internal protected void EnableWriteOnReplicas(string viewName, string headStorageAccountName)
{
// Assert (headStorageAccountName != null)
if (!ReplicaChain.Any() ||
ReplicaChain[0].StorageAccountName != headStorageAccountName)
{
return;
}
// First, enable Write on all replicas
foreach (ReplicaInfo replica in GetCurrentReplicaChain())
{
replica.Status = ReplicaStatus.ReadWrite;
}
// Then, set the head to WriteOnly
ReplicaChain[0].Status = ReplicaStatus.WriteOnly;
// one replica chain ? Force to ReadWrite
if (GetCurrentReplicaChain().Count == 1)
{
ReplicaChain[0].Status = ReplicaStatus.ReadWrite;
}
// Update view id
ViewId++;
}
internal protected void MoveReplicaToHeadAndSetViewToReadOnly(string viewName, string storageAccountName)
{
// Assert (storageAccountName != null)
int matchIndex = ReplicaChain.FindIndex(r => r.StorageAccountName == storageAccountName);
if (matchIndex == -1)
{
return;
}
// - Ensure its status is *None*
ReplicaInfo candidateReplica = ReplicaChain[matchIndex];
var oldStatus = candidateReplica.Status;
candidateReplica.Status = ReplicaStatus.None;
// First check it will be possible to modify the sequence
foreach (ReplicaInfo replica in GetCurrentReplicaChain())
{
// Change is not possible
if (replica.Status == ReplicaStatus.WriteOnly)
{
// Restore previous status
candidateReplica.Status = oldStatus;
var msg = string.Format("View:\'{0}\' : can't set a WriteOnly replica to ReadOnly !!!", viewName);
ReplicatedTableLogger.LogError(msg);
throw new Exception(msg);
}
}
// Do the change ...
// - Move it to the front of the chain
ReplicaChain.RemoveAt(matchIndex);
ReplicaChain.Insert(0, candidateReplica);
// Set all active replicas to *ReadOnly*
foreach (ReplicaInfo replica in GetCurrentReplicaChain())
{
replica.Status = ReplicaStatus.ReadOnly;
}
// Update view id
ViewId++;
// Reset 'ReadViewTailIndex' => user has to set it again
ResetReadViewTailIndex();
}
internal protected void EnableReadWriteOnReplica(string viewName, string headStorageAccountName)
{
if (!ReplicaChain.Any() ||
ReplicaChain[0].StorageAccountName != headStorageAccountName ||
ReplicaChain[0].Status != ReplicaStatus.WriteOnly)
{
return;
}
ReplicaChain[0].Status = ReplicaStatus.ReadWrite;
// Update view id
ViewId++;
}
internal protected void MoveReplicaToHeadAndSetViewToReadOnly(string viewName, string storageAccountName)
{
// Assert (storageAccountName != null)
int matchIndex = ReplicaChain.FindIndex(r => r.StorageAccountName == storageAccountName);
if (matchIndex == -1)
{
return;
}
// - Ensure its status is *None*
ReplicaInfo candidateReplica = ReplicaChain[matchIndex];
candidateReplica.Status = ReplicaStatus.None;
// - Move it to the front of the chain
ReplicaChain.RemoveAt(matchIndex);
ReplicaChain.Insert(0, candidateReplica);
// Set all active replicas to *ReadOnly*
foreach (ReplicaInfo replica in GetCurrentReplicaChain())
{
if (replica.Status == ReplicaStatus.WriteOnly)
{
var msg = string.Format("View:\'{0}\' : can't set a WriteOnly replica to ReadOnly !!!", viewName);
ReplicatedTableLogger.LogError(msg);
throw new Exception(msg);
}
replica.Status = ReplicaStatus.ReadOnly;
}
// Update view id
ViewId++;
}
/// <summary>
/// List of active Replicas i.e. RO / WO / RW
/// </summary>
/// <returns></returns>
public List <ReplicaInfo> GetCurrentReplicaChain()
{
return(ReplicaChain.Where(r => r.Status != ReplicaStatus.None).ToList());
}
