/// <summary>
/// Determinate how to load a PersistenceItem.
/// Subclass should override this method to meet its needs.
/// </summary>
/// <param name="item"></param>
/// <returns></returns>
/// /// <see cref="Biu.Serialization.PersistenceDecision"/>
/// <see cref="Biu.Serialization.PersistentItem"/>
public virtual PersistenceDecision MakeLoadingDecision(PersistentItem item)
{
return(new PersistenceDecision()
{
Key = this.Keys.FirstOrDefault(),
Formatter = this.Formatters.FirstOrDefault()
});
}
public override PersistentResult Save(Stream stream, Func <PersistentItem, string> nameItemFile = null)
{
SHA256Managed sha256 = null;
var result = new PersistentResult();
try
{
var partitions = this.Plan.Partition(stream);
for (int i = 0; i < partitions.Count(); i++)
{
var par = partitions.ElementAt(i);
var decision = this.Plan.MakeSavingDecision(par);
var item = new PersistentItem()
{
ItemType = par.ItemType,
StoredType = decision.StoredType,
Significance = decision.Significance,
Order = i
};
item.File = null == nameItemFile ? null : nameItemFile(item);
item.CreateMemoryStream();
if (null == decision.Key)
{
item.IsEncrypted = false;
var buff = new byte[this.BufferSize];
int nRemaining = (int)par.Size;
int nRead = 0;
do
{
nRead = stream.Read(buff, 0, Math.Min(this.BufferSize, nRemaining));
nRemaining -= nRead;
if (0 != nRead)
{
item.Stream.Write(buff, 0, nRead);
}
} while (0 != nRemaining);
if (null == sha256)
{
sha256 = new SHA256Managed();
}
long nPos = item.Stream.Position;
item.Stream.Seek(0L, SeekOrigin.Begin);
item.Hash = sha256.ComputeHash(item.Stream);
item.Stream.Seek(nPos, SeekOrigin.Begin);
}
else
{
item.IsEncrypted = true;
byte[] hash = null;
this.Transform.EncryptStream(stream, item.Stream, decision.Key, (uint)par.Size, ref hash);
item.Hash = hash;
}
item.EnsureData();
if (null != decision.Formatter)
{
decision.Formatter.Serialize(item);
}
if (decision.CloseStreamWhenDone)
{
item.CloseStream();
}
result.Items.Add(item);
}
result.IsSucceeded = true;
}
catch
{
throw;
}
finally
{
if (null != sha256)
{
sha256.Dispose();
sha256 = null;
}
}
return(result);
}
