Struct MemoryAllocator 

pub struct MemoryAllocator(/* private fields */);

An allocator RocksDB uses for cache block memory instead of the system one.

Pass it to set_memory_allocator on LruCacheOptions or HyperClockCacheOptions before building the cache. One allocator can back several caches. Cloning is cheap and hands out another reference to the same allocator.

The allocator is ignored for compression libraries that allocate internally (currently only XPRESS).

Implementations

impl MemoryAllocator

pub fn new_jemalloc_nodump() -> Result<Self, Error>

Creates a jemalloc allocator that keeps its memory out of core dumps.

The allocator serves every request from one dedicated jemalloc arena and marks that arena MADV_DONTDUMP. A block cache built on it therefore does not land in a core dump, which for a multi-gigabyte cache is the difference between a usable dump and an unusable one. Using a single arena also cuts jemalloc metadata, and jemalloc’s thread-local cache is left on to keep the arena’s mutex from becoming a bottleneck.

Errors

Fails with Not implemented: Not compiled with JEMALLOC when the linked librocksdb has no jemalloc support. That depends on how librocksdb itself was built, which this crate’s jemalloc feature controls only for a vendored build. An externally supplied librocksdb can have jemalloc with the feature off, or lack it with the feature on, so check the result rather than the feature.

Trait Implementations

impl Clone for MemoryAllocator

fn clone(&self) -> MemoryAllocator

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.