Entity hashing helper
Get Started
$ dotnet add package SimpleHasherReadme
Hasher
Simple Hashing helper for entities. Default behaviour calculates the HashCode for all public properties.
HasherIncludeAttribute can be used to include non-public ones.
HasherExcludeAttribute can be used to exclude public ones.
Usage
Normal
using Hasher;
public class Entity
{
public int Property1 { get; set; }
public int Property2 { set => Console.Write(value); } // Skipped
private int Property3 { get; set; } // Skipped
[HasherInclude] private int Property4 { get; set; }
[HasherExclude] public int Property5 { get; set; } // Skipped
}
var entity = new Entity();
var hashCode = entity.ResolveHash();
Async
using Hasher;
public class EntityWithTasks
{
public Task<int> Property1 { get; set; } // Will await this value
public int Property2 { set => Console.Write(value); } // Skipped
private int Property3 { get; set; } // Skipped
[HasherInclude] private int Property4 { get; set; }
[HasherExclude] public int Property5 { get; set; } // Skipped
}
var entity = new EntityWithTasks();
var hashCode = await entity.ResolveHashAsync();
By using ResolveHashAsync we will get the HashCode of the actual Task value, if any, instead of the Task's HashCode.
As a service
serviceCollection.AddHasher();
...
public class MyService
{
private readonly IHasher _hasher;
public MyService(IHasher hasher)
{
_hasher = hasher;
}
public void DoWork<T>(T value)
{
var hash = _hasher.ResolveHash(value);
}
}
Null
Returns 0 for null values.
using Hasher;
string nullString = null;
var hashCode = nullString.ResolveHash(); // == 0
Nested vs Top Level Only
You can enable nested calculations during registration using:
serviceCollection.AddHasher(o => o.EnableNestedHashes());
Custom Mappings
Custom mappings are allowed for certain types. You can configure your mappings using:
serviceCollection.AddHasher(o => o.Register<string>(x => x.Length, x => x.Count(s => s == 's'), x => x.Count(s => s == 'd'))
.Register<Entity>(x => x.Property1, x => x.Property2));
This, obviously, only works when using the injected service (IHashService). Simpler mapping has been supplied for the extension methods by using the HasherConfiguration attribute which offers support for top level property names:
[HasherConfiguration(nameof(MyProperty1), nameof(MyProperty3))]
public class MyClass3
{
public int MyProperty1 { get; set; }
public int MyProperty2 { get; set; } // Skipped
public int MyProperty3 { get; set; }
}