1.5x speed increase by using cmp instead of crc32 #61
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adiov
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After seeing how switching from MD5 to CRC32 cut down our rebalance time by a couple of weeks, I rethought the checksum process to identify even more speed gains.
Since the goal is to check that the new file is an exact copy of the original file, byte-level comparison should be a good alternative to calculating a checksum for the whole file. A
cmpoperation will likely always be faster than any combination of operations used to calculate a checksum. To my delight, this yielded another 1.5x speed improvement.Edit: Apologies for the misleading commit message. I was looking only at the user time rather than the total time. The total time shows 1.5x speed improvement.