Commit Graph
20 Commits
Author SHA1 Message Date
Niels Lohmann 1e101ecac1 Add BON8 support (#2998)
* Add BON8 support

Add to_bon8/from_bon8 and input_format_t::bon8 for BON8, a binary format
that uses the byte values that cannot begin a UTF-8 character as type
markers, so strings need no length prefix. It is the most compact of the
supported binary formats on the benchmark files.

The reader is non-recursive like the other binary readers. A string ends
at the first byte that cannot continue it, so the reader hands the one or
two bytes it reads past a string back to the value that follows. The
writer produces the canonical representation of the specification, except
for NFC normalization; its output is identical to that of the reference
implementation (HikoGUI) on all files of the test data.

The round-trip tests need the .bon8 files of json_test_data 3.2.0.

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

* Address review comments

- Reuse detail::validate_one_utf8 to check strings in to_bon8; the error
  now names the first byte of the invalid sequence.
- Document that to_bon8 leaves bytes in the output adapter on an
  exception, and that string_open is only an output of write_bon8_marker.
- Explain why the pushback buffer of the BON8 reader cannot overflow.

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

* Select the BON8 float prefix by type

get_bon8_float_prefix only depends on the type of its argument, so make
the type a template parameter instead of passing an unused value.

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

* Rename a test variable that Flawfinder mistakes for read()

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

* Fix the BON8 CI failures

- compare the float in write_bon8_float with number_float_t constants,
  so GCC does not warn about a float-to-double conversion
- mark check_bon8_utf8's context as used when exceptions are disabled
- choose the compact float prefix in a helper rather than with nested
  conditional operators (clang-tidy)
- use auto for the cast in the BON8 integer reader (clang-tidy)
- write the int32 minimum test values as long long literals (MSVC C4146)

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

* Amalgamate

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

* Read BON8 strings in bulk from contiguous input

- copy the valid UTF-8 of a string in one step when the input is
  contiguous (twitter.json is read in 1.68 instead of 2.52 ms,
  jeopardy.json in 196 instead of 297 ms, close to CBOR and MessagePack)
- share the new valid_utf8_prefix() with the writer's UTF-8 check, which
  now skips ASCII 8 bytes at a time
- let the fuzzer check that contiguous and stream input give the same
  value or error, and test both paths in the unit tests
- clarify that a second 0xFF after a string is an empty string

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

* Link the BON8 functions from the other binary format pages

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

* Name the bulk scan flag after the input, not BON8

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

* Read BSON keys in bulk from contiguous input

BSON keys (and array indices) are C-style strings, which were read byte
by byte. For contiguous input they are now read up to their \x00-byte in
one step, using the same bulk_scan flag as BON8 strings: twitter.json is
read in 1.46 instead of 2.01 ms, citm_catalog.json in 2.93 instead of
3.33 ms, jeopardy.json in 182 instead of 207 ms. canada.json, whose keys
are almost all one-digit array indices, takes 2 % longer.

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

* Fix the BON8 CI failures of the bulk-read tests

- skip the contiguous-versus-stream tests of BON8 strings and BSON keys
  when exceptions are disabled: they catch the parse errors of invalid
  input, and without exceptions the library aborts instead
- use static_cast for the int64 test value (google-readability-casting)

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

* Move the explicit basic_json instantiation into its own test file

Linking test-regression3_cpp20 with clang and MinGW failed with
"relocation truncated to fit: IMAGE_REL_AMD64_REL32 against `.rdata'",
as test-regression2 did before #5511. The explicit instantiation of
basic_json<> for #4825 compiles every member function, including the
BON8 reader and writer, into that object, and it was already close to
the limit (2,226,104 bytes on develop, 2,234,960 with BON8; clang -O1,
C++20).

Give the instantiation a file of its own: unit-regression3 is now
1,594,736 bytes and unit-explicit_instantiation 1,095,064. The new file
mentions JSON_HAS_CPP_17 and JSON_HAS_CPP_20 so it keeps being built
for the C++17 standard the regression was about.

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

* Convert the bytes of the BON8 test strings explicitly

The str() helper constructed a std::string from a byte range, which
converts each unsigned char implicitly; -fsanitize=integer reports that
for bytes of 0x80 and above (ci_test_clang_sanitizer).

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

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-27 16:56:21 +02:00
Niels Lohmann ec4bdc398a Document the benchmarks, make them build and compare versions again, and pin Google Benchmark (#5556)
* Document the benchmarks, and make them build and compare versions again

The benchmark project hasn't configured since #4793: download_test_data.cmake
compiles cmake/detect_libcpp_version.cpp relative to CMAKE_SOURCE_DIR, which
is tests/benchmarks when that is the top-level project, so try_run fails and
so does `make run_benchmarks`. The path is now relative to the module itself,
which is the same file for the main build.

The Dump benchmark discarded dump()'s result, which is [[nodiscard]] by now;
it warned, and left the optimizer free to shorten the loop. The result is
now kept with benchmark::DoNotOptimize.

A new cache variable, JSON_BENCHMARK_INCLUDE_DIR, names the directory holding
the nlohmann/json.hpp to benchmark (single_include by default, as before),
so the same benchmarks can be built against two versions and compared.

tests/benchmarks/README.md documents what is measured, how to build and run
the benchmarks, how to read the output, and how to compare two versions with
Google Benchmark's compare.py; it recommends doing so by hand before a
release rather than in CI.

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

* Point ci_benchmarks at tests/benchmarks

The target has configured ${PROJECT_SOURCE_DIR}/benchmarks since it was
added in #2561, but the benchmarks live in tests/benchmarks.

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

* Pin Google Benchmark to release 1.9.5

The benchmarks fetched Google Benchmark's main branch, so two builds on
different days could measure with different library code, and CMake 3.30
and later warn that the single-argument FetchContent_Populate() is
deprecated. Fetch the 1.9.5 release archive, verified by its SHA-256,
with FetchContent_MakeAvailable() instead. That needs CMake 3.14; Google
Benchmark itself already needed 3.13.

Its -Werror is switched off, so a newer compiler's new warnings cannot
break the pinned release, and its install rules are no longer added.

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

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-25 20:43:34 +02:00
Niels Lohmann d2514a46f7 Add benchmarks for the binary readers (#5510)
The benchmark suite covered parsing JSON text, dumping, and serializing to
CBOR, but only one binary read: FromMsgpack. Nothing measured from_cbor,
from_ubjson, from_bjdata or from_bson, so a change to binary_reader.hpp had
no baseline to be compared against.

Add read benchmarks for every format, in the two shapes that matter: from a
contiguous buffer, which is what most callers pass, and from a FILE*, which
is what FromMsgpack already measures and which compiles to different code.
FromMsgpack itself is left untouched so its numbers stay comparable across
releases. The input is derived at setup time by serializing a parsed test
file, because the test data repository ships JSON only.

The test files are wide and shallow, but the readers' cost is per container,
so add three value shapes they do not cover -- deeply nested containers, many
sibling containers, and one flat array of numbers -- plus an indefinite-length
CBOR string, a form the writer never emits and which therefore has to be
assembled by hand. UBJSON and BJData are also captured in their size- and
type-annotated form, which the readers handle in a separate code path.

BSON requires an object at the top level, so it cannot reuse the array-rooted
test files; it is captured on the object-rooted ones, and the shapes are
wrapped in an object so every format measures the same value. The setup marks
the benchmark as skipped rather than letting the exception escape if that
requirement is ever violated.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-11 13:15:09 +02:00
Niels Lohmann 471584616f Benchmark parsing of pretty-printed JSON (#5456)
Every input in the benchmark corpus is minified or only lightly spaced, so
none of them exercise the lexer's whitespace handling. Real-world JSON is
frequently indented - configuration files, pretty-printed API responses,
anything kept under version control - where the insignificant whitespace can
outweigh the data itself.

Add a ParseIndented family that re-serializes each document with an
indentation and parses that. The content is identical to the matching
ParseString row, so the pair isolates the cost of the whitespace alone.
Measured here, parsing the indented form costs 16-34% more than the minified
form of the same document, which nothing in the suite currently reports.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-11 08:22:50 +02:00
Niels Lohmann 515d994acb 📄 adjust year (#5044)
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-01-01 20:00:39 +01:00
Niels Lohmann 54be9b04f0 📄 update REUSE (#4960) 2025-10-23 06:56:36 +02:00
Niels Lohmann 1705bfe914 🔖 set version to 3.12.0 (#4727)
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2025-04-11 10:41:14 +02:00
Niels Lohmann f06604fce0 Bump the copyright years (#4606)
* 📄 bump the copyright years

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

* 📄 bump the copyright years

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

* 📄 bump the copyright years

Signed-off-by: Niels Lohmann <niels.lohmann@gmail.com>

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
Signed-off-by: Niels Lohmann <niels.lohmann@gmail.com>
2025-01-19 17:04:17 +01:00
Niels Lohmann 1b9a9d1f21 Update licenses (#4521)
* 📄 update licenses

* 📄 update licenses
2024-11-29 17:38:42 +01:00
Tianyi Chen 935c6eeb5a Optimize binary get_number implementation by reading multiple bytes at once (#4391)
* multibyte binary reader

* wide_string_input_adapter fallback to get_character

Update input_adapters.hpp

* Update json.hpp

* Add from msgpack test

* Test for broken msgpack with stream, address some warnings

* Reading binary number from wchar as an error, address warnings

* Not casting float to int, it violates strict aliasing rule
2024-11-29 09:19:58 +01:00
Niels Lohmann 9cca280a4d JSON for Modern C++ 3.11.3 (#4222) 2023-11-28 22:36:31 +01:00
Niels Lohmann f56c6e2e30 Update documentation for the next release (#4216) 2023-11-26 15:51:19 +01:00
Craig Scott fac07e22c5 Accept NEW CMake policies up to CMake 3.14 (#4112)
Starting with CMake 3.27, deprecation warnings are issued
when asking for policy settings for CMake 3.4 or earlier.
The cmake_minimum_required() command accepts a version
range, which allows NEW policy settings up to the upper end
of that range to be used, but without raising the minimum
CMake version above the bottom of that range. This means
NEW policy settings will be used where available, without
requiring them. This change updates the project's
cmake_minimum_required() calls to use a version range to
extend the upper policy version to 3.14 where it wasn't already
at that version or higher. This prevents the deprecation warning
from CMake 3.27, and gives breathing space before a future
CMake release will start issuing similar deprecation warnings
again.
2023-09-25 09:31:26 +02:00
Niels Lohmann 836b7beca4 Fix CI, again (#4083) 2023-09-07 20:41:12 +02:00
Niels Lohmann 9d69186291 🔖 set version to 3.11.2 2022-08-12 15:04:06 +02:00
Niels Lohmann f2020da0dd 🔖 set version to 3.11.1 2022-08-01 23:27:58 +02:00
Niels Lohmann ce0e13ccea 🔖 set version to 3.11.0 2022-07-31 23:19:06 +02:00
Niels LohmannandFlorian Albrechtskirchinger 527da54dcb Use REUSE framework (#3546)
* 📄 add licenses

* 👷 add REUSE compliance check

* 📝 add badge for REUSE

Co-authored-by: Florian Albrechtskirchinger <falbrechtskirchinger@gmail.com>
2022-07-20 12:38:07 +02:00
Romain Reignier d4daaa897f Optimize output vector adapter write (#3569)
* Add benchmark for cbor serialization and cbor binary data serialization

* Use std::vector::insert method instead of std::copy in output_vector_adapter::write_characters

This change increases a lot the performance when writing lots of binary data.
2022-07-08 08:12:00 +02:00
Niels Lohmann b21c345179 Reorganize directories (#3462)
* 🚚 move files
* 🚚 rename doc folder to docs
* 🚚 rename test folder to tests
2022-05-01 09:41:50 +02:00