public Result <string> TryAcquireLease(string containerName, string blobName)
{
var path = Path.Combine(_root, containerName, blobName);
try
{
var file = new FileInfo(path);
if (!file.Exists)
{
return(null);
}
using (var stream = file.Open(FileMode.Open, FileAccess.ReadWrite, FileShare.None))
using (var epStream = new MetadataPrefixStream(stream))
{
var flags = epStream.ReadFlags();
if ((flags & 0x1) == 0x1)
{
// already locked, conflict
return(Result <string> .CreateError("Conflict"));
}
epStream.WriteFlags((byte)(flags | 0x1));
return(Result.CreateSuccess(epStream.ReadETag()));
}
}
catch (FileNotFoundException)
{
return(Result <string> .CreateError("NotFound"));
}
catch (DirectoryNotFoundException)
{
return(Result <string> .CreateError("NotFound"));
}
}
public Result <string> TryRenewLease(string containerName, string blobName, string leaseId)
{
var path = Path.Combine(_root, containerName, blobName);
try
{
var file = new FileInfo(path);
if (!file.Exists)
{
return(null);
}
using (var stream = file.Open(FileMode.Open, FileAccess.Read, FileShare.None))
using (var epStream = new MetadataPrefixStream(stream))
{
var flags = epStream.ReadFlags();
if ((flags & 0x1) == 0x0)
{
// not locked
return(Result <string> .CreateError("NotFound"));
}
if (leaseId != epStream.ReadETag())
{
// locked by another leaseId, conflict
return(Result <string> .CreateError("Conflict"));
}
return(Result.CreateSuccess("OK"));
}
}
catch (FileNotFoundException)
{
return(Result <string> .CreateError("NotFound"));
}
catch (DirectoryNotFoundException)
{
return(Result <string> .CreateError("NotFound"));
}
}