Crate pallet_schemas

Schemas Pallet

The Schemas pallet provides functionality for handling schemas.

• Configuration: Config
• Extrinsics: Call
• Runtime API: SchemasRuntimeApi
• Custom RPC API: SchemasApiServer
• Event Enum: Event
• Error Enum: Error

Overview

This pallet provides an on chain repository for schemas, thereby allowing participants of the network to flexibly interact and exchange messages with each other without facing the challenge of sharing, managing and validating messages as well as schemas between them.

NOTE: In this pallet we define the payload structure that is used in Messages Pallet.

The Schema pallet provides functions for:

• Registering a new schema.
• Setting maximum schema model size by governance.
• Retrieving latest registered schema id.
• Retrieving schemas by their id.

Terminology

• Schema: The structure that defines how a Message is stored and structured.
• Schema Model: Serialization/Deserialization details of the schema
• Schema Model Type: The type of the following Serialization/Deserialization. It can be Avro, Parquet or …

Implementations

• SchemaValidator: Functions for accessing and validating Schemas. This implementation is what is used in the runtime.
• SchemaProvider: Allows another pallet to resolve schema information.

Genesis config

The Schemas pallet depends on the GenesisConfig.

Re-exports

• pub use pallet::*;
• pub use weights::*;

Modules

• migration
  migration module
• pallet
  The pallet module in each FRAME pallet hosts the most important items needed to construct this pallet.
• weights
  Autogenerated weights for pallet_schemas

Structs

• SchemaInfo
  A structure defining a Schema information (excluding the payload)
• SchemaName
  A structure defining name of a schema
• SchemaVersionId
  A structure defining name of a schema

Constants

• DESCRIPTOR_MAX
  The maximum size of a schema descriptor
• DESCRIPTOR_MIN
  The minimum size of a schema descriptor
• MAX_NUMBER_OF_VERSIONS
  maximum number of versions for a certain schema name -1 is to avoid overflow when converting the (index + 1) to SchemaVersion in SchemaVersionId
• NAMESPACE_MAX
  The maximum size of a namespace in schema
• NAMESPACE_MIN
  The minimum size of a namespace in schema
• SCHEMA_NAME_BYTES_MAX
  The maximum size of schema name including all parts
• SCHEMA_STORAGE_VERSION
  Current storage version of the schemas pallet.
• SEPARATOR_CHAR
  separator character

Type Aliases

• SchemaDescriptor
  schema descriptor type
• SchemaNamePayload
  A schema name following following structure NAMESPACE.DESCRIPTOR
• SchemaNamespace
  schema namespace type