ffi

Filecoin Proofs FFI

C and CGO bindings for Filecoin's Rust libraries

Building

To build and install libfilcrypto, its header file and pkg-config manifest, run:

make

To optionally authenticate with GitHub for assets download (to increase API limits) set GITHUB_TOKEN to personal access token.

If no precompiled static library is available for your operating system, the build tooling will attempt to compile a static library from local Rust sources.

Installation notes

By default, building this will download a pre-built binary of the ffi. The advantages for downloading it are faster build times, and not requiring a rust toolchain and build environment.

The disadvantage to downloading the pre-built binary is that it will not be optimized for your specific hardware. This means that if raw performance is of utmost importance to you, it's highly recommended that you build from source.

Building from Source

To opt out of downloading precompiled assets, set FFI_BUILD_FROM_SOURCE=1:

To allow portable building of the blst dependency, set FFI_USE_BLST_PORTABLE=1:

rm .install-filcrypto \
    ; make clean \
    ; FFI_BUILD_FROM_SOURCE=1 FFI_USE_BLST_PORTABLE=1 make

By default, a 'gpu' option is used in the proofs library. This feature is also used in FFI unless explicitly disabled. To disable building with the 'gpu' dependency, set FFI_USE_GPU=0:

rm .install-filcrypto \
    ; make clean \
    ; FFI_BUILD_FROM_SOURCE=1 FFI_USE_GPU=0 make

Experimental CUDA build support

An experimental 'gpu' option using CUDA can be used in the proofs library. This feature is disabled by default (opencl is the default, when FFI_USE_GPU=1 is set.). To enable building with the 'gpu' CUDA dependency, set FFI_USE_CUDA=1 when building from source.

rm .install-filcrypto \
    ; make clean \
    ; FFI_BUILD_FROM_SOURCE=1 FFI_USE_CUDA=1 make

By default, a 'multicore-sdr' option is used in the proofs library. This feature is also used in FFI unless explicitly disabled. To disable building with the 'multicore-sdr' dependency, set FFI_USE_MULTICORE_SDR=0:

rm .install-filcrypto \
    ; make clean \
    ; FFI_BUILD_FROM_SOURCE=1 FFI_USE_MULTICORE_SDR=0 make

Updating rust-fil-proofs (via rust-filecoin-proofs-api)

If rust-fil-proofs has changed from commit X to Y and you wish to get Y into the filecoin-ffi project, you need to do a few things:

1. Update the cess-proving-system-api Cargo.toml file to point to Y
2. Run cd rust && cargo update -p "cess-proving-system-api" from the root of the cess-ffi project
3. After the previous step alters your Cargo.lock file, commit and push

go get

go get needs some additional steps in order to work as expected.

Get the source, add this repo as a submodule to your repo, build it and point to it:

go get github.com/CESSProject/cess-ffi
git submodule add https://github.com/CESSProject/cess-ffi.git internal/ffi
make -C internal/ffi
go mod edit -replace=github.com/CESSProject/cess-ffi=./internal/ffi

Updating CGO Bindings

The CGO bindings are generated using c-for-go and committed to Git. To generate bindings yourself, install the c-for-go binary, ensure that it's on your path, and then run make cgo-gen. CI builds will fail if generated CGO diverges from what's checked into Git.

Updating the Changelog

The mkreleaselog script (in the project root) can be used to generate a good portion of the filecoin-ffi changelog. For historical reasons, the script must be run from the root of a filecoin-ffi checkout which is in your $GOPATH.

Run it like so:

./mkreleaselog v0.25.0 v0.26.0 > /tmp/v0.26.0.notes.txt

License

MIT or Apache 2.0