[Box Backup] Experimental questions on boxbackup

[Noah yan]

Thanks Ben for answering the questions, also the sources do have lots
of document and it is very clean. Also some questsion following on.

In backupclient/BackupStoreFileEncodeStream.h and cpp file, what is
the concept of a receip for them?

What I understand is that most of the performance cost in the backup
process are in the rsync checksum calculating, rolling, etc, and the
crypting in the BackupStoreFileEncodeStream, am I right?

Thanks again.
Noah

On 7/1/05, Ben Summers <ben@fluffy.co.uk> wrote:
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> On 1 Jul 2005, at 16:32, Noah yan wrote:
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> > Dear All,
> >
> > I am doing some experiment on boxbackup for its performance. Several
> > questions about the rollingchecksum of rsync: thanks in advance for
> > answering
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> see notes/encrypt_rsync.txt which explains what's going on in the
> algorithm. It's not the same as rysnc. The concept is almost the
> same, but the actual algorithms are quite different. Encryption makes
> things difficult.
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> > 1. What the block size of each file are splited to calculate its
> > checksum? Or what is the range if it is fixed
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> see BackupStoreFileEncodeStream::CalculateBlockSizes() in lib/
> backupclient/BackupStoreFileEncodeStream.cpp
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> > 2. What if there are overflow when calcualting the sum, such as the a
> > and b in rollingchecksum algorithm. I noticed that a is 16bit as sum
> > for 8bit data, how overflow is handled if have in the algorithm, or
> > other ways to avoid this?
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> see lib/crypto/RollingChecksum.h / .cpp
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> That's the lovely thing about open source. You have the source! And
> in this case, documentation too.
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> Ben
>=20
>=20
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