The codebase is filled with includes that are unused, and which thus can be removed. At the same time, the files often do not include all headers that contain the definitions used in those files. This change uses clang-format and clang-tidy to clean up the includes, with minor manual intervention to ensure the code compiles on all platforms.
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.
A few unit tests have historically generated a lot of noise
to the console from log writes. This noise was not useful
and made it harder to locate actual test failures.
By changing the log level of these tests from
- severities::kError to
- severities::kDisabled
it was possible to remove that noise coming from the logs.
When fetching ledgers, the existing code would isolate the peer
that sent the most useful responses and issue follow up queries
only to that peer.
This commit increases the query aggressiveness, and changes the
mechanism used to select which peers to issue follow-up queries
to so as to more evenly spread the load along those peers which
provided useful responses.
The existing class offered several constructors which were mostly
unnecessary. This commit eliminates all existing constructors and
introduces a single new one, taking a `Slice`.
The internal buffer is switched from `std::vector` to `Buffer` to
save a minimum of 8 bytes (plus the buffer slack that is inherent
in `std::vector`) per SHAMapItem instance.
This commit combines a number of cleanups, targeting both the
code structure and the code logic. Large changes include:
- Using more strongly-typed classes for SHAMap nodes, instead of relying
on runtime-time detection of class types. This change saves 16 bytes
of memory per node.
- Improving the interface of SHAMap::addGiveItem and SHAMap::addItem to
avoid the need for passing two bool arguments.
- Documenting the "copy-on-write" semantics that SHAMap uses to
efficiently track changes in individual nodes.
- Removing unused code and simplifying several APIs.
- Improving function naming.
