use of org.apache.samza.sql.translator.TranslatorContext in project samza by apache.
the class SamzaSqlApplication method describe.
@Override
public void describe(StreamApplicationDescriptor appDescriptor) {
try {
// TODO: Introduce an API to return a dsl string containing one or more sql statements.
List<String> dslStmts = SamzaSqlDslConverter.fetchSqlFromConfig(appDescriptor.getConfig());
Map<Integer, TranslatorContext> translatorContextMap = new HashMap<>();
// 1. Get Calcite plan
List<String> inputSystemStreams = new LinkedList<>();
List<String> outputSystemStreams = new LinkedList<>();
Collection<RelRoot> relRoots = SamzaSqlApplicationConfig.populateSystemStreamsAndGetRelRoots(dslStmts, appDescriptor.getConfig(), inputSystemStreams, outputSystemStreams);
// 2. Populate configs
SamzaSqlApplicationConfig sqlConfig = new SamzaSqlApplicationConfig(appDescriptor.getConfig(), inputSystemStreams, outputSystemStreams);
// 3. Translate Calcite plan to Samza stream operators
QueryTranslator queryTranslator = new QueryTranslator(appDescriptor, sqlConfig);
SamzaSqlExecutionContext executionContext = new SamzaSqlExecutionContext(sqlConfig);
// QueryId implies the index of the query in multiple query statements scenario. It should always start with 0.
int queryId = 0;
for (RelRoot relRoot : relRoots) {
LOG.info("Translating relRoot {} to samza stream graph with queryId {}", relRoot, queryId);
TranslatorContext translatorContext = new TranslatorContext(appDescriptor, relRoot, executionContext);
translatorContextMap.put(queryId, translatorContext);
queryTranslator.translate(relRoot, sqlConfig.getOutputSystemStreams().get(queryId), translatorContext, queryId);
queryId++;
}
// 4. Set all translator contexts
/*
* TODO When serialization of ApplicationDescriptor is actually needed, then something will need to be updated here,
* since translatorContext is not Serializable. Currently, a new ApplicationDescriptor instance is created in each
* container, so it does not need to be serialized. Therefore, the translatorContext is recreated in each container
* and does not need to be serialized.
*/
appDescriptor.withApplicationTaskContextFactory(new ApplicationTaskContextFactory<SamzaSqlApplicationContext>() {
@Override
public SamzaSqlApplicationContext create(ExternalContext externalContext, JobContext jobContext, ContainerContext containerContext, TaskContext taskContext, ApplicationContainerContext applicationContainerContext) {
return new SamzaSqlApplicationContext(translatorContextMap);
}
});
} catch (RuntimeException e) {
LOG.error("SamzaSqlApplication threw exception.", e);
throw e;
}
}
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