/// <summary>
/// Removes the data at the specified key location.
/// </summary>
/// <param name="key">The key.</param>
public void Remove(TKey key)
{
try
{
writeLock.Enter();
HashtableNode <TKey, TData>[] table = array;
var initialHash = Math.Abs(GetHashCode_HashTable <TKey> .GetHashCode(key)) % table.Length;
var hash = initialHash;
do
{
HashtableNode <TKey, TData> n = table[hash];
if (n.Token == HashtableToken.Empty)
{
return;
}
if (n.Token == HashtableToken.Deleted || !KeyComparer.Equals(key, n.Key))
{
hash = (hash + 1) % table.Length;
}
else
{
table[hash] = DeletedNode;
}
} while (hash != initialHash); // MartinG@DigitalRune: Stop when all entries are checked!
}
finally
{
writeLock.Exit();
}
}
private bool Find(TKey key, out HashtableNode <TKey, TData> node)
{
node = new HashtableNode <TKey, TData>();
var table = array;
var initialHash = Math.Abs(GetHashCode_HashTable <TKey> .GetHashCode(key)) % table.Length;
var hash = initialHash;
do
{
HashtableNode <TKey, TData> n = table[hash];
if (n.Token == HashtableToken.Empty)
{
return(false);
}
if (n.Token == HashtableToken.Deleted || !KeyComparer.Equals(key, n.Key))
{
hash = (hash + 1) % table.Length;
}
else
{
node = n;
return(true);
}
} while (hash != initialHash);
return(false);
}
private bool Insert(HashtableNode <TKey, TData>[] table, TKey key, TData data)
{
var initialHash = Math.Abs(GetHashCode_HashTable <TKey> .GetHashCode(key)) % table.Length;
var hash = initialHash;
bool inserted = false;
do
{
var node = table[hash];
// if node is empty, or marked with a tombstone
if (node.Token == HashtableToken.Empty || node.Token == HashtableToken.Deleted || KeyComparer.Equals(key, node.Key))
{
table[hash] = new HashtableNode <TKey, TData>()
{
Key = key,
Data = data,
Token = HashtableToken.Used
};
inserted = true;
break;
}
else
{
hash = (hash + 1) % table.Length;
}
} while (hash != initialHash);
return(inserted);
}
/// <summary>
/// Sets the value of the item at the specified key location.
/// This is only guaranteed to work correctly if no other thread is modifying the same key.
/// </summary>
/// <param name="key">The key.</param>
/// <param name="value">The new value.</param>
public void UnsafeSet(TKey key, TData value)
{
HashtableNode <TKey, TData>[] table;
bool inserted = false;
do
{
table = array;
var initialHash = Math.Abs(GetHashCode_HashTable <TKey> .GetHashCode(key)) % table.Length;
var hash = initialHash;
do
{
var node = table[hash];
if (KeyComparer.Equals(key, node.Key))
{
table[hash] = new HashtableNode <TKey, TData>()
{
Key = key,
Data = value,
Token = HashtableToken.Used
};
inserted = true;
break;
}
else
{
hash = (hash + 1) % table.Length;
}
} while (hash != initialHash);
} while (table != array);
// MartinG@DigitalRune: I have moved the Add() outside the loop because it uses a
// write-lock and the loop above should run without locks.
if (!inserted)
{
Add(key, value);
}
}