Niels Lohmann 6aefd8c662 Copy short printable-ASCII strings without starting the scanner (#5878) ...

dump() now checks strings of up to 32 bytes against a table of the bytes
that can be written verbatim, four bytes per step, and copies them in one
go if all of them can. That is cheaper than setting up the vector scanner,
whose setup costs more than such a string takes to scan; SQLite's
jsonAppendString() writes strings with the same kind of table loop. Most
object keys and many values are this short (citm_catalog averages 8 bytes
per string, jeopardy 14).

GCC 16 and 13 stopped inlining put_indent() and put_literal() into the
pretty-printing loops once dump_escaped() had grown, which made indented
output up to 13% slower; both are now always inlined.

The new test puts every ASCII character and a 2-byte character at every
position of strings of 1 to 40 bytes and compares the output with the
reference implementation of the existing UTF-8 tests.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

2026-10-21 20:01:28 +02:00

..

nlohmann

Copy short printable-ASCII strings without starting the scanner (#5878)

2026-10-21 20:01:28 +02:00