private bool SendTransactions(SyncContext context, Func<SyncContext, Message, bool> messageSink, IEnumerable<ITransactionInfo> transactionsToSend, string storeId,
Guid prevId)
{
foreach (var txn in transactionsToSend.Where(t => t.TransactionStatus == TransactionStatus.CompletedOk))
{
if (txn.TransactionType == TransactionType.UpdateTransaction)
{
var job = _serverCore.LoadTransaction(storeId, txn);
if (job is UpdateTransaction)
{
var updateJob = job as UpdateTransaction;
var syncTransaction = new ClusterUpdateTransaction
{
StoreId = storeId,
PrevTxnId = prevId,
JobId = txn.JobId,
Preconditions = updateJob.Preconditions,
Deletes = updateJob.DeletePatterns,
Inserts = updateJob.InsertData
};
if (!messageSink(context, syncTransaction.AsMessage()))
{
// If message sink stops accepting messages, fail the entire sync process immediately
return false;
}
}
else
{
return false;
}
}
else if (txn.TransactionType == TransactionType.SparqlUpdateTransaction)
{
var job = _serverCore.LoadTransaction(storeId, txn);
if (job is SparqlUpdateJob)
{
var sparqlJob = job as SparqlUpdateJob;
var syncTransaction = new ClusterSparqlTransaction
{
StoreId = storeId,
PrevTxnId = prevId,
JobId = txn.JobId,
Expression = sparqlJob.Expression
};
if (!messageSink(context, syncTransaction.AsMessage()))
{
// If message sink stops accepting messages, fail the entire sync process immediately
return false;
}
}
}
else
{
return false;
}
}
return true;
}
public bool SyncSlave(Dictionary<string, string> lastTxn, SyncContext context, Func<SyncContext, Message, bool> messageSink )
{
bool syncOk = true;
// Push existing transactions down the pipe
foreach(var storeId in _stores)
{
IEnumerable<ITransactionInfo> transactionsToSend;
if (lastTxn.ContainsKey(storeId))
{
Guid lastJobId = Guid.Parse(lastTxn[storeId]);
transactionsToSend = _serverCore.GetTransactions(storeId).SkipWhile(t => !t.JobId.Equals(lastJobId)).Skip(1);
syncOk &= SendTransactions(context, messageSink, transactionsToSend, storeId, lastJobId);
}
else
{
// For all stores that aren't listed in the lastTxn dictionary
// Send a create store message followed byt all transactions
var createMessage = new Message("+store", storeId);
if (messageSink(context, createMessage))
{
syncOk &= SendTransactions(context, messageSink, _serverCore.GetTransactions(storeId), storeId,
Guid.Empty);
}
else
{
syncOk = false;
}
}
}
// For all stores that are listed in lastTxn dictionary and not in our store list
// send a delete store message
foreach (var storeId in lastTxn.Keys.Where(s=>!_stores.Contains(s)))
{
var deleteMessage = new Message("-store", storeId);
messageSink(context, deleteMessage);
}
return syncOk;
}