private FarmSettingStore GetWriteSettingStore()
{
rrLock.EnterUpgradeableReadLock();
try
{
GetSettingStore();
if (_settingStore == null) // setting store not yet created
{
rrLock.EnterWriteLock();
try
{
_settingStore = FarmSettingStore.Create(this.farm);
}
finally
{
rrLock.ExitWriteLock();
}
}
return(_settingStore);
}
finally
{
rrLock.ExitUpgradeableReadLock();
}
}
public void Remove(string key)
{
rrLock.EnterWriteLock();
try
{
//intentionally nested, both cases getting a write lock, is safe and ensures no race.
//Force the reload of the persisted object, which minimizes chances of a failure due
// to a concurrency failure.
Reset();
FarmSettingStore store = GetWriteSettingStore();
if (store.Settings.ContainsKey(key))
{
store.Settings.Remove(key);
store.Update();
}
}
catch (SPUpdatedConcurrencyException)
{
Reset();
throw;
}
finally
{
rrLock.ExitWriteLock();
}
}
private FarmSettingStore GetSettingStore()
{
rrLock.EnterUpgradeableReadLock();
try
{
//Attempt to reload if the settings store is null and a load hasn't been attempted, or if the last load interval is exceeded.
//in the case of a refresh, then _settingStore will be null and missingSettings will be false.
if ((_settingStore == null && missingSettings == false) || (DateTime.Now.Subtract(lastLoad).TotalSeconds) > cacheInterval)
{
rrLock.EnterWriteLock();
try
{
//make sure first another thread didn't already load...before trying to load it.
if (_settingStore == null)
{
_settingStore = FarmSettingStore.Load(farm);
lastLoad = DateTime.Now;
missingSettings = (_settingStore == null);
}
}
finally
{
rrLock.ExitWriteLock();
}
}
return(_settingStore);
}
finally
{
rrLock.ExitUpgradeableReadLock();
}
}
/// <summary>
/// Gets or sets a value based on the key. If the value is not defined in this PropertyBag, it will look in it's
/// parent property bag.
/// </summary>
/// <value></value>
/// <returns>The config value defined in the property bag. </returns>
public string this[string key]
{
[SharePointPermission(SecurityAction.InheritanceDemand, ObjectModel = true)]
[SharePointPermission(SecurityAction.LinkDemand, ObjectModel = true)]
get
{
FarmSettingStore store = GetSettingStore();
if (store == null)
{
return(null);
}
rrLock.EnterReadLock();
try
{
if (!store.Settings.ContainsKey(key))
{
return(null);
}
return(store.Settings[key]);
}
finally
{
rrLock.ExitReadLock();
}
}
[SharePointPermission(SecurityAction.InheritanceDemand, ObjectModel = true)]
[SharePointPermission(SecurityAction.LinkDemand, ObjectModel = true)]
set
{
rrLock.EnterWriteLock();
try
{
//intentionally nested, both cases getting a write lock, is safe and ensures no race.
//Force the reload of the persisted object, which minimizes chances of a failure due
// to a concurrency failure.
Reset();
FarmSettingStore store = GetWriteSettingStore();
store.Settings[key] = value;
store.Update();
}
catch (SPUpdatedConcurrencyException)
{
Reset();
throw;
}
finally
{
rrLock.ExitWriteLock();
}
}
}
/// <summary>
/// Forces the property bag to reload settings on next access.
/// </summary>
public void Reset()
{
rrLock.EnterWriteLock();
try
{
_settingStore = null;
}
finally
{
rrLock.ExitWriteLock();
}
}
/// <summary>
/// Creates a new FarmSettingStore. This operation cannot be done from a content web application.
/// </summary>
/// <param name="farm">The Farm to create the setting store in</param>
/// <returns></returns>
public static FarmSettingStore Create(SPFarm farm)
{
lock (createlock)
{
//lock to prevent duplicate create attempts on a WFE (still a possible race with other WFE's).
var settingStore = farm.GetChild <FarmSettingStore>(FarmSettingStore.StoreName);
if (settingStore == null) // has not been previously saved
{
settingStore = new FarmSettingStore(FarmSettingStore.StoreName, farm);
settingStore.Update();
}
return(settingStore);
}
}
public bool Contains(string key)
{
FarmSettingStore store = GetSettingStore();
if (store == null)
{
return(false);
}
rrLock.EnterReadLock();
try
{
return(store.Settings.ContainsKey(key));
}
finally
{
rrLock.ExitReadLock();
}
}
/// <summary>
/// For internal use, clears the cached setting store data
/// </summary>
public static void ClearCache()
{
_settingStore = null;
}