/// <summary>
///
/// </summary>
/// <param name="keys"></param>
/// <param name="hash"></param>
/// <returns></returns>
/// <remarks>If any of the keys are null or empty, the method will return false.</remarks>
public static bool TryCreate(string[] keys, out PerfectHash hash)
{
if (keys == null)
{
throw new ArgumentNullException(nameof(keys));
}
int[] codes = new int[keys.Length];
for (int i = 0; i < codes.Length; i++)
{
var key = keys[i];
if (string.IsNullOrEmpty(key))
{
hash = default;
return(false);
}
codes[i] = ComputeCode(key);
}
if (AreUnique(codes, out int min, out int max))
{
var size = max - min + 1;
if (size < 256 * 256) // TODO: isn't it too large?
{
hash = new PerfectHash(min, size);
return(true);
}
}
hash = default;
return(false);
}
private PerfectHashStore(PerfectHash hash, IReadOnlyDictionary <string, object> properties)
{
_hash = hash;
_values = new object[_hash.Size];
foreach (var property in properties)
{
var index = _hash.ComputeHash(property.Key);
_values[index] = property.Value;
}
}
public static PropertyStore Create(IReadOnlyDictionary <string, object> properties)
{
var names = new string[properties.Count];
int i = 0;
foreach (var property in properties)
{
names[i++] = property.Key;
}
if (PerfectHash.TryCreate(names, out var hash))
{
return(new PerfectHashStore(hash, properties));
}
// TODO: this should log very time a non-perfect store is created
return(new DictionaryStore(properties));
}