public async Task Test_Can_MergeSort()
{
int K = 3;
int N = 100;
using (var db = await OpenTestPartitionAsync())
{
var location = await GetCleanDirectory(db, "Queries", "MergeSort");
// clear!
await db.ClearRangeAsync(location, this.Cancellation);
// create K lists
var lists = Enumerable.Range(0, K).Select(i => location.Partition.ByKey(i)).ToArray();
// lists[0] contains all multiples of K ([0, 0], [K, 1], [2K, 2], ...)
// lists[1] contains all multiples of K, offset by 1 ([1, 0], [K+1, 1], [2K+1, 2], ...)
// lists[k-1] contains all multiples of K, offset by k-1 ([K-1, 0], [2K-1, 1], [3K-1, 2], ...)
// more generally: lists[k][i] = (..., MergeSort, k, (i * K) + k) = (k, i)
for (int k = 0; k < K; k++)
{
using (var tr = db.BeginTransaction(this.Cancellation))
{
for (int i = 0; i < N; i++)
{
tr.Set(lists[k].Keys.Encode((i * K) + k), FdbTuple.EncodeKey(k, i));
}
await tr.CommitAsync();
}
}
// MergeSorting all lists together should produce all integers from 0 to (K*N)-1, in order
// we use the last part of the key for sorting
using (var tr = db.BeginTransaction(this.Cancellation))
{
var merge = tr.MergeSort(
lists.Select(list => FdbKeySelectorPair.Create(list.Keys.ToRange())),
kvp => location.Keys.DecodeLast <int>(kvp.Key)
);
Assert.That(merge, Is.Not.Null);
Assert.That(merge, Is.InstanceOf <FdbMergeSortIterator <KeyValuePair <Slice, Slice>, int, KeyValuePair <Slice, Slice> > >());
var results = await merge.ToListAsync();
Assert.That(results, Is.Not.Null);
Assert.That(results.Count, Is.EqualTo(K * N));
for (int i = 0; i < K * N; i++)
{
Assert.That(location.ExtractKey(results[i].Key), Is.EqualTo(FdbTuple.EncodeKey(i % K, i)));
Assert.That(results[i].Value, Is.EqualTo(FdbTuple.EncodeKey(i % K, i / K)));
}
}
}
}
public async Task Test_Range_Except()
{
int K = 3;
int N = 100;
using (var db = await OpenTestPartitionAsync())
{
// get a clean new directory
var location = await GetCleanDirectory(db, "Queries", "Except");
// create K lists
var lists = Enumerable.Range(0, K).Select(i => location.Partition.ByKey(i)).ToArray();
// lists[0] contains all multiples of 1
// lists[1] contains all multiples of 2
// lists[k-1] contains all multiples of K
// more generally: lists[k][i] = (..., Intersect, k, i * (k + 1)) = (k, i)
var series = Enumerable.Range(1, K).Select(k => Enumerable.Range(1, N).Select(x => k * x).ToArray()).ToArray();
//foreach(var serie in series)
//{
// Console.WriteLine(String.Join(", ", serie));
//}
for (int k = 0; k < K; k++)
{
//Console.WriteLine("> k = " + k);
using (var tr = db.BeginTransaction(this.Cancellation))
{
for (int i = 0; i < N; i++)
{
var key = lists[k].Keys.Encode(series[k][i]);
var value = FdbTuple.EncodeKey(k, i);
//Console.WriteLine("> " + key + " = " + value);
tr.Set(key, value);
}
await tr.CommitAsync();
}
}
// Intersect all lists together should produce all integers that are prime numbers
IEnumerable <int> xs = series[0];
for (int i = 1; i < K; i++)
{
xs = xs.Except(series[i]);
}
var expected = xs.ToArray();
Log("Expected: {0}", String.Join(", ", expected));
using (var tr = db.BeginTransaction(this.Cancellation))
{
var merge = tr.Except(
lists.Select(list => FdbKeySelectorPair.Create(list.Keys.ToRange())),
kvp => location.Keys.DecodeLast <int>(kvp.Key)
);
Assert.That(merge, Is.Not.Null);
Assert.That(merge, Is.InstanceOf <FdbExceptIterator <KeyValuePair <Slice, Slice>, int, KeyValuePair <Slice, Slice> > >());
var results = await merge.ToListAsync();
Assert.That(results, Is.Not.Null);
Assert.That(results.Count, Is.EqualTo(expected.Length));
for (int i = 0; i < results.Count; i++)
{
Assert.That(location.Keys.DecodeLast <int>(results[i].Key), Is.EqualTo(expected[i]));
}
}
}
}
