scpp

Stellar Consensus Protocol code

This code has been extracted from stellar-core. It is built as a dependency of agora, and bindings are written in the D Programming Language to interact with it.

The path of each file matches the path in stellar-core relative to the root of the git repository, in order to make comparison and updating simpler. Files in extra are extra C++ files added to the build (e.g. to instantiate templates so the D side can use it).

Commit used for extraction: f31c8f90d7abc634fc89818e013a32dc5f2badc8 Timestamp of commit: Tue Jun 15 02:40:38 2021 -0700

Porting notes

Some files have been modified after porting:

• Some private declarations were changed to public. This allows us to test size & layout checks for our D glue layer, for example:

  agora/source/scpp/src/crypto/ByteSlice.h

  Line 21 in 76e4ca7

  public: // BPFK note: cannot be private as we require runtime layout checks

  used in https://github.com/bosagora/agora/blob/76e4ca7d77b123ef867d3ce99c1c1b26afab761d/source/scpp/extra/DSizeChecks.cpp and https://github.com/bosagora/agora/blob/76e4ca7d77b123ef867d3ce99c1c1b26afab761d/source/scpp/extra/DLayoutChecks.cpp.

• Stellar-specific definitions are in src/xdr/. Notably, the .x files are XDR definitions files which xdrcpp processes to generate the .h file. Since we don't have a similar tool for D, we generated the .h files from the XDR and copied both over. xdrpp also provides some base types (e.g. xvector) which are binded in D. We use a different hash and public key type than Stellar. Fortunately, all those types are confined to Stellar-types.h.

Update process

• Checkout stellar-core
• Perform a full build (not an installation) using Stellar's instructions
• Copy the required files
• Update the bindings

The full build step is required to make sure the .h for XDR are up to date, as there is no XDR -> D converter, we use XDR -> C++ -> D instead. Alternatively, one can use the experimental update.d update script.

LICENSE

This code is distributed under the Apache License 2.0, as the rest of stellar-core.