public GetChangesParameters GetChanges(uint batchSize,
SyncKnowledge destinationKnowledge)
{
Log("GetChangeBatch: {0}", sqlProvider.Connection.ConnectionString);
var changesWrapper = new GetChangesParameters();
changesWrapper.ChangeBatch = sqlProvider.GetChangeBatch(batchSize,
destinationKnowledge, out changesWrapper.DataRetriever);
var context = changesWrapper.DataRetriever as DbSyncContext;
//Check to see if data is batched
if (context != null && context.IsDataBatched)
{
Log("GetChangeBatch: Data Batched. Current Batch #:{0}", ++batchCount);
//Dont send the file location info. Just send the file name
var fileName = new FileInfo(context.BatchFileName).Name;
batchIdToFileMapper[fileName] = context.BatchFileName;
context.BatchFileName = fileName;
}
return(changesWrapper);
}
/// <summary>
/// Get changes for a client using the knowledge that is passed in.
/// </summary>
/// <param name="serverBlob">Client knowledge as byte[]</param>
/// <returns>Response containing the new knowledge and the list of changes.</returns>
public GetChangesResponse GetChanges(byte[] serverBlob)
{
bool isNewClient = false;
var response = new GetChangesResponse();
var syncBlob = new SyncBlob();
byte[] clientKnowledgeBlob = null;
// If the incoming knowledge blob is null, then we need to initialize a new scope
// for this request.
if (null == serverBlob || 0 == serverBlob.Length)
{
// Create a new Guid and use that as the client Id.
Guid clientId = Guid.NewGuid();
_clientScopeName = String.Format(CultureInfo.InvariantCulture, "{0}_{1}", _scopeName, clientId);
_clientSyncId = new SyncId(clientId);
CreateNewScopeForClient();
isNewClient = true;
syncBlob.ClientScopeName = clientId.ToString();
}
else
{
SyncBlob incomingBlob = SyncBlob.DeSerialize(serverBlob);
PopulateClientScopeNameAndSyncId(incomingBlob);
syncBlob.ClientScopeName = incomingBlob.ClientScopeName;
clientKnowledgeBlob = incomingBlob.ClientKnowledge;
if (null != incomingBlob.BatchCode && null != incomingBlob.NextBatch)
{
// This is a batched request, so handle it separately.
return GetChanges(incomingBlob.ClientKnowledge, incomingBlob.BatchCode.Value, incomingBlob.NextBatch.Value);
}
}
// Intialize a SqlSyncProvider object.
_sqlSyncProvider = CreateSqlSyncProviderInstance(_clientScopeName, _serverConnectionString, _configuration.SyncObjectSchema);
var sessionContext = new SyncSessionContext(_sqlSyncProvider.IdFormats, new SyncCallbacks());
_sqlSyncProvider.BeginSession(SyncProviderPosition.Remote, sessionContext);
try
{
// Get the SyncKnowledge from the blob. If the blob is null, initialize a default SyncKnowledge object.
SyncKnowledge clientKnowledge = GetSyncKnowledgeFromBlob(clientKnowledgeBlob);
DbSyncContext dbSyncContext;
uint changeBatchSize = (_configuration.IsBatchingEnabled)
? (uint)_configuration.DownloadBatchSizeInKB
: 0;
RowSorter rowSorter = null;
do
{
object changeDataRetriever;
// Get the next batch.
_sqlSyncProvider.GetChangeBatch(changeBatchSize, clientKnowledge,
out changeDataRetriever);
dbSyncContext = (DbSyncContext)changeDataRetriever;
// Only initialize the RowSorter, if the data is batched.
if (null == rowSorter && _configuration.IsBatchingEnabled)
{
// Clone the client knowledge.
var clonedClientKnowledge = clientKnowledge.Clone();
// Combine with the MadeWithKnowledge of the server.
clonedClientKnowledge.Combine(dbSyncContext.MadeWithKnowledge);
// Use the new knowledge and get and instance of the RowSorter class.
rowSorter = GetRowSorter(clonedClientKnowledge);
}
// Remove version information from the result dataset.
RemoveSyncVersionColumns(dbSyncContext.DataSet);
// For a new client, we don't want to send tombstones. This will reduce amount of data
// transferred and the client doesn't care about tombstones anyways.
if (isNewClient)
{
RemoveTombstoneRowsFromDataSet(dbSyncContext.DataSet);
}
// Add the dataset to the row sorter. Only use this if batching is enabled.
if (_configuration.IsBatchingEnabled)
{
rowSorter.AddUnsortedDataSet(dbSyncContext.DataSet);
// Delete the batch file generated by the provider, since we have read it.
// Otherwise we will keep accumulating files which are not needed.
if (!String.IsNullOrEmpty(dbSyncContext.BatchFileName) && File.Exists(dbSyncContext.BatchFileName))
{
File.Delete(dbSyncContext.BatchFileName);
}
}
} while (!dbSyncContext.IsLastBatch && dbSyncContext.IsDataBatched);
List<IOfflineEntity> entities;
if (_configuration.IsBatchingEnabled)
{
// If batching is enabled.
Batch batch = SaveBatchesAndReturnFirstBatch(rowSorter);
if (null == batch)
{
entities = new List<IOfflineEntity>();
}
else
{
// Conver to to entities.
entities = _converter.ConvertDataSetToEntities(batch.Data);
//Only combine the knowledge of this batch.
clientKnowledge.Combine(SyncKnowledge.Deserialize(_sqlSyncProvider.IdFormats,
batch.LearnedKnowledge));
response.IsLastBatch = batch.IsLastBatch;
syncBlob.IsLastBatch = batch.IsLastBatch;
if (batch.IsLastBatch)
{
syncBlob.NextBatch = null;
syncBlob.BatchCode = null;
}
else
{
syncBlob.NextBatch = batch.NextBatch;
syncBlob.BatchCode = batch.BatchCode;
}
}
}
else
{
// No batching.
response.IsLastBatch = true;
entities = _converter.ConvertDataSetToEntities(dbSyncContext.DataSet);
// combine the client and the server knowledge.
// the server may have an updated knowledge from the last time the client sync'd.
clientKnowledge.Combine(dbSyncContext.MadeWithKnowledge);
}
// Save data in the response object.
syncBlob.ClientKnowledge = clientKnowledge.Serialize();
response.ServerBlob = syncBlob.Serialize();
response.EntityList = entities;
}
finally
{
_sqlSyncProvider.EndSession(sessionContext);
}
return response;
}
