public void Test_Subspace_With_Binary_Prefix()
{
var subspace = new FdbSubspace(Slice.Create(new byte[] { 42, 255, 0, 127 }));
Assert.That(subspace.Key.ToString(), Is.EqualTo("*<FF><00><7F>"));
Assert.That(subspace.Copy(), Is.Not.SameAs(subspace));
Assert.That(subspace.Copy().Key, Is.EqualTo(subspace.Key));
// concat(Slice) should append the slice to the binary prefix directly
Assert.That(subspace.Concat(Slice.FromInt32(0x01020304)).ToString(), Is.EqualTo("*<FF><00><7F><04><03><02><01>"));
Assert.That(subspace.Concat(Slice.FromAscii("hello")).ToString(), Is.EqualTo("*<FF><00><7F>hello"));
// pack(...) should use tuple serialization
Assert.That(subspace.Pack(123).ToString(), Is.EqualTo("*<FF><00><7F><15>{"));
Assert.That(subspace.Pack("hello").ToString(), Is.EqualTo("*<FF><00><7F><02>hello<00>"));
Assert.That(subspace.Pack(Slice.FromAscii("world")).ToString(), Is.EqualTo("*<FF><00><7F><01>world<00>"));
Assert.That(subspace.Pack(FdbTuple.Create("hello", 123)).ToString(), Is.EqualTo("*<FF><00><7F><02>hello<00><15>{"));
// if we derive a tuple from this subspace, it should keep the binary prefix when converted to a key
var t = subspace.Append("world", 123, false);
Assert.That(t, Is.Not.Null);
Assert.That(t.Count, Is.EqualTo(3));
Assert.That(t.Get <string>(0), Is.EqualTo("world"));
Assert.That(t.Get <int>(1), Is.EqualTo(123));
Assert.That(t.Get <bool>(2), Is.False);
var k = t.ToSlice();
Assert.That(k.ToString(), Is.EqualTo("*<FF><00><7F><02>world<00><15>{<14>"));
// if we unpack the key with the binary prefix, we should get a valid tuple
var t2 = subspace.Unpack(k);
Assert.That(t2, Is.Not.Null);
Assert.That(t2.Count, Is.EqualTo(3));
Assert.That(t2.Get <string>(0), Is.EqualTo("world"));
Assert.That(t2.Get <int>(1), Is.EqualTo(123));
Assert.That(t2.Get <bool>(2), Is.False);
}
public void Test_Subspace_With_Tuple_Prefix()
{
var subspace = new FdbSubspace(FdbTuple.Create("hello"));
Assert.That(subspace.Key.ToString(), Is.EqualTo("<02>hello<00>"));
Assert.That(subspace.Copy(), Is.Not.SameAs(subspace));
Assert.That(subspace.Copy().Key, Is.EqualTo(subspace.Key));
// concat(Slice) should append the slice to the tuple prefix directly
Assert.That(subspace.Concat(Slice.FromInt32(0x01020304)).ToString(), Is.EqualTo("<02>hello<00><04><03><02><01>"));
Assert.That(subspace.Concat(Slice.FromAscii("world")).ToString(), Is.EqualTo("<02>hello<00>world"));
// pack(...) should use tuple serialization
Assert.That(subspace.Pack(123).ToString(), Is.EqualTo("<02>hello<00><15>{"));
Assert.That(subspace.Pack("world").ToString(), Is.EqualTo("<02>hello<00><02>world<00>"));
// even though the subspace prefix is a tuple, appending to it will only return the new items
var t = subspace.Append("world", 123, false);
Assert.That(t, Is.Not.Null);
Assert.That(t.Count, Is.EqualTo(3));
Assert.That(t.Get <string>(0), Is.EqualTo("world"));
Assert.That(t.Get <int>(1), Is.EqualTo(123));
Assert.That(t.Get <bool>(2), Is.False);
// but ToSlice() should include the prefix
var k = t.ToSlice();
Assert.That(k.ToString(), Is.EqualTo("<02>hello<00><02>world<00><15>{<14>"));
// if we unpack the key with the binary prefix, we should get a valid tuple
var t2 = subspace.Unpack(k);
Assert.That(t2, Is.Not.Null);
Assert.That(t2.Count, Is.EqualTo(3));
Assert.That(t2.Get <string>(0), Is.EqualTo("world"));
Assert.That(t2.Get <int>(1), Is.EqualTo(123));
Assert.That(t2.Get <bool>(2), Is.False);
}
private async Task PushQueueAsync(IFdbTransaction tr, FdbSubspace queue, Slice taskId)
{
//TODO: use a high contention algo ?
// - must support Push and Pop
// - an empty queue must correspond to an empty subspace
// get the current size of the queue
var range = queue.ToRange();
var lastKey = await tr.Snapshot.GetKeyAsync(FdbKeySelector.LastLessThan(range.End)).ConfigureAwait(false);
int count = lastKey < range.Begin ? 0 : queue.Unpack(lastKey).Get <int>(0) + 1;
// set the value
tr.Set(queue.Pack(count, GetRandomId()), taskId);
}
public void Test_Subspace_With_Binary_Prefix()
{
var subspace = new FdbSubspace(Slice.Create(new byte[] { 42, 255, 0, 127 }));
Assert.That(subspace.Key.ToString(), Is.EqualTo("*<FF><00><7F>"));
Assert.That(subspace.Copy(), Is.Not.SameAs(subspace));
Assert.That(subspace.Copy().Key, Is.EqualTo(subspace.Key));
// concat(Slice) should append the slice to the binary prefix directly
Assert.That(subspace.Concat(Slice.FromInt32(0x01020304)).ToString(), Is.EqualTo("*<FF><00><7F><04><03><02><01>"));
Assert.That(subspace.Concat(Slice.FromAscii("hello")).ToString(), Is.EqualTo("*<FF><00><7F>hello"));
// pack(...) should use tuple serialization
Assert.That(subspace.Pack(123).ToString(), Is.EqualTo("*<FF><00><7F><15>{"));
Assert.That(subspace.Pack("hello").ToString(), Is.EqualTo("*<FF><00><7F><02>hello<00>"));
Assert.That(subspace.Pack(Slice.FromAscii("world")).ToString(), Is.EqualTo("*<FF><00><7F><01>world<00>"));
Assert.That(subspace.Pack(FdbTuple.Create("hello", 123)).ToString(), Is.EqualTo("*<FF><00><7F><02>hello<00><15>{"));
// if we derive a tuple from this subspace, it should keep the binary prefix when converted to a key
var t = subspace.Append("world", 123, false);
Assert.That(t, Is.Not.Null);
Assert.That(t.Count, Is.EqualTo(3));
Assert.That(t.Get<string>(0), Is.EqualTo("world"));
Assert.That(t.Get<int>(1), Is.EqualTo(123));
Assert.That(t.Get<bool>(2), Is.False);
var k = t.ToSlice();
Assert.That(k.ToString(), Is.EqualTo("*<FF><00><7F><02>world<00><15>{<14>"));
// if we unpack the key with the binary prefix, we should get a valid tuple
var t2 = subspace.Unpack(k);
Assert.That(t2, Is.Not.Null);
Assert.That(t2.Count, Is.EqualTo(3));
Assert.That(t2.Get<string>(0), Is.EqualTo("world"));
Assert.That(t2.Get<int>(1), Is.EqualTo(123));
Assert.That(t2.Get<bool>(2), Is.False);
}
private async Task <KeyValuePair <Slice, Slice> > FindRandomItem(IFdbTransaction tr, FdbSubspace ring)
{
var range = ring.ToRange();
// start from a random position around the ring
Slice key = ring.Pack(GetRandomId());
// We want to find the next item in the clockwise direction. If we reach the end of the ring, we "wrap around" by starting again from the start
// => So we do find_next(key <= x < MAX) and if that does not produce any result, we do a find_next(MIN <= x < key)
// When the ring only contains a few items (or is empty), there is more than 50% change that we wont find anything in the first read.
// To reduce the latency for this case, we will issue both range reads at the same time, and discard the second one if the first returned something.
// This should reduce the latency in half when the ring is empty, or when it contains only items before the random key.
var candidate = await tr.GetRange(key, range.End).FirstOrDefaultAsync();
if (!candidate.Key.IsPresent)
{
candidate = await tr.GetRange(range.Begin, key).FirstOrDefaultAsync();
}
return(candidate);
}
private async Task PushQueueAsync(IFdbTransaction tr, FdbSubspace queue, Slice taskId)
{
//TODO: use a high contention algo ?
// - must support Push and Pop
// - an empty queue must correspond to an empty subspace
// get the current size of the queue
var range = queue.ToRange();
var lastKey = await tr.Snapshot.GetKeyAsync(FdbKeySelector.LastLessThan(range.End)).ConfigureAwait(false);
int count = lastKey < range.Begin ? 0 : queue.Unpack(lastKey).Get<int>(0) + 1;
// set the value
tr.Set(queue.Pack(count, GetRandomId()), taskId);
}
private async Task<KeyValuePair<Slice, Slice>> FindRandomItem(IFdbTransaction tr, FdbSubspace ring)
{
var range = ring.ToRange();
// start from a random position around the ring
Slice key = ring.Pack(GetRandomId());
// We want to find the next item in the clockwise direction. If we reach the end of the ring, we "wrap around" by starting again from the start
// => So we do find_next(key <= x < MAX) and if that does not produce any result, we do a find_next(MIN <= x < key)
// When the ring only contains a few items (or is empty), there is more than 50% change that we wont find anything in the first read.
// To reduce the latency for this case, we will issue both range reads at the same time, and discard the second one if the first returned something.
// This should reduce the latency in half when the ring is empty, or when it contains only items before the random key.
var candidate = await tr.GetRange(key, range.End).FirstOrDefaultAsync();
if (!candidate.Key.IsPresent)
{
candidate = await tr.GetRange(range.Begin, key).FirstOrDefaultAsync();
}
return candidate;
}
private static Slice GetSubDirKey(FdbSubspace parent, string path)
{
Contract.Requires(parent != null && path != null);
// for a path equal to ("foo","bar","baz") and index = -1, we need to generate (parent, SUBDIRS, "baz")
// but since the last item of path can be of any type, we will use tuple splicing to copy the last item without changing its type
return parent.Pack(SUBDIRS, path);
}
public void Test_Subspace_With_Tuple_Prefix()
{
var subspace = new FdbSubspace(FdbTuple.Create("hello"));
Assert.That(subspace.Key.ToString(), Is.EqualTo("<02>hello<00>"));
Assert.That(subspace.Copy(), Is.Not.SameAs(subspace));
Assert.That(subspace.Copy().Key, Is.EqualTo(subspace.Key));
// concat(Slice) should append the slice to the tuple prefix directly
Assert.That(subspace.Concat(Slice.FromInt32(0x01020304)).ToString(), Is.EqualTo("<02>hello<00><04><03><02><01>"));
Assert.That(subspace.Concat(Slice.FromAscii("world")).ToString(), Is.EqualTo("<02>hello<00>world"));
// pack(...) should use tuple serialization
Assert.That(subspace.Pack(123).ToString(), Is.EqualTo("<02>hello<00><15>{"));
Assert.That(subspace.Pack("world").ToString(), Is.EqualTo("<02>hello<00><02>world<00>"));
// even though the subspace prefix is a tuple, appending to it will only return the new items
var t = subspace.Append("world", 123, false);
Assert.That(t, Is.Not.Null);
Assert.That(t.Count, Is.EqualTo(3));
Assert.That(t.Get<string>(0), Is.EqualTo("world"));
Assert.That(t.Get<int>(1), Is.EqualTo(123));
Assert.That(t.Get<bool>(2), Is.False);
// but ToSlice() should include the prefix
var k = t.ToSlice();
Assert.That(k.ToString(), Is.EqualTo("<02>hello<00><02>world<00><15>{<14>"));
// if we unpack the key with the binary prefix, we should get a valid tuple
var t2 = subspace.Unpack(k);
Assert.That(t2, Is.Not.Null);
Assert.That(t2.Count, Is.EqualTo(3));
Assert.That(t2.Get<string>(0), Is.EqualTo("world"));
Assert.That(t2.Get<int>(1), Is.EqualTo(123));
Assert.That(t2.Get<bool>(2), Is.False);
}
private static void SetLayer(IFdbTransaction trans, FdbSubspace subspace, Slice layer)
{
if (layer.IsNull) layer = Slice.Empty;
trans.Set(subspace.Pack(LayerSuffix), layer);
}