public static byte[]? TryGet(this TrackingMap trackingMap, IReadOnlyStore store, byte[]?key)
{
key ??= Array.Empty <byte>();
if (trackingMap.TryGetValue(key, out var mapValue))
{
return(mapValue.Match <byte[]?>(v => v.ToArray(), _ => null));
}
return(store.TryGet(key));
}
void CommitSnapshot(TrackingMap writeBatchMap)
{
var priorCollection = Volatile.Read(ref trackingMap);
do
{
var updatedCollection = Volatile.Read(ref trackingMap);
foreach (var change in writeBatchMap)
{
updatedCollection = updatedCollection.SetItem(change.Key, change.Value);
}
var interlockedResult = Interlocked.CompareExchange(ref trackingMap, updatedCollection, priorCollection);
if (object.ReferenceEquals(priorCollection, interlockedResult))
{
break;
}
priorCollection = interlockedResult;
}while (true);
}
static void AtomicUpdate(ref TrackingMap trackingMap, byte[]?key, OneOf <byte[]?, None> value)
{
key = key == null?Array.Empty <byte>() : key.AsSpan().ToArray();
var _value = value.Match <OneOf <ReadOnlyMemory <byte>, None> >(
v => v == null ? default(ReadOnlyMemory <byte>) : v.AsSpan().ToArray(),
n => n);
var priorCollection = Volatile.Read(ref trackingMap);
do
{
var updatedCollection = priorCollection.SetItem(key, _value);
var interlockedResult = Interlocked.CompareExchange(ref trackingMap, updatedCollection, priorCollection);
if (object.ReferenceEquals(priorCollection, interlockedResult))
{
break;
}
priorCollection = interlockedResult;
}while (true);
}
public static IEnumerable <(byte[] Key, byte[] Value)> Seek(this TrackingMap trackingMap, IReadOnlyStore store, byte[]?key, SeekDirection direction)
{
key ??= Array.Empty <byte>();
if (key.Length == 0 && direction == SeekDirection.Backward)
{
return(Enumerable.Empty <(byte[] key, byte[] value)>());
}
var comparer = direction == SeekDirection.Forward
? ReadOnlyMemoryComparer.Default
: ReadOnlyMemoryComparer.Reverse;
var memoryItems = trackingMap
.Where(kvp => kvp.Value.IsT0)
.Where(kvp => key.Length == 0 || comparer.Compare(kvp.Key, key) >= 0)
.Select(kvp => (Key: kvp.Key.ToArray(), Value: kvp.Value.AsT0.ToArray()));
var storeItems = store
.Seek(key, direction)
.Where <(byte[] Key, byte[] Value)>(kvp => !trackingMap.ContainsKey(kvp.Key));
return(memoryItems.Concat(storeItems).OrderBy(kvp => kvp.Key, comparer));
}
/// <summary>
/// Edits the specified tracking map id.
/// </summary>
/// <param name="trackingMapId">The tracking map id.</param>
/// <param name="trackingMap">The tracking map.</param>
/// <returns>TrackingMap.</returns>
public TrackingMap Edit(int trackingMapId, TrackingMap trackingMap)
{
return(_trackingMapRepository.Edit(trackingMapId, trackingMap));
}
/// <summary>
/// Creates the specified tracking map.
/// </summary>
/// <param name="trackingMap">The tracking map.</param>
/// <returns><c>true</c> if save success, <c>false</c> otherwise</returns>
public TrackingMap Create(TrackingMap trackingMap)
{
return(_trackingMapRepository.Create(trackingMap));
}
public Snapshot(IReadOnlyStore store, TrackingMap trackingMap, Action <TrackingMap> commitAction)
{
this.store = store;
this.trackingMap = trackingMap;
this.commitAction = commitAction;
}
