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https://issues.apache.org/jira/browse/OAK-1828?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15027079#comment-15027079
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Michael Dürig commented on OAK-1828:
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I just committed a pretty comprehensive refactoring of the {{SegmentWriter}}:
http://svn.apache.org/r1716466 Encapsulate the state of the segment being
written and its coordination wrt. concurrent access in a separate class
http://svn.apache.org/r1716467 Better encapsulate records cache
http://svn.apache.org/r1716468 Simplify flushing of segments
http://svn.apache.org/r1716469 Factor out duplicate align methods
http://svn.apache.org/r1716470 Eliminate passing the SegmentTracker into the
SegmentWriter
http://svn.apache.org/r1716471 Remove SegmentWriter.getTracker
http://svn.apache.org/r1716472 Move anonymous record writers to top level
http://svn.apache.org/r1716473 Some JavaDoc
As an immediate follow up we should come up with a better name for
{{SegmentBuilder}}. [~frm] came up with {{SegmentBufferWriter}} and I like the
idea as it writes segments and buffer implies the low level aspects it actually
handles. [~alex.parvulescu] WDYT?
> Improved SegmentWriter
> ----------------------
>
> Key: OAK-1828
> URL: https://issues.apache.org/jira/browse/OAK-1828
> Project: Jackrabbit Oak
> Issue Type: Sub-task
> Components: segmentmk
> Reporter: Jukka Zitting
> Assignee: Alex Parvulescu
> Priority: Minor
> Labels: technical_debt
> Fix For: 1.3.12
>
> Attachments: record-writers-v0.patch, record-writers-v1.patch,
> record-writers-v2.patch
>
>
> At about 1kLOC and dozens of methods, the SegmentWriter class currently a bit
> too complex for one of the key components of the TarMK. It also uses a
> somewhat non-obvious mix of synchronized and unsynchronized code to
> coordinate multiple concurrent threads that may be writing content at the
> same time. The synchronization blocks are also broader than what really would
> be needed, which in some cases causes unnecessary lock contention in
> concurrent write loads.
> To improve the readability and maintainability of the code, and to increase
> performance of concurrent writes, it would be useful to split part of the
> SegmentWriter functionality to a separate RecordWriter class that would be
> responsible for writing individual records into a segment. The
> SegmentWriter.prepare() method would return a new RecordWriter instance, and
> the higher-level SegmentWriter methods would use the returned instance for
> all the work that's currently guarded in synchronization blocks.
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