[jira] [Commented] (PIG-3662) Static loadcaster in BinStorage can cause exception

["Lorand Bendig (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/PIG-3662?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13868509#comment-13868509 ] 

Lorand Bendig commented on PIG-3662:
------------------------------------

OK, sure. Thank you for committing it!

> Static loadcaster in BinStorage can cause exception
> ---------------------------------------------------
>
>                 Key: PIG-3662
>                 URL: https://issues.apache.org/jira/browse/PIG-3662
>             Project: Pig
>          Issue Type: Bug
>            Reporter: Lorand Bendig
>            Assignee: Lorand Bendig
>             Fix For: 0.13.0
>
>         Attachments: PIG-3662.patch
>
>
> I came a cross this issue when testing PIG-3642. Consider the following two testcases from {{TestEvalPipeline2}} executed in local mode:
> {{testBinStorageByteCast}}:
> {code}
> A = load 'table_testBinStorageByteCast' as (a0, a1, a2);
> store A into 'table_testBinStorageByteCast.temp' using BinStorage();
> A = load 'table_testBinStorageByteCast.temp' using BinStorage() as (a0, a1, a2);
> B = foreach A generate (long)a0;
> dump B;
> {code}
> {{testBinStorageByteArrayCastsSimple}}:
> {code}
> A = load 'table_bs_ac';
> store A into 'TestEvalPipeline2_BinStorageByteArrayCasts' using
>   org.apache.pig.builtin.BinStorage();
> B = load 'TestEvalPipeline2_BinStorageByteArrayCasts'  using 
>   BinStorage('Utf8StorageConverter') as (name: int, age: int, gpa: float, 
> lage: long, dgpa: double); 
> dump B;
> {code}
> The first testcase should fail (same example at: http://pig.apache.org/docs/r0.12.0/func.html#binstorage) while the second one should pass.
> When I run *only* _testBinStorageByteArrayCastsSimple_ there's no problem, but when it runs *after* _testBinStorageByteCast_, it fails with the same exception as _testBinStorageByteArrayCastsSimple_ :
> {{java.lang.Exception: org.apache.pig.backend.executionengine.ExecException: ERROR 1118: Cannot cast bytes loaded from BinStorage. Please provide a custom converter.}}
> Reason:
> When 'table_testBinStorageByteCast.temp' is loaded, _BinStorage#getLoadCaster()_ sets _UnImplementedLoadCaster_ since casterString is not defined. This causes the exception when _BinStorage#bytesToLong()_ is called during the cast of a0 which is correct. Now move on to the next testcase where _'TestEvalPipeline2_BinStorageByteArrayCasts'_ is loaded. We expect BinStorage to use _Utf8StorageConverter_ as a loadcaster but it will use _UnImplementedLoadCaster_ instead, which results in an exception. It's because caster and casterString are *static* variables in BinStorage, however these are set and accessed like instance variables. Therefore, when BinStorage('Utf8StorageConverter') gets instantiated, it will contain the already initialized caster from the previous run. _BinStorage#getLoadCaster()_ will just return this instead of instantiating Utf8StorageConverter from the provided constructor parameter.
> Are caster and casterString just by accident static? If so, I'd address this issue with the patch attached.



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