jellyfin-server/MediaBrowser.Server.Implementations/Sync/TargetDataProvider.cs
2015-03-10 14:10:38 -04:00

244 lines
7.9 KiB
C#

using MediaBrowser.Common.Configuration;
using MediaBrowser.Common.Extensions;
using MediaBrowser.Common.IO;
using MediaBrowser.Controller.Sync;
using MediaBrowser.Model.Logging;
using MediaBrowser.Model.Serialization;
using MediaBrowser.Model.Sync;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
namespace MediaBrowser.Server.Implementations.Sync
{
public class TargetDataProvider : ISyncDataProvider
{
private readonly SyncTarget _target;
private readonly IServerSyncProvider _provider;
private readonly SemaphoreSlim _dataLock = new SemaphoreSlim(1, 1);
private List<LocalItem> _items;
private readonly ILogger _logger;
private readonly IJsonSerializer _json;
private readonly IFileSystem _fileSystem;
private readonly IApplicationPaths _appPaths;
private readonly string _serverId;
private readonly SemaphoreSlim _cacheFileLock = new SemaphoreSlim(1, 1);
public TargetDataProvider(IServerSyncProvider provider, SyncTarget target, string serverId, ILogger logger, IJsonSerializer json, IFileSystem fileSystem, IApplicationPaths appPaths)
{
_logger = logger;
_json = json;
_provider = provider;
_target = target;
_fileSystem = fileSystem;
_appPaths = appPaths;
_serverId = serverId;
}
private string GetCachePath()
{
return Path.Combine(_appPaths.DataPath, "sync", _target.Id.GetMD5().ToString("N") + ".json");
}
private string GetRemotePath()
{
var parts = new List<string>
{
_serverId,
"data.json"
};
return _provider.GetFullPath(parts, _target);
}
private async Task CacheData(Stream stream)
{
var cachePath = GetCachePath();
await _cacheFileLock.WaitAsync().ConfigureAwait(false);
try
{
Directory.CreateDirectory(Path.GetDirectoryName(cachePath));
using (var fileStream = _fileSystem.GetFileStream(cachePath, FileMode.Create, FileAccess.Write, FileShare.Read, true))
{
await stream.CopyToAsync(fileStream).ConfigureAwait(false);
}
}
catch (Exception ex)
{
_logger.ErrorException("Error saving sync data to {0}", ex, cachePath);
}
finally
{
_cacheFileLock.Release();
}
}
private async Task EnsureData(CancellationToken cancellationToken)
{
if (_items == null)
{
try
{
using (var stream = await _provider.GetFile(GetRemotePath(), _target, new Progress<double>(), cancellationToken))
{
_items = _json.DeserializeFromStream<List<LocalItem>>(stream);
}
}
catch (FileNotFoundException)
{
_items = new List<LocalItem>();
}
catch (DirectoryNotFoundException)
{
_items = new List<LocalItem>();
}
using (var memoryStream = new MemoryStream())
{
_json.SerializeToStream(_items, memoryStream);
// Now cache it
memoryStream.Position = 0;
await CacheData(memoryStream).ConfigureAwait(false);
}
}
}
private async Task SaveData(CancellationToken cancellationToken)
{
using (var stream = new MemoryStream())
{
_json.SerializeToStream(_items, stream);
// Save to sync provider
stream.Position = 0;
await _provider.SendFile(stream, GetRemotePath(), _target, new Progress<double>(), cancellationToken).ConfigureAwait(false);
// Now cache it
stream.Position = 0;
await CacheData(stream).ConfigureAwait(false);
}
}
private async Task<T> GetData<T>(Func<List<LocalItem>, T> dataFactory)
{
await _dataLock.WaitAsync().ConfigureAwait(false);
try
{
await EnsureData(CancellationToken.None).ConfigureAwait(false);
return dataFactory(_items);
}
finally
{
_dataLock.Release();
}
}
private async Task UpdateData(Func<List<LocalItem>, List<LocalItem>> action)
{
await _dataLock.WaitAsync().ConfigureAwait(false);
try
{
await EnsureData(CancellationToken.None).ConfigureAwait(false);
_items = action(_items);
await SaveData(CancellationToken.None).ConfigureAwait(false);
}
finally
{
_dataLock.Release();
}
}
public Task<List<string>> GetServerItemIds(SyncTarget target, string serverId)
{
return GetData(items => items.Where(i => string.Equals(i.ServerId, serverId, StringComparison.OrdinalIgnoreCase)).Select(i => i.ItemId).ToList());
}
public Task AddOrUpdate(SyncTarget target, LocalItem item)
{
return UpdateData(items =>
{
var list = items.Where(i => !string.Equals(i.Id, item.Id, StringComparison.OrdinalIgnoreCase))
.ToList();
list.Add(item);
return list;
});
}
public Task Delete(SyncTarget target, string id)
{
return UpdateData(items => items.Where(i => !string.Equals(i.Id, id, StringComparison.OrdinalIgnoreCase)).ToList());
}
public Task<LocalItem> Get(SyncTarget target, string id)
{
return GetData(items => items.FirstOrDefault(i => string.Equals(i.Id, id, StringComparison.OrdinalIgnoreCase)));
}
private async Task<List<LocalItem>> GetCachedData()
{
if (_items == null)
{
await _cacheFileLock.WaitAsync().ConfigureAwait(false);
try
{
if (_items == null)
{
try
{
_items = _json.DeserializeFromFile<List<LocalItem>>(GetCachePath());
}
catch (FileNotFoundException)
{
_items = new List<LocalItem>();
}
catch (DirectoryNotFoundException)
{
_items = new List<LocalItem>();
}
}
}
finally
{
_cacheFileLock.Release();
}
}
return _items.ToList();
}
public async Task<List<string>> GetCachedServerItemIds(SyncTarget target, string serverId)
{
var items = await GetCachedData().ConfigureAwait(false);
return items.Where(i => string.Equals(i.ServerId, serverId, StringComparison.OrdinalIgnoreCase))
.Select(i => i.ItemId)
.ToList();
}
public async Task<List<LocalItem>> GetCachedItems(SyncTarget target, string serverId, string itemId)
{
var items = await GetCachedData().ConfigureAwait(false);
return items.Where(i => string.Equals(i.ServerId, serverId, StringComparison.OrdinalIgnoreCase) && string.Equals(i.ItemId, itemId, StringComparison.OrdinalIgnoreCase))
.ToList();
}
}
}