/// <summary>
/// Reserve a list of resources for a customer
/// Decrease all reserved resources by 1.
/// </summary>
/// <param name="context"></param>
/// <param name="c"></param>
/// <param name="i"></param>
/// <returns>true if reservation is successful</returns>
public bool Reserve(Transaction context, Customer c, RID i)
{
WaitForReady();
Enlist(context);
_lockManager.LockForWrite(context, c);
_lockManager.LockForWrite(context, i);
Resource resource = _transactionStorage.Read(context, i);
if (resource == null)
{
throw new InvalidOperationException(i + " does not exist!");
}
if (resource.getCount() == 0)
{
return(false);
}
HashSet <RID> r = _transactionStorage.Read(context, c) ?? new HashSet <RID>();
r.Add(resource.getID());
Console.WriteLine("Reserving flight: Stops={0}", r.Count);
_transactionStorage.Write(context, c, r);
resource.decrCount();
_transactionStorage.Write(context, i, resource);
return(true);
}
public bool Delete(Transaction context, RID rId, int count)
{
// enlist with TM
this.Enlist(context);
// read in the resource
Resource data = null;
bool removed = this.dataStore.Read(context, rId, out data);
if (!removed ||
null == data)
{
// silently discard
return(false);
}
// update the resource
if (data.getCount() > count)
{
data.decrCount(count);
}
else
{
data.setCount(0);
}
// write the resource back
return(this.dataStore.Write(context, rId, data));
}
/// <summary>
/// Deletes certain amount of resource.
/// </summary>
/// <param name="context"></param>
/// <param name="rid"></param>
/// <param name="count"></param>
/// <returns>true the given resources exists. False if not</returns>
public bool Delete(Transaction context, RID rid, int count)
{
WaitForReady();
Enlist(context);
_lockManager.LockForWrite(context, rid);
Resource resource = _transactionStorage.Read(context, rid);
if (resource == null)
{
// silently discard
return(false);
}
if (resource.getCount() > count)
{
resource.decrCount(count);
}
else
{
resource.setCount(0);
}
_transactionStorage.Write(context, rid, resource);
return(true);
}
public bool Reserve(Transaction context, Customer customer, RID resource)
{
// enlist with TM
this.Enlist(context);
// get the resource info
Resource item = null;
bool result = this.dataStore.Read(context, resource, out item);
if (!result)
{
throw new InvalidOperationException(resource + " does not exist!");
}
if (item.getCount() <= 0)
{
return(false);
}
// get the reservation record
Reservation data = null;
result = this.dataStore.Read(context, customer, out data);
if (!result)
{
data = new Reservation(customer);
}
// only allow one reservation per item
if (data.Resources.Contains(resource))
{
return(false);
}
// update the data
data.Resources.Add(resource);
item.decrCount();
// write back the records
result = this.dataStore.Write(context, customer, data);
if (!result)
{
return(result);
}
result = this.dataStore.Write(context, resource, item);
if (!result)
{
return(result);
}
return(true);
}