Faster json string parsing #118
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This significantly speeds up JSON string decoding. Using some ideas borrowed from yyjson, as well as some general performance tricks, we: - Use a new lookup table for determining interesting char values that require special handling. - Have separate processing loops for ascii and unicode - Split off the (less common) escape handling routine into a separate function. - Manually unroll the string processing loops - Apply an inline asm hack to get GCC to generate better code Besides a faster string parsing inner loop, this also lets us determine if a string is all ascii characters for free. In this case, we skip calling `PyUnicode_DecodeUTF8` and instead manually create the new string object, further accelerating decoding.
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This significantly speeds up JSON string decoding. Using some ideas borrowed from yyjson, as well as some general performance tricks, we:
Besides a faster string parsing inner loop, this also lets us determine if a string is all ascii characters for free. In this case, we skip calling
PyUnicode_DecodeUTF8and instead manually create the new string object, further accelerating decoding.In general, this results in:
\\n->\n)