README

这是一个PHP库，用于压缩具有重复结构和值的大型JSON文档。它有助于在保持文档结构和键名的同时，减少JSON文件的大小，例如在存储或通过网络传输时。

受到compress-json的启发。感谢@beenotung。

此库与compress-json（NodeJS的同一库）完全兼容。

功能

• 支持所有JSON类型
• 保留对象键顺序
• 重复值只存储一次
• 数字以base62格式编码（0-9A-Za-z）
• 为存储和压缩大量数据时的缓存提供自定义内存提供程序（请参阅类AbstractMemory）。您可以通过Compressor::createWithMemory()方法传递自定义内存提供程序。
• 在toJson或decompressJson方法中分别传递自定义的json_encode或json_decode参数

安装

通过Composer

composer require inkrot/php-compress-json

使用方法

压缩

use CompressJson\Core\Compressor;

$data = [
    'key1' => 'value1',
    'key2' => 'value3',
    'key3' => [
        'nestedKey1' => 'value1'
    ]
];
$compressedJson = Compressor::create()
    ->compress($data)
    ->toJson();

print_r($compressedJson); // encoded string in JSON format

输出

[["key1","key2","key3","a|0|1|2","value1","value3","nestedKey1","a|6","o|7|4","o|3|4|5|8"],"9"]

解压缩

use CompressJson\Core\Compressor;

$compressedJson = '[["key1","key2","key3","a|0|1|2","value1","value3","nestedKey1","a|6","o|7|4","o|3|4|5|8"],"9"]';
$data = Compressor::create()
    ->decompressJson($compressedJson);

print_r($data); // array

输出

Array
(
    [key1] => value1
    [key2] => value3
    [key3] => Array
        (
            [nestedKey1] => value1
        )

)

高效压缩的示例结构

use CompressJson\Core\Compressor;
$data = [
    'count' => 3,
    'names' => ['New York', 'London', 'Paris', 'Beijing', 'Moscow'],
    'cities' => [
        [
            'id' => 1,
            'name' => 'New York',
            'countryName' => 'USA',
            'location' => [
                'latitude' => 40.714606,
                'longitude' => -74.002800,
            ],
            'localityType' => 'BIG_CITY',
        ],
        [
            'id' => 2,
            'name' => 'London',
            'countryName' => 'UK',
            'location' => [
                'latitude' => 51.507351,
                'longitude' => -0.127696,
            ],
            'localityType' => 'COUNTRY_CAPITAL',
        ],
        [
            'id' => 3,
            'name' => 'Paris',
            'countryName' => 'France',
            'location' => [
                'latitude' => 48.856663,
                'longitude' => 2.351556,
            ],
            'localityType' => 'COUNTRY_CAPITAL',
        ],
        [
            'id' => 4,
            'name' => 'Beijing',
            'countryName' => 'China',
            'location' => [
                'latitude' => 39.901850,
                'longitude' => 116.391441,
            ],
            'localityType' => 'COUNTRY_CAPITAL',
        ],
        [
            'id' => 5,
            'name' => 'Moscow',
            'countryName' => 'Russia',
            'location' => [
                'latitude' => 55.755864,
                'longitude' => 37.617698,
            ],
            'localityType' => 'COUNTRY_CAPITAL',
        ],
    ]
];
$compressedJson = Compressor::create()
    ->compress($data)
    ->toJson();
    
print_r(json_encode($data));
echo PHP_EOL;
print_r($compressedJson);

纯JSON（749个字符）

{"count":3,"names":["New York","London","Paris","Beijing","Moscow"],"cities":[{"id":1,"name":"New York","countryName":"USA","location":{"latitude":40.714606,"longitude"
:-74.0028},"localityType":"BIG_CITY"},{"id":2,"name":"London","countryName":"UK","location":{"latitude":51.507351,"longitude":-0.127696},"localityType":"COUNTRY_CAPITAL
"},{"id":3,"name":"Paris","countryName":"France","location":{"latitude":48.856663,"longitude":2.351556},"localityType":"COUNTRY_CAPITAL"},{"id":4,"name":"Beijing","coun
tryName":"China","location":{"latitude":39.90185,"longitude":116.391441},"localityType":"COUNTRY_CAPITAL"},{"id":5,"name":"Moscow","countryName":"Russia","location":{"l
atitude":55.755864,"longitude":37.617698},"localityType":"COUNTRY_CAPITAL"}]}

压缩JSON（562个字符）

[["count","names","cities","a|0|1|2","n|3","New York","London","Paris","Beijing","Moscow","a|5|6|7|8|9","id","name","countryName","location","localityType","a|B|C|D|E|F
","n|1","USA","latitude","longitude","a|J|K","n|e.2Xkv","n|-1C.28G","o|L|M|N","BIG_CITY","o|G|H|5|I|O|P","n|2","UK","n|p.dz7","n|-0.2vFR","o|L|T|U","COUNTRY_CAPITAL","o
|G|R|6|S|V|W","France","n|m.1XNq","n|2.2kQz","o|L|Z|a","o|G|4|7|Y|b|W","n|4","China","n|d.F7F","n|1s.bVh","o|L|f|g","o|G|d|8|e|h|W","n|5","Russia","n|t.1xtN","n|b.3lHA"
,"o|L|l|m","o|G|j|9|k|n|W","a|Q|X|c|i|o","o|3|4|A|p"],"q"]

在此示例中，压缩给出了25%的效率。然而，结构越复杂和重复，压缩效率就越高。

测试

composer test

鸣谢

• Islam Zaripov（作者）
• Beeno Tung的compress-json（NodeJS的同一库）

许可证

BSD 2-Clause License（免费开源软件）