Messages in this thread |  | | Subject | Re: [PATCH 0/1] cover-letter/lz4: Implement lz4 with dynamic offset length. | From | Maninder Singh <> | Date | Mon, 02 Apr 2018 11:33:54 +0530 |
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Hello,
>> (Added cover letter to avoid much text in patch description) >> >> LZ4 specification defines 2 byte offset length for 64 KB data. >> But in case of ZRAM we compress data per page and in most of >> architecture PAGE_SIZE is 4KB. So we can decide offset length based >> on actual offset value. For this we can reserve 1 bit to decide offset >> length (1 byte or 2 byte). 2 byte required only if ofsset is greater than 127, >> else 1 byte is enough. > >So what happens if I compress the data on a system with no dyn >offset and then send it over the network to a machine which has >dyn offset? Or, say, I have a USB stick with a compression enabled >FS, store files on a dyn offset enabled PC and then mount that USB >stick on a machine with no dyn offset support. And vice versa.
lz4_dyn is not an extension of LZ4 so there is no backward compatibility. Consider this as a different algorithm adapted from LZ4 for better compression ratio.
Thanks Maninder Singh
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