public override async Task <bool> Open(long auditKey, SelectQuery query, CancellationToken cancellationToken)
{
AuditKey = auditKey;
_selectQuery = query;
if (_isOpen)
{
throw new ConnectionException("The file reader connection is already open.");
}
// if a filename was specified in the query, use this, otherwise, get a list of files from the incoming directory.
if (string.IsNullOrEmpty(query?.FileName))
{
_files = await _fileConnection.GetFileEnumerator(CacheFlatFile, EFlatFilePath.Incoming,
CacheFlatFile.FileMatchPattern);
}
else
{
_files = await _fileConnection.GetFileEnumerator(CacheFlatFile, query.Path,
query.FileName);
}
if (_files.MoveNext() == false)
{
throw new ConnectionException($"There are no matching files in the incoming directory.");
}
var fileStream = await _fileConnection.GetReadFileStream(CacheFlatFile, EFlatFilePath.Incoming, _files.Current.FileName);
if (_fileNameOrdinal >= 0)
{
_baseRow[_fileNameOrdinal] = _files.Current.FileName;
}
try
{
await _fileHandler.SetStream(fileStream, query);
}
catch (Exception ex)
{
throw new ConnectionException($"Failed to read the file {_files.Current.FileName}. {ex.Message}", ex);
}
return(true);
}
public override async Task <bool> Open(long auditKey, SelectQuery query, CancellationToken cancellationToken)
{
AuditKey = auditKey;
try
{
if (_isOpen)
{
throw new ConnectionException("The information hub connection is already open.");
}
var downloadUrl = await _dexihConnection.GetDownloadUrl();
var intanceId = await _dexihConnection.GetRemoteAgentInstanceId();
// call the central web server to requet the query start.
var message = Json.SerializeObject(new
{
HubName = ReferenceConnection.DefaultDatabase,
CacheTable.SourceConnectionName,
TableName = CacheTable.Name,
TableSchema = CacheTable.Schema,
Query = query,
DownloadUrl = downloadUrl,
InstanceId = intanceId
}, "");
var content = new StringContent(message, Encoding.UTF8, "application/json");
var response = await _dexihConnection.HttpPost("OpenTableQuery", content);
if ((bool)response["success"])
{
_dataUrl = response["value"].ToString();
}
else
{
throw new ConnectionException($"Error {response?["message"]}", new Exception(response["exceptionDetails"].ToString()));
}
// use the returned url, to start streaming the data.
using (var httpClient = new HttpClient())
{
var response2 = await httpClient.GetAsync(_dataUrl, HttpCompletionOption.ResponseHeadersRead, cancellationToken);
if (response2.StatusCode == HttpStatusCode.InternalServerError)
{
var responseString = await response2.Content.ReadAsStringAsync();
var result = JObject.Parse(responseString);
var returnValue = result.ToObject <ReturnValue>();
throw new ConnectionException("Dexih Reader Failed. " + returnValue.Message,
returnValue.Exception);
}
var responseStream = await response2.Content.ReadAsStreamAsync();
var config = new FileConfiguration();
_fileHandler = new FileHandlerText(CacheTable, config);
await _fileHandler.SetStream(responseStream, null);
_baseRow = new object[CacheTable.Columns.Count];
return(true);
}
}
catch (Exception ex)
{
throw new ConnectionException($"Opening connection to information hub failed. {ex.Message}", ex);
}
}
