Jeremy — Page 2

While working on a project I needed to generate fake data for my tests. After a little searching I came across Faker.NET. Although this post isn’t about Faker.NET it is the catalyst.

The fake data I was generating has GUID identifiers, and although it is very simple to generate GUIDs I wanted to generate the same GUID every time. Using the GUID constructors is cumbersome so I decided I would much prefer to pass in an simple value like an integer and have a GUID generated from that. Turns out that’s a trivial task but the resulting extension methods have come in rather handy, and I wanted to share them.

One side note about the string overload method. This method is simply using the hash code for the string to generated the GUID. This allows for long strings but the rules for strings and hash codes also apply. Meaning that two identical strings will give you the same GUID, but it is possible for two different strings to generate the same GUID. It is not guaranteed to be unique.

public static class GuidExtensions
{
    public static Guid ToGuid(this short value)
    {
        return ConvertToGuid((ulong)value);
    }

    public static Guid ToGuid(this ushort value)
    {
        return ConvertToGuid(value);
    }

    public static Guid ToGuid(this int value)
    {
        return ConvertToGuid((ulong) value);
    }

    public static Guid ToGuid(this uint value)
    {
        return ConvertToGuid(value);
    }

    public static Guid ToGuid(this long value)
    {
        return ConvertToGuid((ulong)value);
    }

    public static Guid ToGuid(this ulong value)
    {
        return ConvertToGuid(value);
    }

    public static Guid ToGuid(this string value)
    {
        return string.IsNullOrEmpty(value)
            ? Guid.Empty
            : ToGuid((ulong) value.GetHashCode());
    }

    public static Guid ToGuid(this DateTime value)
    {
        return ConvertToGuid((ulong)value.Ticks);
    }

    internal static Guid ConvertToGuid(ulong value)
    {
        var valueBytes = BitConverter.GetBytes(value).Reverse().ToArray();
        var emptyBytes = Guid.Empty.ToByteArray().Take(16 - valueBytes.Length);
        var guidBytes = emptyBytes.Concat(valueBytes).ToArray();

        return new Guid(guidBytes);
    }    
}

public static class GuidExtensions

{

public static Guid ToGuid(this short value)

{

return ConvertToGuid((ulong)value);

}

public static Guid ToGuid(this ushort value)

{

return ConvertToGuid(value);

}

public static Guid ToGuid(this int value)

{

return ConvertToGuid((ulong) value);

}

public static Guid ToGuid(this uint value)

{

return ConvertToGuid(value);

}

public static Guid ToGuid(this long value)

{

return ConvertToGuid((ulong)value);

}

public static Guid ToGuid(this ulong value)

{

return ConvertToGuid(value);

}

public static Guid ToGuid(this string value)

{

return string.IsNullOrEmpty(value)

? Guid.Empty

: ToGuid((ulong) value.GetHashCode());

}

public static Guid ToGuid(this DateTime value)

{

return ConvertToGuid((ulong)value.Ticks);

}

internal static Guid ConvertToGuid(ulong value)

{

var valueBytes = BitConverter.GetBytes(value).Reverse().ToArray();

var emptyBytes = Guid.Empty.ToByteArray().Take(16 - valueBytes.Length);

var guidBytes = emptyBytes.Concat(valueBytes).ToArray();

return new Guid(guidBytes);

}

Generating sequential GUIDs is now rather straight forward.

for (int i = 0; i &lt; 33; i++)
{
    Debug.WriteLine("Value {0} = {1}", i, i.ToGuid());
}

Debug Trace:
Value 0 = 00000000-0000-0000-0000-000000000000
Value 1 = 00000000-0000-0000-0000-000000000001
Value 2 = 00000000-0000-0000-0000-000000000002
Value 3 = 00000000-0000-0000-0000-000000000003
Value 4 = 00000000-0000-0000-0000-000000000004
Value 5 = 00000000-0000-0000-0000-000000000005
Value 6 = 00000000-0000-0000-0000-000000000006
Value 7 = 00000000-0000-0000-0000-000000000007
Value 8 = 00000000-0000-0000-0000-000000000008
Value 9 = 00000000-0000-0000-0000-000000000009
Value 10 = 00000000-0000-0000-0000-00000000000a
Value 11 = 00000000-0000-0000-0000-00000000000b
Value 12 = 00000000-0000-0000-0000-00000000000c
Value 13 = 00000000-0000-0000-0000-00000000000d
Value 14 = 00000000-0000-0000-0000-00000000000e
Value 15 = 00000000-0000-0000-0000-00000000000f
Value 16 = 00000000-0000-0000-0000-000000000010
Value 17 = 00000000-0000-0000-0000-000000000011
Value 18 = 00000000-0000-0000-0000-000000000012
Value 19 = 00000000-0000-0000-0000-000000000013
Value 20 = 00000000-0000-0000-0000-000000000014
Value 21 = 00000000-0000-0000-0000-000000000015
Value 22 = 00000000-0000-0000-0000-000000000016
Value 23 = 00000000-0000-0000-0000-000000000017
Value 24 = 00000000-0000-0000-0000-000000000018
Value 25 = 00000000-0000-0000-0000-000000000019
Value 26 = 00000000-0000-0000-0000-00000000001a
Value 27 = 00000000-0000-0000-0000-00000000001b
Value 28 = 00000000-0000-0000-0000-00000000001c
Value 29 = 00000000-0000-0000-0000-00000000001d
Value 30 = 00000000-0000-0000-0000-00000000001e
Value 31 = 00000000-0000-0000-0000-00000000001f
Value 32 = 00000000-0000-0000-0000-000000000020

for (int i = 0; i < 33; i++)

{

Debug.WriteLine("Value {0} = {1}", i, i.ToGuid());

}

Debug Trace:

Value 0 = 00000000-0000-0000-0000-000000000000

Value 1 = 00000000-0000-0000-0000-000000000001

Value 2 = 00000000-0000-0000-0000-000000000002

Value 3 = 00000000-0000-0000-0000-000000000003

Value 4 = 00000000-0000-0000-0000-000000000004

Value 5 = 00000000-0000-0000-0000-000000000005

Value 6 = 00000000-0000-0000-0000-000000000006

Value 7 = 00000000-0000-0000-0000-000000000007

Value 8 = 00000000-0000-0000-0000-000000000008

Value 9 = 00000000-0000-0000-0000-000000000009

Value 10 = 00000000-0000-0000-0000-00000000000a

Value 11 = 00000000-0000-0000-0000-00000000000b

Value 12 = 00000000-0000-0000-0000-00000000000c

Value 13 = 00000000-0000-0000-0000-00000000000d

Value 14 = 00000000-0000-0000-0000-00000000000e

Value 15 = 00000000-0000-0000-0000-00000000000f

Value 16 = 00000000-0000-0000-0000-000000000010

Value 17 = 00000000-0000-0000-0000-000000000011

Value 18 = 00000000-0000-0000-0000-000000000012

Value 19 = 00000000-0000-0000-0000-000000000013

Value 20 = 00000000-0000-0000-0000-000000000014

Value 21 = 00000000-0000-0000-0000-000000000015

Value 22 = 00000000-0000-0000-0000-000000000016

Value 23 = 00000000-0000-0000-0000-000000000017

Value 24 = 00000000-0000-0000-0000-000000000018

Value 25 = 00000000-0000-0000-0000-000000000019

Value 26 = 00000000-0000-0000-0000-00000000001a

Value 27 = 00000000-0000-0000-0000-00000000001b

Value 28 = 00000000-0000-0000-0000-00000000001c

Value 29 = 00000000-0000-0000-0000-00000000001d

Value 30 = 00000000-0000-0000-0000-00000000001e

Value 31 = 00000000-0000-0000-0000-00000000001f

Value 32 = 00000000-0000-0000-0000-000000000020

Some additional tests.

Debug.WriteLine("Short Max Value {0} = {1}", short.MaxValue, short.MaxValue.ToGuid());
Debug.WriteLine("Unsigned Short Max Value {0} = {1}", ushort.MaxValue, ushort.MaxValue.ToGuid());

Debug.WriteLine("Int Max Value {0} = {1}", int.MaxValue, int.MaxValue.ToGuid());
Debug.WriteLine("Unsigned Int Max Value {0} = {1}", uint.MaxValue, uint.MaxValue.ToGuid());

Debug.WriteLine("Long Max Value {0} = {1}", long.MaxValue, long.MaxValue.ToGuid());
Debug.WriteLine("Unsigned Long Max Value {0} = {1}", ulong.MaxValue, ulong.MaxValue.ToGuid());

Debug.WriteLine("UTC Date Time Now {0} = {1}", DateTime.UtcNow, DateTime.UtcNow.ToGuid());
Debug.WriteLine("Max Date Time {0} = {1}", DateTime.MaxValue, DateTime.MaxValue.ToGuid());

var value = "Hello World";
Debug.WriteLine("String \"{0}\" = {1}", value, value.ToGuid());

Debug Trace:
Short Max Value 32767 = 00000000-0000-0000-0000-000000007fff
Unsigned Short Max Value 65535 = 00000000-0000-0000-0000-00000000ffff

Int Max Value 2147483647 = 00000000-0000-0000-0000-00007fffffff
Unsigned Int Max Value 4294967295 = 00000000-0000-0000-0000-0000ffffffff

Long Max Value 9223372036854775807 = 00000000-0000-0000-7fff-ffffffffffff
Unsigned Long Max Value 18446744073709551615 = 00000000-0000-0000-ffff-ffffffffffff

UTC Date Time Now 02/07/2015 16:28:26 = 00000000-0000-0000-08d2-110a3bda2d4d
Max Date Time 12/31/9999 23:59:59 = 00000000-0000-0000-2bca-2875f4373fff

String "Hello World" = 00000000-0000-0000-0000-0000541f3ae8

Debug.WriteLine("Short Max Value {0} = {1}", short.MaxValue, short.MaxValue.ToGuid());

Debug.WriteLine("Unsigned Short Max Value {0} = {1}", ushort.MaxValue, ushort.MaxValue.ToGuid());

Debug.WriteLine("Int Max Value {0} = {1}", int.MaxValue, int.MaxValue.ToGuid());

Debug.WriteLine("Unsigned Int Max Value {0} = {1}", uint.MaxValue, uint.MaxValue.ToGuid());

Debug.WriteLine("Long Max Value {0} = {1}", long.MaxValue, long.MaxValue.ToGuid());

Debug.WriteLine("Unsigned Long Max Value {0} = {1}", ulong.MaxValue, ulong.MaxValue.ToGuid());

Debug.WriteLine("UTC Date Time Now {0} = {1}", DateTime.UtcNow, DateTime.UtcNow.ToGuid());

Debug.WriteLine("Max Date Time {0} = {1}", DateTime.MaxValue, DateTime.MaxValue.ToGuid());

var value = "Hello World";

Debug.WriteLine("String \"{0}\" = {1}", value, value.ToGuid());

Debug Trace:

Short Max Value 32767 = 00000000-0000-0000-0000-000000007fff

Unsigned Short Max Value 65535 = 00000000-0000-0000-0000-00000000ffff

Int Max Value 2147483647 = 00000000-0000-0000-0000-00007fffffff

Unsigned Int Max Value 4294967295 = 00000000-0000-0000-0000-0000ffffffff

Long Max Value 9223372036854775807 = 00000000-0000-0000-7fff-ffffffffffff

Unsigned Long Max Value 18446744073709551615 = 00000000-0000-0000-ffff-ffffffffffff

UTC Date Time Now 02/07/2015 16:28:26 = 00000000-0000-0000-08d2-110a3bda2d4d

Max Date Time 12/31/9999 23:59:59 = 00000000-0000-0000-2bca-2875f4373fff

String "Hello World" = 00000000-0000-0000-0000-0000541f3ae8

As you can see there are a lot of leading zeros which opens up the idea of additional methods that could be used to generate upper values. I think I’ll leave that for another post.

Troubleshooting Decoupled OWIN Authorization Server and Resource Server

Extension Methods for Generating GUIDs

Speaking at the Triangle Azure User Group (TriAUG) about API Management on Feb 24