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Niels Lohmann
40a14c4ed8
The SAX interface documents that the string handed to json_sax::string() may be moved from, and the DOM handlers already move the one handed to binary(). string() did not, so every string value was copy-constructed out of the lexer's token buffer, which then kept the buffer alive at its high-water mark until the next token overwrote it. Moving hands that buffer to the new value instead. The allocation count is unchanged - the value needed one either way - but the copy is gone. jeopardy 247.3 ms -> 240.9 ms (-2.6%) citm_catalog 4.61 ms -> 4.48 ms (-2.8%) 40k 30-char strings 7.80 ms -> 7.64 ms (-2.1%) Note this deliberately does not extend to the object key. Moving the key hands the lexer's buffer - sized for the largest token seen so far - to a key that is usually short, so the next value has to grow a fresh buffer. Measured, that costs 11.9% on a document of many small keys with longer values. Signed-off-by: Niels Lohmann <mail@nlohmann.me>