public static bool Exists(Tx tx, byte[] key)
{
using (var cursor = tx.CreateCursor()) {
var exists = cursor.MoveTo(key);
return(exists);
}
}
static IEnumerable <TOut> InternalScan <TOut>(Tx tx, byte[] key,
Func <Slice, byte[], TOut> convert, string traceName, int skip = 0)
{
tx.TraceStart(traceName);
ushort x = 0;
var slice = Slice.Create(key);
var range = FdbKeyRange.StartsWith(slice);
using (var c = tx.CreateCursor()) {
if (!c.MoveToFirstAfter(key))
{
tx.TraceStop(traceName, x);
yield break;
}
var pair = c.Current;
for (var i = 0; i < int.MaxValue; i++)
{
var current = Slice.Create(pair.Key);
if (!range.Contains(current))
{
tx.TraceStop(traceName, x);
break;
}
if (i >= skip)
{
x += 1;
yield return(convert(current, pair.Value));
}
if (!c.MoveNext())
{
tx.TraceStop(traceName, x);
break;
}
pair = c.Current;
}
}
}
public static void DeleteRange(Tx tx, byte[] key, string traceName)
{
tx.TraceStart(traceName);
ushort x = 0;
var slice = Slice.Create(key);
var range = FdbKeyRange.StartsWith(slice);
using (var c = tx.CreateCursor()) {
if (!c.MoveToFirstAfter(key))
{
tx.TraceStop(traceName, x);
return;
}
var pair = c.Current;
for (var i = 0; i < int.MaxValue; i++)
{
var current = Slice.Create(pair.Key);
if (!range.Contains(current))
{
tx.TraceStop(traceName, x);
break;
}
x += 1;
tx.Delete(pair.Key);
if (!c.MoveNext())
{
tx.TraceStop(traceName, x);
break;
}
pair = c.Current;
}
}
tx.TraceStop(traceName);
}