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Eryk · Aug 30th, 2005, 6:11 PM

Quote:

Originally Posted by Cerulean

Gzip does a good job of getting text files waay down. You can then pad the data up to 400. Should be pretty easy.
Here's a template you can use when you code it in C++ - it's written in Python (solely because I got curious).

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import zlib

def make400Bytes(s):
    assert len(s) > 400
    compressed = zlib.compress(s)
    if len(compressed) > 400:
        print "Ouch, data size compression problem. Dataset too big, or bad data"
        return None
    compressed = compressed + "#" * (400 - len(compressed))
    return compressed

def make600Bytes(s):
    return zlib.decompress(s.rstrip("#"))


before = """Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Integer at purus. Aliquam posuere nibh. Vestibulum vitae turpis non arcu venenatis luctus. Sed at nisi. Aliquam erat volutpat. Sed urna. Quisque sit amet arcu eu tellus luctus mollis. Phasellus rhoncus vulputate sem. Nunc lacinia nibh. Ut fermentum augue nec odio. Duis fringilla tincidunt elit. 
Mauris urna metus, placerat vitae, porttitor non, scelerisque et, libero. Donec nibh quam, mollis eget, placerat quis, sollicitudin in, magna. Nullam non urna. Vestibulum metus arcu, condimentum pellentesque, porttitor in, tempus ac, erat. Pelle"""
 
print "len(before) =", len(before) # 600
after = make400Bytes(before)
print "len(after) =", len(after) # down to 400
afterAfter = make600Bytes(after)
print "len(afterAfter) =", len(afterAfter) # back up to 600

I'm not sure, but I don't think the C zlib library is simple as the standard-library Python one with a "compress" and "decompress" function pair. If so, it should be quite easily to translate.

Hate to say this but I'm using javascript

I'll be sure to look at it though and see if I can apply it to JS.

iignotus · Aug 30th, 2005, 6:17 PM

So you're trying to store compressed text in a database instead of normal text? To make the database smaller?

Eryk · Aug 30th, 2005, 6:22 PM

I'm writing a script to be used on third party software, which so happens to be a forum system. I creating an RPG, the information for each user will be stored in their signature, limited to 400 characters.

That's where the character limit comes from. It's nothing to do with file/db size.

Cerulean · Aug 30th, 2005, 7:20 PM

Quote:

hate to say this but I'm using javascript

Well, then either implement the zlib compression algorithm in JavaScript and use that, or just call a server-side script via XmlHTTPRequest that sends the data and receives the encrypted/decrypted version.

Eryk · Aug 30th, 2005, 7:39 PM

Thanks a lot for the idea. I can use PHP to implement it.

iignotus · Aug 30th, 2005, 8:43 PM

Quote:

Originally Posted by Eryk

I'm writing a script to be used on third party software, which so happens to be a forum system. I creating an RPG, the information for each user will be stored in their signature, limited to 400 characters.

That's where the character limit comes from. It's nothing to do with file/db size.

You should've said that in your first post. Always try to be as descriptive as possible.

You're probably going to have a lot of trouble getting a meaningful display out of echoing compressed data into a signature. I'd suggest writing the information-creation routine so that it creates less data in the first place, or rewrite a whole other compression idea that is lossy (like shorthand) and gives a meaningful display of the data.

Eryk · Aug 30th, 2005, 8:56 PM

I understand the idea that detail is important, but I figured the maximum number of characters would be fine, and not why I wanted it that way.

The signature will be hidden using javascript, it's not meant to display the data directly, but rather to be read by javascript.

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Aug 30th, 2005, 6:22 PM	#13
Eryk Programmer Join Date: Jul 2005 Posts: 62 Rep Power: 4	I'm writing a script to be used on third party software, which so happens to be a forum system. I creating an RPG, the information for each user will be stored in their signature, limited to 400 characters. That's where the character limit comes from. It's nothing to do with file/db size.

Aug 30th, 2005, 7:39 PM	#15
Eryk Programmer Join Date: Jul 2005 Posts: 62 Rep Power: 4	Thanks a lot for the idea. I can use PHP to implement it.

Aug 30th, 2005, 8:56 PM	#17
Eryk Programmer Join Date: Jul 2005 Posts: 62 Rep Power: 4	I understand the idea that detail is important, but I figured the maximum number of characters would be fine, and not why I wanted it that way. The signature will be hidden using javascript, it's not meant to display the data directly, but rather to be read by javascript.

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Data Compression