protected function loadColumnsProperties(SystemTableMetaModelLoaderCallContext $callcontext, DataSourceMetaData $datasource) {
$tableColumnsProperties = NULL;
$webhcatProxy = new WebHCat_CURLProxy($datasource);
// loading list of available tables
$tableNames = $this->loadTableNames($datasource);
if (isset($tableNames)) {
// preparing requests to load table structure
$tableHandlers = NULL;
foreach ($tableNames as $tableName) {
$tableHandlers[] = $webhcatProxy->initializeHandler('GET', "/templeton/v1/ddl/database/{$datasource->database}/table/$tableName");
}
// processing available tables
$executor = new MultipleCURLHandlerExecutor($tableHandlers);
$executor->start();
while (($handler = $executor->findCompletedHandler()) !== FALSE) {
$responseColumns = $executor->processResponse($handler);
if (!isset($responseColumns['columns'])) {
continue;
}
foreach ($responseColumns['columns'] as $columnIndex => $responseColumn) {
$tableColumnsProperties[] = array(
self::CN_TABLE_NAME => $responseColumns['table'],
self::CN_COLUMN_NAME => $responseColumn['name'],
self::CN_COLUMN_INDEX => $columnIndex,
self::CN_COLUMN_TYPE => $responseColumn['type']);
}
}
}
return $tableColumnsProperties;
}
public function execute(
DataSourceHandler $handler,
DataControllerCallContext $callcontext,
$connection, $sql,
__SQLDataSourceHandler__AbstractQueryCallbackProxy $callbackInstance) {
$datasource = $connection->datasource;
$outputFolder = uniqid('dp', TRUE);
$webhcatProxy = new WebHCat_CURLProxy($datasource);
// executing the sql statement
$statementHandler = $webhcatProxy->initializeHandler(
'POST',
'/templeton/v1/hive',
array('execute' => $sql, 'statusdir' => $outputFolder, 'define=hive.cli.print.header' => 'true'));
$executor = new SingleCURLHandlerExecutor($statementHandler);
$responseJob = $executor->execute();
// ... and preparing job identifier
if (!isset($responseJob['id'])) {
LogHelper::log_debug($responseJob);
throw new IllegalStateException(t(
'Job ID is not available: %error',
array('%error' => (isset($responseJob['info']['stderr']) ? $responseJob['info']['stderr']: 'error message is not provided'))));
}
$jobId = $responseJob['id'];
// waiting for the execution job to complete
$jobHandler = $webhcatProxy->initializeHandler('GET', "/templeton/v1/queue/$jobId");
$executor = new SingleCURLHandlerExecutor($jobHandler);
$responseJobStatus = NULL;
while (TRUE) {
$responseJobStatus = $executor->execute();
if ($responseJobStatus['completed'] == 'done') {
break;
}
usleep(1000000);
}
if ($responseJobStatus['exitValue'] != 0) {
throw new IllegalStateException(t(
'%resourceId execution completed unsuccessfully: %errorCode',
array('%resourceId' => $jobHandler->resourceId, '%errorCode' => $responseJobStatus['exitValue'])));
}
$webhdfsProxy = new WebHDFS_CURLProxy($datasource);
// reading result of the execution
$data = NULL;
while (TRUE) {
$resultHandler = $webhdfsProxy->initializeHandler(
'GET',
"/webhdfs/v1/user/{$datasource->username}/$outputFolder/stdout",
array('op' => 'OPEN'));
$executor = new SingleCURLHandlerExecutor($resultHandler);
$data = $executor->execute();
// the file should contain at least column names
if (isset($data)) {
break;
}
// it looks like the result is empty. That happens because the file is not flushed yet
usleep(10000);
}
// deleting the output folder. We do not need it any more
$resultHandler = $webhdfsProxy->initializeHandler(
'DELETE',
"/webhdfs/v1/user/{$datasource->username}/$outputFolder",
array('op' => 'DELETE', 'recursive' => 'true'));
$executor = new SingleCURLHandlerExecutor($resultHandler);
$executor->execute();
// parsing data
$parsedDataProvider = new SampleDataPreparer(FALSE);
$parser = new DelimiterDataParser("\t");
$parser->isHeaderPresent = TRUE;
$parser->parse(
new StreamDataProvider($data),
array(
new ColumnNamePreparer(),
new ColumnPublicNamePreparer(),
new ColumnTypeAutoDetector(),
$parsedDataProvider));
// calculating column database type
foreach ($parser->metadata->getColumns() as $column) {
$databaseType = NULL;
switch ($column->type->applicationType) {
case StringDataTypeHandler::DATA_TYPE:
$databaseType = 'string';
break;
case IntegerDataTypeHandler::DATA_TYPE:
$databaseType = 'int';
break;
default:
throw new UnsupportedOperationException(t(
'Cannot provide data type mapping for %columnName column: %datatype',
array('%columnName' => $column->name, '%datatype' => $column->type->applicationType)));
}
$column->type->databaseType = $databaseType;
}
$statement = new HiveStatement($parser->metadata, $parsedDataProvider->records);
return $callbackInstance->callback($callcontext, $connection, $statement);
}