Examples with CreateFunctionDesc org.apache.hadoop.hive.ql.ddl.function.create.CreateFunctionDesc used on opensource projects

Example 1 with CreateFunctionDesc

use of org.apache.hadoop.hive.ql.ddl.function.create.CreateFunctionDesc in project hive by apache.

the class CreateFunctionHandler method handle.

@Override
public List<Task<?>> handle(Context context) throws SemanticException {
    try {
        FunctionDescBuilder builder = new FunctionDescBuilder(context);
        CreateFunctionDesc descToLoad = builder.build();
        this.functionName = builder.metadata.function.getFunctionName();
        context.log.debug("Loading function desc : {}", descToLoad.toString());
        Task<DDLWork> createTask = TaskFactory.get(new DDLWork(readEntitySet, writeEntitySet, descToLoad, true, context.getDumpDirectory(), context.getMetricCollector()), context.hiveConf);
        context.log.debug("Added create function task : {}:{},{}", createTask.getId(), descToLoad.getName(), descToLoad.getClassName());
        // different handlers, unless this is a common pattern that is seen, leaving this here.
        if (context.dmd != null) {
            updatedMetadata.set(context.dmd.getEventTo().toString(), builder.destinationDbName, null, null);
        }
        readEntitySet.add(toReadEntity(new Path(context.location), context.hiveConf));
        if (builder.replCopyTasks.isEmpty()) {
            // reply copy only happens for jars on hdfs not otherwise.
            return Collections.singletonList(createTask);
        } else {
            /**
             *  This is to understand how task dependencies work.
             *  All root tasks are executed in parallel. For bootstrap replication there should be only one root task of creating db. Incremental can be multiple ( have to verify ).
             *  Task has children, which are put in queue for execution after the parent has finished execution.
             *  One -to- One dependency can be satisfied by adding children to a given task, do this recursively where the relation holds.
             *  for many to one , create a barrier task that is the child of every item in 'many' dependencies, make the 'one' dependency as child of barrier task.
             *  add the 'many' to parent/root tasks. The execution environment will make sure that the child barrier task will not get executed unless all parents of the barrier task are complete,
             *  which should only happen when the last task is finished, at which point the child of the barrier task is picked up.
             */
            Task<?> barrierTask = TaskFactory.get(new DependencyCollectionWork(), context.hiveConf);
            builder.replCopyTasks.forEach(t -> t.addDependentTask(barrierTask));
            barrierTask.addDependentTask(createTask);
            return builder.replCopyTasks;
        }
    } catch (Exception e) {
        throw (e instanceof SemanticException) ? (SemanticException) e : new SemanticException("Error reading message members", e);
    }
}