go-fvm-sdk

go-fvm-sdk enables GO developers to write FVM contracts in TinyGo. To learn more about FVM, please check out resources on fvm forum.

Key features of go-fvm-sdk are...

• Compiles GO contracts into WASM
• Full compatibility with FVM system call interface
• unit/integration test support
• Deploy native WASM actor on FVM!

Why TinyGO

• Support most Go syntax and libraries.
• Smaller footprint which is great for use cases on the blockchain.
• Nimble management of GC and Memory, which is great for contracts with runtime constraints of tens to hundreds of milliseconds and memory constraints of a few megabytes.

Install

Install Gov1.20.x or above and TinyGov0.27 or above.

Note: latest Go or TinyGo versions may not be tested.

Use Binary

Go to releases and download the executables.

Rename your executable to fvm_go_sdk and add execution permission.

$ mv fvm_go_sdk_vX.Y.Z_xxx fvm_go_sdk
$ chmod +x fvm_go_sdk

Build from source

Install OpenCl and Rust.

Clone fvm_go_sdk repo and make.

$ sudo apt install ocl-icd-opencl-dev jq    # install dependencies
$ cargo install cargo-edit                  # install cargo plugin, builtin-actor require
$ rustup target add wasm32-unknown-unknown  # install wasm target
$ git clone [email protected]:ipfs-force-community/go-fvm-sdk.git
$ make

Note: it may take a while before you finish buiding from source.

Check if fvm_go_sdk is operational.

$ fvm_go_sdk -h

Once you have fvm_go_sdk ready, Go and TinyGo need to be patched in order to have the compiled WASM contract compatible with FVM.

$ fvm_go_sdk patch

Successful patching of go-fvm-sdk will give the following output. And you are done with installation!

patching file src/reflect/value.go
Hunk #1 succeeded at 754 (offset 3 lines).
patching file targets/wasi.json
Hunk #2 succeeded at 10 with fuzz 1.

Create your first Contract!

It is recommended that you create your first project using our template.

$ fvm_go_sdk new -- <YOUR_ACTOR_NAME>

fvm_go_sdk will generate the following scaffolding for you.

.
├── README.md 
├── actor
│   ├── actor.go # Write your contract here
│   └── cbor_gen.go
├── client
│   └── client.go # client for installation and deployment of the contract
├── entry.go # Main entry point of the contract. If you change interfaces of your actor, please build again to renew the entry point file
├── gen
│   ├── go.mod
│   ├── go.sum
│   └── main.go
├── go.mod
├── go.sum
├── <YOUR_ACTOR_NAME>.wasm # WASM contract compiled from actor.go
└── test.json

Compile your contract. And you now have your very first contract ready to be depolyed!

$ fvm_go_sdk build

Deploy your Contract

Follow this instruction to setup local devnet with fvm branch experimental/fvm-m2.

Install actor.

$ lotus chain install-actor <path-to-wasm-bytecode>

Instantiate actor.

$ lotus chain create-actor <code-cid> <encoded-params>

Invoke actor.

$ lotus chain invoke <address> <method_num>

Tips

• Do not use ASM code.
• Avoid using the reflect library. If you have to, make sure that TinyGo supports it.
• Use go list command to check actor dependency issue.

$ go list -json -deps > deps.json