Github user bbende commented on a diff in the pull request:
https://github.com/apache/nifi/pull/2639#discussion_r194456502
--- Diff:
nifi-nar-bundles/nifi-hadoop-bundle/nifi-hdfs-processors/src/main/java/org/apache/nifi/processors/hadoop/GetHDFSFileInfo.java
---
@@ -0,0 +1,803 @@
+/*
+ * 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.hadoop;
+
+import java.io.IOException;
+import java.security.PrivilegedExceptionAction;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.TimeUnit;
+import java.util.regex.Pattern;
+
+import org.apache.commons.lang3.StringUtils;
+import org.apache.hadoop.fs.FileStatus;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.fs.permission.FsAction;
+import org.apache.hadoop.fs.permission.FsPermission;
+import org.apache.hadoop.security.UserGroupInformation;
+import org.apache.nifi.annotation.behavior.InputRequirement;
+import org.apache.nifi.annotation.behavior.InputRequirement.Requirement;
+import org.apache.nifi.annotation.behavior.TriggerSerially;
+import org.apache.nifi.annotation.behavior.TriggerWhenEmpty;
+import org.apache.nifi.annotation.behavior.WritesAttribute;
+import org.apache.nifi.annotation.behavior.WritesAttributes;
+import org.apache.nifi.annotation.documentation.CapabilityDescription;
+import org.apache.nifi.annotation.documentation.SeeAlso;
+import org.apache.nifi.annotation.documentation.Tags;
+import org.apache.nifi.components.AllowableValue;
+import org.apache.nifi.components.PropertyDescriptor;
+import org.apache.nifi.components.PropertyValue;
+import org.apache.nifi.components.ValidationContext;
+import org.apache.nifi.components.ValidationResult;
+import org.apache.nifi.expression.ExpressionLanguageScope;
+import org.apache.nifi.flowfile.FlowFile;
+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.exception.ProcessException;
+import org.apache.nifi.processor.util.StandardValidators;
+import
org.apache.nifi.processors.hadoop.GetHDFSFileInfo.HDFSFileInfoRequest.Groupping;
+
+@TriggerSerially
+@TriggerWhenEmpty
+@InputRequirement(Requirement.INPUT_ALLOWED)
+@Tags({"hadoop", "HDFS", "get", "list", "ingest", "source", "filesystem"})
+@CapabilityDescription("Retrieves a listing of files and directories from
HDFS. "
+ + "This processor creates a FlowFile(s) that represents the HDFS
file/dir with relevant information. "
+ + "Main purpose of this processor to provide functionality similar
to HDFS Client, i.e. count, du, ls, test, etc. "
+ + "Unlike ListHDFS, this processor is stateless, supports incoming
connections and provides information on a dir level. "
+ )
+@WritesAttributes({
+ @WritesAttribute(attribute="hdfs.objectName", description="The name of
the file/dir found on HDFS."),
+ @WritesAttribute(attribute="hdfs.path", description="The path is set
to the absolute path of the object's parent directory on HDFS. "
+ + "For example, if an object is a directory 'foo', under
directory '/bar' then 'hdfs.objectName' will have value 'foo', and 'hdfs.path'
will be '/bar'"),
+ @WritesAttribute(attribute="hdfs.type", description="The type of an
object. Possible values: directory, file, link"),
+ @WritesAttribute(attribute="hdfs.owner", description="The user that
owns the object in HDFS"),
+ @WritesAttribute(attribute="hdfs.group", description="The group that
owns the object in HDFS"),
+ @WritesAttribute(attribute="hdfs.lastModified", description="The
timestamp of when the object in HDFS was last modified, as milliseconds since
midnight Jan 1, 1970 UTC"),
+ @WritesAttribute(attribute="hdfs.length", description=""
+ + "In case of files: The number of bytes in the file in HDFS.
"
+ + "In case of dirs: Retuns storage space consumed by
directory. "
+ + ""),
+ @WritesAttribute(attribute="hdfs.count.files", description="In case of
type='directory' will represent total count of files under this dir. "
+ + "Won't be populated to other types of HDFS objects. "),
+ @WritesAttribute(attribute="hdfs.count.dirs", description="In case of
type='directory' will represent total count of directories under this dir
(including itself). "
+ + "Won't be populated to other types of HDFS objects. "),
+ @WritesAttribute(attribute="hdfs.replication", description="The number
of HDFS replicas for the file"),
+ @WritesAttribute(attribute="hdfs.permissions", description="The
permissions for the object in HDFS. This is formatted as 3 characters for the
owner, "
+ + "3 for the group, and 3 for other users. For example
rw-rw-r--"),
+ @WritesAttribute(attribute="hdfs.status", description="The status
contains comma separated list of file/dir paths, which couldn't be
listed/accessed. "
+ + "Status won't be set if no errors occured."),
+ @WritesAttribute(attribute="hdfs.full.tree", description="When
destination is 'attribute', will be populated with full tree of HDFS directory
in JSON format.")
--- End diff --
I'm wondering if we should only allow destination of attributes when group
is set to none, because otherwise this could create quite a large string for a
flow file attribute. Imagine the size of the JSON document if you had grouping
"all" with recursive "true" and found 10k files/dirs. Large flow file
attributes can negatively impact the flow file repo as well as GC/heap usage,
but maybe it is a use-at-your-own-risk situation?
---
