osu/osu.Game/Database/RealmFileStore.cs

124 lines
4.3 KiB
C#

// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
// See the LICENCE file in the repository root for full licence text.
using System;
using System.Diagnostics;
using System.IO;
using osu.Framework.Extensions;
using osu.Framework.IO.Stores;
using osu.Framework.Logging;
using osu.Framework.Platform;
using osu.Game.Extensions;
using osu.Game.IO;
using osu.Game.Models;
using Realms;
namespace osu.Game.Database
{
/// <summary>
/// Handles the storing of files to the file system (and database) backing.
/// </summary>
public class RealmFileStore
{
private readonly RealmAccess realm;
public readonly IResourceStore<byte[]> Store;
public readonly Storage Storage;
public RealmFileStore(RealmAccess realm, Storage storage)
{
this.realm = realm;
Storage = storage.GetStorageForDirectory(@"files");
Store = new StorageBackedResourceStore(Storage);
}
/// <summary>
/// Add a new file to the game-wide database, copying it to permanent storage if not already present.
/// </summary>
/// <param name="data">The file data stream.</param>
/// <param name="realm">The realm instance to add to. Should already be in a transaction.</param>
/// <param name="addToRealm">Whether the <see cref="RealmFile"/> should immediately be added to the underlying realm. If <c>false</c> is provided here, the instance must be manually added.</param>
/// <param name="preferHardLinks">Whether this import should use hard links rather than file copy operations if available.</param>
public RealmFile Add(Stream data, Realm realm, bool addToRealm = true, bool preferHardLinks = false)
{
string hash = data.ComputeSHA2Hash();
var existing = realm.Find<RealmFile>(hash);
var file = existing ?? new RealmFile { Hash = hash };
if (!checkFileExistsAndMatchesHash(file))
copyToStore(file, data, preferHardLinks);
if (addToRealm && !file.IsManaged)
realm.Add(file);
return file;
}
private void copyToStore(RealmFile file, Stream data, bool preferHardLinks)
{
if (data is FileStream fs && preferHardLinks)
{
// attempt to do a fast hard link rather than copy.
if (HardLinkHelper.TryCreateHardLink(Storage.GetFullPath(file.GetStoragePath(), true), fs.Name))
return;
}
data.Seek(0, SeekOrigin.Begin);
using (var output = Storage.CreateFileSafely(file.GetStoragePath()))
data.CopyTo(output);
data.Seek(0, SeekOrigin.Begin);
}
private bool checkFileExistsAndMatchesHash(RealmFile file)
{
string path = file.GetStoragePath();
// we may be re-adding a file to fix missing store entries.
if (!Storage.Exists(path))
return false;
// even if the file already exists, check the existing checksum for safety.
using (var stream = Storage.GetStream(path))
return stream.ComputeSHA2Hash() == file.Hash;
}
public void Cleanup()
{
Logger.Log(@"Beginning realm file store cleanup");
int totalFiles = 0;
int removedFiles = 0;
// can potentially be run asynchronously, although we will need to consider operation order for disk deletion vs realm removal.
realm.Write(r =>
{
foreach (var file in r.All<RealmFile>().Filter(@$"{nameof(RealmFile.Usages)}.@count = 0"))
{
totalFiles++;
Debug.Assert(file.BacklinksCount == 0);
try
{
removedFiles++;
Storage.Delete(file.GetStoragePath());
r.Remove(file);
}
catch (Exception e)
{
Logger.Error(e, $@"Could not delete databased file {file.Hash}");
}
}
});
Logger.Log($@"Finished realm file store cleanup ({removedFiles} of {totalFiles} deleted)");
}
}
}