Add compress and uncompress utility methods #9
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- Add basic constants of zlib. - Add conditions to replace numeric code errors. - Add the utility methods 'zlib-compress' and 'zlib-uncompress'. - Use 'compress2' binding method of zlib to pass compression level. - Add basic test of compress/decompress.
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This shouldn't be using strings / c-strings / etc in this way but rather something like what I did in the leveldb bindings: https://github.com/dylan-foundry/leveldb-dylan
Using byte-storage-address will work for a couple of types, I don't recall the full details at the moment.
But at any rate, the byte data shouldn't be stored into regular strings.
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(If you need help with how to do that stuff, let me me know here or elsewhere and I'll find the time to help you figure it out.) |
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Thank you for your support. I'll read leveldb-dylan and ask you for help later. |
| zlib-binding | ||
| ============ | ||
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| This module binds the functions of the zlib library. |
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Something like this is a little more explicit: "This module creates Dylan bindings that directly reflect the zlib C library."
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| :type: :drm:`<integer>` | ||
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| Return codes for the compression/decompression |
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You should delete "the" here. Perhaps "Return codes for (de)compression functions"
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| .. constant:: $z-need-dict | ||
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| If a preset dictionary is needed. |
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| .. constant:: $z-ok | ||
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| Returned if the operation was a success. |
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Optional: you could remove "Returned if" from all these constants since that part is implied. In this case: "The operation was a success." It's up to you though; either way is perfectly clear.
| .. constant:: $z-buf-error | ||
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| If no progress was possible or if there was not enough room in the | ||
| output buffer when ``$z-finish`` is used. |
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Remove both "if"s and be consistent with tense: was possible ... was used.
| Byte length of the destination buffer, which must be at least | ||
| the value returned by :func:`z-compress-bound`. At exit it | ||
| contains the actual size of compressed data. An instance of | ||
| :drm:`<integer>` |
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Dylan doesn't have "out" parameters so it's not possible for destination-length to contain the actual size on exit. Not sure what this should say instead. Delete the middle sentence?
| :discussion: | ||
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| It's equivalent to :func:`z-compress-2` with a *level* parameter | ||
| :const:`$z-default-compression`. |
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| :signature: | ||
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| z-compress-2 *string* *destination-length* *source* *source-length* *level* => (*return-code*) |
| :parameter destination: | ||
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| Destination buffer of the compressed string. | ||
| An instance of :class:`<C-string>` |
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In the code this is type <c-buffer-offset>. Not sure what that is.
| Returns an upper bound on the compressed size after | ||
| :func:`z-compress` or :func:`z-compress-2` on *source-length* | ||
| bytes. It would be used before a :func:`z-compress` or | ||
| :func:`z-compress-2` call to allocate the destination buffer. |
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It may be used ... to decide the size of the destination buffer.
Thanks to the comments of @cgay
Add utility methods compress, uncompress and documentation.