/// <summary>
/// Handle a conflict
/// The int returned is the conflict count I need
/// </summary>
/// changeApplicationAction, conflictCount, resolvedRow, conflictApplyInt
internal async Task <(int conflictResolvedCount, SyncRow resolvedRow, int rowAppliedCount)> HandleConflictAsync(
Guid localScopeId, Guid senderScopeId,
DbSyncAdapter syncAdapter, SyncContext context, SyncConflict conflict,
ConflictResolutionPolicy policy, long lastTimestamp,
DbConnection connection, DbTransaction transaction)
{
SyncRow finalRow;
ApplyAction conflictApplyAction;
int rowAppliedCount = 0;
(conflictApplyAction, finalRow) = await this.GetConflictActionAsync(context, conflict, policy, connection, transaction).ConfigureAwait(false);
// Conflict rollbacked by user
if (conflictApplyAction == ApplyAction.Rollback)
{
throw new RollbackException("Rollback action taken on conflict");
}
// Local provider wins, update metadata
if (conflictApplyAction == ApplyAction.Continue)
{
var isMergeAction = finalRow != null;
var row = isMergeAction ? finalRow : conflict.LocalRow;
// Conflict on a line that is not present on the datasource
if (row == null)
{
return(0, finalRow, 0);
}
// if we have a merge action, we apply the row on the server
if (isMergeAction)
{
// if merge, we update locally the row and let the update_scope_id set to null
var isUpdated = await syncAdapter.ApplyUpdateAsync(row, lastTimestamp, null, true);
// We don't update metadatas so the row is updated (on server side)
// and is mark as updated locally.
// and will be returned back to sender, since it's a merge, and we need it on the client
if (!isUpdated)
{
throw new Exception("Can't update the merge row.");
}
}
finalRow = isMergeAction ? row : conflict.LocalRow;
// We don't do anything, since we let the original row. so we resolved one conflict but applied no rows
return(conflictResolvedCount : 1, finalRow, rowAppliedCount : 0);
}
// We gonna apply with force the line
if (conflictApplyAction == ApplyAction.RetryWithForceWrite)
{
// TODO : Should Raise an error ?
if (conflict.RemoteRow == null)
{
return(0, finalRow, 0);
}
bool operationComplete = false;
switch (conflict.Type)
{
// Remote source has row, Local don't have the row, so insert it
case ConflictType.RemoteExistsLocalExists:
case ConflictType.RemoteExistsLocalNotExists:
case ConflictType.RemoteExistsLocalIsDeleted:
case ConflictType.UniqueKeyConstraint:
operationComplete = await syncAdapter.ApplyUpdateAsync(conflict.RemoteRow, lastTimestamp, senderScopeId, true);
rowAppliedCount = 1;
break;
// Conflict, but both have delete the row, so nothing to do
case ConflictType.RemoteIsDeletedLocalIsDeleted:
case ConflictType.RemoteIsDeletedLocalNotExists:
operationComplete = true;
rowAppliedCount = 0;
break;
// The remote has delete the row, and local has insert or update it
// So delete the local row
case ConflictType.RemoteIsDeletedLocalExists:
operationComplete = await syncAdapter.ApplyDeleteAsync(conflict.RemoteRow, lastTimestamp, senderScopeId, true);
rowAppliedCount = 1;
break;
case ConflictType.RemoteCleanedupDeleteLocalUpdate:
case ConflictType.ErrorsOccurred:
return(0, finalRow, 0);
}
finalRow = conflict.RemoteRow;
//After a force update, there is a problem, so raise exception
if (!operationComplete)
{
finalRow = null;
return(0, finalRow, rowAppliedCount);
}
return(1, finalRow, rowAppliedCount);
}
return(0, finalRow, 0);
}