[ 
https://issues.apache.org/jira/browse/NIFI-2854?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15671525#comment-15671525
 ] 

ASF GitHub Bot commented on NIFI-2854:
--------------------------------------

Github user markap14 commented on a diff in the pull request:

    https://github.com/apache/nifi/pull/1202#discussion_r88324289
  
    --- Diff: 
nifi-commons/nifi-schema-utils/src/main/java/org/apache/nifi/repository/schema/FieldMapRecord.java
 ---
    @@ -0,0 +1,81 @@
    +/*
    + * 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.repository.schema;
    +
    +import java.util.HashMap;
    +import java.util.Map;
    +
    +public class FieldMapRecord implements Record {
    +    private final Map<String, Object> values;
    +    private final RecordSchema schema;
    +
    +    public FieldMapRecord(final Map<RecordField, Object> values, final 
RecordSchema schema) {
    +        this.schema = schema;
    +        this.values = convertFieldToName(values);
    +    }
    +
    +    private static Map<String, Object> convertFieldToName(final 
Map<RecordField, Object> map) {
    +        final Map<String, Object> nameMap = new HashMap<>(map.size());
    +        for (final Map.Entry<RecordField, Object> entry : map.entrySet()) {
    +            nameMap.put(entry.getKey().getFieldName(), entry.getValue());
    +        }
    +        return nameMap;
    +    }
    +
    +    @Override
    +    public Object getFieldValue(final RecordField field) {
    +        return values.get(field.getFieldName());
    +    }
    +
    +    @Override
    +    public RecordSchema getSchema() {
    +        return schema;
    +    }
    +
    +    @Override
    +    public Object getFieldValue(final String fieldName) {
    +        return values.get(fieldName);
    +    }
    +
    +    @Override
    +    public String toString() {
    +        return "FieldMapRecord[" + values + "]";
    +    }
    +
    +    @Override
    +    public int hashCode() {
    +        return 33 + 41 * values.hashCode();
    +    }
    +
    +    @Override
    +    public boolean equals(final Object obj) {
    --- End diff --
    
    It could be but would require exposing private member variables and the 
logic is trivial enough that I don't think it's necessary.


> Enable repositories to support upgrades and rollback in well defined scenarios
> ------------------------------------------------------------------------------
>
>                 Key: NIFI-2854
>                 URL: https://issues.apache.org/jira/browse/NIFI-2854
>             Project: Apache NiFi
>          Issue Type: Improvement
>          Components: Core Framework
>            Reporter: Mark Payne
>            Assignee: Mark Payne
>             Fix For: 1.1.0
>
>
> The flowfile, swapfile, provenance, and content repositories play a very 
> important roll in NiFi's ability to be safely upgraded and rolled back.  We 
> need to have well documented behaviors, designs, and version adherence so 
> that users can safely rely on these mechanisms.
> Once this is formalized and in place we should update our versioning guidance 
> to reflect this as well.
> The following would be true from NiFi 1.2.0 onward
> * No changes to how the repositories are persisted to disk can be made which 
> will break forward/backward compatibility and specifically this means that 
> things like the way each is serialized to disk cannot change.
> * If changes are made which impact forward or backward compatibility they 
> should be reserved for major releases only and should include a utility to 
> help users with pre-existing data convert from some older format to the newer 
> format.  It may not be feasible to have rollback on major releases.
> * The content repository should not be changed within a major release cycle 
> in any way that will harm forward or backward compatibility.
> * The flow file repository can change in that new fields can be added to 
> existing write ahead log record types but no fields can be removed nor can 
> any new types be added.  Once a field is considered required it must remain 
> required.  Changes may only be made across minor version changes - not 
> incremental.
> * Swap File storage should follow very similar rules to the flow file 
> repository.  Adding a schema to the swap file header may allow some variation 
> there but the variation should only be hints to optimize how they're 
> processed and not change their behavior otherwise. Changes are only permitted 
> during minor version releases.
> * Provenance repository changes are only permitted during minor version 
> releases.  These changes may include adding or removing fields from existing 
> event types.  If a field is considered required it must always be considered 
> required.  If a field is removed then it must not be a required field and 
> there must be a sensible default an older version could use if that value is 
> not found in new data once rolled back.  New event types may be added.  
> Fields or event types not known to older version, if seen after a rollback, 
> will simply be ignored.



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

Reply via email to