Module schema

Module is available if borsh is built with features = ["unstable__schema"].

Since Borsh is not a self-descriptive format we have a way to describe types serialized with Borsh so that we can deserialize serialized blobs without having Rust types available. Additionally, this can be used to serialize content provided in a different format, e.g. JSON object {"user": "alice", "message": "Message"} can be serialized by JS code into Borsh format such that it can be deserialized into struct UserMessage {user: String, message: String} on Rust side.

The important components are: BorshSchema trait, Definition and Declaration types, and BorshSchemaContainer struct.

• BorshSchema trait allows any type that implements it to be self-descriptive, i.e. generate it’s own schema;
• Declaration is used to describe the type identifier, e.g. HashMap<u64, String>;
• Definition is used to describe the structure of the type;
• BorshSchemaContainer is used to store all declarations and definitions that are needed to work with a single type.

Modules

hashes

Module is available if borsh is built with features = ["std"] or features = ["hashbrown"].

Structs

BorshSchemaContainer

All schema information needed to deserialize a single type.

Enums

Definition

The type that we use to represent the definition of the Borsh type.

Fields

The collection representing the fields of a struct.

SchemaContainerValidateError

Possible error when validating a BorshSchemaContainer, generated for some type T, for violation of any well-known rules with respect to borsh serialization.

SchemaMaxSerializedSizeError

Possible error when calculating theoretical maximum size of encoded type T.

Traits

BorshSchema

The declaration and the definition of the type that can be used to (de)serialize Borsh without the Rust type that produced it.

Functions

add_definition

Helper method to add a single type definition to the map.

Type Aliases

Declaration

The type that we use to represent the declaration of the Borsh type.

DiscriminantValue

The type that we use for value of discriminant.

FieldName

The name of the field in the struct (can be used to convert JSON to Borsh using the schema).

VariantName

The type that we use for the name of the variant.