SideVM

About SideVM

SideVM is the core extension of Phat Contract. Despite the advantages above, the raw Phat Contract still has limitations compared with current Web2 backend programs:

Lifecycle limitation. The Phat Contract execution is triggered when users send on-chain transactions or off-chain queries to it, and the instance is destroyed when the execution finishes. This makes it impossible to do async requests or keep a long-live network connection;
Program environment limitation. The Phat Contract inherits the limitations of Ink! and only supports no_std crates. This also limits the resources a contract can use (e.g. listening to a port for connections).

SideVM is proposed to tackle these limitations. It runs in a different runtime. This means it can continuously execute, support std library, and listen to the port.

Prepare Environment

The SideVM support is already equipped to our public testnet. But it requires manual authorization to your contract to enable it to call the start_sidevm() function. Contact us is the #dev channel in our Discord server to get support.

Also, you can run your local testnet following our tutorial and then do the testing.

Play with it

Programming SideVM

We use https://github.com/Phala-Network/phat-contract-examples/tree/master/start_sidevm as an example. It contains both the Phat contract and the SideVM program under sideprog folder.

The SideVM part listens to a local port. It will be launched by this line of code if called.

Compile Phat Contract and SideVM Program

Just make under the folder and it will give you

SideVM program sideprog.wasm
Phat contract under target/ink/start_sidevm.contract

Upload SideVM Program and Instantiate the Contract

We have a frontend but it does not support the SideVM program upload yet. So we need to upload it manually.

Upload SideVM Program

Use Polkadot.js and change the endpoint to Phala (PoC 6) under TEST NETWORKS.

In Developer - Extrinsics, choose phalaFatContracts and clusterUploadResource. Change resourceType to SidevmCode, and drag your sideprog.wasm here.

Submit the transaction and you shall see its success.

Interact with Phat UI

Go to https://phat.phala.network/, click sign in and link your address. You need to ensure the RPC Endpoint is wss://poc6.phala.network/ws and Default PRuntime Endpoint https://phat-cluster-us.phala.network/poc6/pruntime/0xac5087e0.

Click Upload and drag your target/ink/start_sidevm.contract. Choose the default constructor and Cluster 0x0000000000000000000000000000000000000000000000000000000000000000. Click Submit. You should see something like

Start SideVM with Query

You can directly interact with your contract with Contract UI.

The start_sidevm query is used to start the SideVM program. It contains the invoke to pink::start_sidevm().

From the Worker log, we can see

Actually, we implemented the log server with SideVM too (ref).