public async Task SaveAsync(TKey key, TEntity entity)
{
var name = this.GetName(key);
try
{
// This is fast and allows to have git-style subfolders in atomic strategy
// to avoid NTFS performance degradation (when there are more than
// 10000 files per folder). Kudos to Gabriel Schenker for pointing this out
var subfolder = Path.GetDirectoryName(name);
if (subfolder != null && !Directory.Exists(subfolder))
{
Directory.CreateDirectory(subfolder);
}
// we are locking this file.
using (var file = File.Open(name, FileMode.Create, FileAccess.ReadWrite, FileShare.None))
// some serializers have nasty habbit of closing the
// underling stream
using (var mem = new MemoryStream())
{
this._strategy.Serialize(entity, mem);
var data = mem.ToArray();
StorageProfiler.CountWriteRequest(name);
// upload only if we changed
await file.WriteAsync(data, 0, data.Length);
// truncate this file
file.SetLength(data.Length);
}
}
catch (DirectoryNotFoundException)
{
var s = string.Format(
"Container '{0}' does not exist.",
this._folder);
throw new InvalidOperationException(s);
}
}
public async Task <TEntity> AddOrUpdateAsync(TKey key, Func <TEntity> addFactory, Func <TEntity, TEntity> update, AddOrUpdateHint hint = AddOrUpdateHint.ProbablyExists)
{
var name = this.GetName(key);
try
{
// This is fast and allows to have git-style subfolders in atomic strategy
// to avoid NTFS performance degradation (when there are more than
// 10000 files per folder). Kudos to Gabriel Schenker for pointing this out
var subfolder = Path.GetDirectoryName(name);
if (subfolder != null && !Directory.Exists(subfolder))
{
Directory.CreateDirectory(subfolder);
}
// we are locking this file.
using (var file = File.Open(name, FileMode.OpenOrCreate, FileAccess.ReadWrite, FileShare.None))
{
var initial = new byte[0];
TEntity result;
if (file.Length == 0)
{
result = addFactory();
}
else
{
using (var mem = new MemoryStream())
{
StorageProfiler.CountReadRequest(name);
await file.CopyToAsync(mem);
mem.Seek(0, SeekOrigin.Begin);
var entity = this._strategy.Deserialize <TEntity>(mem);
initial = mem.ToArray();
result = update(entity);
}
}
// some serializers have nasty habbit of closing the
// underling stream
using (var mem = new MemoryStream())
{
this._strategy.Serialize(result, mem);
var data = mem.ToArray();
if (!data.SequenceEqual(initial))
{
StorageProfiler.CountWriteRequest(name);
// upload only if we changed
file.Seek(0, SeekOrigin.Begin);
await file.WriteAsync(data, 0, data.Length);
// truncate this file
file.SetLength(data.Length);
}
}
return(result);
}
}
catch (DirectoryNotFoundException)
{
var s = string.Format(
"Container '{0}' does not exist.",
this._folder);
throw new InvalidOperationException(s);
}
}