Do not copy string content if possible while base64 encoding/decoding #7997
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dreamer-dead
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mike-myers-tob
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Looks pretty similar to other string_view changes. Any of the c folks want to weigh in? (@alessandrogario @Smjert @marcosd4h ) |
Smjert
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Oct 3, 2023
Smjert
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Oct 3, 2023
| std::string decode(std::string&& encoded) { | ||
| boost::erase_all(encoded, "\r\n"); | ||
| boost::erase_all(encoded, "\n"); | ||
| boost::trim_right_if(encoded, boost::is_any_of("=")); |
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Something I don't get from the original function is why we need to do this at all.
This seems an unnecessary performance hit to incur into, which might not be necessary to do (and we also have to scan the string again to understand if it's necessary to), when I think the caller should provide a valid base64 decodable string.
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Main intent of this PR is to avoid string copying while encoding/decoding.
The
encodechange is quite trivial since it didn't copy the input.But the
decodecase is opposite: it needs to remove few symbols from the input string.So I decided to split code of
decodefunction into 2 overloads: first that takes astring_viewand a special function that takes a rvalue reference and can change the string content.I believe that the added linear lookup with
find_first_of("\r\n=")will not make things worse in comparison with previous code but now the encoded string is not copied every time.PTAL