/// <summary>
/// Copies all the files and directories from the source directory recursively into this directory.
/// </summary>
/// <param name="this">The destination directory.</param>
/// <param name="source">The source directory.</param>
/// <param name="overwrite">Whether or not to overwrite existing files.</param>
/// <returns>An enumerable of copied files.</returns>
public static async IAsyncEnumerable <IFile> CopyFromDirectory(this IDirectory @this, IReadOnlyDirectory source, bool overwrite)
{
if (@this == source)
{
yield break;
}
// Do the parent directory
foreach (var f in source.EnumerateFiles())
{
yield return(await @this.CopyFromAsync(f, overwrite));
}
var queuedDirs =
source.EnumerateDirectories()
.Select(d => (@this, d)).ToList();
// BFS over all the children.
Queue <(IDirectory, IReadOnlyDirectory)> dirsToProcess = new (queuedDirs);
while (dirsToProcess.Count > 0)
{
var(parent, src) = dirsToProcess.Dequeue();
var dst = parent.OpenDirectory(src.Name);
foreach (var f in src.EnumerateFiles())
{
yield return(await dst.CopyFromAsync(f, overwrite));
}
var children = src.EnumerateDirectories()
.Select(d => (dst, d)).ToList();
foreach (var childDirectory in children)
{
dirsToProcess.Enqueue(childDirectory);
}
}
}
public async override Task <ISaveGame> CreateSave(IReadOnlyDirectory saveContents)
{
if (!this.ProfileRoot.ContainsDirectory("base"))
{
await this.CreateBaseSave(saveContents);
}
using var rollingHash = new RollingHash(32);
// setup
var newGuid = Guid.NewGuid();
var saveName = $"{DateTimeOffset.UtcNow.ToString(DateFormat)}-{newGuid}";
var saveDirectory = this.ProfileRoot.OpenDirectory(saveName);
var contentDirectory = saveDirectory.OpenDirectory("content");
// diff is for anything that exists in the base directory
var diffDir = contentDirectory.OpenDirectory("diff");
// copy is for anything that does not and can not be diffed.
var copyDir = contentDirectory.OpenDirectory("copy");
// Traverse base directory in tandem with saveContents
var baseDir = this.ProfileRoot.OpenDirectory("base/content").AsReadOnly();
foreach (var f in saveContents.EnumerateFiles())
{
if (!baseDir.ContainsFile(f.Name))
{
await copyDir.CopyFromAsync(f);
continue;
}
using var targetStream = f.OpenReadStream();
using var baseStream = baseDir.OpenFile(f.Name).OpenReadStream();
using var outStream = diffDir.OpenFile(f.Name).OpenStream();
using var decoder = new VcEncoder(baseStream, targetStream, outStream,
rollingHash: rollingHash, blockSize: 32);
VCDiffResult result = await decoder.EncodeAsync();
if (result != VCDiffResult.SUCCESS)
{
throw new IOException($"Failed to encode delta for {f.Name}");
}
}
foreach (var d in saveContents.EnumerateDirectories().Where(d => !baseDir.ContainsDirectory(d.Name)))
{
// Copy all directories not in the base.
await foreach (var _ in copyDir.OpenDirectory(d.Name).CopyFromDirectory(d))
{
}
}
var queuedDirs = (from targetDir in saveContents.EnumerateDirectories()
where baseDir.ContainsDirectory(targetDir.Name)
select(diffDir, baseDir.OpenDirectory(targetDir.Name), targetDir)).ToList();
Queue <(IDeletableDirectory parentDir, IReadOnlyDirectory baseDir, IReadOnlyDirectory targetDir)> dirsToProcess =
new(queuedDirs);
while (dirsToProcess.Count > 0)
{
var(parent, src, diff) = dirsToProcess.Dequeue();
var dst = parent.OpenDirectory(src.Name);
foreach (var f in src.EnumerateFiles())
{
if (!diff.ContainsFile(f.Name))
{
continue;
}
using var baseStream = f.OpenReadStream();
using var targetStream = diff.OpenFile(f.Name).OpenReadStream();
using var outStream = dst.OpenFile(f.Name).OpenStream();
using var decoder = new VcEncoder(baseStream, targetStream, outStream,
rollingHash: rollingHash, blockSize: 32);
VCDiffResult result = await decoder.EncodeAsync();
if (result != VCDiffResult.SUCCESS)
{
throw new IOException($"Failed to decode delta for {f.Name}");
}
}
var children = from targetDir in diff.EnumerateDirectories()
where src.ContainsDirectory(targetDir.Name)
select(dst, src.OpenDirectory(targetDir.Name), targetDir);
foreach (var childDirectory in children)
{
dirsToProcess.Enqueue(childDirectory);
}
}
this.ProfileRoot.OpenFile("latest").WriteAllText(saveName, Encoding.UTF8);
return(this.GetSave(saveDirectory) !);
}
