public static void Set <T>(Tx tx, byte[] key, T dto)
{
using (var mem = new MemoryStream()) {
Serializer.Serialize(mem, dto);
tx.Put(key, mem.ToArray());
}
}
public static bool Exists(Tx tx, byte[] key)
{
using (var cursor = tx.CreateCursor()) {
var exists = cursor.MoveTo(key);
return(exists);
}
}
public static IEnumerable <KeyValuePair <TKey, ulong> > ScanUInt64 <TKey>(Tx tx, byte[] key,
Func <IFdbTuple, TKey> keygen, string traceName, int skip = 0)
{
return(InternalScan(tx, key, (slice, bytes) => {
var value = Slice.Create(bytes).ToUInt64();
var k = keygen(FdbTuple.Unpack(slice));
return new KeyValuePair <TKey, ulong>(k, value);
}, traceName, skip));
}
public static long GetValueAsInt64(Tx tx, byte[] key, long defaultValue = 0)
{
var data = tx.Get(key);
if (data == null)
{
return(defaultValue);
}
return(Slice.Create(data).ToInt64());
}
public static IEnumerable <KeyValuePair <TKey, TValue> > Scan <TKey, TValue>(Tx tx, byte[] key,
Func <IFdbTuple, TKey> keygen, string traceName, int skip = 0)
{
return(InternalScan(tx, key, (slice, bytes) => {
using (var mem = new MemoryStream(bytes)) {
var value = Serializer.Deserialize <TValue>(mem);
var k = keygen(FdbTuple.Unpack(slice));
return new KeyValuePair <TKey, TValue>(k, value);
}
}, traceName, skip));
}
public static T GetOrDefault <T>(Tx tx, byte[] key, T defaultValue = default(T))
{
var data = tx.Get(key);
if (data == null)
{
return(defaultValue);
}
using (var mem = new MemoryStream(data)) {
return(Serializer.Deserialize <T>(mem));
}
}
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);
}
public Tx Read()
{
return(Tx.StartRead(_env, _db));
}
public Tx Write()
{
return(Tx.StartWrite(_env, _db));
}
public static IEnumerable <TKey> ScanKeys <TKey>(Tx tx, byte[] key, Func <IFdbTuple, TKey> keygen,
string traceName, int skip = 0)
{
return(InternalScan(tx, key, (slice, bytes) => keygen(FdbTuple.Unpack(slice)), traceName, skip));
}
public static void SetEmpty(Tx tx, byte[] key)
{
tx.Put(key, EmptyBuffer);
}
public static void SetValue(Tx tx, byte[] key, long value)
{
tx.Put(key, Slice.FromInt64(value).GetBytes());
}
public static void Delete(Tx tx, byte[] key)
{
tx.TraceStart("Delete");
tx.Delete(key);
tx.TraceStop("Delete");
}
