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This commit is contained in:
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@@ -4,6 +4,7 @@ Though JSON is a ubiquitous data format, it is not a very compact format suitabl
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a network. Hence, the library supports
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- [BJData](bjdata.md) (Binary JData),
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- [BON8](bon8.md) (Binary Object Notation 8),
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- [BSON](bson.md) (Binary JSON),
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- [CBOR](cbor.md) (Concise Binary Object Representation),
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- [MessagePack](messagepack.md), and
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@@ -18,6 +19,7 @@ to efficiently encode JSON values to byte vectors and to decode such vectors.
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| Format | Serialization | Deserialization |
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|-------------|-----------------------------------------------|----------------------------------------------|
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| BJData | complete | complete |
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| BON8 | incomplete: no unsigned integers above int64 | complete |
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| BSON | incomplete: top-level value must be an object | incomplete, but all JSON types are supported |
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| CBOR | complete | incomplete, but all JSON types are supported |
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| MessagePack | complete | complete |
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@@ -28,6 +30,7 @@ to efficiently encode JSON values to byte vectors and to decode such vectors.
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| Format | Binary values | Binary subtypes |
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|-------------|---------------|-----------------|
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| BJData | not supported | not supported |
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| BON8 | not supported | not supported |
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| BSON | supported | supported |
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| CBOR | supported | supported |
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| MessagePack | supported | supported |
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@@ -42,6 +45,7 @@ See [binary values](../binary_values.md) for more information.
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| BJData | 53.2 % | 91.1 % | 78.1 % | 96.6 % |
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| BJData (size) | 58.6 % | 92.1 % | 86.7 % | 97.4 % |
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| BJData (size+type) | 58.6 % | 92.1 % | 86.5 % | 97.4 % |
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| BON8 | 50.5 % | 83.8 % | 63.5 % | 87.5 % |
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| BSON | 85.8 % | 95.2 % | 95.8 % | 106.7 % |
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| CBOR | 50.5 % | 86.3 % | 68.4 % | 88.0 % |
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| MessagePack | 50.5 % | 86.0 % | 68.5 % | 87.9 % |
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File diff suppressed because one or more lines are too long
@@ -0,0 +1,159 @@
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# BON8
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BON8 (Binary Object Notation 8) is a compact binary serialization format for JSON values. It uses the byte values that
|
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cannot begin a UTF-8 character as type markers, so strings are stored as plain UTF-8 without a length prefix: a string
|
||||
ends at the first byte that cannot continue it. Integers from -10 to 39, `true`, `false`, `null`, and the floating-point
|
||||
values -1.0, 0.0, and 1.0 take a single byte, and arrays and objects with up to four elements need no terminator.
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||||
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||||
!!! abstract "References"
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||||
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- [BON8 specification](https://github.com/hikoworks/hikogui/blob/main/docs/BON8.md)
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- [Reference implementation](https://github.com/hikoworks/hikogui/blob/main/src/hikogui/codec/BON8.hpp) in HikoGUI
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|
||||
## Serialization
|
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|
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The library uses the following mapping from JSON values types to BON8 types according to the BON8 specification:
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| JSON value type | value/range | BON8 type | first byte |
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|-----------------|----------------------------------------------|-------------------------------|------------|
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| null | `null` | null | 0xFA |
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| boolean | `true` | true | 0xF9 |
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||||
| boolean | `false` | false | 0xF8 |
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||||
| number_integer | -9223372036854775808..-2147483649 | int64 | 0x8D |
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||||
| number_integer | -2147483648..-33818507 | int32 | 0x8C |
|
||||
| number_integer | -33818506..-264075 | 4-byte negative integer | 0xF0..0xF7 |
|
||||
| number_integer | -264074..-1931 | 3-byte negative integer | 0xE0..0xEF |
|
||||
| number_integer | -1930..-11 | 2-byte negative integer | 0xC2..0xDF |
|
||||
| number_integer | -10..-1 | 1-byte negative integer | 0xB8..0xC1 |
|
||||
| number_integer | 0..39 | 1-byte positive integer | 0x90..0xB7 |
|
||||
| number_integer | 40..3879 | 2-byte positive integer | 0xC2..0xDF |
|
||||
| number_integer | 3880..528167 | 3-byte positive integer | 0xE0..0xEF |
|
||||
| number_integer | 528168..67637031 | 4-byte positive integer | 0xF0..0xF7 |
|
||||
| number_integer | 67637032..2147483647 | int32 | 0x8C |
|
||||
| number_integer | 2147483648..9223372036854775807 | int64 | 0x8D |
|
||||
| number_unsigned | 0..39 | 1-byte positive integer | 0x90..0xB7 |
|
||||
| number_unsigned | 40..3879 | 2-byte positive integer | 0xC2..0xDF |
|
||||
| number_unsigned | 3880..528167 | 3-byte positive integer | 0xE0..0xEF |
|
||||
| number_unsigned | 528168..67637031 | 4-byte positive integer | 0xF0..0xF7 |
|
||||
| number_unsigned | 67637032..2147483647 | int32 | 0x8C |
|
||||
| number_unsigned | 2147483648..9223372036854775807 | int64 | 0x8D |
|
||||
| number_float | `-1.0` | -1.0 | 0xFB |
|
||||
| number_float | `0.0` | 0.0 | 0xFC |
|
||||
| number_float | `1.0` | 1.0 | 0xFD |
|
||||
| number_float | *any other value representable by a float* | binary32 | 0x8E |
|
||||
| number_float | *any value NOT representable by a float* | binary64 | 0x8F |
|
||||
| string | *empty* | end of string | 0xFF |
|
||||
| string | *non-empty* | UTF-8 string | 0x00..0x7F, 0xC2..0xF4 |
|
||||
| array | *size*: 0..4 | array with count | 0x80..0x84 |
|
||||
| array | *size*: 5 or more | array (terminated by 0xFE) | 0x85 |
|
||||
| object | *size*: 0..4 | object with count | 0x86..0x8A |
|
||||
| object | *size*: 5 or more | object (terminated by 0xFE) | 0x8B |
|
||||
| binary | *size*: 0..4 | array with count | 0x80..0x84 |
|
||||
| binary | *size*: 5 or more | array (terminated by 0xFE) | 0x85 |
|
||||
|
||||
An integer that takes 2 to 4 bytes starts with a UTF-8 lead byte (0xC2..0xF7) that is followed by a byte that cannot
|
||||
continue a UTF-8 character: 0x00..0x7F for positive and 0xC0..0xFF for negative integers. A string is terminated by
|
||||
0xFF only if it is empty, if another string follows it, or if it is the last value of the message; otherwise, the first
|
||||
byte of the next value ends it.
|
||||
|
||||
!!! success "Complete mapping"
|
||||
|
||||
Except for the values listed below, any JSON value can be converted to a BON8 value.
|
||||
|
||||
Any BON8 output created by `to_bon8` can be successfully parsed by `from_bon8`.
|
||||
|
||||
!!! warning "Unsupported values"
|
||||
|
||||
The following values can **not** be converted to a BON8 value:
|
||||
|
||||
- unsigned integers above 9223372036854775807, because BON8 has no unsigned 64-bit integer type
|
||||
([out_of_range.407](../../home/exceptions.md#jsonexceptionout_of_range407))
|
||||
- strings that are not valid UTF-8, because the end of a string is determined from its encoding
|
||||
([type_error.316](../../home/exceptions.md#jsonexceptiontype_error316))
|
||||
|
||||
!!! info "NaN/infinity handling"
|
||||
|
||||
`-0.0`, `Infinity`, and `-Infinity` are serialized as binary32 (type 0x8E, 5 bytes total). `NaN` is serialized as
|
||||
the binary32 value 0x7F800001 that the specification recommends. This is in contrast to the
|
||||
[dump](../../api/basic_json/dump.md) function which serializes NaN or Infinity to `null`.
|
||||
|
||||
!!! warning "Binary values"
|
||||
|
||||
BON8 has no binary type. Binary values are serialized as arrays of integers (0..255), so they are read back as
|
||||
arrays. The subtype is not serialized.
|
||||
|
||||
!!! info "Canonical representation"
|
||||
|
||||
The output follows the specification's canonical representation rules: every value uses the shortest encoding,
|
||||
floating-point numbers use binary32 whenever that loses no precision, and object keys are sorted by their UTF-8
|
||||
code units. There are two exceptions:
|
||||
|
||||
- Strings are not normalized to Unicode Normalization Form C (NFC).
|
||||
- Object keys are written in the order of the object type, which is sorted for `json`, but not for
|
||||
[`ordered_json`](../../api/ordered_json.md).
|
||||
|
||||
??? example
|
||||
|
||||
```cpp
|
||||
--8<-- "examples/to_bon8.cpp"
|
||||
```
|
||||
|
||||
Output:
|
||||
|
||||
```c
|
||||
--8<-- "examples/to_bon8.output"
|
||||
```
|
||||
|
||||
## Deserialization
|
||||
|
||||
The library maps BON8 types to JSON value types as follows:
|
||||
|
||||
| BON8 type | JSON value type | first byte |
|
||||
|-------------------------------|-----------------|------------------------|
|
||||
| UTF-8 string | string | 0x00..0x7F |
|
||||
| array with count | array | 0x80..0x84 |
|
||||
| array (terminated by 0xFE) | array | 0x85 |
|
||||
| object with count | object | 0x86..0x8A |
|
||||
| object (terminated by 0xFE) | object | 0x8B |
|
||||
| int32 | number_unsigned or number_integer | 0x8C |
|
||||
| int64 | number_unsigned or number_integer | 0x8D |
|
||||
| binary32 | number_float | 0x8E |
|
||||
| binary64 | number_float | 0x8F |
|
||||
| 1-byte positive integer | number_unsigned | 0x90..0xB7 |
|
||||
| 1-byte negative integer | number_integer | 0xB8..0xC1 |
|
||||
| UTF-8 string | string | 0xC2..0xF4, followed by 0x80..0xBF |
|
||||
| 2- to 4-byte positive integer | number_unsigned | 0xC2..0xF7, followed by 0x00..0x7F |
|
||||
| 2- to 4-byte negative integer | number_integer | 0xC2..0xF7, followed by 0xC0..0xFF |
|
||||
| false | `false` | 0xF8 |
|
||||
| true | `true` | 0xF9 |
|
||||
| null | `null` | 0xFA |
|
||||
| -1.0 | number_float | 0xFB |
|
||||
| 0.0 | number_float | 0xFC |
|
||||
| 1.0 | number_float | 0xFD |
|
||||
| empty string | string | 0xFF |
|
||||
|
||||
Non-negative integers are read as number_unsigned, negative integers as number_integer.
|
||||
|
||||
!!! info
|
||||
|
||||
Values that do not use the canonical representation, such as integers with a longer encoding than necessary,
|
||||
arrays and objects with up to four elements that are terminated by 0xFE, unsorted object keys, or a 0xFF after a
|
||||
string that would also end without it, are accepted. A second 0xFF is not a terminator but an empty string.
|
||||
|
||||
Strings must be valid UTF-8, and the last string of a message must be terminated by 0xFF.
|
||||
|
||||
!!! info
|
||||
|
||||
Any BON8 output created by `to_bon8` can be successfully parsed by `from_bon8`.
|
||||
|
||||
??? example
|
||||
|
||||
```cpp
|
||||
--8<-- "examples/from_bon8.cpp"
|
||||
```
|
||||
|
||||
Output:
|
||||
|
||||
```json
|
||||
--8<-- "examples/from_bon8.output"
|
||||
```
|
||||
File diff suppressed because one or more lines are too long
@@ -0,0 +1,188 @@
|
||||
# BON8
|
||||
|
||||
BON8 (Binary Object Notation 8) is a compact binary serialization format for JSON values. It uses the byte values that cannot begin a UTF-8 character as type markers, so strings are stored as plain UTF-8 without a length prefix: a string ends at the first byte that cannot continue it. Integers from -10 to 39, `true`, `false`, `null`, and the floating-point values -1.0, 0.0, and 1.0 take a single byte, and arrays and objects with up to four elements need no terminator.
|
||||
|
||||
References
|
||||
|
||||
- [BON8 specification](https://github.com/hikoworks/hikogui/blob/main/docs/BON8.md)
|
||||
- [Reference implementation](https://github.com/hikoworks/hikogui/blob/main/src/hikogui/codec/BON8.hpp) in HikoGUI
|
||||
|
||||
## Serialization
|
||||
|
||||
The library uses the following mapping from JSON values types to BON8 types according to the BON8 specification:
|
||||
|
||||
| JSON value type | value/range | BON8 type | first byte |
|
||||
| --------------- | ------------------------------------------ | --------------------------- | ---------------------- |
|
||||
| null | `null` | null | 0xFA |
|
||||
| boolean | `true` | true | 0xF9 |
|
||||
| boolean | `false` | false | 0xF8 |
|
||||
| number_integer | -9223372036854775808..-2147483649 | int64 | 0x8D |
|
||||
| number_integer | -2147483648..-33818507 | int32 | 0x8C |
|
||||
| number_integer | -33818506..-264075 | 4-byte negative integer | 0xF0..0xF7 |
|
||||
| number_integer | -264074..-1931 | 3-byte negative integer | 0xE0..0xEF |
|
||||
| number_integer | -1930..-11 | 2-byte negative integer | 0xC2..0xDF |
|
||||
| number_integer | -10..-1 | 1-byte negative integer | 0xB8..0xC1 |
|
||||
| number_integer | 0..39 | 1-byte positive integer | 0x90..0xB7 |
|
||||
| number_integer | 40..3879 | 2-byte positive integer | 0xC2..0xDF |
|
||||
| number_integer | 3880..528167 | 3-byte positive integer | 0xE0..0xEF |
|
||||
| number_integer | 528168..67637031 | 4-byte positive integer | 0xF0..0xF7 |
|
||||
| number_integer | 67637032..2147483647 | int32 | 0x8C |
|
||||
| number_integer | 2147483648..9223372036854775807 | int64 | 0x8D |
|
||||
| number_unsigned | 0..39 | 1-byte positive integer | 0x90..0xB7 |
|
||||
| number_unsigned | 40..3879 | 2-byte positive integer | 0xC2..0xDF |
|
||||
| number_unsigned | 3880..528167 | 3-byte positive integer | 0xE0..0xEF |
|
||||
| number_unsigned | 528168..67637031 | 4-byte positive integer | 0xF0..0xF7 |
|
||||
| number_unsigned | 67637032..2147483647 | int32 | 0x8C |
|
||||
| number_unsigned | 2147483648..9223372036854775807 | int64 | 0x8D |
|
||||
| number_float | `-1.0` | -1.0 | 0xFB |
|
||||
| number_float | `0.0` | 0.0 | 0xFC |
|
||||
| number_float | `1.0` | 1.0 | 0xFD |
|
||||
| number_float | *any other value representable by a float* | binary32 | 0x8E |
|
||||
| number_float | *any value NOT representable by a float* | binary64 | 0x8F |
|
||||
| string | *empty* | end of string | 0xFF |
|
||||
| string | *non-empty* | UTF-8 string | 0x00..0x7F, 0xC2..0xF4 |
|
||||
| array | *size*: 0..4 | array with count | 0x80..0x84 |
|
||||
| array | *size*: 5 or more | array (terminated by 0xFE) | 0x85 |
|
||||
| object | *size*: 0..4 | object with count | 0x86..0x8A |
|
||||
| object | *size*: 5 or more | object (terminated by 0xFE) | 0x8B |
|
||||
| binary | *size*: 0..4 | array with count | 0x80..0x84 |
|
||||
| binary | *size*: 5 or more | array (terminated by 0xFE) | 0x85 |
|
||||
|
||||
An integer that takes 2 to 4 bytes starts with a UTF-8 lead byte (0xC2..0xF7) that is followed by a byte that cannot continue a UTF-8 character: 0x00..0x7F for positive and 0xC0..0xFF for negative integers. A string is terminated by 0xFF only if it is empty, if another string follows it, or if it is the last value of the message; otherwise, the first byte of the next value ends it.
|
||||
|
||||
Complete mapping
|
||||
|
||||
Except for the values listed below, any JSON value can be converted to a BON8 value.
|
||||
|
||||
Any BON8 output created by `to_bon8` can be successfully parsed by `from_bon8`.
|
||||
|
||||
Unsupported values
|
||||
|
||||
The following values can **not** be converted to a BON8 value:
|
||||
|
||||
- unsigned integers above 9223372036854775807, because BON8 has no unsigned 64-bit integer type ([out_of_range.407](https://json.nlohmann.me/home/exceptions/#jsonexceptionout_of_range407))
|
||||
- strings that are not valid UTF-8, because the end of a string is determined from its encoding ([type_error.316](https://json.nlohmann.me/home/exceptions/#jsonexceptiontype_error316))
|
||||
|
||||
NaN/infinity handling
|
||||
|
||||
`-0.0`, `Infinity`, and `-Infinity` are serialized as binary32 (type 0x8E, 5 bytes total). `NaN` is serialized as the binary32 value 0x7F800001 that the specification recommends. This is in contrast to the [dump](https://json.nlohmann.me/api/basic_json/dump/index.md) function which serializes NaN or Infinity to `null`.
|
||||
|
||||
Binary values
|
||||
|
||||
BON8 has no binary type. Binary values are serialized as arrays of integers (0..255), so they are read back as arrays. The subtype is not serialized.
|
||||
|
||||
Canonical representation
|
||||
|
||||
The output follows the specification's canonical representation rules: every value uses the shortest encoding, floating-point numbers use binary32 whenever that loses no precision, and object keys are sorted by their UTF-8 code units. There are two exceptions:
|
||||
|
||||
- Strings are not normalized to Unicode Normalization Form C (NFC).
|
||||
- Object keys are written in the order of the object type, which is sorted for `json`, but not for [`ordered_json`](https://json.nlohmann.me/api/ordered_json/index.md).
|
||||
|
||||
Example
|
||||
|
||||
```
|
||||
#include <iostream>
|
||||
#include <iomanip>
|
||||
#include <nlohmann/json.hpp>
|
||||
|
||||
using json = nlohmann::json;
|
||||
using namespace nlohmann::literals;
|
||||
|
||||
int main()
|
||||
{
|
||||
// create a JSON value
|
||||
json j = R"({"compact": true, "format": "BON8", "schema": 0})"_json;
|
||||
|
||||
// serialize it to BON8
|
||||
std::vector<std::uint8_t> v = json::to_bon8(j);
|
||||
|
||||
// print the vector content
|
||||
for (auto& byte : v)
|
||||
{
|
||||
std::cout << "0x" << std::hex << std::setw(2) << std::setfill('0') << (int)byte << " ";
|
||||
}
|
||||
std::cout << std::endl;
|
||||
}
|
||||
```
|
||||
|
||||
Output:
|
||||
|
||||
```
|
||||
0x89 0x63 0x6f 0x6d 0x70 0x61 0x63 0x74 0xf9 0x66 0x6f 0x72 0x6d 0x61 0x74 0xff 0x42 0x4f 0x4e 0x38 0xff 0x73 0x63 0x68 0x65 0x6d 0x61 0x90
|
||||
```
|
||||
|
||||
## Deserialization
|
||||
|
||||
The library maps BON8 types to JSON value types as follows:
|
||||
|
||||
| BON8 type | JSON value type | first byte |
|
||||
| ----------------------------- | --------------------------------- | ---------------------------------- |
|
||||
| UTF-8 string | string | 0x00..0x7F |
|
||||
| array with count | array | 0x80..0x84 |
|
||||
| array (terminated by 0xFE) | array | 0x85 |
|
||||
| object with count | object | 0x86..0x8A |
|
||||
| object (terminated by 0xFE) | object | 0x8B |
|
||||
| int32 | number_unsigned or number_integer | 0x8C |
|
||||
| int64 | number_unsigned or number_integer | 0x8D |
|
||||
| binary32 | number_float | 0x8E |
|
||||
| binary64 | number_float | 0x8F |
|
||||
| 1-byte positive integer | number_unsigned | 0x90..0xB7 |
|
||||
| 1-byte negative integer | number_integer | 0xB8..0xC1 |
|
||||
| UTF-8 string | string | 0xC2..0xF4, followed by 0x80..0xBF |
|
||||
| 2- to 4-byte positive integer | number_unsigned | 0xC2..0xF7, followed by 0x00..0x7F |
|
||||
| 2- to 4-byte negative integer | number_integer | 0xC2..0xF7, followed by 0xC0..0xFF |
|
||||
| false | `false` | 0xF8 |
|
||||
| true | `true` | 0xF9 |
|
||||
| null | `null` | 0xFA |
|
||||
| -1.0 | number_float | 0xFB |
|
||||
| 0.0 | number_float | 0xFC |
|
||||
| 1.0 | number_float | 0xFD |
|
||||
| empty string | string | 0xFF |
|
||||
|
||||
Non-negative integers are read as number_unsigned, negative integers as number_integer.
|
||||
|
||||
Info
|
||||
|
||||
Values that do not use the canonical representation, such as integers with a longer encoding than necessary, arrays and objects with up to four elements that are terminated by 0xFE, unsorted object keys, or a 0xFF after a string that would also end without it, are accepted. A second 0xFF is not a terminator but an empty string.
|
||||
|
||||
Strings must be valid UTF-8, and the last string of a message must be terminated by 0xFF.
|
||||
|
||||
Info
|
||||
|
||||
Any BON8 output created by `to_bon8` can be successfully parsed by `from_bon8`.
|
||||
|
||||
Example
|
||||
|
||||
```
|
||||
#include <iostream>
|
||||
#include <iomanip>
|
||||
#include <nlohmann/json.hpp>
|
||||
|
||||
using json = nlohmann::json;
|
||||
|
||||
int main()
|
||||
{
|
||||
// create byte vector
|
||||
std::vector<std::uint8_t> v = {0x89, 0x63, 0x6f, 0x6d, 0x70, 0x61, 0x63, 0x74,
|
||||
0xf9, 0x66, 0x6f, 0x72, 0x6d, 0x61, 0x74, 0xff,
|
||||
0x42, 0x4f, 0x4e, 0x38, 0xff, 0x73, 0x63, 0x68,
|
||||
0x65, 0x6d, 0x61, 0x90
|
||||
};
|
||||
|
||||
// deserialize it with BON8
|
||||
json j = json::from_bon8(v);
|
||||
|
||||
// print the deserialized JSON value
|
||||
std::cout << std::setw(2) << j << std::endl;
|
||||
}
|
||||
```
|
||||
|
||||
Output:
|
||||
|
||||
```
|
||||
{
|
||||
"compact": true,
|
||||
"format": "BON8",
|
||||
"schema": 0
|
||||
}
|
||||
```
|
||||
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@@ -188,7 +188,7 @@ The library maps CBOR types to JSON value types as follows:
|
||||
|
||||
!!! warning "Tagged items"
|
||||
|
||||
Tagged items (0xC0..0xDB) will throw a parse error by default. They can be ignored by passing `cbor_tag_handler_t::ignore` to function `from_cbor`, in which case the tag is skipped and the enclosed data item is parsed on its own. They can be stored by passing `cbor_tag_handler_t::store` to function `from_cbor`. Note that no tag is ever interpreted: for instance, a text string tagged with tag 0 (date/time) stays a string.
|
||||
Tagged items (0xC0..0xDB) will throw a parse error by default. They can be ignored by passing `cbor_tag_handler_t::ignore` to function `from_cbor`, in which case the tag is skipped and the enclosed data item is parsed on its own. Passing `cbor_tag_handler_t::store` to function `from_cbor` stores tagged byte strings (for bytes 0xd8..0xdb) as binary values with the tag as subtype; other tagged values are read as if the tag were ignored. If several tags precede a byte string, only the innermost one is stored. Note that no tag is ever interpreted: for instance, a text string tagged with tag 0 (date/time) stays a string.
|
||||
|
||||
??? example
|
||||
|
||||
|
||||
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@@ -193,7 +193,7 @@ UTF-8 validation of text strings
|
||||
|
||||
Tagged items
|
||||
|
||||
Tagged items (0xC0..0xDB) will throw a parse error by default. They can be ignored by passing `cbor_tag_handler_t::ignore` to function `from_cbor`, in which case the tag is skipped and the enclosed data item is parsed on its own. They can be stored by passing `cbor_tag_handler_t::store` to function `from_cbor`. Note that no tag is ever interpreted: for instance, a text string tagged with tag 0 (date/time) stays a string.
|
||||
Tagged items (0xC0..0xDB) will throw a parse error by default. They can be ignored by passing `cbor_tag_handler_t::ignore` to function `from_cbor`, in which case the tag is skipped and the enclosed data item is parsed on its own. Passing `cbor_tag_handler_t::store` to function `from_cbor` stores tagged byte strings (for bytes 0xd8..0xdb) as binary values with the tag as subtype; other tagged values are read as if the tag were ignored. If several tags precede a byte string, only the innermost one is stored. Note that no tag is ever interpreted: for instance, a text string tagged with tag 0 (date/time) stays a string.
|
||||
|
||||
Example
|
||||
|
||||
|
||||
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@@ -3,6 +3,7 @@
|
||||
Though JSON is a ubiquitous data format, it is not a very compact format suitable for data exchange, for instance, over a network. Hence, the library supports
|
||||
|
||||
- [BJData](https://json.nlohmann.me/features/binary_formats/bjdata/index.md) (Binary JData),
|
||||
- [BON8](https://json.nlohmann.me/features/binary_formats/bon8/index.md) (Binary Object Notation 8),
|
||||
- [BSON](https://json.nlohmann.me/features/binary_formats/bson/index.md) (Binary JSON),
|
||||
- [CBOR](https://json.nlohmann.me/features/binary_formats/cbor/index.md) (Concise Binary Object Representation),
|
||||
- [MessagePack](https://json.nlohmann.me/features/binary_formats/messagepack/index.md), and
|
||||
@@ -17,6 +18,7 @@ to efficiently encode JSON values to byte vectors and to decode such vectors.
|
||||
| Format | Serialization | Deserialization |
|
||||
| ----------- | --------------------------------------------- | -------------------------------------------- |
|
||||
| BJData | complete | complete |
|
||||
| BON8 | incomplete: no unsigned integers above int64 | complete |
|
||||
| BSON | incomplete: top-level value must be an object | incomplete, but all JSON types are supported |
|
||||
| CBOR | complete | incomplete, but all JSON types are supported |
|
||||
| MessagePack | complete | complete |
|
||||
@@ -27,6 +29,7 @@ to efficiently encode JSON values to byte vectors and to decode such vectors.
|
||||
| Format | Binary values | Binary subtypes |
|
||||
| ----------- | ------------- | --------------- |
|
||||
| BJData | not supported | not supported |
|
||||
| BON8 | not supported | not supported |
|
||||
| BSON | supported | supported |
|
||||
| CBOR | supported | supported |
|
||||
| MessagePack | supported | supported |
|
||||
@@ -41,6 +44,7 @@ See [binary values](https://json.nlohmann.me/features/binary_values/index.md) fo
|
||||
| BJData | 53.2 % | 91.1 % | 78.1 % | 96.6 % |
|
||||
| BJData (size) | 58.6 % | 92.1 % | 86.7 % | 97.4 % |
|
||||
| BJData (size+type) | 58.6 % | 92.1 % | 86.5 % | 97.4 % |
|
||||
| BON8 | 50.5 % | 83.8 % | 63.5 % | 87.5 % |
|
||||
| BSON | 85.8 % | 95.2 % | 95.8 % | 106.7 % |
|
||||
| CBOR | 50.5 % | 86.3 % | 68.4 % | 88.0 % |
|
||||
| MessagePack | 50.5 % | 86.0 % | 68.5 % | 87.9 % |
|
||||
|
||||
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@@ -187,6 +187,41 @@ as an array of uint8 values. The library implements this translation.
|
||||
}
|
||||
```
|
||||
|
||||
### BON8
|
||||
|
||||
[BON8](binary_formats/bon8.md) neither supports binary values nor subtypes. The library serializes binary values as an
|
||||
array of integers.
|
||||
|
||||
??? example
|
||||
|
||||
Code:
|
||||
|
||||
```cpp
|
||||
// create a binary value of subtype 42 (will be ignored in BON8)
|
||||
json j;
|
||||
j["binary"] = json::binary({0xCA, 0xFE, 0xBA, 0xBE}, 42);
|
||||
|
||||
// convert to BON8
|
||||
auto v = json::to_bon8(j);
|
||||
```
|
||||
|
||||
`v` is a `std::vector<std::uint8_t>` with the following 16 elements:
|
||||
|
||||
```c
|
||||
0x87 // object with 1 member
|
||||
0x62 0x69 0x6E 0x61 0x72 0x79 // "binary"
|
||||
0x84 // array with 4 elements
|
||||
0xC3 0x22 0xC3 0x56 0xC3 0x12 0xC3 0x16 // content (each byte as a 2-byte integer)
|
||||
```
|
||||
|
||||
Note that the subtype is lost, and deserializing `v` would yield the following value:
|
||||
|
||||
```json
|
||||
{
|
||||
"binary": [202, 254, 186, 190]
|
||||
}
|
||||
```
|
||||
|
||||
### BSON
|
||||
|
||||
[BSON](binary_formats/bson.md) supports binary values and subtypes. If a subtype is given, it is used and added as an
|
||||
|
||||
File diff suppressed because one or more lines are too long
@@ -174,6 +174,40 @@ Note that subtype (42) is **not** serialized and that BJData has **no binary typ
|
||||
}
|
||||
```
|
||||
|
||||
### BON8
|
||||
|
||||
[BON8](https://json.nlohmann.me/features/binary_formats/bon8/index.md) neither supports binary values nor subtypes. The library serializes binary values as an array of integers.
|
||||
|
||||
Example
|
||||
|
||||
Code:
|
||||
|
||||
```
|
||||
// create a binary value of subtype 42 (will be ignored in BON8)
|
||||
json j;
|
||||
j["binary"] = json::binary({0xCA, 0xFE, 0xBA, 0xBE}, 42);
|
||||
|
||||
// convert to BON8
|
||||
auto v = json::to_bon8(j);
|
||||
```
|
||||
|
||||
`v` is a `std::vector<std::uint8_t>` with the following 16 elements:
|
||||
|
||||
```
|
||||
0x87 // object with 1 member
|
||||
0x62 0x69 0x6E 0x61 0x72 0x79 // "binary"
|
||||
0x84 // array with 4 elements
|
||||
0xC3 0x22 0xC3 0x56 0xC3 0x12 0xC3 0x16 // content (each byte as a 2-byte integer)
|
||||
```
|
||||
|
||||
Note that the subtype is lost, and deserializing `v` would yield the following value:
|
||||
|
||||
```
|
||||
{
|
||||
"binary": [202, 254, 186, 190]
|
||||
}
|
||||
```
|
||||
|
||||
### BSON
|
||||
|
||||
[BSON](https://json.nlohmann.me/features/binary_formats/bson/index.md) supports binary values and subtypes. If a subtype is given, it is used and added as an unsigned 8-bit integer. If no subtype is given, the generic binary subtype 0x00 is used.
|
||||
|
||||
File diff suppressed because one or more lines are too long
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+1
-1
File diff suppressed because one or more lines are too long
+1
-1
@@ -25,7 +25,7 @@ This section describes the features of the library in detail. If you are new to
|
||||
## Serializing values
|
||||
|
||||
- [Serialization](https://json.nlohmann.me/features/serialization/index.md) — turn a value back into JSON text with [`dump`](https://json.nlohmann.me/api/basic_json/dump/index.md), including pretty-printing and handling of non-ASCII and invalid UTF-8.
|
||||
- [Binary formats](https://json.nlohmann.me/features/binary_formats/index.md) — encode values more compactly as [BJData](https://json.nlohmann.me/features/binary_formats/bjdata/index.md), [BSON](https://json.nlohmann.me/features/binary_formats/bson/index.md), [CBOR](https://json.nlohmann.me/features/binary_formats/cbor/index.md), [MessagePack](https://json.nlohmann.me/features/binary_formats/messagepack/index.md), or [UBJSON](https://json.nlohmann.me/features/binary_formats/ubjson/index.md).
|
||||
- [Binary formats](https://json.nlohmann.me/features/binary_formats/index.md) — encode values more compactly as [BJData](https://json.nlohmann.me/features/binary_formats/bjdata/index.md), [BON8](https://json.nlohmann.me/features/binary_formats/bon8/index.md), [BSON](https://json.nlohmann.me/features/binary_formats/bson/index.md), [CBOR](https://json.nlohmann.me/features/binary_formats/cbor/index.md), [MessagePack](https://json.nlohmann.me/features/binary_formats/messagepack/index.md), or [UBJSON](https://json.nlohmann.me/features/binary_formats/ubjson/index.md).
|
||||
- [Binary values](https://json.nlohmann.me/features/binary_values/index.md) — store and exchange raw byte sequences.
|
||||
|
||||
## How values are stored and configured
|
||||
|
||||
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File diff suppressed because one or more lines are too long
@@ -117,7 +117,7 @@ For the [{fmt}](https://github.com/fmtlib/fmt) library, the library ships a
|
||||
## Serializing to other formats
|
||||
|
||||
Besides JSON text, a value can also be serialized to the more compact [binary formats](binary_formats/index.md)
|
||||
(BJData, BSON, CBOR, MessagePack, UBJSON).
|
||||
(BJData, BON8, BSON, CBOR, MessagePack, UBJSON).
|
||||
|
||||
## See also
|
||||
|
||||
|
||||
File diff suppressed because one or more lines are too long
@@ -218,7 +218,7 @@ For the [{fmt}](https://github.com/fmtlib/fmt) library, the library ships a [`fo
|
||||
|
||||
## Serializing to other formats
|
||||
|
||||
Besides JSON text, a value can also be serialized to the more compact [binary formats](https://json.nlohmann.me/features/binary_formats/index.md) (BJData, BSON, CBOR, MessagePack, UBJSON).
|
||||
Besides JSON text, a value can also be serialized to the more compact [binary formats](https://json.nlohmann.me/features/binary_formats/index.md) (BJData, BON8, BSON, CBOR, MessagePack, UBJSON).
|
||||
|
||||
## See also
|
||||
|
||||
|
||||
File diff suppressed because one or more lines are too long
File diff suppressed because one or more lines are too long
File diff suppressed because one or more lines are too long
@@ -547,7 +547,7 @@ Grisu2 algorithm, which produces the shortest representation that round-trips. O
|
||||
### Required for the binary formats
|
||||
|
||||
`NumberFloatType` must be `#!cpp float` or `#!cpp double`. The writers for
|
||||
[CBOR, MessagePack, UBJSON, BJData, and BSON](../binary_formats/index.md) map a floating-point value onto an IEEE 754
|
||||
[CBOR, MessagePack, UBJSON, BJData, BON8, and BSON](../binary_formats/index.md) map a floating-point value onto an IEEE 754
|
||||
binary32 or binary64 field and have no encoding for `#!cpp long double`.
|
||||
|
||||
### Compatible types
|
||||
|
||||
File diff suppressed because one or more lines are too long
@@ -915,7 +915,7 @@ If `std::numeric_limits<NumberFloatType>` describes an IEEE 754 binary32 or bina
|
||||
|
||||
### Required for the binary formats
|
||||
|
||||
`NumberFloatType` must be `float` or `double`. The writers for [CBOR, MessagePack, UBJSON, BJData, and BSON](https://json.nlohmann.me/features/binary_formats/index.md) map a floating-point value onto an IEEE 754 binary32 or binary64 field and have no encoding for `long double`.
|
||||
`NumberFloatType` must be `float` or `double`. The writers for [CBOR, MessagePack, UBJSON, BJData, BON8, and BSON](https://json.nlohmann.me/features/binary_formats/index.md) map a floating-point value onto an IEEE 754 binary32 or binary64 field and have no encoding for `long double`.
|
||||
|
||||
### Compatible types
|
||||
|
||||
|
||||
Reference in New Issue
Block a user