From: Zooko O'Whielacronx zooko@zooko.com Date: Wed, 24 Jan 2007 21:20:53 +0000 (+0530) Subject: nicer API -- you don't have to shuffle the shares into place before calling decode_all() X-Git-Url: https://git.rkrishnan.org/pf/content/en/CLI.txt?a=commitdiff_plain;h=36c3742929ee18191510240bc79131131021bac0;p=tahoe-lafs%2Fzfec.git nicer API -- you don't have to shuffle the shares into place before calling decode_all() Instead it does that shuffling in C inside fecmodule. darcs-hash:ea6a582d227615043c682aac3647560ac0da2125 --- diff --git a/pyfec/fec/fecmodule.c b/pyfec/fec/fecmodule.c index 50dc695..7758ee7 100644 --- a/pyfec/fec/fecmodule.c +++ b/pyfec/fec/fecmodule.c @@ -322,6 +322,8 @@ Decoder_init(Encoder *self, PyObject *args, PyObject *kwdict) { return 0; } +#define SWAP(a,b,t) {t tmp; tmp=a; a=b; b=tmp;} + static char Decoder_decode__doc__[] = "\ Decode a list shares into a list of segments.\n\ @param shares a sequence of buffers containing share data (for best performance, make it a tuple instead of a list)\n\ @@ -394,6 +396,20 @@ Decoder_decode(Decoder *self, PyObject *args) { oldsz = sz; } + /* move src packets into position */ + for (i=0; ikk;) { + if (csharenums[i] >= self->kk || csharenums[i] == i) + i++; + else { + /* put pkt in the right position. */ + unsigned char c = csharenums[i]; + + SWAP (csharenums[i], csharenums[c], int); + SWAP (cshares[i], cshares[c], gf*); + SWAP (fastsharesitems[i], fastsharesitems[c], PyObject*); + } + } + /* Allocate space for all of the recovered shares. */ for (i=0; i= len(nums_and_shares) or num == i: - i += 1 - else: - nums_and_shares[i] = nums_and_shares[num] - nums_and_shares[num] = (num, share,) - _assert([ (i, (num, share,),) for (i, (num, share,),) in enumerate(nums_and_shares) if num < len(nums_and_shares) and num != i ] == [], [ (i, (num, share,),) for (i, (num, share,),) in enumerate(nums_and_shares) if num < len(nums_and_shares) and num != i ]) - def _h(k, m, ss): # sys.stdout.write("k: %s, m: %s, len(ss): %r, len(ss[0]): %r" % (k, m, len(ss), len(ss[0]),)) ; sys.stdout.flush() encer = fec.Encoder(k, m) @@ -28,7 +16,6 @@ def _h(k, m, ss): _assert(isinstance(nums_and_shares, list), nums_and_shares) _assert(len(nums_and_shares) == m, len(nums_and_shares), m) nums_and_shares = random.sample(nums_and_shares, k) - shuffle(nums_and_shares) shares = [ x[1] for x in nums_and_shares ] nums = [ x[0] for x in nums_and_shares ] # sys.stdout.write("about to construct Decoder.\n") ; sys.stdout.flush()