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Re: [jgit-dev] Question on large object streams

Great! We will be happy to try this solution. Thanks :)

On Wed, Oct 6, 2010 at 7:19 PM, Shawn Pearce <spearce@xxxxxxxxxxx> wrote:
> On Wed, Oct 6, 2010 at 7:42 AM, Dmitry Neverov <dmitry.neverov@xxxxxxxxx> wrote:
>> One more question on this: why can't we inflate base object and use
>> RandomAccessFile to read from it?
> I almost had that working.  We use a BufferedInputStream wrapped
> around a FileInputStream, and use skip(long) to fast-forward to the
> position we want.  In this case that translates into a seek system
> call, which is the same as using RandomAccessFile.  But I added a new
> interface that let me reset the file pointer to 0 through the
> FileChannel.  On Linux this had no performance difference from just
> closing the file and re-opening it.  But on Win32 that could actually
> be pretty expensive.
> Maybe instead of using the loose objects as our cache we need an
> independent disk based delta base cache that stores the files as raw
> content, rather than wrapped up in a zlib stream, so we can do random
> seeks to match copy instructions.  This is a whole lot more code to
> write, because we also need to manage pruning items from the cache to
> prevent the disk usage from becoming too high.
> --
> Shawn.

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