JsonCompressor

JsonCompressor is a lightweight Go library that compresses JSON structures into arrays by preserving only the values while maintaining the field order. It's particularly useful when you need to reduce JSON payload size while retaining the ability to reconstruct the original structure.

Features

• Compress any struct with JSON tags into an array format
• Decompress arrays back into their original struct format
• Recursive handling of nested structures, pointers, slices/arrays and string-keyed maps
• Preserves field order based on struct definition
• Type-safe conversion

Installation

go get github.com/go-sphere/jsoncompressor

Usage

type Person struct {
    Name    string   `json:"name"`
    Age     int      `json:"age"`
    Hobbies []string `json:"hobbies"`
    Address struct {
        City    string `json:"city"`
        Country string `json:"country"`
    } `json:"address"`
}

// Create a sample struct
person := Person{
    Name:    "John Doe",
    Age:     30,
    Hobbies: []string{"reading", "coding"},
    Address: struct {
        City    string `json:"city"`
        Country string `json:"country"`
    }{
        City:    "New York",
        Country: "USA",
    },
}

// Compress
compressed, err := jsoncompressor.Marshal(person)
if err != nil {
    log.Fatal(err)
}
// Result: ["John Doe", 30, ["reading", "coding"], ["New York", "USA"]]

// Decompress
var decompressed Person
err = jsoncompressor.Unmarshal(compressed, &decompressed)
if err != nil {
    log.Fatal(err)
}

Supported types

Go type	Compressed form
struct	Array of its field values
pointer	The pointed-to value's form, or null when nil
slice / array	Array
map with string keys	Object
types implementing json.Marshaler and json.Unmarshaler	Their MarshalJSON output
scalars / interface{}	Value as-is

Channels, functions, unsafe.Pointer, uintptr and maps with non-string keys are unsupported: Marshal returns an error when it meets one.

Notes

• Only exported fields with a non-empty json tag take part; untagged fields and fields tagged json:"-" are skipped
• Field order must be consistent between compression and decompression
• Requires proper type matching for successful decompression
• Types implementing both json.Marshaler and json.Unmarshaler (such as time.Time) keep their own JSON form instead of being expanded into an array; embedding one in a struct promotes those methods, as with encoding/json
• Integers decode exactly across the full int64/uint64 range; numbers stored into interface{} fields decode as float64, as with encoding/json

License

MIT License

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.