Github user ottobackwards commented on a diff in the pull request:
https://github.com/apache/nifi/pull/2802#discussion_r199351889
--- Diff:
nifi-nar-bundles/nifi-standard-bundle/nifi-standard-processors/src/main/java/org/apache/nifi/processors/standard/CalculateAttributeHash.java
---
@@ -0,0 +1,199 @@
+/*
+ * 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.standard;
+
+import org.apache.commons.codec.binary.Hex;
+import org.apache.commons.codec.digest.DigestUtils;
+import org.apache.commons.lang3.StringUtils;
+import org.apache.nifi.annotation.behavior.DynamicProperty;
+import org.apache.nifi.annotation.behavior.EventDriven;
+import org.apache.nifi.annotation.behavior.InputRequirement;
+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.documentation.CapabilityDescription;
+import org.apache.nifi.annotation.documentation.Tags;
+import org.apache.nifi.components.AllowableValue;
+import org.apache.nifi.components.PropertyDescriptor;
+import org.apache.nifi.flowfile.FlowFile;
+import org.apache.nifi.logging.ComponentLog;
+import org.apache.nifi.processor.AbstractProcessor;
+import org.apache.nifi.processor.ProcessContext;
+import org.apache.nifi.processor.ProcessSession;
+import org.apache.nifi.processor.ProcessorInitializationContext;
+import org.apache.nifi.processor.Relationship;
+import org.apache.nifi.processor.util.StandardValidators;
+
+import java.nio.charset.Charset;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.SortedMap;
+import java.util.TreeMap;
+import java.util.concurrent.atomic.AtomicReference;
+
+@EventDriven
+@SideEffectFree
+@SupportsBatching
+@Tags({"attributes", "hash"})
+@InputRequirement(InputRequirement.Requirement.INPUT_REQUIRED)
+@CapabilityDescription("Calculates a hash value for the value specified
attributes and write it to an output attribute. Please refer to
https://csrc.nist.gov/Projects/Hash-Functions/NIST-Policy-on-Hash-Functions
help decide on which algorithm to use.")
+@WritesAttribute(attribute = "<Specified Attribute Name per Dynamic
Property>", description = "This Processor adds an attribute whose value is the
result of "
--- End diff --
After looking through this, I'm not certain what you are saying here. Do
you mean that we don't let them give whatever name they want to the new hash
attributes and instead just name them attr.hash always? I don't understand
about 'overwriting the attribute'. Can you explain that a little more?
HashAttributes already has this capability.
---