Mailing-List: contact java-dev-help@lucene.apache.org; run by ezmlm
Precedence: bulk
Reply-To: java-dev@lucene.apache.org
Message-ID: <22519926.13051271025581174.JavaMail.jira@thor>
Date: Sun, 11 Apr 2010 18:39:41 -0400 (EDT)
From: "Earwin Burrfoot (JIRA)" <jira@apache.org>
To: java-dev@lucene.apache.org
Subject: [jira] Commented: (LUCENE-2316) Define clear semantics for
 Directory.fileLength
In-Reply-To: <156817700.245141268489487313.JavaMail.jira@brutus.apache.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit


    [ https://issues.apache.org/jira/browse/LUCENE-2316?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12855787#action_12855787 ] 

Earwin Burrfoot commented on LUCENE-2316:
-----------------------------------------

I like Marvin's suggestion - deprecate/delete Dir.fileLength, and rely on InStream.length if needed (I believe if we actually open the file for reading, NFS gives us the correct length?).
If not - throw FNFE, and go for backcompat break instead of new/deprecate cycle.

> Define clear semantics for Directory.fileLength
> -----------------------------------------------
>
>                 Key: LUCENE-2316
>                 URL: https://issues.apache.org/jira/browse/LUCENE-2316
>             Project: Lucene - Java
>          Issue Type: Improvement
>          Components: Index
>            Reporter: Shai Erera
>            Priority: Minor
>             Fix For: 3.1
>
>
> On this thread: http://mail-archives.apache.org/mod_mbox/lucene-java-dev/201003.mbox/%3C126142c1003121525v24499625u1589bbef4c0792e7@mail.gmail.com%3E it was mentioned that Directory's fileLength behavior is not consistent between Directory implementations if the given file name does not exist. FSDirectory returns a 0 length while RAMDirectory throws FNFE.
> The problem is that the semantics of fileLength() are not defined. As proposed in the thread, we'll define the following semantics:
> * Returns the length of the file denoted by <code>name</code> if the file exists. The return value may be anything between 0 and Long.MAX_VALUE.
> * Throws FileNotFoundException if the file does not exist. Note that you can call dir.fileExists(name) if you are not sure whether the file exists or not.
> For backwards we'll create a new method w/ clear semantics. Something like:
> {code}
> /**
>  * @deprecated the method will become abstract when #fileLength(name) has been removed.
>  */
> public long getFileLength(String name) throws IOException {
>   long len = fileLength(name);
>   if (len == 0 && !fileExists(name)) {
>     throw new FileNotFoundException(name);
>   }
>   return len;
> }
> {code}
> The first line just calls the current impl. If it throws exception for a non-existing file, we're ok. The second line verifies whether a 0 length is for an existing file or not and throws an exception appropriately.

-- 
This message is automatically generated by JIRA.
-
If you think it was sent incorrectly contact one of the administrators: https://issues.apache.org/jira/secure/Administrators.jspa
-
For more information on JIRA, see: http://www.atlassian.com/software/jira

        
---------------------------------------------------------------------
To unsubscribe, e-mail: java-dev-unsubscribe@lucene.apache.org
For additional commands, e-mail: java-dev-help@lucene.apache.org