On Mon, Nov 10, 2008 at 11:31:33PM +0000, Gregory Stark wrote: > No, I just meant that you could calculate the CRC by scanning the whole buffer > efficiently using one of the good word-wise CRC algorithms, then look at the > line pointers to find the hint bits and subtract them out of the CRC. The > result should be zero after adjusting for the hint bits.
If you're going to look at the line pointers anyway, couldn't you just
do it in one pass, like:
n = 0
next = &tuple[n].hintbits
pos = 0
while pos < BLOCK_SIZE:
if pos == next:
CRC_ADD( block[pos] & mask )
n++
next = &tuple[n].hintbits # If n == numtups, next = BLOCK_SIZE
else:
CRC_ADD( block[pos]
pos++
This only handles one byte of hintbits but can easily be extended. No
need to actually *store* the hintbit free version anywhere...
Have a nice day,
--
Martijn van Oosterhout <[EMAIL PROTECTED]> http://svana.org/kleptog/
> Please line up in a tree and maintain the heap invariant while
> boarding. Thank you for flying nlogn airlines.
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