private bool TryGetLock(string fileId, out LockInfo lockInfo)
{
//TODO: This lock implementation is not thread safe and not persisted and all in all just an example.
if (Locks.TryGetValue(fileId, out lockInfo))
{
if (lockInfo.Expired)
{
Locks.Remove(fileId);
return false;
}
return true;
}
return false;
}
public async Task<IActionResult> PerformAction(string id, [FromQuery]string access_token)
{
var editSession = await GetEditSessionAsync(id);
string wopiOverrideHeader = HttpContext.Request.Headers[WopiHeaders.WopiOverride];
//TODO: Replace the else-ifs with separate methods (https://github.com/petrsvihlik/WopiHost/issues/7)
// http://stackoverflow.com/questions/39302121/header-based-routing-in-asp-net-core
if (wopiOverrideHeader.Equals("COBALT"))
{
var responseAction = editSession.SetFileContent(await HttpContext.Request.Body.ReadBytesAsync());
HttpContext.Response.Headers.Add(WopiHeaders.CorrelationId, HttpContext.Request.Headers[WopiHeaders.CorrelationId]);
HttpContext.Response.Headers.Add("request-id", HttpContext.Request.Headers[WopiHeaders.CorrelationId]);
return new Results.FileResult(responseAction, "application/octet-stream");
}
else if (wopiOverrideHeader.Equals("LOCK") || wopiOverrideHeader.Equals("UNLOCK") || wopiOverrideHeader.Equals("REFRESH_LOCK") || wopiOverrideHeader.Equals("GET_LOCK"))
{
string oldLock = Request.Headers[WopiHeaders.OldLock];
string newLock = Request.Headers[WopiHeaders.Lock];
LockInfo existingLock = null;
bool lockAcquired = TryGetLock(id, out existingLock);
lock (Locks)
{
switch (wopiOverrideHeader)
{
case "GET_LOCK":
break;
case "LOCK":
if (oldLock != null)
{
if (lockAcquired)
{
if (existingLock.Lock == oldLock)
{
// Replace the existing lock with the new one
Locks[id] = new LockInfo { DateCreated = DateTime.UtcNow, Lock = newLock };
Response.Headers[WopiHeaders.OldLock] = newLock;
return new OkResult();
}
else
{
// The existing lock doesn't match the requested one. Return a lock mismatch error along with the current lock
return ReturnLockMismatch(Response, existingLock.Lock);
}
}
else
{
// The requested lock does not exist. That's also a lock mismatch error.
return ReturnLockMismatch(Response, reason: "File not locked");
}
}
else
{
if (lockAcquired)
{
// There is a valid existing lock on the file
return ReturnLockMismatch(Response, existingLock.Lock);
}
else
{
// The file is not currently locked, create and store new lock information
Locks[id] = new LockInfo { DateCreated = DateTime.UtcNow, Lock = newLock };
return new OkResult();
}
}
case "UNLOCK":
if (lockAcquired)
{
if (existingLock.Lock == newLock)
{
// Remove valid lock
Locks.Remove(id);
return new OkResult();
}
else
{
// The existing lock doesn't match the requested one. Return a lock mismatch error along with the current lock
return ReturnLockMismatch(Response, existingLock.Lock);
}
}
else
{
// The requested lock does not exist.
return ReturnLockMismatch(Response, reason: "File not locked");
}
case "REFRESH_LOCK":
if (lockAcquired)
{
if (existingLock.Lock == newLock)
{
// Extend the lock timeout
existingLock.DateCreated = DateTime.UtcNow;
return new OkResult();
}
else
{
// The existing lock doesn't match the requested one. Return a lock mismatch error along with the current lock
return ReturnLockMismatch(Response, existingLock.Lock);
}
}
else
{
// The requested lock does not exist. That's also a lock mismatch error.
return ReturnLockMismatch(Response, reason: "File not locked");
}
}
}
return new OkResult();
}
else
{
// Unsupported action
return new NotImplementedResult();
}
}