[jira] [Comment Edited] (KYLIN-2956) building trie dictionary blocked on value of length over 4095

["Wang, Gang (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/KYLIN-2956?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16294449#comment-16294449 ] 

Wang, Gang edited comment on KYLIN-2956 at 12/18/17 2:16 AM:
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I think when building trie dictionary, 32767 is too huge as the value length limit, 8191 should make sense. Fix as '0xFFFFE000'.


was (Author: gwang3):
I think when building trie dictionary, 32767 is too huge as the value length limit, 8191 should make length. Fix as '0xFFFFE000'.

> building trie dictionary blocked on value of length over 4095 
> --------------------------------------------------------------
>
>                 Key: KYLIN-2956
>                 URL: https://issues.apache.org/jira/browse/KYLIN-2956
>             Project: Kylin
>          Issue Type: Bug
>          Components: General
>            Reporter: Wang, Gang
>            Assignee: Wang, Gang
>         Attachments: 0001-KYLIN-2956-building-trie-dictionary-blocked-on-value.patch
>
>
> In the new release, Kylin will check the value length when building trie dictionary, in class TrieDictionaryBuilder method buildTrieBytes, through method:
> private void positiveShortPreCheck(int i, String fieldName) {
>     if (!BytesUtil.isPositiveShort(i)) {
>         throw new IllegalStateException(fieldName + " is not positive short, usually caused by too long dict value.");
>     }
> }
> public static boolean isPositiveShort(int i) {
>     return (i & 0xFFFF7000) == 0;
> }
> And 0xFFFF7000 in binary:  1111 1111 1111 1111 0111 0000 0000 0000, so the value length should be less than  0000 0000 0000 0000 0001 0000 0001 1111, values 4095 in decimalism.
> I wonder why is 0xFFFF7000, should 0xFFFF8000 (1111 1111 1111 1111 1000 0000 0000 0000), support max length:  0000 0000 0000 0000 0111 1111 1111 1111  (32767) 
> be what you want? 
> Or 32767 may be too large, I prefer use 0xFFFFE000, 0xFFFFE000 (1111 1111 1111 1111 1110 0000 0000 0000), support max length: 0000 0000 0000 0000 0001 1111 1111 1111  (8191) 
>      



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