Struct FID

Represents an ultra-efficient 64 bit in-process-wide unique identifier "Fast Id". The ID is going to wrap-around after at least 2 weeks (19 days). The ID consists of 3 segments: [timestamp: 24bit][threadseed: 24bit][counter: 16 bit]. This is needed because: a). FID stays unique after process restarts b). This design does not use interlock on global seed, but uses thread-static vars which is 10-20 times faster

The timestamp is the number of 100ms intervals elapsed since Jan 1 2015 expressed as a 24 bit unsigned int, which gives 2^24 = 16,777,216 combinations which covers 19 days (around 2 weeks) at 100 msec resolution, consequently the ID will generate duplicates after this period. This struct is useful for creating unique IDs for protocol/traffic messages that live for a limited time (no more than 2 weeks). Caution: This ID does not identify the machine or process, only items within the process, however when a hosting process restarts(i.e. crash or reboot) the new IDs will not collide with IDs generated right before the crash for at least 14 days (14 day sliding window). In a parallel test on 6 Core i7 3.2 GHz this class generates 405 million IDs/sec, which is 57 times faster than Guid that only generates 7 million IDs/sec

Implements
System.IEquatable<FID>
Inherited Members
System.Object.Equals(System.Object, System.Object)
System.Object.GetType()
System.Object.ReferenceEquals(System.Object, System.Object)
Namespace: Azos
Assembly: Azos.dll
Syntax
[Serializable]
public struct FID : IEquatable<FID>, IDistributedStableHashProvider

Constructors

FID(UInt64)

Creates instance from ULONG value. Use FID.Generate() to create new IDs instead

Declaration
public FID(ulong id)
Parameters
Type Name Description
System.UInt64 id

Fields

ID

Returns 64 bit process-wide unique ID which is unique for up to 2 weeks

Declaration
public readonly ulong ID
Field Value
Type Description
System.UInt64

Methods

Equals(FID)

Declaration
public bool Equals(FID other)
Parameters
Type Name Description
FID other
Returns
Type Description
System.Boolean

Equals(Object)

Declaration
public override bool Equals(object obj)
Parameters
Type Name Description
System.Object obj
Returns
Type Description
System.Boolean
Overrides
System.ValueType.Equals(System.Object)

Generate()

Generates new process-wide unique ID which is unique for up to 2 weeks

Declaration
public static FID Generate()
Returns
Type Description
FID

GetDistributedStableHash()

Declaration
public ulong GetDistributedStableHash()
Returns
Type Description
System.UInt64

GetHashCode()

Declaration
public override int GetHashCode()
Returns
Type Description
System.Int32
Overrides
System.ValueType.GetHashCode()

ToFakeGuidTag()

Converts to Guid by copying ID twice - this is used when in correlation in logs to associate multiple messages into topic. Warning: the returned Guid is a fake one (hence the name), and not really unique pe UUID spec

Declaration
public Guid ToFakeGuidTag()
Returns
Type Description
System.Guid

ToString()

Declaration
public override string ToString()
Returns
Type Description
System.String
Overrides
System.ValueType.ToString()

Implements

System.IEquatable<T>

Extension Methods