This extension method performs a BinarySearch in a TeaFile file. http://discretelogics.com/teafiles

TeaFileBinarySearch.cs

public static int BinarySearch<T, U>(this TeaFile<T> tf, U target, Func<T, U> indexer) where T : struct
{
    var lo = 0;
    var hi = (int)tf.Count - 1;
    var comp = Comparer<U>.Default;

    while(lo <= hi)
    {
        var median = lo + (hi - lo >> 1);
        var num = comp.Compare(indexer(tf.Items[median]), target);
        if (num == 0)
            return median;
        if (num < 0)
            lo = median + 1;
        else
            hi = median - 1;
    }

    return ~lo;
}