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Extreme compression! #2

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v-python opened this issue Jan 24, 2015 · 3 comments
Open

Extreme compression! #2

v-python opened this issue Jan 24, 2015 · 3 comments

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@v-python
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Taking this code out for a spin, because I use Python to generate JS code in one application, I loaded a random text file off my system into Python, it was 253990 characters, and ran compress, and got 41993 characters back. It decompressed fine. Yay!

But then I tried out compressToUTF16, and got 8 characters back. And there seems not to be a decompressFromUTF16! But I sort of doubt that 8 characters could hold the original file...

@v-python
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Ah, the problem is in the "elif status == 2:" case, where output is assigned with = rather than +=

@v-python
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Here's a decompressFromUTF16... sorry, I haven't figured out Pull Requests, etc.

def decompressFromUTF16( self, string ):
    if not string:
         return ""
    output = ""
    status=0
    i = 0

    while i < len( string ):
        c = ord(string[i]) - 32
        i += 1

        if status == 0:
            status = 1
            current = c << 1
        elif status == 1:
            status = 2
            output += chr(current + (c >> 14))
            current = (c & 16383) << 2
        elif status == 2:
            status = 3
            output += chr(current + (c >> 13))
            current = (c & 8191) << 3
        elif status == 3:
            status = 4
            output += chr(current + (c >> 12))
            current = (c & 4095) << 4
        elif status == 4:
            status = 5
            output += chr(current + (c >> 11))
            current = (c & 2047) << 5
        elif status == 5:
            status = 6
            output += chr(current + (c >> 10))
            current = (c & 1023) << 6
        elif status == 6:
            status = 7
            output += chr(current + (c >> 9))
            current = (c & 511) << 7
        elif status == 7:
            status = 8
            output += chr(current + (c >> 8))
            current = (c & 255) << 8
        elif status == 8:
            status = 9
            output += chr(current + (c >> 7))
            current = (c & 127) << 9
        elif status == 9:
            status = 10
            output += chr(current + (c >> 6))
            current = (c & 63) << 10
        elif status == 10:
            status = 11
            output += chr(current + (c >> 5))
            current = (c & 31) << 11
        elif status == 11:
            status = 12
            output += chr(current + (c >> 4))
            current = (c & 15) << 12
        elif status == 12:
            status = 13
            output += chr(current + (c >> 3))
            current = (c & 7) << 13
        elif status == 13:
            status = 14
            output += chr(current + (c >> 2))
            current = (c & 3) << 14
        elif status == 14:
            status = 15
            output += chr(current + (c >> 1))
            current = (c & 1) << 15
        elif status == 15:
            status = 0
            output += chr(current + c)
            current = (c & 1) << 15

    return self.decompress(output);

@eduardtomasek
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thanks

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