C:\temp\TheNewGuids.txt";
using (StreamWriter writer = new StreamWriter(filepath, true))
{
writer.WriteLine("GUID Created = " + newGuid.ToString());
}
return newGuid;
}
}
private Guid GenerateComb()
{
byte[] guidArray = Guid.NewGuid().ToByteArray();
DateTime baseDate = new DateTime(1900, 1, 1);
DateTime now = DateTime.UtcNow;
// Get the days and milliseconds which will be used to build the byte string
TimeSpan days = new TimeSpan(now.Ticks - baseDate.Ticks);
TimeSpan msecs = now.TimeOfDay;
// Convert to a byte array
// Note that SQL Server is accurate to 1/300th of a millisecond so we divide by 3.333333
byte[] daysArray = BitConverter.GetBytes(days.Days);
byte[] msecsArray = BitConverter.GetBytes((long) (msecs.TotalMilliseconds / 3.333333));
// Reverse the bytes to match SQL Servers ordering
Array.Reverse(daysArray);
Array.Reverse(msecsArray);
// Copy the bytes into the guid
Array.Copy(daysArray, daysArray.Length - 2, guidArray, guidArray.Length - 6, 2);
Array.Copy(msecsArray, msecsArray.Length - 4, guidArray, guidArray.Length - 4, 4);
return new Guid(guidArray);
}
using System;
namespace Atlas.Core.Kernel.Extensions
{
public static class Guids
{
public static Guid Comb(this Guid source)
{
byte[] guidArray = source.ToByteArray();
DateTime baseDate = new DateTime(1900, 1, 1);
DateTime now = DateTime.Now;
// Get the days and milliseconds which will be used to build the byte string
TimeSpan days = new TimeSpan(now.Ticks - baseDate.Ticks);
TimeSpan msecs = now.TimeOfDay;
// Convert to a byte array
// Note that SQL Server is accurate to 1/300th of a millisecond so we divide by 3.333333
byte[] daysArray = BitConverter.GetBytes(days.Days);
byte[] msecsArray = BitConverter.GetBytes((long)(msecs.TotalMilliseconds / 3.333333));
// Reverse the bytes to match SQL Servers ordering
Array.Reverse(daysArray);
Array.Reverse(msecsArray);
// Copy the bytes into the guid
Array.Copy(daysArray, daysArray.Length - 2, guidArray, guidArray.Length - 6, 2);
Array.Copy(msecsArray, msecsArray.Length - 4, guidArray, guidArray.Length - 4, 4);
return new Guid(guidArray);
}
}
}