/// <summary>
/// 生产唯一识别号
/// </summary>
/// <param name="guidType"></param>
/// <returns></returns>
public static string Next(SequentialGuidType guidType = SequentialGuidType.SequentialAsString)
{
byte[] randomBytes = new byte[10];
_rng.GetBytes(randomBytes);
long timestamp = DateTime.UtcNow.Ticks / 10000L;
byte[] timestampBytes = BitConverter.GetBytes(timestamp);
if (BitConverter.IsLittleEndian)
{
Array.Reverse(timestampBytes);
}
byte[] guidBytes = new byte[16];
switch (guidType)
{
case SequentialGuidType.SequentialAsString:
case SequentialGuidType.SequentialAsBinary:
Buffer.BlockCopy(timestampBytes, 2, guidBytes, 0, 6);
Buffer.BlockCopy(randomBytes, 0, guidBytes, 6, 10);
if (guidType == SequentialGuidType.SequentialAsString && BitConverter.IsLittleEndian)
{
Array.Reverse(guidBytes, 0, 4);
Array.Reverse(guidBytes, 4, 2);
}
break;
case SequentialGuidType.SequentialAtEnd:
Buffer.BlockCopy(randomBytes, 0, guidBytes, 0, 10);
Buffer.BlockCopy(timestampBytes, 2, guidBytes, 10, 6);
break;
}
return(new Guid(guidBytes).ToString("N"));
}
private static Guid New(SequentialGuidType guidType)
{
var randomBytes = new byte[10];
Rng.GetBytes(randomBytes);
var timestamp = DateTime.UtcNow.Ticks / 10000L;
var timestampBytes = BitConverter.GetBytes(timestamp);
if(BitConverter.IsLittleEndian)
Array.Reverse(timestampBytes);
var guidBytes = new byte[16];
switch(guidType) {
case SequentialGuidType.SequentialAsString:
case SequentialGuidType.SequentialAsBinary:
Buffer.BlockCopy(timestampBytes, 2, guidBytes, 0, 6);
Buffer.BlockCopy(randomBytes, 0, guidBytes, 6, 10);
// If formatting as a string, we have to reverse the order
// of the Data1 and Data2 blocks on little-endian systems.
if(guidType == SequentialGuidType.SequentialAsString && BitConverter.IsLittleEndian) {
Array.Reverse(guidBytes, 0, 4);
Array.Reverse(guidBytes, 4, 2);
}
break;
case SequentialGuidType.SequentialAtEnd:
Buffer.BlockCopy(randomBytes, 0, guidBytes, 0, 10);
Buffer.BlockCopy(timestampBytes, 2, guidBytes, 10, 6);
break;
}
return new Guid(guidBytes);
}
/// <summary>
///
/// </summary>
/// <param name="guidType"></param>
/// <returns></returns>
public static Guid NewGuid(SequentialGuidType guidType)
{
byte[] randomBytes = new byte[10];
_rng.GetBytes(randomBytes);
long timestamp = DateTime.Now.Ticks / 10000L;
byte[] timestampBytes = BitConverter.GetBytes(timestamp);
if (BitConverter.IsLittleEndian)
{
Array.Reverse(timestampBytes);
}
byte[] guidBytes = new byte[16];
switch (guidType)
{
case SequentialGuidType.String:
case SequentialGuidType.Binary:
Buffer.BlockCopy(timestampBytes, 2, guidBytes, 0, 6);
Buffer.BlockCopy(randomBytes, 0, guidBytes, 6, 10);
if (guidType == SequentialGuidType.String && BitConverter.IsLittleEndian)
{
Array.Reverse(guidBytes, 0, 4);
Array.Reverse(guidBytes, 4, 2);
}
break;
case SequentialGuidType.AtEnd:
Buffer.BlockCopy(randomBytes, 0, guidBytes, 0, 10);
Buffer.BlockCopy(timestampBytes, 2, guidBytes, 10, 6);
break;
}
return new Guid(guidBytes);
}
/// <summary>
/// Base implementation of IPocoPersistor using Entity Framework 6
/// </summary>
/// <param name="connectionName">Connection name in .config files (default is 'Ractor', it
/// is also used as a prefix for zero-based distributed connections, e.g. Ractor.0 )</param>
/// <param name="readOnlyShards"></param>
/// <param name="guidType">Use AtEnd only for MS SQL Server, for MySQL and others DBMS without
/// native GUID types use binary</param>
/// <param name="migrationDataLossAllowed"></param>
public DatabasePersistor(string connectionName = "Ractor",
DbMigrationsConfiguration <DataContext> migrationConfig = null,
DbMigrationsConfiguration <DistributedDataContext> distributedMigrationConfig = null,
IEnumerable <byte> readOnlyShards = null,
SequentialGuidType guidType = SequentialGuidType.SequentialAsBinary)
{
// Validate name presence
_connectionName = Config.DataConnectionName(connectionName);
// TODO delete this line when migrations are tested
DataContext.UpdateAutoMigrations(_connectionName, migrationConfig);
_guidType = guidType;
if (readOnlyShards != null)
{
foreach (var readOnlyShard in readOnlyShards)
{
_readOnlyShards.Add(readOnlyShard);
}
}
_shards = Config.DistibutedDataConnectionNames(_connectionName).ToDictionary(x => x.Key, y => y.Value);
if (_readOnlyShards.Count >= _shards.Count)
{
throw new ArgumentException("Too few writable shards!");
}
// check and register shards
using (var ctx = GetContext()) {
var two = ctx.Database.SqlQuery <int>("SELECT 1+1").SingleOrDefault(); // check DB engine is working
if (two != 2)
{
throw new ApplicationException("Connection string is not working: " + connectionName);
}
}
CheckShardsAndSetEpoch(distributedMigrationConfig);
}
/// <summary>
/// 生成连续 GUID
/// </summary>
/// <param name="guidType"></param>
/// <param name="serviceProvider"></param>
/// <returns></returns>
public static Guid NextID(SequentialGuidType guidType = SequentialGuidType.SequentialAsString, IServiceProvider serviceProvider = default)
{
var sequentialGuid = (App.GetService(typeof(SequentialGuidIDGenerator), serviceProvider) as IDistributedIDGenerator);
return((Guid)sequentialGuid.Create(new SequentialGuidSettings {
GuidType = guidType
}));
}
private const int NumberOfBytesInData2 = 2; // Size of Data2 block of GUID
/// <summary>
/// Initializes a new instance of the <see cref="SequentialGuidFactory"/> class, which will generate keys as specified by <paramref name="sequentialGuidType"/>.
/// </summary>
/// <param name="sequentialGuidType">The type of sequential GUID values generated by the current instance.</param>
/// <exception cref="ArgumentOutOfRangeException"><paramref name="sequentialGuidType"/> is not set to a recognized value.</exception>
public SequentialGuidFactory(SequentialGuidType sequentialGuidType)
{
if (!Enum.IsDefined(typeof(SequentialGuidType), sequentialGuidType))
{
throw new ArgumentOutOfRangeException(nameof(sequentialGuidType));
}
SequentialGuidType = sequentialGuidType;
}
/// <summary>
/// Gets the next sequential guid, depending on where you are storing will dictate which type you want
/// Note: When called within the same millisecond there is no guarntee it will be in sequence but it will be unique
/// </summary>
/// <param name="guidType"></param>
/// <returns></returns>
public static Guid Next(SequentialGuidType? guidType = null)
{
if (_random == null)
{
_random = new Random(_globalRandom.Next());
_count = (ushort)_random.Next();
}
byte[] countBytes = BitConverter.GetBytes(_count++);
byte[] randomBytes = new byte[10 - countBytes.Length];
_random.NextBytes(randomBytes);
long timestamp = DateTime.UtcNow.Ticks / 10000L;
byte[] timestampBytes = BitConverter.GetBytes(timestamp);
if (BitConverter.IsLittleEndian)
{
Array.Reverse(timestampBytes);
}
byte[] guidBytes = new byte[16];
if (!guidType.HasValue)
{
guidType = DefaultType;
}
switch (guidType)
{
case SequentialGuidType.SequentialAsString:
case SequentialGuidType.SequentialAsBinary:
Buffer.BlockCopy(timestampBytes, 2, guidBytes, 0, 6);
Buffer.BlockCopy(countBytes, 0, guidBytes, 6, countBytes.Length);
Buffer.BlockCopy(randomBytes, 0, guidBytes, 6 + countBytes.Length, randomBytes.Length);
// If formatting as a string, we have to reverse the order
// of the Data1 and Data2 blocks on little-endian systems.
if (guidType == SequentialGuidType.SequentialAsString && BitConverter.IsLittleEndian)
{
Array.Reverse(guidBytes, 0, 4);
Array.Reverse(guidBytes, 4, 2);
}
break;
case SequentialGuidType.SequentialAtEnd:
Buffer.BlockCopy(countBytes, 0, guidBytes, 0, countBytes.Length);
Buffer.BlockCopy(randomBytes, 0, guidBytes, countBytes.Length, randomBytes.Length);
Buffer.BlockCopy(timestampBytes, 2, guidBytes, 10, 6);
break;
}
return new Guid(guidBytes);
}
/// <summary>
/// 全局唯一Guid
/// 参考abp中生成连续的guid改编而成
/// </summary>
public static Guid Create(SequentialGuidType guidType)
{
var provider = GlobalConfigurations.Instance.GetGuidGeneratorProvider(guidType);
if (provider == null)
{
throw new NotImplementedException("不支持的guidType");
}
return(provider.Create());
}
public static Guid NewRandomBucketGuid(SequentialGuidType guidType = SequentialGuidType.SequentialAsString, DateTime?utcDateTime = null)
{
var bs = new byte[1];
bs[0] = 0;
while (bs[0] == 0)
{
Rng.GetBytes(bs);
} // 1-255
return(new Guid(GuidSequentialArray(bs[0], guidType, utcDateTime)));
}
/// <summary>
/// Returns a new GUID value which is sequentially ordered when formatted as
/// a string, a byte array, or ordered by the least significant six bytes of the
/// Data4 block, as specified by <paramref name="guidType" />.
/// </summary>
/// <param name="guidType">
/// Specifies the type of sequential GUID (i.e. whether sequential as a string,
/// as a byte array, or according to the Data4 block. This can affect
/// performance under various database types; see below.
/// </param>
/// <returns>
/// A <see cref="Guid" /> structure whose value is created by replacing
/// certain randomly-generated bytes with a sequential timestamp.
/// </returns>
public static Guid Create(SequentialGuidType guidType)
{
// We start with 16 bytes of cryptographically strong random data.
byte[] randomBytes = new byte[10];
SequentialGuidGenerator.RandomGenerator.GetBytes(randomBytes);
long timestamp = timestampProvider.GetTimestamp().Ticks / 10000L;
// Then get the bytes
byte[] timestampBytes = BitConverter.GetBytes(timestamp);
// Since we're converting from an Int64, we have to reverse on
// little-endian systems.
if (BitConverter.IsLittleEndian)
{
Array.Reverse(timestampBytes);
}
byte[] guidBytes = new byte[16];
switch (guidType)
{
case SequentialGuidType.SequentialAsString:
case SequentialGuidType.SequentialAsBinary:
// For string and byte-array version, we copy the timestamp first, followed
// by the random data.
Buffer.BlockCopy(timestampBytes, 2, guidBytes, 0, 6);
Buffer.BlockCopy(randomBytes, 0, guidBytes, 6, 10);
// If formatting as a string, we have to compensate for the fact
// that .NET regards the Data1 and Data2 block as an Int32 and an Int16,
// respectively. That means that it switches the order on little-endian
// systems. So again, we have to reverse.
if (guidType == SequentialGuidType.SequentialAsString && BitConverter.IsLittleEndian)
{
Array.Reverse(guidBytes, 0, 4);
Array.Reverse(guidBytes, 4, 2);
}
break;
case SequentialGuidType.SequentialAtEnd:
// For sequential-at-the-end versions, we copy the random data first,
// followed by the timestamp.
Buffer.BlockCopy(randomBytes, 0, guidBytes, 0, 10);
Buffer.BlockCopy(timestampBytes, 2, guidBytes, 10, 6);
break;
}
return(new Guid(guidBytes));
}
/// <summary>
/// Generates a new GUID value which is sequentially ordered when formatted as a string, a byte array, or ordered by the least significant six bytes of the Data4 block, as specified by <paramref name="guidType" />.
/// </summary>
/// <param name="guidType">Specifies the type of sequential GUID (i.e. whether sequential as a string, as a byte array, or according to the Data4 block). This can affect performance under various database types.</param>
/// <returns>A <see cref="Guid" /> structure whose value is created by replacing certain randomly-generated bytes with a sequential timestamp.</returns>
private static Guid NewSequentialGuid(SequentialGuidType guidType)
{
// slower but more random
byte[] randomBytes = new byte[10];
RandomGenerator.GetBytes(randomBytes);
////// faster but less random
////byte[] randomBytes = Guid.NewGuid().ToByteArray();
long timestamp = DateTime.UtcNow.Ticks / TicksFactor;
byte[] timestampBytes = BitConverter.GetBytes(timestamp);
if (BitConverter.IsLittleEndian)
{
Array.Reverse(timestampBytes);
}
byte[] guidBytes = new byte[16];
switch (guidType)
{
case SequentialGuidType.SequentialAsString:
Buffer.BlockCopy(timestampBytes, 2, guidBytes, 0, 6);
Buffer.BlockCopy(randomBytes, 0, guidBytes, 6, 10);
if (BitConverter.IsLittleEndian)
{
Array.Reverse(guidBytes, 0, 4);
Array.Reverse(guidBytes, 4, 2);
}
break;
case SequentialGuidType.SequentialAsBinary:
Buffer.BlockCopy(timestampBytes, 2, guidBytes, 0, 6);
Buffer.BlockCopy(randomBytes, 0, guidBytes, 6, 10);
break;
case SequentialGuidType.SequentialAtEnd:
Buffer.BlockCopy(randomBytes, 0, guidBytes, 0, 10);
Buffer.BlockCopy(timestampBytes, 2, guidBytes, 10, 6);
break;
}
return(new Guid(guidBytes));
}
/// <summary>
/// Generates the GUIDs and displays them in the form.
/// </summary>
/// <param name="sender">The Generate button.</param>
/// <param name="e">Additional information related to the event.</param>
private void GenerateButton_Click(object sender, EventArgs e)
{
int count = 100;
SequentialGuidType method = (SequentialGuidType)this.methodComboBox.SelectedItem;
// Initialize the RTF text to enable color highlighting
StringBuilder text = new StringBuilder();
text.Append("{\\rtf1\\ansi\\deff0\n{\\colortbl;\\red0\\green0\\blue0;\\red128\\green0\\blue0;}\n");
for (int i = 0; i < count; i++)
{
Guid guid = SequentialGuid.Create(method);
string output = string.Empty;
switch (method)
{
case SequentialGuidType.SequentialAsBinary:
byte[] bytes = guid.ToByteArray();
foreach (byte b in bytes)
{
output += string.Format("{0:x2}", b);
}
output = "\\cf2\n" + output.Substring(0, 12) + "\n\\cf1\n" + output.Substring(12) + "\n\\line\n";
break;
case SequentialGuidType.SequentialAsString:
output = guid.ToString();
output = "\\cf2\n" + output.Substring(0, 13) + "\n\\cf1\n" + output.Substring(13) + "\n\\line\n";
break;
case SequentialGuidType.SequentialAtEnd:
output = guid.ToString();
output = "\\cf1\n" + output.Substring(0, 24) + "\n\\cf2\n" + output.Substring(24) + "\n\\line\n";
break;
default:
output = guid.ToString();
break;
}
text.Append(output);
System.Threading.Thread.Sleep(1);
}
this.resultsTextBox.Rtf = text.ToString();
}
public Guid NewSequentialGuid(SequentialGuidType guidType)
{
byte[] randomBytes = new byte[10];
_rng.GetBytes(randomBytes);
long timestamp = DateTime.UtcNow.Ticks / 10000L;
byte[] timestampBytes = BitConverter.GetBytes(timestamp);
if (BitConverter.IsLittleEndian)
{
Array.Reverse(timestampBytes);
}
byte[] guidBytes = new byte[16];
switch (guidType)
{
case SequentialGuidType.SequentialAsString:
case SequentialGuidType.SequentialAsBinary:
// For string and byte-array version, we copy the timestamp first, followed
// by the random data.
Buffer.BlockCopy(timestampBytes, 2, guidBytes, 0, 6);
Buffer.BlockCopy(randomBytes, 0, guidBytes, 6, 10);
// If formatting as a string, we have to compensate for the fact
// that .NET regards the Data1 and Data2 block as an Int32 and an Int16,
// respectively. That means that it switches the order on little-endian
// systems. So again, we have to reverse.
if (guidType == SequentialGuidType.SequentialAsString && BitConverter.IsLittleEndian)
{
Array.Reverse(guidBytes, 0, 4);
Array.Reverse(guidBytes, 4, 2);
}
break;
case SequentialGuidType.SequentialAtEnd:
// For sequential-at-the-end versions, we copy the random data first,
// followed by the timestamp.
Buffer.BlockCopy(randomBytes, 0, guidBytes, 0, 10);
Buffer.BlockCopy(timestampBytes, 2, guidBytes, 10, 6);
break;
}
return(new Guid(guidBytes));
}
public static Guid NewSequentialGuid(SequentialGuidType guidType)
{
var randomBytes = new byte[10];
Rng.GetBytes(randomBytes);
lock (Rng) {
counter++;
randomBytes[0] = (byte)counter;
randomBytes[1] = (byte)(counter >> 8);
}
var timestamp = DateTime.Now.Ticks / 10000L;
var timestampBytes = BitConverter.GetBytes(timestamp);
if (BitConverter.IsLittleEndian)
{
Array.Reverse(timestampBytes);
}
var guidBytes = new byte[16];
switch (guidType)
{
case SequentialGuidType.SequentialAsString:
case SequentialGuidType.SequentialAsBinary:
Buffer.BlockCopy(timestampBytes, 2, guidBytes, 0, 6);
Buffer.BlockCopy(randomBytes, 0, guidBytes, 6, 10);
// If formatting as a string, we have to reverse the order
// of the Data1 and Data2 blocks on little-endian systems.
if (guidType == SequentialGuidType.SequentialAsString == BitConverter.IsLittleEndian)
{
Array.Reverse(guidBytes, 0, 4);
Array.Reverse(guidBytes, 4, 2);
}
break;
case SequentialGuidType.SequentialAtEnd:
Buffer.BlockCopy(randomBytes, 0, guidBytes, 0, 10);
Buffer.BlockCopy(timestampBytes, 2, guidBytes, 10, 6);
break;
}
return(new Guid(guidBytes));
}
public static long ExtractDateTimeTicks(byte[] guidBytes, SequentialGuidType guidType = SequentialGuidType.SequentialAsString)
{
byte[] timestampBytes = new byte[8];
switch (guidType)
{
case SequentialGuidType.SequentialAsString:
case SequentialGuidType.SequentialAsBinary:
Buffer.BlockCopy(guidBytes, 0, timestampBytes, 2, 4);
break;
case SequentialGuidType.SequentialAtEnd:
Buffer.BlockCopy(guidBytes, 2, timestampBytes, 12, 4);
break;
}
return(BitConverter.ToInt64(timestampBytes, 0));
}
internal static byte[] GuidSequentialArray(byte bucket, SequentialGuidType guidType, DateTime?utcDateTime = null)
{
//if (bucket > 63) throw new ArgumentOutOfRangeException("bucket", "Bucket is too large! 64 buckets ought to be enough for anybody!");
var bytes = new byte[16];
Rng.GetBytes(bytes);
long ticks = utcDateTime.HasValue? utcDateTime.Value.Ticks : GetTicks();
// Convert to a byte array
byte[] ticksArray = BitConverter.GetBytes(ticks);
if (BitConverter.IsLittleEndian)
{
Array.Reverse(ticksArray);
}
// Copy the bytes into the guid
switch (guidType)
{
case SequentialGuidType.SequentialAsString:
case SequentialGuidType.SequentialAsBinary:
Array.Copy(ticksArray, 1, bytes, 0, 7); // 7 bytes for ticks ~ 228 years
// If formatting as a string, we have to reverse the order
// of the Data1 and Data2 blocks on little-endian systems.
if (guidType == SequentialGuidType.SequentialAsString && BitConverter.IsLittleEndian)
{
Array.Reverse(bytes, 0, 4);
Array.Reverse(bytes, 4, 2);
Array.Reverse(bytes, 6, 2);
}
break;
case SequentialGuidType.SequentialAtEnd:
Buffer.BlockCopy(ticksArray, 1, bytes, 9, 7);
break;
}
var guidTypeByte = (byte)guidType;
// first two bits for sequence type, other 6 bits for bucket
bytes[8] = (byte)(((guidTypeByte & 3) << 6) | (bucket & 63));
return(bytes);
}
public static Guid Generate(SequentialGuidType sequentialGuidType)
{
var randomBytes = new byte[10];
Rng.GetBytes(randomBytes);
var timestamp = DateTime.UtcNow.Ticks / 10000L;
var timestampBytes = BitConverter.GetBytes(timestamp);
if (BitConverter.IsLittleEndian)
{
Array.Reverse(timestampBytes);
}
var guidBytes = new byte[16];
switch (sequentialGuidType)
{
case SequentialGuidType.SequentialAsString:
case SequentialGuidType.SequentialAsBinary:
Buffer.BlockCopy(timestampBytes, 2, guidBytes, 0, 6);
Buffer.BlockCopy(randomBytes, 0, guidBytes, 6, 10);
// If formatting as a string, we have to reverse the order
// of the Data1 and Data2 blocks on little-endian systems.
if (sequentialGuidType == SequentialGuidType.SequentialAsString && BitConverter.IsLittleEndian)
{
Array.Reverse(guidBytes, 0, 4);
Array.Reverse(guidBytes, 4, 2);
}
break;
case SequentialGuidType.SequentialAtEnd:
Buffer.BlockCopy(randomBytes, 0, guidBytes, 0, 10);
Buffer.BlockCopy(timestampBytes, 2, guidBytes, 10, 6);
break;
default:
throw new ArgumentOutOfRangeException(nameof(sequentialGuidType), sequentialGuidType, null);
}
return(new Guid(guidBytes));
}
public static Guid NewSequentialGuid(SequentialGuidType guidType = SequentialGuidType.SequentialAtEnd)
{
byte[] randomBytes = new byte[10];
_rng.GetBytes(randomBytes);
long timestamp = DateTime.UtcNow.Ticks / 10000L;
byte[] timestampBytes = BitConverter.GetBytes(timestamp);
if (BitConverter.IsLittleEndian)
{
Array.Reverse(timestampBytes);
}
byte[] guidBytes = new byte[16];
switch (guidType)
{
case SequentialGuidType.NoSequential:
return(Guid.NewGuid());
case SequentialGuidType.SequentialAsString:
case SequentialGuidType.SequentialAsBinary:
Buffer.BlockCopy(timestampBytes, 2, guidBytes, 0, 6);
Buffer.BlockCopy(randomBytes, 0, guidBytes, 6, 10);
// If formatting as a string, we have to reverse the order
// of the Data1 and Data2 blocks on little-endian systems.
if (guidType == SequentialGuidType.SequentialAsString && BitConverter.IsLittleEndian)
{
Array.Reverse(guidBytes, 0, 4);
Array.Reverse(guidBytes, 4, 2);
}
break;
case SequentialGuidType.SequentialAtEnd:
Buffer.BlockCopy(randomBytes, 0, guidBytes, 0, 10);
Buffer.BlockCopy(timestampBytes, 2, guidBytes, 10, 6);
break;
}
return(new Guid(guidBytes));
}
public static Guid NewGuid(SequentialGuidType guidType)
{
var randomBytes = new byte[10];
_random.NextBytes(randomBytes);
//private static readonly RNGCryptoServiceProvider _rng = new RNGCryptoServiceProvider();
//_rng.GetBytes(randomBytes);
var timestamp = DateTime.UtcNow.Ticks / 10000L;
var timestampBytes = BitConverter.GetBytes(timestamp);
if (BitConverter.IsLittleEndian)
{
Array.Reverse(timestampBytes);
}
var guidBytes = new byte[16];
switch (guidType)
{
case SequentialGuidType.SequentialAsString:
case SequentialGuidType.SequentialAsBinary:
Buffer.BlockCopy(timestampBytes, 2, guidBytes, 0, 6);
Buffer.BlockCopy(randomBytes, 0, guidBytes, 6, 10);
// If formatting as a string, we have to reverse the order
// of the Data1 and Data2 blocks on little-endian systems.
if (guidType == SequentialGuidType.SequentialAsString && BitConverter.IsLittleEndian)
{
Array.Reverse(guidBytes, 0, 4);
Array.Reverse(guidBytes, 4, 2);
}
break;
case SequentialGuidType.SequentialAtEnd:
Buffer.BlockCopy(randomBytes, 0, guidBytes, 0, 10);
Buffer.BlockCopy(timestampBytes, 2, guidBytes, 10, 6);
break;
}
return(new Guid(guidBytes));
}
internal static byte[] GuidSequentialArray(byte bucket, SequentialGuidType guidType, DateTime? utcDateTime = null) {
//if (bucket > 63) throw new ArgumentOutOfRangeException("bucket", "Bucket is too large! 64 buckets ought to be enough for anybody!");
var bytes = new byte[16];
Rng.GetBytes(bytes);
long ticks = utcDateTime.HasValue? utcDateTime.Value.Ticks : GetTicks();
// Convert to a byte array
byte[] ticksArray = BitConverter.GetBytes(ticks);
if (BitConverter.IsLittleEndian) {
Array.Reverse(ticksArray);
}
// Copy the bytes into the guid
switch (guidType) {
case SequentialGuidType.SequentialAsString:
case SequentialGuidType.SequentialAsBinary:
Array.Copy(ticksArray, 1, bytes, 0, 7); // 7 bytes for ticks ~ 228 years
// If formatting as a string, we have to reverse the order
// of the Data1 and Data2 blocks on little-endian systems.
if (guidType == SequentialGuidType.SequentialAsString && BitConverter.IsLittleEndian) {
Array.Reverse(bytes, 0, 4);
Array.Reverse(bytes, 4, 2);
Array.Reverse(bytes, 6, 2);
}
break;
case SequentialGuidType.SequentialAtEnd:
Buffer.BlockCopy(ticksArray, 1, bytes, 9, 7);
break;
}
var guidTypeByte = (byte) guidType;
// first two bits for sequence type, other 6 bits for bucket
bytes[8] = (byte)(( (guidTypeByte & 3) << 6 ) | (bucket & 63) );
return bytes;
}
/// <summary>
/// Gets the DateTime from sequential GUID.
/// </summary>
/// <param name="guid">The GUID.</param>
/// <param name="guidType">Specifies the type of sequential GUID (i.e. whether sequential as a string, as a byte array, or according to the Data4 block). This can affect performance under various database types.</param>
/// <returns> DateTime object expressed as the Coordinated Universal Time (UTC).</returns>
private static DateTime GetTimestampFromGuid(Guid guid, SequentialGuidType guidType)
{
byte[] guidBytes = guid.ToByteArray();
byte[] timestampBytes = new byte[8];
switch (guidType)
{
case SequentialGuidType.SequentialAsString:
if (BitConverter.IsLittleEndian)
{
Array.Reverse(guidBytes, 0, 4);
Array.Reverse(guidBytes, 4, 2);
}
Buffer.BlockCopy(guidBytes, 0, timestampBytes, 2, 6);
break;
case SequentialGuidType.SequentialAsBinary:
Buffer.BlockCopy(guidBytes, 0, timestampBytes, 2, 6);
break;
case SequentialGuidType.SequentialAtEnd:
Buffer.BlockCopy(guidBytes, 10, timestampBytes, 2, 6);
break;
}
if (BitConverter.IsLittleEndian)
{
Array.Reverse(timestampBytes);
}
long dateTimeData = BitConverter.ToInt64(timestampBytes, 0) * TicksFactor;
DateTime result = DateTime.FromBinary(dateTimeData);
return(result);
}
public static Guid Generate(SequentialGuidType sequentialGuidType)
{
var randomBytes = new byte[10];
Rng.GetBytes(randomBytes);
var timestamp = DateTime.UtcNow.Ticks / 10000L;
var timestampBytes = BitConverter.GetBytes(timestamp);
if (BitConverter.IsLittleEndian)
{
Array.Reverse(timestampBytes);
}
var guidBytes = new byte[16];
switch (sequentialGuidType)
{
case SequentialGuidType.SequentialAsString:
case SequentialGuidType.SequentialAsBinary:
Buffer.BlockCopy(timestampBytes, 2, guidBytes, 0, 6);
Buffer.BlockCopy(randomBytes, 0, guidBytes, 6, 10);
// If formatting as a string, we have to reverse the order
// of the Data1 and Data2 blocks on little-endian systems.
if (sequentialGuidType == SequentialGuidType.SequentialAsString && BitConverter.IsLittleEndian)
{
Array.Reverse(guidBytes, 0, 4);
Array.Reverse(guidBytes, 4, 2);
}
break;
case SequentialGuidType.SequentialAtEnd:
Buffer.BlockCopy(randomBytes, 0, guidBytes, 0, 10);
Buffer.BlockCopy(timestampBytes, 2, guidBytes, 10, 6);
break;
default:
throw new ArgumentOutOfRangeException(nameof(sequentialGuidType), sequentialGuidType, null);
}
return new Guid(guidBytes);
}
public static Guid Create(SequentialGuidType guidType = SequentialGuidType.SequentialAsString)
{
byte[] randomBytes = Guid.NewGuid().ToByteArray();
long timestamp = DateTime.UtcNow.Ticks / 10000L;
var timestampBytes = BitConverter.GetBytes(timestamp);
if (BitConverter.IsLittleEndian)
{
Array.Reverse(timestampBytes);
}
var guidBytes = new byte[16];
switch (guidType)
{
case SequentialGuidType.SequentialAsString:
case SequentialGuidType.SequentialAsBinary:
Buffer.BlockCopy(timestampBytes, 2, guidBytes, 0, 6);
Buffer.BlockCopy(randomBytes, 0, guidBytes, 6, 10);
// If formatting as a string, we have to reverse the order
// of the Data1 and Data2 blocks on little-endian systems.
if (guidType == SequentialGuidType.SequentialAsString && BitConverter.IsLittleEndian)
{
Array.Reverse(guidBytes, 0, 4);
Array.Reverse(guidBytes, 4, 2);
}
break;
case SequentialGuidType.SequentialAtEnd:
Buffer.BlockCopy(randomBytes, 0, guidBytes, 0, 10);
Buffer.BlockCopy(timestampBytes, 2, guidBytes, 10, 6);
break;
default:
throw new Exception($"Case missing for {guidType}");
}
return(new Guid(guidBytes));
}
public static Guid NewSequentialGuid(DateTime created, Guid sourceGuid, SequentialGuidType resultingGuidType)
{
var randomBytes = sourceGuid.ToByteArray();
var timestamp = created.Ticks / 10000L;
var timestampBytes = BitConverter.GetBytes(timestamp);
if (BitConverter.IsLittleEndian)
Array.Reverse(timestampBytes);
var guidBytes = new byte[16];
switch (resultingGuidType)
{
case (SequentialGuidType.SequentialAsString):
case (SequentialGuidType.SequentialAsBinary):
{
Buffer.BlockCopy(timestampBytes, 2, guidBytes, 0, 6);
Buffer.BlockCopy(randomBytes, 0, guidBytes, 6, 10);
// If formatting as a string, we have to reverse the order
// of the Data1 and Data2 blocks on little-endian systems.
if (resultingGuidType == SequentialGuidType.SequentialAsString &&
BitConverter.IsLittleEndian)
{
Array.Reverse(guidBytes, 0, 4);
Array.Reverse(guidBytes, 4, 2);
}
break;
}
case (SequentialGuidType.SequentialAtEnd):
{
Buffer.BlockCopy(randomBytes, 0, guidBytes, 0, 10);
Buffer.BlockCopy(timestampBytes, 2, guidBytes, 10, 6);
break;
}
}
return new Guid(guidBytes);
}
///<summary>
/// Generates a GuidComb (COMBined GUID/timestamp). This is a Guid generation model, suggested by Jimmy Nilsson, where some bytes have been replaced by a timestamp-based value that is guaranteed to increase, but not decrease, with each new value generated.
/// The goal is to remove the database performance limitations of using GUIDS as surrogate primary keys.
///</summary>
///<returns><see cref="Guid"/></returns>
/// TODO: Determine the database type from service locator and predetermine what the guidType should be
public static Guid Generate(SequentialGuidType guidType)
{
byte[] randomBytes = new byte[10];
_rng.GetBytes(randomBytes);
// TODO: Implement DependencyInjection for date time instance
//long timestamp = ServiceLocator.Current.GetInstance<IDateTimeProvider>().UtcNow.Ticks / 10000L;
long timestamp = DateTime.UtcNow.Ticks / 10000L;
byte[] timestampBytes = BitConverter.GetBytes(timestamp);
if (BitConverter.IsLittleEndian)
{
Array.Reverse(timestampBytes);
}
byte[] guidBytes = new byte[16];
switch (guidType)
{
case SequentialGuidType.SequentialAsString:
case SequentialGuidType.SequentialAsBinary:
Buffer.BlockCopy(timestampBytes, 2, guidBytes, 0, 6);
Buffer.BlockCopy(randomBytes, 0, guidBytes, 6, 10);
// If formatting as a string, we have to reverse the order
// of the Data1 and Data2 blocks on little-endian systems.
if (guidType == SequentialGuidType.SequentialAsString && BitConverter.IsLittleEndian)
{
Array.Reverse(guidBytes, 0, 4);
Array.Reverse(guidBytes, 4, 2);
}
break;
case SequentialGuidType.SequentialAtEnd:
Buffer.BlockCopy(randomBytes, 0, guidBytes, 0, 10);
Buffer.BlockCopy(timestampBytes, 2, guidBytes, 10, 6);
break;
}
return(new Guid(guidBytes));
}
public static Guid Create(SequentialGuidType guidType)
{
var randomBytes = new byte[10];
_RandomGenerator.GetBytes(randomBytes);
var timestamp = DateTimeOffset.UtcNow.Ticks / 10000L;
var timestampBytes = BitConverter.GetBytes(timestamp);
if (BitConverter.IsLittleEndian)
{
Array.Reverse(timestampBytes);
}
var guidBytes = new byte[16];
switch (guidType)
{
case SequentialGuidType.SequentialAsString:
case SequentialGuidType.SequentialAsBinary:
Buffer.BlockCopy(timestampBytes, 2, guidBytes, 0, 6);
Buffer.BlockCopy(randomBytes, 0, guidBytes, 6, 10);
if (guidType == SequentialGuidType.SequentialAsString && BitConverter.IsLittleEndian)
{
Array.Reverse(guidBytes, 0, 4);
Array.Reverse(guidBytes, 4, 2);
}
break;
case SequentialGuidType.SequentialAtEnd:
Buffer.BlockCopy(randomBytes, 0, guidBytes, 0, 10);
Buffer.BlockCopy(timestampBytes, 2, guidBytes, 10, 6);
break;
}
return(new Guid(guidBytes));
}
/// <summary>
/// Initialize the generator.
/// </summary>
/// <param name="type">The sequential guid type.</param>
public SequentialGuidGenerator(SequentialGuidType type)
{
_type = type;
}
private static Guid NewGuid(SequentialGuidType guidType)
{
long timestamp = DateTime.UtcNow.Ticks / 10000L;
//timestamp += Threading.Interlocked.Increment(ref guidSequenceNumber);
byte[] timestampBytes = BitConverter.GetBytes(timestamp);
if (BitConverter.IsLittleEndian)
{
Array.Reverse(timestampBytes);
}
byte[] guidBytes = Guid.NewGuid().ToByteArray();
switch (guidType)
{
case SequentialGuidType.SequentialAsString:
case SequentialGuidType.SequentialAsBinary:
Buffer.BlockCopy(timestampBytes, 2, guidBytes, 0, 6);
// If formatting as a string, we have to reverse the order
// of the Data1 and Data2 blocks on little-endian systems.
if (guidType == SequentialGuidType.SequentialAsString && BitConverter.IsLittleEndian)
{
Array.Reverse(guidBytes, 0, 4);
Array.Reverse(guidBytes, 4, 2);
}
break;
case SequentialGuidType.SequentialAtEnd:
Buffer.BlockCopy(timestampBytes, 2, guidBytes, 10, 6);
break;
}
return new Guid(guidBytes);
}
public Guid Create(SequentialGuidType guidType)
{
// We start with 16 bytes of cryptographically strong random data.
byte[] randomBytes = new byte[10];
_rng.GetBytes(randomBytes);
// An alternate method: use a normally-created GUID to get our initial
// random data:
// byte[] randomBytes = Guid.NewGuid().ToByteArray();
// This is faster than using RNGCryptoServiceProvider, but I don't
// recommend it because the .NET Framework makes no guarantee of the
// randomness of GUID data, and future versions (or different
// implementations like Mono) might use a different method.
// Now we have the random basis for our GUID. Next, we need to
// create the six-byte block which will be our timestamp.
// We start with the number of milliseconds that have elapsed since
// DateTime.MinValue. This will form the timestamp. There's no use
// being more specific than milliseconds, since DateTime.Now has
// limited resolution.
// Using millisecond resolution for our 48-bit timestamp gives us
// about 5900 years before the timestamp overflows and cycles.
// Hopefully this should be sufficient for most purposes. :)
long timestamp = DateTime.UtcNow.Ticks / 10000L;
// Then get the bytes
byte[] timestampBytes = BitConverter.GetBytes(timestamp);
// Since we're converting from an Int64, we have to reverse on
// little-endian systems.
if (BitConverter.IsLittleEndian)
{
Array.Reverse(timestampBytes);
}
byte[] guidBytes = new byte[16];
switch (guidType)
{
case SequentialGuidType.SequentialAsString:
case SequentialGuidType.SequentialAsBinary:
// For string and byte-array version, we copy the timestamp first, followed
// by the random data.
Buffer.BlockCopy(timestampBytes, 2, guidBytes, 0, 6);
Buffer.BlockCopy(randomBytes, 0, guidBytes, 6, 10);
// If formatting as a string, we have to compensate for the fact
// that .NET regards the Data1 and Data2 block as an Int32 and an Int16,
// respectively. That means that it switches the order on little-endian
// systems. So again, we have to reverse.
if (guidType == SequentialGuidType.SequentialAsString && BitConverter.IsLittleEndian)
{
Array.Reverse(guidBytes, 0, 4);
Array.Reverse(guidBytes, 4, 2);
}
break;
case SequentialGuidType.SequentialAtEnd:
// For sequential-at-the-end versions, we copy the random data first,
// followed by the timestamp.
Buffer.BlockCopy(randomBytes, 0, guidBytes, 0, 10);
Buffer.BlockCopy(timestampBytes, 2, guidBytes, 10, 6);
break;
}
return new Guid(guidBytes);
}
/// <summary>
/// 获取有序的唯一ID。
/// </summary>
/// <returns></returns>
public static Guid GenerateComb(SequentialGuidType sequentialGuidType = SequentialGuidType.SequentialAtEnd)
{
return(SequentialGuidGenerator.NewSequentialGuid(sequentialGuidType));
}
/// <summary>
/// Generate new Guid for a bucket
/// </summary>
public static Guid NewBucketGuid(byte bucket, SequentialGuidType guidType = SequentialGuidType.SequentialAsString, DateTime?utcDateTime = null)
{
return(new Guid(GuidSequentialArray(bucket, guidType, utcDateTime)));
}
/// <summary>
/// Generate a new Guid that will have the same bucket as the root Guid
/// </summary>
public static Guid NewBucketGuid(Guid rootGuid, SequentialGuidType guidType = SequentialGuidType.SequentialAsString)
{
return(new Guid(GuidSequentialArray(rootGuid.ToByteArray()[8], guidType)));
}
public SequentialGuidIdGenerator(SequentialGuidType sequentialGuidType)
{
_sequentialGuidType = sequentialGuidType;
}
/// <summary>
/// Gets the DateTime from sequential GUID.
/// </summary>
/// <param name="guid">The GUID.</param>
/// <param name="guidType">Specifies the type of sequential GUID (i.e. whether sequential as a string, as a byte array, or according to the Data4 block). This can affect performance under various database types.</param>
/// <returns> DateTime object expressed as the Coordinated Universal Time (UTC).</returns>
private static DateTime GetTimestampFromGuid(Guid guid, SequentialGuidType guidType) {
byte[] guidBytes = guid.ToByteArray();
byte[] timestampBytes = new byte[8];
switch (guidType) {
case SequentialGuidType.SequentialAsString:
if (BitConverter.IsLittleEndian) {
Array.Reverse(guidBytes, 0, 4);
Array.Reverse(guidBytes, 4, 2);
}
Buffer.BlockCopy(guidBytes, 0, timestampBytes, 2, 6);
break;
case SequentialGuidType.SequentialAsBinary:
Buffer.BlockCopy(guidBytes, 0, timestampBytes, 2, 6);
break;
case SequentialGuidType.SequentialAtEnd:
Buffer.BlockCopy(guidBytes, 10, timestampBytes, 2, 6);
break;
}
if (BitConverter.IsLittleEndian) {
Array.Reverse(timestampBytes);
}
long dateTimeData = BitConverter.ToInt64(timestampBytes, 0) * TicksFactor;
DateTime result = DateTime.FromBinary(dateTimeData);
return result;
}
/// <summary>
/// Returns a new GUID value which is sequentially ordered when formatted as
/// a string, a byte array, or ordered by the least significant six bytes of the
/// Data4 block, as specified by <paramref name="guidType" />.
/// </summary>
/// <param name="guidType">
/// Specifies the type of sequential GUID (i.e. whether sequential as a string,
/// as a byte array, or according to the Data4 block. This can affect
/// performance under various database types; see below.
/// </param>
/// <returns>
/// A <see cref="Guid" /> structure whose value is created by replacing
/// certain randomly-generated bytes with a sequential timestamp.
/// </returns>
/// <remarks>
/// <para>
/// This method creates a new GUID value which combines a random component
/// with the current timestamp, also known as a COMB. The general concept
/// is outlined in Jimmy Nilsson's article "The Cost of GUIDs as Primary Keys",
/// and involves replacing either the least significant or most significant
/// six bytes of the GUID with the current timestamp. This reduces the
/// random component of the GUID from 16 bytes to 10 bytes, but this is
/// still sufficient to prevent a collision under most real-world circumstances.
/// </para>
/// <para>
/// The purpose of sequential GUIDs is not to promote the use of GUIDs as
/// sortable entities. In fact, GUIDs generated very close together may
/// have the same timestamp and are not guaranteed to be sequentially ordered
/// at all. The intent is to increase performance when doing repeated
/// inserts into database tables that have a clustered index on a GUID
/// column, so that later entries do not have to be inserted into the middle
/// of the table, but can simply be appended to the end.
/// </para>
/// <para>
/// According to experiments, Microsoft SQL Server sorts GUID values using
/// the least significant six bytes of the Data4 block; therefore, GUIDs being
/// generated for use with SQL Server should pass a <paramref name="guidType" />
/// value of <c>SequentialAtEnd</c>. GUIDs generated for most other database
/// types should be passed a <paramref name="guidType" /> value of
/// <c>SequentialAsString</c> or <c>SequentialAsByteArray</c>.
/// </para>
/// <para>
/// Various standards already define a time-based UUID; however, the
/// format specified by these standards splits the timestamp into
/// several components, limiting its usefulness as a sequential ID.
/// Additionally, the format used for such UUIDs is not compatible
/// with the GUID ordering on Microsoft SQL Server.
/// </para>
/// </remarks>
public static Guid Create(SequentialGuidType guidType = SequentialGuidType.SequentialAsString)
{
// We start with 16 bytes of cryptographically strong random data.
byte[] randomBytes = new byte[10];
SequentialGuid.RandomGenerator.GetBytes(randomBytes);
// An alternate method: use a normally-created GUID to get our initial
// random data:
// byte[] randomBytes = Guid.NewGuid().ToByteArray();
// This is faster than using RNGCryptoServiceProvider, but I don't
// recommend it because the .NET Framework makes no guarantee of the
// randomness of GUID data, and future versions (or different
// implementations like Mono) might use a different method.
// Now we have the random basis for our GUID. Next, we need to
// create the six-byte block which will be our timestamp.
// We start with the number of milliseconds that have elapsed since
// DateTime.MinValue. This will form the timestamp. There's no use
// being more specific than milliseconds, since DateTime.Now has
// limited resolution.
// Using millisecond resolution for our 48-bit timestamp gives us
// about 5900 years before the timestamp overflows and cycles.
// Hopefully this should be sufficient for most purposes. :)
long timestamp = DateTime.UtcNow.Ticks / 10000L;
// Then get the bytes
byte[] timestampBytes = BitConverter.GetBytes(timestamp);
// Since we're converting from an Int64, we have to reverse on
// little-endian systems.
if (BitConverter.IsLittleEndian)
{
Array.Reverse(timestampBytes);
}
byte[] guidBytes = new byte[16];
switch (guidType)
{
case SequentialGuidType.SequentialAsString:
case SequentialGuidType.SequentialAsBinary:
// For string and byte-array version, we copy the timestamp first, followed
// by the random data.
Buffer.BlockCopy(timestampBytes, 2, guidBytes, 0, 6);
Buffer.BlockCopy(randomBytes, 0, guidBytes, 6, 10);
// If formatting as a string, we have to compensate for the fact
// that .NET regards the Data1 and Data2 block as an Int32 and an Int16,
// respectively. That means that it switches the order on little-endian
// systems. So again, we have to reverse.
if (guidType == SequentialGuidType.SequentialAsString && BitConverter.IsLittleEndian)
{
Array.Reverse(guidBytes, 0, 4);
Array.Reverse(guidBytes, 4, 2);
}
break;
case SequentialGuidType.SequentialAtEnd:
// For sequential-at-the-end versions, we copy the random data first,
// followed by the timestamp.
Buffer.BlockCopy(randomBytes, 0, guidBytes, 0, 10);
Buffer.BlockCopy(timestampBytes, 2, guidBytes, 10, 6);
break;
}
return(new Guid(guidBytes));
}
/// <summary>
/// Sets the default sequential GUID generation type.
/// This method should be called at the application initialization.
/// </summary>
/// <param name="value">A sequential GUID generation type.</param>
public static void SetDefaultSequentialGuidType(SequentialGuidType value)
{
defaultSequentialGuidType = value;
}
/// <summary>
/// 得到唯一标识提供者
/// </summary>
/// <param name="sequentialGuidType">唯一标识类型</param>
/// <returns></returns>
public IGuidGeneratorProvider GetGuidGeneratorProvider(SequentialGuidType sequentialGuidType)
{
return(GetGuidGeneratorProvider(sequentialGuidType.Id));
}
public static Guid NewGuid(SequentialGuidType guidType = SequentialGuidType.SequentialAsString, DateTime? utcDateTime = null) {
return new Guid(GuidSequentialArray(0, guidType, utcDateTime));
}
/// <summary>
/// Generate a new Guid that will have the same bucket as the root Guid
/// </summary>
public static Guid NewBucketGuid(Guid rootGuid, SequentialGuidType guidType = SequentialGuidType.SequentialAsString) {
return new Guid(GuidSequentialArray(rootGuid.ToByteArray()[8], guidType));
}
/// <summary>
/// Generate new Guid for a bucket
/// </summary>
public static Guid NewBucketGuid(byte bucket, SequentialGuidType guidType = SequentialGuidType.SequentialAsString, DateTime? utcDateTime = null) {
return new Guid(GuidSequentialArray(bucket, guidType,utcDateTime));
}
public static Guid NewRandomBucketGuid(SequentialGuidType guidType = SequentialGuidType.SequentialAsString, DateTime? utcDateTime = null) {
var bs = new byte[1];
bs[0] = 0;
while (bs[0] == 0) { Rng.GetBytes(bs); } // 1-255
return new Guid(GuidSequentialArray(bs[0], guidType, utcDateTime));
}
public static Guid NewRandomBucketGuid(SequentialGuidType guidType = SequentialGuidType.SequentialAsString, DateTime?utcDateTime = null)
{
return(new Guid(GuidSequentialArray((byte)Rng.Next(1, 256), guidType, utcDateTime)));
}
public static Guid NewGuid(SequentialGuidType guidType = SequentialGuidType.SequentialAsString, DateTime?utcDateTime = null)
{
return(new Guid(GuidSequentialArray(0, guidType, utcDateTime)));
}
public static Guid NewSequentialGuid(SequentialGuidType guidType) => NewSequentialGuid(DateTime.UtcNow, Guid.NewGuid(), guidType);
/// <summary>
/// Generates a new GUID value which is sequentially ordered when formatted as a string, a byte array, or ordered by the least significant six bytes of the Data4 block, as specified by <paramref name="guidType" />.
/// </summary>
/// <param name="guidType">Specifies the type of sequential GUID (i.e. whether sequential as a string, as a byte array, or according to the Data4 block). This can affect performance under various database types.</param>
/// <returns>A <see cref="Guid" /> structure whose value is created by replacing certain randomly-generated bytes with a sequential timestamp.</returns>
private static Guid NewSequentialGuid(SequentialGuidType guidType) {
// slower but more random
byte[] randomBytes = new byte[10];
RandomGenerator.GetBytes(randomBytes);
////// faster but less random
////byte[] randomBytes = Guid.NewGuid().ToByteArray();
long timestamp = DateTime.UtcNow.Ticks / TicksFactor;
byte[] timestampBytes = BitConverter.GetBytes(timestamp);
if (BitConverter.IsLittleEndian) {
Array.Reverse(timestampBytes);
}
byte[] guidBytes = new byte[16];
switch (guidType) {
case SequentialGuidType.SequentialAsString:
Buffer.BlockCopy(timestampBytes, 2, guidBytes, 0, 6);
Buffer.BlockCopy(randomBytes, 0, guidBytes, 6, 10);
if (BitConverter.IsLittleEndian) {
Array.Reverse(guidBytes, 0, 4);
Array.Reverse(guidBytes, 4, 2);
}
break;
case SequentialGuidType.SequentialAsBinary:
Buffer.BlockCopy(timestampBytes, 2, guidBytes, 0, 6);
Buffer.BlockCopy(randomBytes, 0, guidBytes, 6, 10);
break;
case SequentialGuidType.SequentialAtEnd:
Buffer.BlockCopy(randomBytes, 0, guidBytes, 0, 10);
Buffer.BlockCopy(timestampBytes, 2, guidBytes, 10, 6);
break;
}
return new Guid(guidBytes);
}