Module no_proto::schema

Schemas are JSON used to declare & store the shape of buffer objects.

No Proto Schemas are JSON objects that describe how the data in a NP_ buffer is stored.

Every schema object has at least a "type" key that provides the kind of value stored at that part of the schema. Additional keys are dependent on the type of schema.

Schemas are validated and sanity checked by the NP_Factory struct upon creation. You cannot pass an invalid schema into a factory constructor and build/parse buffers with it.

If you're familiar with typescript, schemas can be described by this recursive interface:

interface NP_Schema {
    type: string;
     
    // used by list types
    of?: NP_Schema
     
    // used by map types
    value?: NP_Schema
 
    // used by tuple types
    values?: NP_Schema[]
 
    // used by table types
    columns?: [string, NP_Schema][]
}

Schemas do not have to contain collections, for example a perfectly valid schema for just a string would be:

{
    "type": "string"
}

Nesting is easy to perform. For example, this is a list of tables. Each table has two columns: id and title. Both columns are a string type.

{
    "type": "list",
    "of": {
        "type": "table",
        "columns": [
            ["id",    {type: "string"}]
            ["title", {type: "string"}]
        ]
    }
}

A list of strings is just as easy...

{
    "type": "list",
    "of": { type: "string" }
}

Each type has trade offs associated with it. The table and documentation below go into further detail.

Here is a table of supported types.

Type	Rust Type / Struct	Bytes (Size)	Limits / Notes
table	NP_Table	4 bytes - ~4GB	Linked list with indexed keys that map against up to 255 named columns.
list	NP_List	8 bytes - ~4GB	Linked list with up to 65,535 items.
map	NP_Map	4 bytes - ~4GB	Linked list with Vec<u8> keys.
tuple	NP_Tuple	4 bytes - ~4GB	Static sized collection of specific values.
any	NP_Any	4 bytes - ~4GB	Generic type.
string	String	4 bytes - ~4GB	Utf-8 formatted string.
bytes	NP_Bytes	4 bytes - ~4GB	Arbitrary bytes.
int8	i8	1 byte	-127 to 127
int16	i16	2 bytes	-32,768 to 32,768
int32	i32	4 bytes	-2,147,483,648 to 2,147,483,648
int64	i64	8 bytes	-9.22e18 to 9.22e18
uint8	u8	1 byte	0 - 255
uint16	u16	2 bytes	0 - 65,535
uint32	u32	4 bytes	0 - 4,294,967,295
uint64	u64	8 bytes	0 - 1.84e19
float	f32	4 bytes	-3.4e38 to 3.4e38
double	f64	8 bytes	-1.7e308 to 1.7e308
option	NP_Option	1 byte	Up to 255 strings in schema.
bool	bool	1 byte
dec64	NP_Dec	9 bytes	Big Integer Decimal format.
geo4	NP_Geo	4 bytes	1.5km resolution (city) geographic coordinate
geo8	NP_Geo	8 bytes	16mm resolution (marble) geographic coordinate
geo16	NP_Geo	16 bytes	3.5nm resolution (flea) geographic coordinate
tid	NP_TimeID	16 bytes	8 byte u64 for time with 8 bytes of random numbers.
uuid	NP_UUID	16 bytes	v4 UUID, 2e37 possible UUID v4s
date	NP_Date	8 bytes	Good to store unix epoch (in seconds) until the year 584,942,417,355

table

list

map

tuple

any

string

bytes

int8, int16, int32, int64

uint8, uint16, uint32, uint64

float, double

option

bool

dec64

geo4, ge8, geo16

tid

uuid

date