Question

I have a table in the DB with two columns, roles and permissions that looks like this:

role – permission
user – addItem
admin – removeItem
admin – advancedSearch
guest – simpleSearch
user – editItem
manager – editUser
…etc.

I need to store these in the .net’s cache so that I can check if a permission exists for a specific role.

(Here’s the psuedo-code)

if ("permission" is in Cache["role"]) // Authorize access

But how do I add and store them in the Cache for best result?

In PHP I’d do something like this I guess:

array ( "user"  => array ( "addItem", "editItem"),
        "admin"  => array ( "removeItem", "advancedSearch"),
         ....

Is there an equivalent or better/faster way in C#?

Thanks!
/Niklas

Answer 1

Maybe something like a Dictionary<string, HashSet<string>>?

For example:

var pairs = new[] { 
    new{Role="user",Permission="addItem"},
    new{Role="admin",Permission="removeItem"},
    new{Role="admin",Permission="advancedSearch"},
    new{Role="guest",Permission="simpleSearch"},
    new{Role="user",Permission="addItem"},
    new{Role="manager",Permission="editUser"},
};
Dictionary<string, HashSet<string>> cache = pairs.GroupBy(pair => pair.Role)
    .ToDictionary(grp => grp.Key, grp => new HashSet<string>(
          grp.Select(g => g.Permission)));
cache["user"].Contains("addItem");

---

Or if reading from a data-reader (comment):

var cache = new Dictionary<string, HashSet<string>>();
using (var reader = GetReader()) {
    while (reader.Read()){
        string role = reader.GetString(0),
            permission = reader.GetString(1);
        HashSet<string> permissions;
        if (!cache.TryGetValue(role, out permissions)){
            cache.Add(role, permissions = new HashSet<string>());
        }
        permissions.Add(permission);
    }
}