grin/doc/code_structure.md

grin code structure

grin is built in rust, a memory safe, compiled language. Performance critical parts like the Cuckoo mining algorithm are built as plugins, making it easy to swap between algorithm implementations for various hardware. Grin comes with CPU and experimental GPU support.

Files in project root

List of files tracked in git and some files you'll create when you use grin.

• CODE_OF_CONDUCT - How to behave if you want to participate. Taken from rust. Slightly modified.
• CONTRIBUTING - How to help and become part of grin.
• Cargo.toml and Cargo.lock (locally created, not in git) - defines how to the project code is to be compiled and built
• LICENSE - Apache 2.0 license
• README - The first document you should read, with pointers to find more detail.
• rustfmt.toml - configuration file for rustfmt. Required before contributing new code.

Folder structure

After checking out grin, building and using, these are the folders you'll have:

• api Code for ApiEndpoints accessible over REST.
• chain The blockchain implementation. Accepts a block (see pipe.rs) and adds it to the chain, or reject it.
• config Code for handling configuration.
• core All core types: Hash, Block, Input, Output, and how to serialize them. Core mining algorithm, and more.
• doc All documentation.
• servers Many parts (adapters, lib, miner, seed, server, sync, types) that the grin server needs, including mining server.
• keychain Code for working safely with keys and doing blinding.
• p2p All peer to peer connection and protocol-related logic (handshake, block propagation, etc.).
• pool Code for the transaction pool implementation.
• server A folder you're supposed to create, before starting your server: cd to project root; mkdir server; cd server; grin server start (or run) and it will create a subfolder .grin
  • .grin
    • chain - a Rocksdb with the blockchain blocks and related information
    • peers - a Rocksdb with the list of Grin peers you're connected to
    • txhashset - contains folders kernel, rangeproof and output that each have a pmmr_dat.bin
• src Code for the grin binary.
• store Data store - a thin wrapper for Rocksdb, a key-value database forked from LevelDB.
• target Where the grin binary ends up, after the compile and build process finishes. In case of trouble, see troubleshooting
• util Low-level rust utilities.
• wallet Simple command line wallet implementation. Will generate:
  • wallet.dat - your "outputs", that once confirmed and matured, can be spent with the grin wallet send command. (locally created, not in git)
  • wallet.seed - your secret wallet seed. (locally created, not in git)

grin dependencies

• secp256k1 Integration and rust bindings for libsecp256k1, and some changes waiting to be upstreamed. Imported in util/Cargo.toml.