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🐛 serialize 32-bit floating-point numbers as float 32 in MessagePack …
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…(0xCA) #2196
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@nlohmann
nlohmann committed Jun 17, 2020
1 parent e7452d8 commit 88a3701
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Showing 5 changed files with 64 additions and 17 deletions.
7 changes: 2 additions & 5 deletions doc/mkdocs/docs/features/binary_formats/messagepack.md
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Original file line number Diff line number Diff line change
Expand Up @@ -31,7 +31,8 @@ number_unsigned | 128..255 | uint 8 | 0xCC
number_unsigned | 256..65535 | uint 16 | 0xCD
number_unsigned | 65536..4294967295 | uint 32 | 0xCE
number_unsigned | 4294967296..18446744073709551615 | uint 64 | 0xCF
number_float | *any value* | float 64 | 0xCB
number_float | *any value representable by a float* | float 32 | 0xCA
number_float | *any value NOT representable by a float* | float 64 | 0xCB
string | *length*: 0..31 | fixstr | 0xA0..0xBF
string | *length*: 32..255 | str 8 | 0xD9
string | *length*: 256..65535 | str 16 | 0xDA
Expand Down Expand Up @@ -61,10 +62,6 @@ binary | *size*: 65536..4294967295 | bin 32 | 0xC6
- arrays with more than 4294967295 elements
- objects with more than 4294967295 elements

!!! info "Unused MessagePack types"

The following MessagePack types are not used in the conversion: float 32 (0xCA)

!!! info "NaN/infinity handling"

If NaN or Infinity are stored inside a JSON number, they are serialized properly. function which serializes NaN or Infinity to `null`.
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14 changes: 12 additions & 2 deletions include/nlohmann/detail/output/binary_writer.hpp
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Expand Up @@ -504,8 +504,18 @@ class binary_writer

case value_t::number_float:
{
oa->write_character(get_msgpack_float_prefix(j.m_value.number_float));
write_number(j.m_value.number_float);
if (static_cast<double>(j.m_value.number_float) >= static_cast<double>(std::numeric_limits<float>::lowest()) and
static_cast<double>(j.m_value.number_float) <= static_cast<double>((std::numeric_limits<float>::max)()) and
static_cast<double>(static_cast<float>(j.m_value.number_float)) == static_cast<double>(j.m_value.number_float))
{
oa->write_character(get_msgpack_float_prefix(static_cast<float>(j.m_value.number_float)));
write_number(static_cast<float>(j.m_value.number_float));
}
else
{
oa->write_character(get_msgpack_float_prefix(j.m_value.number_float));
write_number(j.m_value.number_float);
}
break;
}

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6 changes: 2 additions & 4 deletions include/nlohmann/json.hpp
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Expand Up @@ -7040,7 +7040,8 @@ class basic_json
number_unsigned | 256..65535 | uint 16 | 0xCD
number_unsigned | 65536..4294967295 | uint 32 | 0xCE
number_unsigned | 4294967296..18446744073709551615 | uint 64 | 0xCF
number_float | *any value* | float 64 | 0xCB
number_float | *any value representable by a float* | float 32 | 0xCA
number_float | *any value NOT representable by a float* | float 64 | 0xCB
string | *length*: 0..31 | fixstr | 0xA0..0xBF
string | *length*: 32..255 | str 8 | 0xD9
string | *length*: 256..65535 | str 16 | 0xDA
Expand All @@ -7064,9 +7065,6 @@ class basic_json
- arrays with more than 4294967295 elements
- objects with more than 4294967295 elements
@note The following MessagePack types are not used in the conversion:
- float 32 (0xCA)
@note Any MessagePack output created @ref to_msgpack can be successfully
parsed by @ref from_msgpack.
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20 changes: 14 additions & 6 deletions single_include/nlohmann/json.hpp
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Original file line number Diff line number Diff line change
Expand Up @@ -12714,8 +12714,18 @@ class binary_writer

case value_t::number_float:
{
oa->write_character(get_msgpack_float_prefix(j.m_value.number_float));
write_number(j.m_value.number_float);
if (static_cast<double>(j.m_value.number_float) >= static_cast<double>(std::numeric_limits<float>::lowest()) and
static_cast<double>(j.m_value.number_float) <= static_cast<double>((std::numeric_limits<float>::max)()) and
static_cast<double>(static_cast<float>(j.m_value.number_float)) == static_cast<double>(j.m_value.number_float))
{
oa->write_character(get_msgpack_float_prefix(static_cast<float>(j.m_value.number_float)));
write_number(static_cast<float>(j.m_value.number_float));
}
else
{
oa->write_character(get_msgpack_float_prefix(j.m_value.number_float));
write_number(j.m_value.number_float);
}
break;
}

Expand Down Expand Up @@ -22821,7 +22831,8 @@ class basic_json
number_unsigned | 256..65535 | uint 16 | 0xCD
number_unsigned | 65536..4294967295 | uint 32 | 0xCE
number_unsigned | 4294967296..18446744073709551615 | uint 64 | 0xCF
number_float | *any value* | float 64 | 0xCB
number_float | *any value representable by a float* | float 32 | 0xCA
number_float | *any value NOT representable by a float* | float 64 | 0xCB
string | *length*: 0..31 | fixstr | 0xA0..0xBF
string | *length*: 32..255 | str 8 | 0xD9
string | *length*: 256..65535 | str 16 | 0xDA
Expand All @@ -22845,9 +22856,6 @@ class basic_json
- arrays with more than 4294967295 elements
- objects with more than 4294967295 elements

@note The following MessagePack types are not used in the conversion:
- float 32 (0xCA)

@note Any MessagePack output created @ref to_msgpack can be successfully
parsed by @ref from_msgpack.

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34 changes: 34 additions & 0 deletions test/src/unit-msgpack.cpp
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Expand Up @@ -783,6 +783,40 @@ TEST_CASE("MessagePack")
CHECK(json::from_msgpack(result) == v);
CHECK(json::from_msgpack(result, true, false) == j);
}

SECTION("1.0")
{
double v = 1.0;
json j = v;
std::vector<uint8_t> expected =
{
0xca, 0x3f, 0x80, 0x00, 0x00
};
const auto result = json::to_msgpack(j);
CHECK(result == expected);

// roundtrip
CHECK(json::from_msgpack(result) == j);
CHECK(json::from_msgpack(result) == v);
CHECK(json::from_msgpack(result, true, false) == j);
}

SECTION("128.128")
{
double v = 128.1280059814453125;
json j = v;
std::vector<uint8_t> expected =
{
0xca, 0x43, 0x00, 0x20, 0xc5
};
const auto result = json::to_msgpack(j);
CHECK(result == expected);

// roundtrip
CHECK(json::from_msgpack(result) == j);
CHECK(json::from_msgpack(result) == v);
CHECK(json::from_msgpack(result, true, false) == j);
}
}
}

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