5 ms·
TL;DR they rediscovered the context-dependent variable block size technique that Tarsnap uses: https://www.tarsnap.com/download/EuroBSDCon13.pdf https://www.tar
by teraflop 4y ago
TL;DR they rediscovered the context-dependent variable block size technique that Tarsnap uses: https://www.tarsnap.com/download/EuroBSDCon13.pdf https://www.tarsnap.com/download/EuroBSDCon13.pdf
- crazygringo 4y agoThey don't claim to have invented CDC, or FastCDC, they just made and are sharing a useful implementation of it. And if that Tarsnap presentation is from 2013, and FastCDC was published in 2016 [1] according to Wikipedia [2], then presumably Tarsnap didn't invent FastCDC either. [1] https://www.usenix.org/system/files/conference/atc16/atc16-paper-xia.pdf https://www.usenix.org/system/files/conference/atc16/atc16-p... [2] https://en.wikipedia.org/wiki/Rolling_hash#Gear_fingerprint_and_content-based_chunking_algorithm_FastCDC https://en.wikipedia.org/wiki/Rolling_hash#Gear_fingerprint_...
- jyxent 4y agoAnother well-cited predecessor is "A low-bandwidth network file system." (https://dl.acm.org/doi/abs/10.1145/502034.502052 https://dl.acm.org/doi/abs/10.1145/502034.502052), which was published in 2001. It uses Rabin fingerprinting to define chunk boundaries.
- kccqzy 4y agoThe Tarsnap technique is interesting but that presentation is a bit hard to follow. What are the examples for values alpha and p?