markap14 commented on a change in pull request #4948: URL: https://github.com/apache/nifi/pull/4948#discussion_r666550072
########## File path: nifi-nar-bundles/nifi-scripting-bundle/nifi-scripting-processors/src/main/java/org/apache/nifi/processors/script/ScriptedRouterProcessor.java ########## @@ -0,0 +1,213 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You under the Apache License, Version 2.0 + * (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +package org.apache.nifi.processors.script; + +import org.apache.nifi.annotation.behavior.EventDriven; +import org.apache.nifi.annotation.behavior.InputRequirement; +import org.apache.nifi.annotation.behavior.Restricted; +import org.apache.nifi.annotation.behavior.Restriction; +import org.apache.nifi.annotation.behavior.SideEffectFree; +import org.apache.nifi.annotation.behavior.SupportsBatching; +import org.apache.nifi.annotation.behavior.WritesAttribute; +import org.apache.nifi.annotation.behavior.WritesAttributes; +import org.apache.nifi.components.PropertyDescriptor; +import org.apache.nifi.components.RequiredPermission; +import org.apache.nifi.flowfile.FlowFile; +import org.apache.nifi.processor.ProcessContext; +import org.apache.nifi.processor.ProcessSession; +import org.apache.nifi.processor.Relationship; +import org.apache.nifi.processor.exception.ProcessException; +import org.apache.nifi.processor.io.InputStreamCallback; +import org.apache.nifi.schema.access.SchemaNotFoundException; +import org.apache.nifi.serialization.MalformedRecordException; +import org.apache.nifi.serialization.RecordReader; +import org.apache.nifi.serialization.RecordReaderFactory; +import org.apache.nifi.serialization.RecordSetWriter; +import org.apache.nifi.serialization.RecordSetWriterFactory; +import org.apache.nifi.serialization.record.PushBackRecordSet; +import org.apache.nifi.serialization.record.Record; +import org.apache.nifi.serialization.record.RecordSchema; +import org.apache.nifi.serialization.record.RecordSet; + +import javax.script.ScriptEngine; +import javax.script.ScriptException; +import java.io.IOException; +import java.io.InputStream; +import java.io.OutputStream; +import java.util.HashMap; +import java.util.List; +import java.util.Map; +import java.util.Optional; +import java.util.function.BiFunction; + +@EventDriven +@SupportsBatching +@SideEffectFree +@InputRequirement(InputRequirement.Requirement.INPUT_REQUIRED) +@Restricted(restrictions = { + @Restriction(requiredPermission = RequiredPermission.EXECUTE_CODE, + explanation = "Provides operator the ability to execute arbitrary code assuming all permissions that NiFi has.") +}) +@WritesAttributes({ + @WritesAttribute(attribute = "mime.type", description = "Sets the mime.type attribute to the MIME Type specified by the Record Writer"), + @WritesAttribute(attribute = "record.count", description = "The number of records within the flow file."), + @WritesAttribute(attribute = "record.error.message", description = "This attribute provides on failure the error message encountered by the Reader or Writer.") +}) +public abstract class ScriptedRouterProcessor<T> extends ScriptedProcessor { + private final Class<T> scriptResultType; + + /** + * @param scriptResultType Defines the expected result type of the user-provided script. + */ + protected ScriptedRouterProcessor(final Class<T> scriptResultType) { + this.scriptResultType = scriptResultType; + } + + @Override + protected List<PropertyDescriptor> getSupportedPropertyDescriptors() { + return DESCRIPTORS; + } + + @Override + public void onTrigger(final ProcessContext context, final ProcessSession session) throws ProcessException { + final FlowFile flowFile = session.get(); + if (flowFile == null) { + return; + } + + final ScriptRunner scriptRunner = pollScriptRunner(); + if (scriptRunner == null) { + // This shouldn't happen. But just in case. + session.rollback(); + return; + } + + boolean success = false; + + try { + final ScriptEvaluator evaluator; + + try { + final ScriptEngine scriptEngine = scriptRunner.getScriptEngine(); + evaluator = createEvaluator(scriptEngine, flowFile); + } catch (final ScriptException se) { + getLogger().error("Failed to initialize script engine", se); + session.transfer(flowFile, getFailureRelationship()); + return; + } + + success = route(context, session, flowFile, evaluator); + } finally { + offerScriptRunner(scriptRunner); + } + + session.transfer(flowFile, success ? getOriginalRelationship() : getFailureRelationship()); + } + + private boolean route( + final ProcessContext context, + final ProcessSession session, + final FlowFile incomingFlowFile, + final ScriptEvaluator evaluator + ) { + final RecordReaderFactory readerFactory = context.getProperty(RECORD_READER).asControllerService(RecordReaderFactory.class); + final RecordSetWriterFactory writerFactory = context.getProperty(RECORD_WRITER).asControllerService(RecordSetWriterFactory.class); + final Map<String, String> originalAttributes = incomingFlowFile.getAttributes(); + + try { + session.read(incomingFlowFile, new InputStreamCallback() { + @Override + public void process(final InputStream in) throws IOException { + try ( + final RecordReader reader = readerFactory.createRecordReader(originalAttributes, in, incomingFlowFile.getSize(), getLogger()) + ) { + final RecordSchema schema = writerFactory.getSchema(originalAttributes, reader.getSchema()); + final RecordSet recordSet = reader.createRecordSet(); + final PushBackRecordSet pushBackSet = new PushBackRecordSet(recordSet); + final Map<Relationship, RecordBatchingProcessorFlowFileBuilder> recordSetFlowFileBuilders = new HashMap<>(); + final BiFunction<FlowFile, OutputStream, RecordSetWriter> recordSetWriterFactory = (outgoingFlowFile, out) -> { + try { + return writerFactory.createWriter(getLogger(), schema, out, outgoingFlowFile); + } catch (final IOException | SchemaNotFoundException e) { + throw new ProcessException("Could not create RecordSetWriter", e); + } + }; + + int index = 0; + + // Reading in records and evaluate script + while (pushBackSet.isAnotherRecord()) { + final Record record = pushBackSet.next(); + final Object evaluatedValue = evaluator.evaluate(record, index++); + getLogger().debug("Evaluated scripted against {} (index {}), producing result of {}", record, index - 1, evaluatedValue); + + if (evaluatedValue != null && scriptResultType.isInstance(evaluatedValue)) { + final Optional<Relationship> outgoingRelationship = resolveRelationship(scriptResultType.cast(evaluatedValue)); + + if (outgoingRelationship.isPresent()) { + if (!recordSetFlowFileBuilders.containsKey(outgoingRelationship.get())) { + recordSetFlowFileBuilders.put(outgoingRelationship.get(), new RecordBatchingProcessorFlowFileBuilder(incomingFlowFile, session, recordSetWriterFactory)); + } + + final int recordCount = recordSetFlowFileBuilders.get(outgoingRelationship.get()).addRecord(record); + session.adjustCounter("Record Processed", recordCount, false); + } else { + getLogger().debug("Record with evaluated value {} has no outgoing relationship determined", String.valueOf(evaluatedValue)); + } + } else { + throw new ProcessException("Script returned a value of " + evaluatedValue + + " but this Processor requires that the object returned by an instance of " + scriptResultType.getSimpleName()); + } + } + + // Sending outgoing flow files + recordSetFlowFileBuilders.forEach((relationship, builder) -> session.transfer(builder.build(), relationship)); + } catch (final ScriptException | SchemaNotFoundException | MalformedRecordException e) { + throw new ProcessException("Failed to parse incoming FlowFile", e); + } + } + }); + + return true; + } catch (final Exception e) { + getLogger().error("Error during routing records", e); + return false; + } + } + + /** + * @return Returns with the relationship used for route the incoming FlowFile in case of successful processing. + */ + protected abstract Relationship getOriginalRelationship(); + + /** + * @return Returns with the relationship used for route the incoming FlowFile in case of unsuccessful processing. + */ + protected abstract Relationship getFailureRelationship(); + + /** + * Returns a relationship based on the script's result value. As the script uses a given record as input, this helps + * to dissolve the result value for the routing. + * + * @param scriptResult The value returned by the script. + * + * @return Returns with a relationship if there is one to determine based on the value. If it is not possible to determine + * an {code Optional#empty} is expected. Records with empty relationship will not be routed into any relationship (expect for Review comment: Think that was supposed to be 'except for' instead of 'expect for' -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: issues-unsubscr...@nifi.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
