A bridge connects two blockchains: a locking chain and an issuing chain (also called a mainchain and a sidechain). Both are independent ledgers, with their own validators and potentially their own custom transactions. Importantly, there is a way to move assets from the locking chain to the issuing chain and a way to return those assets from the issuing chain back to the locking chain: the bridge. This key operation is called a cross-chain transfer. A cross-chain transfer is not a single transaction. It happens on two chains, requires multiple transactions, and involves an additional server type called a "witness". A bridge does not exchange assets between two ledgers. Instead, it locks assets on one ledger (the "locking chain") and represents those assets with wrapped assets on another chain (the "issuing chain"). A good model to keep in mind is a box with an infinite supply of wrapped assets. Putting an asset from the locking chain into the box will release a wrapped asset onto the issuing chain. Putting a wrapped asset from the issuing chain back into the box will release one of the existing locking chain assets back onto the locking chain. There is no other way to get assets into or out of the box. Note that there is no way for the box to "run out of" wrapped assets - it has an infinite supply. Co-authored-by: Gregory Popovitch <greg7mdp@gmail.com>
rippled Source
Some of these directories come from entire outside repositories brought in
using [git-subtree][]. This means that the source files are inserted directly
into the rippled repository. They can be edited and committed just as if they
were normal files.
[git-subtree]: https://github.com/apenwarr/git-subtree
If you create a commit that contains files both from a subtree, and from the
rippled source tree, please use care when designing the commit message, since
it will appear in the subtree's individual repository when the changes are
pushed back to the upstream. Better yet, do not mix files from subtrees and
ripple in the same commit at all.
Source folders:
| Folder | Upstream Repo | Description |
|---|---|---|
beast |
N/A | legacy utility code that was formerly associated with boost::beast |
ed25519-donna |
https://github.com/floodyberry/ed25519-donna | Ed25519 digital signatures |
ripple |
N/A | Core source code for rippled |
secp256k1 |
https://github.com/bitcoin-core/secp256k1 | ECDSA digital signatures using the secp256k1 curve |
test |
N/A | Unit tests for rippled |
The following dependencies are downloaded and built using ExternalProject (or FetchContent, where possible). Refer to CMakeLists.txt file for details about how these sources are built :
| Name | Upstream Repo | Description |
|---|---|---|
lz4 |
https://github.com/lz4/lz4 | LZ4 lossless compression algorithm |
nudb |
https://github.com/vinniefalco/NuDB | Constant-time insert-only key/value database for SSD drives (Less memory usage than RocksDB.) |
snappy |
https://github.com/google/snappy | "Snappy" lossless compression algorithm. |
soci |
https://github.com/SOCI/soci | Abstraction layer for database access. |
sqlite |
https://www.sqlite.org/src | An embedded database engine that writes to simple files. |
rocksdb |
https://github.com/facebook/rocksdb | Fast key/value database. (Supports rotational disks better than NuDB.) |
protobuf |
https://github.com/google/protobuf | Protocol buffer data interchange format. Only downloaded/built if a suitable version is not found by find_package, or if the local_protobuf option is explicitly set |