Struct DiskConfig 

pub struct DiskConfig {
    pub root: PathBuf,
    pub max_bytes: u64,
    pub shard_chars: usize,
    pub queue_capacity: usize,
    pub writer_threads: usize,
    pub reader_threads: usize,
    pub prefetch_capacity: usize,
    pub reserve_bytes: u64,
    pub free_space_ttl: Duration,
    pub free_space_probe: FreeSpaceProbe,
}

How the store is sized, laid out, and how much writing it will do off the calling thread.

Fields

root: PathBuf

Directory the store owns. Created if absent.

max_bytes: u64

Byte budget for blocks the store is accounting for. Eviction keeps the store at or under this.

shard_chars: usize

Hex characters of the hash used as the shard subdirectory name. 2 gives 256 shards, which keeps directory sizes sane well past a million blocks.

queue_capacity: usize

Writes that may be waiting for a writer thread at once. When it is full, DiskKvStore::put writes on the calling thread instead of dropping the block – backpressure, not loss.

writer_threads: usize

Background writer threads. 0 is legitimate and means every write happens on the thread that asked for it.

reader_threads: usize

Background reader threads, serving prefetches and any demand read that does not want to block its own thread. 0 means every read happens on the thread that asked for it, and a prefetch is a no-op.

prefetch_capacity: usize

Blocks that may sit in the prefetch staging area at once. A prefetch is a hint, so this is a hard refusal rather than backpressure: reading ahead must never be the thing that runs the process out of memory.

reserve_bytes: u64

Bytes to leave free on the filesystem. The store evicts to stay this far away from a full disk, rather than letting ENOSPC be the mechanism that tells it to stop.

free_space_ttl: Duration

How long a free-space reading is trusted before it is taken again.

free_space_probe: FreeSpaceProbe

How free space is measured. Defaults to statvfs on unix, and to “cannot tell” elsewhere.

Implementations

impl DiskConfig

pub fn new(root: impl Into<PathBuf>) -> Self

pub fn with_max_bytes(self, max_bytes: u64) -> Self

pub fn with_shard_chars(self, shard_chars: usize) -> Self

pub fn with_queue_capacity(self, queue_capacity: usize) -> Self

pub fn with_writer_threads(self, writer_threads: usize) -> Self

pub fn with_reader_threads(self, reader_threads: usize) -> Self

pub fn with_prefetch_capacity(self, prefetch_capacity: usize) -> Self

pub fn with_reserve_bytes(self, reserve_bytes: u64) -> Self

pub fn with_free_space_ttl(self, free_space_ttl: Duration) -> Self

pub fn with_free_space_probe(self, probe: FreeSpaceProbe) -> Self

Trait Implementations

impl Clone for DiskConfig

fn clone(&self) -> DiskConfig

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for DiskConfig

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.