[
https://issues.apache.org/jira/browse/LUCENE-2373?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12854254#action_12854254
]
Earwin Burrfoot commented on LUCENE-2373:
-----------------------------------------
And then IndexOutput.seek() can be deleted. Cool.
> Change StandardTermsDictWriter to work with streaming and append-only
> filesystems
> ---------------------------------------------------------------------------------
>
> Key: LUCENE-2373
> URL: https://issues.apache.org/jira/browse/LUCENE-2373
> Project: Lucene - Java
> Issue Type: Improvement
> Components: Index
> Reporter: Andrzej Bialecki
> Fix For: 3.1
>
>
> Since early 2.x times Lucene used a skip/seek/write trick to patch the length
> of the terms dict into a place near the start of the output data file. This
> however made it impossible to use Lucene with append-only filesystems such as
> HDFS.
> In the post-flex trunk the following code in StandardTermsDictWriter
> initiates this:
> {code}
> // Count indexed fields up front
> CodecUtil.writeHeader(out, CODEC_NAME, VERSION_CURRENT);
> out.writeLong(0); // leave space for end
> index pointer
> {code}
> and completes this in close():
> {code}
> out.seek(CodecUtil.headerLength(CODEC_NAME));
> out.writeLong(dirStart);
> {code}
> I propose to change this layout so that this pointer is stored simply at the
> end of the file. It's always 8 bytes long, and we known the final length of
> the file from Directory, so it's a single additional seek(length - 8) to read
> it, which is not much considering the benefits.
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
