Comments on: asc-gzip/.xfd compression http://www.ourada.org/blog/archives/375 Wed, 26 May 2010 20:30:39 +0000 hourly 1 http://wordpress.org/?v=3.0.1 By: Steven’s weblog » asc-gzip/.xfd decompression http://www.ourada.org/blog/archives/375/comment-page-1#comment-25712 Steven’s weblog » asc-gzip/.xfd decompression Thu, 10 Dec 2009 17:30:14 +0000 http://www.ourada.org/blog/?p=375#comment-25712 [...] to post code for asc-gzip/.xfd decompression to go with my asc-gzip/.xfd compression code. See this comment. I’m also reposting it here because the comment formatting is a little more bad than the [...] [...] to post code for asc-gzip/.xfd decompression to go with my asc-gzip/.xfd compression code. See this comment. I’m also reposting it here because the comment formatting is a little more bad than the [...]

]]> By: Scott Stafford http://www.ourada.org/blog/archives/375/comment-page-1#comment-25711 Scott Stafford Thu, 10 Dec 2009 17:08:03 +0000 http://www.ourada.org/blog/?p=375#comment-25711 Thanks for your post. Of course, I needed the opposite, I had one I needed to decompress. So I backwarded your algorithm and here is the result: <pre> def decompress(fc): fc2 = fc.splitlines(True) fc3 = "".join(fc2[1:]) # could verify that it's asc-gzip here if we wanted to... unb64 = base64.standard_b64decode(fc3) ctr = 0 ret = [] while 1: if ctr == len(unb64): break ccltop = ord(unb64[ctr]) ctr += 1 cclbottom = ord(unb64[ctr]) ctr += 1 compressedchunklen = ccltop * 256 + cclbottom cltop = ord(unb64[ctr]) ctr += 1 clbottom = ord(unb64[ctr]) ctr += 1 chunklen = cltop * 256 + clbottom #~ print compressedchunklen, chunklen compressedchunk = unb64[ctr:ctr+compressedchunklen] ctr += compressedchunklen chunk = zlib.decompress(compressedchunk) assert(len(chunk) == chunklen) ret.append(chunk) return "".join(ret) </pre> Thanks for your post. Of course, I needed the opposite, I had one I needed to decompress. So I backwarded your algorithm and here is the result:

def decompress(fc):
    fc2 = fc.splitlines(True)
    fc3 = "".join(fc2[1:]) # could verify that it's asc-gzip here if we wanted to...
    unb64 = base64.standard_b64decode(fc3)

    ctr = 0
    ret = []
    while 1:
        if ctr == len(unb64): break

        ccltop = ord(unb64[ctr])
        ctr += 1
        cclbottom = ord(unb64[ctr])
        ctr += 1
        compressedchunklen = ccltop * 256 + cclbottom

        cltop = ord(unb64[ctr])
        ctr += 1
        clbottom = ord(unb64[ctr])
        ctr += 1
        chunklen = cltop * 256 + clbottom
        #~ print compressedchunklen, chunklen

        compressedchunk = unb64[ctr:ctr+compressedchunklen]
        ctr += compressedchunklen

        chunk = zlib.decompress(compressedchunk)
        assert(len(chunk) ==  chunklen)
        ret.append(chunk)

    return "".join(ret)
]]> By: anna http://www.ourada.org/blog/archives/375/comment-page-1#comment-25551 anna Wed, 21 Oct 2009 18:11:20 +0000 http://www.ourada.org/blog/?p=375#comment-25551 ahhh, code beautiful code! Remember the night I "watched you write code"? OO ahhh, code beautiful code! Remember the night I “watched you write code”? OO

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