Struct GDID

Represents a Global Distributed ID key (key field) used in distributed databases that identify entities with a combination of unsigned 32 bit integer 'Era' and unsigned 64 bit integer 'ID'. The first 32 bit integer is an 'era' in which the 'ID' (64 bit) was created, consequently a GDID is a 12 byte = 96 bit integer that can hold 2^96 = 79,228,162,514,264,337,593,543,950,336 combinations. The ID consists of two segments: 4 bit authority + 60 bits counter. Authority segment occupies the most significant 4 bits of uint64, so the system may efficiently query the data store to identify the highest stored ID value in a range. Authorities identify one of 16 possible ID generation sources in the global distributed system, therefore ID duplications are not possible between authorities. Within a single era, GDID structure may identify 2^60 = 1,152,921,504,606,846,976(per authority) * 16(authorities) = 2^64 = 18,446,744,073,709,551,616 total combinations. Because of such a large number of combinations supported by GDID.ID alone (having the same Era), some systems may always use Era=0 and only store the ID part (i.e. as UNSIGNED BIGINT in SQL datastores). Note GDID.Zero is never returned by generators as it represents the absence of a value (special value)

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

Constructors

GDID(Byte[], Int32)

Declaration
public GDID(byte[] bytes, int startIdx = 0)
Parameters
Type Name Description
System.Byte[] bytes
System.Int32 startIdx

GDID(UInt32, Int32, UInt64)

Declaration
public GDID(uint era, int authority, ulong counter)
Parameters
Type Name Description
System.UInt32 era
System.Int32 authority
System.UInt64 counter

GDID(UInt32, UInt64)

Declaration
public GDID(uint era, ulong id)
Parameters
Type Name Description
System.UInt32 era
System.UInt64 id

Fields

AUTHORITY_MASK

Declaration
public const ulong AUTHORITY_MASK = 17293822569102704640UL
Field Value
Type Description
System.UInt64

AUTHORITY_MAX

Provides maximum value for authority segment

Declaration
public const int AUTHORITY_MAX = 15
Field Value
Type Description
System.Int32

COUNTER_MASK

Declaration
public const ulong COUNTER_MASK = 1152921504606846975UL
Field Value
Type Description
System.UInt64

COUNTER_MAX

Provides maximum value for counter segment

Declaration
public const ulong COUNTER_MAX = 1152921504606846975UL
Field Value
Type Description
System.UInt64

Era

Declaration
public readonly uint Era
Field Value
Type Description
System.UInt32

ID

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

Zero

Zero GDID singleton

Declaration
public static readonly GDID Zero
Field Value
Type Description
GDID

Properties

Authority

Returns the 0..15 index of the authority that issued this ID

Declaration
public int Authority { get; }
Property Value
Type Description
System.Int32

Bytes

Returns the GDID buffer as BigEndian Era:ID tuple

Declaration
public byte[] Bytes { get; }
Property Value
Type Description
System.Byte[]

Counter

Returns the 60 bits of counter segment of this id (without athority segment upper 4 bits)

Declaration
public ulong Counter { get; }
Property Value
Type Description
System.UInt64

IsZero

True is this instance is invalid - represents 0:0:0

Declaration
public bool IsZero { get; }
Property Value
Type Description
System.Boolean

Methods

CompareTo(GDID)

Declaration
public int CompareTo(GDID other)
Parameters
Type Name Description
GDID other
Returns
Type Description
System.Int32

CompareTo(Object)

Declaration
public int CompareTo(object obj)
Parameters
Type Name Description
System.Object obj
Returns
Type Description
System.Int32

Equals(GDID)

Declaration
public bool Equals(GDID other)
Parameters
Type Name Description
GDID 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)

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()

Parse(String)

Declaration
public static GDID Parse(string str)
Parameters
Type Name Description
System.String str
Returns
Type Description
GDID

ToHexString()

Declaration
public string ToHexString()
Returns
Type Description
System.String

ToString()

Returns the guaranted parsable stable string representation of GDID in the form 'Era:Authority:Counter'

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

TryParse(String, out GDID)

Declaration
public static bool TryParse(string str, out GDID gdid)
Parameters
Type Name Description
System.String str
GDID gdid
Returns
Type Description
System.Boolean

TryParse(String, out Nullable<GDID>)

Declaration
public static bool TryParse(string str, out GDID? gdid)
Parameters
Type Name Description
System.String str
System.Nullable<GDID> gdid
Returns
Type Description
System.Boolean

WriteAsJSON(TextWriter, Int32, JSONWritingOptions)

Declaration
public void WriteAsJSON(TextWriter wri, int nestingLevel, JSONWritingOptions options = null)
Parameters
Type Name Description
System.IO.TextWriter wri
System.Int32 nestingLevel
JSONWritingOptions options

Operators

Equality(GDID, GDID)

Declaration
public static bool operator ==(GDID x, GDID y)
Parameters
Type Name Description
GDID x
GDID y
Returns
Type Description
System.Boolean

GreaterThan(GDID, GDID)

Declaration
public static bool operator>(GDID x, GDID y)
Parameters
Type Name Description
GDID x
GDID y
Returns
Type Description
System.Boolean

GreaterThanOrEqual(GDID, GDID)

Declaration
public static bool operator >=(GDID x, GDID y)
Parameters
Type Name Description
GDID x
GDID y
Returns
Type Description
System.Boolean

Inequality(GDID, GDID)

Declaration
public static bool operator !=(GDID x, GDID y)
Parameters
Type Name Description
GDID x
GDID y
Returns
Type Description
System.Boolean

LessThan(GDID, GDID)

Declaration
public static bool operator <(GDID x, GDID y)
Parameters
Type Name Description
GDID x
GDID y
Returns
Type Description
System.Boolean

LessThanOrEqual(GDID, GDID)

Declaration
public static bool operator <=(GDID x, GDID y)
Parameters
Type Name Description
GDID x
GDID y
Returns
Type Description
System.Boolean

Implements

System.IComparable<T>
System.IEquatable<T>
System.IComparable

Extension Methods