rsync mechanism of breaking files into chunks

shashank929 · 05-05-2009, 02:34 AM

I'm trying to understand the implementation of rsync where it breaks the files into chunks and computes weak checksum for each of them. But unable to get how it breaks the file and into chunks of what sizes.
Can anyone tell me how it is implmentated in rsync or give me any link where the code is explained.

Thanks in advance....

kaz2100 · 05-05-2009, 07:24 AM

Hya,

Is wikipedia good enough for theory?

In Debian, I roughly browsed source tree, it looks like (may be wrong)

Code:

#define MAX_BLOCK_SIZE ((int32)1 << 17)
#define OLD_MAX_BLOCK_SIZE ((int32)1 << 29)

in rsync.h

Happy Penguins!

shashank929 · 05-06-2009, 01:28 AM

Thanks for that.....
I downloaded the code from site of rsync and in its rsync.h BLOCK_SIZE is 700.

Actually I've gone through wikipedia for theory but I want to understand the code of rsync which is not very well documented. Is there any other souce where I can find some help abt. it.

shashank929 · 05-08-2009, 06:54 AM

Thanks for that.....
I downloaded the code from site of rsync and in its rsync.h BLOCK_SIZE is 700.
and the MAX_BLOCK_SIZE is ((int32)1<<17)

so, does this mean that the block size variable and is set as 700 bytes
and maximum value for it is the same as size of the integer(i thought this because of the 17 left shifts)

please help me with this......