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https://issues.apache.org/jira/browse/CSV-131?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14129499#comment-14129499
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Holger Stratmann commented on CSV-131:
--------------------------------------
The PositionTrackingTest_20140907 is "just" a test for the initial patch with
no changes to the other (non-test) classes. This is non-overlapping with the
initial patch.
PositionTrackingFull_v101_20140910 contains a new "full" version of the main
classes with an additional change as described in my last comment and the tests
that go along with that. If you use this file, you can disregard the others.
Sorry for the confusion.
> save positions of records to enable random access
> -------------------------------------------------
>
> Key: CSV-131
> URL: https://issues.apache.org/jira/browse/CSV-131
> Project: Commons CSV
> Issue Type: Improvement
> Components: Parser
> Affects Versions: 1.1
> Reporter: Holger Stratmann
> Priority: Minor
> Attachments: PositionTrackingFull_v101_20140910.patch,
> PositionTrackingTest_20140907.patch, PositionTracking_20140907.patch
>
> Original Estimate: 1h
> Remaining Estimate: 1h
>
> It would be good to have {{CSVRecord}} save its position in the source stream.
> Reason: Knowing the position of the records would enable random access to
> retrieve records from the source (after reading it once to build an index) if
> the file is too large to be read into memory (or if we don't want to read the
> full file to access a record in the middle).
> Additional info: I have created a "random access csv reader" and a "csv
> viewer" (Swing) for arbitrarily large CSV files. It requires one additional
> scan of the file to build an index (multi-byte charsets supported). The index
> can be saved to a file so it only needs to be built once. Because the lexer
> uses a BufferedReader, we need "internal information" to know where each
> record starts.
> The change to "core" is minor: one field in {{CSVRecord}}s and some
> associated methods to store the position.
> Patch will be attached.
> Code for random access (both UI and non-UI) will be proposed (and possibly
> submitted) as a separate issue. It could also be an independent add-on but
> requires this one little change to Commons CSV.
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