Files
rippled/src
Nik Bougalis c3acbce82d Optimize SHAMapItem and leverage new slab allocator: (#4218)
The `SHAMapItem` class contains a variable-sized buffer that
holds the serialized data associated with a particular item
inside a `SHAMap`.

Prior to this commit, the buffer for the serialized data was
allocated separately. Coupled with the fact that most instances
of `SHAMapItem` were wrapped around a `std::shared_ptr` meant
that an instantiation might result in up to three separate
memory allocations.

This commit switches away from `std::shared_ptr` for `SHAMapItem`
and uses `boost::intrusive_ptr` instead, allowing the reference
count for an instance to live inside the instance itself. Coupled
with using a slab-based allocator to optimize memory allocation
for the most commonly sized buffers, the net result is significant
memory savings. In testing, the reduction in memory usage hovers
between 400MB and 650MB. Other scenarios might result in larger
savings.

In performance testing with NFTs, this commit reduces memory size by
about 15% sustained over long duration.

Commit 2 of 3 in #4218.
2023-04-10 17:13:03 -07:00
..
2019-03-18 16:19:24 -07:00

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