Module sc_service::client

Substrate Client and associated logic.

The Client is one of the most important components of Substrate. It mainly comprises two parts:

• A database containing the blocks and chain state, generally referred to as the Backend.
• A runtime environment, generally referred to as the Executor.

Initialization

Creating a Client is done by calling the new method and passing to it a Backend and an Executor.

The former is typically provided by the sc-client-db crate.

The latter typically requires passing one of:

• A LocalCallExecutor running the runtime locally.
• A RemoteCallExecutor that will ask a third-party to perform the executions.
• A RemoteOrLocalCallExecutor combination of the two.

Additionally, the fourth generic parameter of the Client is a marker type representing the ways in which the runtime can interface with the outside. Any code that builds a Client is responsible for putting the right marker.

Structs

• Client
  Substrate Client
• ClientConfig
  Client configuration items.
• LocalCallExecutor
  Call executor that executes methods locally, querying all required data from local backend.

Functions

• new_in_mem
  Create an instance of in-memory client.
• new_with_backend
  Create a client with the explicitly provided backend. This is useful for testing backend implementations.