private static RecordWritable instantiateWritable(
@Nullable Configuration conf, Id.DatasetInstance datasetInstanceId) throws IOException {
Dataset dataset = instantiate(conf, datasetInstanceId);
if (!(dataset instanceof RecordWritable)) {
dataset.close();
throw new IOException(
String.format(
"Dataset %s does not implement RecordWritable, and hence cannot be written to in Hive.",
datasetInstanceId != null ? datasetInstanceId : getDatasetInstanceId(conf)));
}
return (RecordWritable) dataset;
}
/**
* Returns record type of the RecordScannable.
*
* @param conf Configuration that contains RecordScannable name to load, CDAP and HBase
* configurations.
* @return Record type of RecordScannable dataset.
* @throws IOException in case the conf does not contain a valid RecordScannable.
*/
private static Type getRecordType(Configuration conf, Id.DatasetInstance id) throws IOException {
Dataset dataset = instantiate(conf, id);
try {
if (dataset instanceof RecordWritable) {
return ((RecordWritable) dataset).getRecordType();
} else if (dataset instanceof RecordScannable) {
return ((RecordScannable) dataset).getRecordType();
}
throw new IOException(
String.format(
"Dataset %s does not implement neither RecordScannable nor RecordWritable.",
getDatasetInstanceId(conf)));
} finally {
dataset.close();
}
}
private static synchronized Dataset firstLoad(
DatasetFramework framework,
QueryHandle queryHandle,
Id.DatasetInstance datasetInstanceId,
ClassLoader classLoader)
throws DatasetManagementException, IOException {
ClassLoader datasetClassLoader =
DATASET_CLASSLOADER_MAP.getUnchecked(queryHandle).get(datasetInstanceId);
if (datasetClassLoader != null) {
// Some other call in parallel may have already loaded it, so use the same classlaoder
return framework.getDataset(
datasetInstanceId, DatasetDefinition.NO_ARGUMENTS, datasetClassLoader);
}
// No classloader for dataset exists, load the dataset and save the classloader.
Dataset dataset =
framework.getDataset(datasetInstanceId, DatasetDefinition.NO_ARGUMENTS, classLoader);
if (dataset != null) {
DATASET_CLASSLOADER_MAP
.getUnchecked(queryHandle)
.put(datasetInstanceId, dataset.getClass().getClassLoader());
}
return dataset;
}
