/// <summary>
/// Gets changes rows count estimation,
/// </summary>
internal virtual async Task <(SyncContext, DatabaseChangesSelected)> InternalGetEstimatedChangesCountAsync(
SyncContext context, MessageGetChangesBatch message,
DbConnection connection, DbTransaction transaction,
CancellationToken cancellationToken, IProgress <ProgressArgs> progress)
{
// Call interceptor
await this.InterceptAsync(new DatabaseChangesSelectingArgs(context, message, connection, transaction), cancellationToken).ConfigureAwait(false);
// Create stats object to store changes count
var changes = new DatabaseChangesSelected();
if (context.SyncWay == SyncWay.Upload && context.SyncType == SyncType.Reinitialize)
{
return(context, changes);
}
foreach (var syncTable in message.Schema.Tables)
{
// if we are in upload stage, so check if table is not download only
if (context.SyncWay == SyncWay.Upload && syncTable.SyncDirection == SyncDirection.DownloadOnly)
{
continue;
}
// if we are in download stage, so check if table is not download only
if (context.SyncWay == SyncWay.Download && syncTable.SyncDirection == SyncDirection.UploadOnly)
{
continue;
}
// Get Command
var command = await this.GetSelectChangesCommandAsync(context, syncTable, message.Setup, message.IsNew, connection, transaction);
// Set parameters
this.SetSelectChangesCommonParameters(context, syncTable, message.ExcludingScopeId, message.IsNew, message.LastTimestamp, command);
// launch interceptor if any
var args = new TableChangesSelectingArgs(context, syncTable, command, connection, transaction);
await this.InterceptAsync(args, cancellationToken).ConfigureAwait(false);
if (args.Cancel || args.Command == null)
{
continue;
}
// Statistics
var tableChangesSelected = new TableChangesSelected(syncTable.TableName, syncTable.SchemaName);
// Get the reader
using var dataReader = await args.Command.ExecuteReaderAsync().ConfigureAwait(false);
while (dataReader.Read())
{
bool isTombstone = false;
for (var i = 0; i < dataReader.FieldCount; i++)
{
if (dataReader.GetName(i) == "sync_row_is_tombstone")
{
isTombstone = Convert.ToInt64(dataReader.GetValue(i)) > 0;
break;
}
}
// Set the correct state to be applied
if (isTombstone)
{
tableChangesSelected.Deletes++;
}
else
{
tableChangesSelected.Upserts++;
}
}
dataReader.Close();
// Check interceptor
var changesArgs = new TableChangesSelectedArgs(context, null, tableChangesSelected, connection, transaction);
await this.InterceptAsync(changesArgs, cancellationToken).ConfigureAwait(false);
if (tableChangesSelected.Deletes > 0 || tableChangesSelected.Upserts > 0)
{
changes.TableChangesSelected.Add(tableChangesSelected);
}
}
// Raise database changes selected
var databaseChangesSelectedArgs = new DatabaseChangesSelectedArgs(context, message.LastTimestamp, null, changes, connection);
this.ReportProgress(context, progress, databaseChangesSelectedArgs);
await this.InterceptAsync(databaseChangesSelectedArgs, cancellationToken).ConfigureAwait(false);
return(context, changes);
}