public LockMessage(String loginName, bool isLocked, LockBatch batch)
{
msgType = NotificationMessage.MessageType.LockMessage;
lockBatch = batch;
this.loginName = loginName;
this.isLocked = isLocked;
}
/// <summary>
/// Tries to lock the items passed in LockBatch.
/// </summary>
/// <param name="login">The login of the user is our transaction id</param>
/// <param name="batch">The items to lock</param>
/// <param name="mode">The lock mode</param>
/// <returns>True on lock success, false on rollback</returns>
public bool Lock(String login, LockBatch batch, LockMode mode)
{
lock(locks)
{
foreach (LockItem item in batch.ItemsToLock)
{
if (SetLocks(login, batch, mode, item) == false)
{
return false;
}
}
return true;
}
}
/// <summary>
/// Unlock the locks for given user and mode.
/// </summary>
/// <param name="login">The login name of the user the unlock should be processed for</param>
/// <param name="batch">The items to unlock</param>
/// <param name="mode">The lock mode to unlock</param>
/// <returns>True on all items could be unlocked. False if unlocking of at least one item has failed.</returns>
public bool Unlock(String login, LockBatch batch, LockMode mode)
{
lock(locks)
{
bool allLocksReleased = true;
foreach (LockItem item in batch.ItemsToLock)
{
if (ReleaseLocks(login, mode, item) == false)
{
allLocksReleased = false;
}
}
return allLocksReleased;
}
}
public LockBatch GetCurrentLocks(string loginName)
{
LockBatch batch = new LockBatch();
lock(locks)
{
LockItem cpLockItem = new LockItem();
cpLockItem.ItemType = ResourceMap.ModelTypeToItemType<CollectionPoint>();
cpLockItem.IDsToLock = locks.GetLockedIdsForItemType(cpLockItem.ItemType, loginName, LockMode.Locked);
LockItem cLocks = new LockItem();
cLocks.ItemType = ResourceMap.ModelTypeToItemType<Customer>();
cLocks.IDsToLock = locks.GetLockedIdsForItemType(cLocks.ItemType, loginName, LockMode.Locked);
batch.ItemsToLock = new List<LockItem>(new LockItem[] { cpLockItem, cLocks });
}
return batch;
}
public LockBatch GetItemsToLock(int id)
{
Console.WriteLine("Customer Strategy called.");
LockBatch batch = new LockBatch();
LockItem lockItem = new LockItem();
lockItem.ItemType = ItemType.CollectionPoint;
lockItem.IDsToLock = new List<int>(new int[] { 1, 2, 3 });
LockItem lockItem2 = new LockItem();
lockItem2.ItemType = ItemType.Customer;
List<int> aLotOfIds = new List<int>();
for (int i = 1; i < 30; i++)
{
aLotOfIds.Add(i);
}
lockItem2.IDsToLock = aLotOfIds;
batch.ItemsToLock = new List<LockItem>(new LockItem[] { lockItem, lockItem2 });
return batch;
}
public LockBatch GetItemsToLock(int id)
{
Console.WriteLine("CollectionPoint lock strategy for id: {0} called.", id);
ResourceCache currentItems = tm.Cache;
List<CollectionPoint> allCollectionPoints = currentItems.GetAllItems<CollectionPoint>();
List<Customer> allCustomers = currentItems.GetAllItems<Customer>();
LockItem cpLockItem = new LockItem();
cpLockItem.ItemType = ItemType.CollectionPoint;
cpLockItem.IDsToLock = new List<int>();
LockItem customerLockItem = new LockItem();
customerLockItem.ItemType = ItemType.Customer;
customerLockItem.IDsToLock = new List<int>();
LockBatch batch = new LockBatch();
CollectionPoint targetItem = currentItems.GetItem<CollectionPoint>(id);
if(targetItem != null)
{
batch.ItemsToLock = new List<LockItem>(new LockItem[] { cpLockItem, customerLockItem });
cpLockItem.IDsToLock.Add(id); //root id of the lock request
// get the customers
List<Customer> targetCustomers = targetItem.Customers;
// add the customers of target item first
foreach(Customer currentCustomer in targetCustomers)
{
customerLockItem.IDsToLock.Add(currentCustomer.Id);
}
// go over the other CollectionPoints and get the dependencies
int oldCustomerCount = -1;
//TODO: do we need to observe oldCollectionPoint count too?
do
{
oldCustomerCount = customerLockItem.IDsToLock.Count;
foreach(CollectionPoint currentCollectionPoint in allCollectionPoints)
{
if(cpLockItem.IDsToLock.Contains(currentCollectionPoint.Id) == false)
{
bool dependencyExists = false;
List<int> customerIdsOfCurrentCP = new List<int>();
//check if this collection point contains at least one customer with
//which is allready marked as locked
foreach(Customer currentCustomer in currentCollectionPoint.Customers)
{
customerIdsOfCurrentCP.Add(currentCustomer.Id);
if(customerLockItem.IDsToLock.Contains(currentCustomer.Id))
{
dependencyExists = true;
}
}
if(dependencyExists == true)
{
// if new dependency found we need to add the CollectionPoint
// and the customer not allready marked to be locked
foreach(int customerId in customerIdsOfCurrentCP)
{
if(customerLockItem.IDsToLock.Contains(customerId) == false)
{
customerLockItem.IDsToLock.Add(customerId);
}
}
cpLockItem.IDsToLock.Add(currentCollectionPoint.Id);
}
}
}
} while (oldCustomerCount.Equals(customerLockItem.IDsToLock.Count) == false);
}
else
{
Console.WriteLine("CollectionPoint root item: {0} isn't cached by the data source!", id);
batch.ItemsToLock = null;
}
return batch;
}
private bool SetLocks(String login, LockBatch batch, LockMode mode, LockItem item)
{
foreach (int id in item.IDsToLock)
{
List<LockData> currentLocks = locks.GetLocksForItem(id, item.ItemType);
LockData newLock = new LockData(login, mode);
// for future write-lock development
// we have to pass currentLocks as a whole to assure that ll
// for this user are present in currentLocks
// write locks can only be set if the ll for this user are set
foreach(LockData lockData in currentLocks)
{
if(newLock.Equals(lockData) == false
&& !LockMatrix.IsModeCompatible(lockData.mode, mode))
{
Console.WriteLine("Lock conflict, rollback locks for user: {0}", login);
Unlock(login, batch, mode);
return false;
}
}
if(currentLocks.Contains(newLock) == false)
{
currentLocks.Add(newLock);
locks.UpdateLocksForItem(id, item.ItemType, currentLocks);
}
}
return true;
}