pezkuwichain
379cb741ed
This commit systematically rebrands various references from Parity Technologies' Polkadot/Substrate ecosystem to PezkuwiChain within the kurdistan-sdk. Key changes include: - Updated external repository URLs (zombienet-sdk, parity-db, parity-scale-codec, wasm-instrument) to point to pezkuwichain forks. - Modified internal documentation and code comments to reflect PezkuwiChain naming and structure. - Replaced direct references to with or specific paths within the for XCM, Pezkuwi, and other modules. - Cleaned up deprecated issue and PR references in various and files, particularly in and modules. - Adjusted image and logo URLs in documentation to point to PezkuwiChain assets. - Removed or rephrased comments related to external Polkadot/Substrate PRs and issues. This is a significant step towards fully customizing the SDK for the PezkuwiChain ecosystem.
78 lines
3.9 KiB
Rust
78 lines
3.9 KiB
Rust
//! # Custom RPC do's and don'ts
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//!
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//! **TLDR:** Don't create new custom RPCs. Instead, rely on custom Runtime APIs, combined with
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//! `state_call`.
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//!
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//! ## Background
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//!
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//! Pezkuwi-SDK offers the ability to query and subscribe storages directly. However what it does
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//! not have is [view functions](https://github.com/pezkuwichain/pezkuwi-sdk/issues/101). This is an
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//! essential feature to avoid duplicated logic between runtime and the client SDK. Custom RPC was
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//! used as a solution. It allow the RPC node to expose new RPCs that clients can be used to query
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//! computed properties.
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//!
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//! ## Problems with Custom RPC
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//!
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//! Unfortunately, custom RPC comes with many problems. To list a few:
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//!
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//! - It is offchain logic executed by the RPC node and therefore the client has to trust the RPC
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//! node.
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//! - To upgrade or add a new RPC logic, the RPC node has to be upgraded. This can cause significant
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//! trouble when the RPC infrastructure is decentralized as we will need to coordinate multiple
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//! parties to upgrade the RPC nodes.
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//! - A lot of boilerplate code is required to add custom RPC.
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//! - It prevents dApps from using a light client or an alternative client.
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//! - It makes ecosystem tooling integration much more complicated. For example, dApps will not
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//! be able to use [Chopsticks](https://github.com/AcalaNetwork/chopsticks) for testing as
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//! Chopsticks will not have the custom RPC implementation.
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//! - Poorly implemented custom RPC can be a DoS vector.
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//!
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//! Hence, we should avoid custom RPC.
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//!
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//! ## Alternatives
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//!
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//! Generally, [`pezsc_rpc::state::StateBackend::call`] aka. `state_call` should be used instead of
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//! custom RPC.
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//!
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//! Usually, each custom RPC comes with a corresponding runtime API which implements the business
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//! logic. So instead of invoke the custom RPC, we can use `state_call` to invoke the runtime API
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//! directly. This is a trivial change on the dApp and no change on the runtime side. We may remove
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//! the custom RPC from the node side if wanted.
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//!
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//! There are some other cases that a simple runtime API is not enough. For example, implementation
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//! of Ethereum RPC requires an additional offchain database to index transactions. In this
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//! particular case, we can have the RPC implemented on another client.
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//!
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//! For example, the Acala EVM+ RPC are implemented by
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//! [eth-rpc-adapter](https://github.com/AcalaNetwork/bodhi.js/tree/master/packages/eth-rpc-adapter).
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//! Alternatively, the [Frontier](https://github.com/polkadot-evm/frontier) project also provided
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//! Ethereum RPC compatibility directly in the node-side software.
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//!
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//! ## Create a new Runtime API
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//!
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//! For example, let's take a look at the process through which the account nonce can be queried
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//! through an RPC. First, a new runtime-api needs to be declared:
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#![doc = docify::embed!("../../bizinikiwi/pezframe/system/rpc/runtime-api/src/lib.rs", AccountNonceApi)]
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//!
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//! This API is implemented at the runtime level, always inside [`pezsp_api::impl_runtime_apis!`].
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//!
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//! As noted, this is already enough to make this API usable via `state_call`.
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//!
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//! ## Create a new custom RPC (Legacy)
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//!
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//! Should you wish to implement the legacy approach of exposing this runtime-api as a custom
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//! RPC-api, then a custom RPC server has to be defined.
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#![doc = docify::embed!("../../bizinikiwi/utils/pezframe/rpc/system/src/lib.rs", SystemApi)]
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//!
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//! ## Add a new RPC to the node (Legacy)
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//!
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//! Finally, this custom RPC needs to be integrated into the node side. This is usually done in a
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//! `rpc.rs` in a typical template, as follows:
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#![doc = docify::embed!("../../templates/minimal/node/src/rpc.rs", create_full)]
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//!
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//! ## Future
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//!
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//! - [XCQ](https://forum.polkadot.network/t/cross-consensus-query-language-xcq/7583) will be a good
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//! solution for most of the query needs.
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//! - [New JSON-RPC Specification](https://github.com/paritytech/json-rpc-interface-spec)
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