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From "Sachin Goyal (JIRA)" <j...@apache.org>
Subject [jira] [Updated] (AVRO-680) Allow for non-string keys
Date Sat, 26 Jul 2014 08:17:38 GMT

     [ https://issues.apache.org/jira/browse/AVRO-680?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]

Sachin Goyal updated AVRO-680:
------------------------------

    Attachment: non_string_map_keys4.patch

[~cutting], I have incorporated the above suggestions.

Apparently, it isn't exactly possible to call ReflectDatumWriter#writeNonStringMap() from
inside ReflectDatumWriter#writeArray(). This is so because if that happens, then it means
the array-part of non-string-map is already processed and we are at the individual record
level. And at this level, we cannot distinguish the map-entry from a normal array-element.
Due to this, mapEntry.getKey() and mapEntry.getValue() could not be called, leading us back
to relying on the names "key" and "value".

So, I have written a slightly modified version where ReflectDatumWriter#writeNonStringMap()
writes an array and calls ReflectDatumWriter#writeNonStringMapEntry() to write the individual
entries.

Also added test-case for JsonEncoder.

Please review and let me know your comments.

> Allow for non-string keys
> -------------------------
>
>                 Key: AVRO-680
>                 URL: https://issues.apache.org/jira/browse/AVRO-680
>             Project: Avro
>          Issue Type: Improvement
>    Affects Versions: 1.7.6, 1.7.7
>            Reporter: Jeremy Hanna
>         Attachments: AVRO-680.patch, non_string_map_keys.zip, non_string_map_keys2.zip,
non_string_map_keys3.zip, non_string_map_keys4.patch
>
>
> Based on an email thread back in April, Doug Cutting proposed a possible solution for
having non-string keys:
> Stu Hood wrote:
> > I can understand the reasoning behind AVRO-9, but now I need to look for an alternative
to a 'map' that will allow me to store an association of bytes keys to values.
> A map of Foo has the same binary format as an array of records, each
> with a string field and a Foo field.  So an application can use an array
> schema similar to this to represent map-like structures with, e.g.,
> non-string keys.
> Perhaps we could establish standard properties that indicate that a
> given array of records should be represented in a map-like way if
> possible?  E.g.,:
> {"type": "array", "isMap": true, "items": {"type":"record", ...}}
> Doug



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