/// <summary>
/// <para>Deletes an object from the store by version.</para>
/// </summary>
/// <param name="keySpace">
/// <para>The key space of the entry.</para>
/// </param>
/// <param name="key">
/// <para>The key of the entry.</para>
/// </param>
/// <param name="updated">
/// <para>The last updated <see cref="DateTime"/> of the version to be deleted. If the entry's last updated date is not newer than this value, then the entry will be deleted, otherwise not.</para>
/// </param>
/// <returns>
/// <para>
/// <see langword="true"/> if the entry was deleted; otherwise <see langword="false"/>. The entry is deleted if it existed prior and was as old or older than <paramref name="updated"/>.</para>
/// </returns>
public bool DeleteVersion(DataBuffer keySpace, StorageKey key, DateTime updated)
{
using (var item = StreamPool.GetItem())
{
var stream = item.Item;
if (stream.Capacity < sizeof(long))
{
stream.Capacity = sizeof(long);
}
var buffer = GetReadBuffer(stream);
buffer = buffer.Restrict(sizeof(long));
var len = Storage.Get(keySpace, key, sizeof(long), buffer);
if (len < 0)
{
return(false);
}
var seg = buffer.ByteArraySegmentValue;
var ticks = BitConverter.ToInt64(seg.Array, seg.Offset);
var entryUpdated = new DateTime(ticks);
if (entryUpdated <= updated)
{
return(Storage.Delete(keySpace, key));
}
return(false);
}
}
/// <summary>
/// <para>Reads an object from the store.</para>
/// </summary>
/// <typeparam name="T">
/// <para>The type of the object.</para>
/// </typeparam>
/// <param name="keySpace">
/// <para>The key space of the entry.</para>
/// </param>
/// <param name="key">
/// <para>The key of the entry.</para>
/// </param>
/// <param name="creator">
/// <para>Delegate that provides an empty instance for
/// deserialization.</para>
/// </param>
/// <returns>
/// <para>A <see cref="StorageEntry{T}"/> containing the entry.</para>
/// </returns>
public StorageEntry <T> Get <T>(DataBuffer keySpace, StorageKey key, Func <T> creator)
{
if (Storage.StreamsData)
{
var data = Storage.GetBuffer(keySpace, key);
if (data == null)
{
return(StorageEntry <T> .NotFound);
}
DataBuffer buffer = data;
using (var stream = new MemoryStream(data, false))
{
return(GetCore(buffer, stream, creator()));
}
}
else
{
using (var item = StreamPool.GetItem())
{
DataBuffer buffer;
var stream = GetStream(item, keySpace, key, out buffer);
if (stream == null)
{
return(StorageEntry <T> .NotFound);
}
return(GetCore(buffer, stream, creator()));
}
}
}
/// <summary>
/// <para>Writes an object to the store.</para>
/// </summary>
/// <typeparam name="T">
/// <para>The type of the object.</para>
/// </typeparam>
/// <param name="keySpace">
/// <para>The key space of the entry.</para>
/// </param>
/// <param name="key">
/// <para>The key of the entry.</para>
/// </param>
/// <param name="entry">
/// <para>The entry to write.</para>
/// </param>
public void Put <T>(DataBuffer keySpace, StorageKey key, StorageEntry <T> entry)
{
AddKeySpaceInfo <T>(keySpace);
using (var item = StreamPool.GetItem())
{
var stream = item.Item;
stream.Write(BitConverter.GetBytes(entry.Expires.Ticks), 0, sizeof(long));
stream.Write(BitConverter.GetBytes(entry.Updated.Ticks), 0, sizeof(long));
Serializer.Serialize(stream, entry.Instance);
Storage.Put(keySpace, key, GetWriteBuffer(stream));
}
}
/// <summary>
/// <para>Gets the expiration time of an object.</para>
/// </summary>
/// <param name="keySpace">
/// <para>The key space of the entry.</para>
/// </param>
/// <param name="key">
/// <para>The key of the entry.</para>
/// </param>
/// <returns>
/// <para>A <see cref="Nullable{DateTime}"/> containing the expiration time if found; otherwise <see langword="null"/>.</para>
/// </returns>
public DateTime?GetExpires(DataBuffer keySpace, StorageKey key)
{
using (var item = StreamPool.GetItem())
{
var stream = item.Item;
if (stream.Capacity < sizeof(long))
{
stream.Capacity = sizeof(long);
}
var buffer = GetReadBuffer(stream);
buffer = buffer.Restrict(sizeof(long));
var len = Storage.Get(keySpace, key, 0, buffer);
if (len < 0)
{
return(null);
}
var seg = buffer.ByteArraySegmentValue;
var ticks = BitConverter.ToInt64(seg.Array, seg.Offset);
return(new DateTime(ticks));
}
}