Struct DiskCache 

pub struct DiskCache { /* private fields */ }

DiskCache is a ChunkCache implementor that saves data on the file system

Implementations

impl DiskCache

pub async fn num_items(&self) -> usize

pub async fn total_bytes(&self) -> u64

pub fn initialize(config: &CacheConfig) -> Result<Self, ChunkCacheError>

initialize will create a new DiskCache with the capacity and cache root based on the config the cache file system layout is rooted at the provided config.cache_directory and initialize will attempt to load any pre-existing cache state into memory.

an configured size of 0 caused initialization to fail

The cache layout is as follows:

each key (cas hash) in the cache is a directory, containing “cache items” that each provide some range of data.

keys are grouped into subdirectories under the cache rootbased on the first 2 chacters of their file name, which is base64 encoded, leading to at most 64 * 64 directories under the cache root.

cache_root/ ├── [ab]/ │ ├── [key 1 (ab123…)]/ │ │ ├── [range 0-100, file_len, file_hash] │ │ ├── [range 102-300, file_len, file_hash] │ │ └── [range 900-1024, file_len, file_hash] │ ├── [key 2 (ab456…)]/ │ └── [range 0-1020, file_len, file_hash] ├── [cd]/ │ └── [key 3 (cd123…)]/ │ ├── [range 30-31, file_len, file_hash] │ ├── [range 400-402, file_len, file_hash] │ ├── [range 404-405, file_len, file_hash] │ └── [range 679-700, file_len, file_hash]

Trait Implementations

impl ChunkCache for DiskCache

fn get<'life0, 'life1, 'life2, 'async_trait>( &'life0 self, key: &'life1 Key, range: &'life2 ChunkRange, ) -> Pin<Box<dyn Future<Output = Result<Option<CacheRange>, ChunkCacheError>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait, 'life2: 'async_trait,

get should return an Ok() variant if significant error occurred, check the error variant for issues with IO or parsing contents etc.

fn put<'life0, 'life1, 'life2, 'life3, 'life4, 'async_trait>( &'life0 self, key: &'life1 Key, range: &'life2 ChunkRange, chunk_byte_indices: &'life3 [u32], data: &'life4 [u8], ) -> Pin<Box<dyn Future<Output = Result<(), ChunkCacheError>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait, 'life2: 'async_trait, 'life3: 'async_trait, 'life4: 'async_trait,

put should return Ok(()) if the put succeeded with no error, check the error variant for issues with validating the input, cache state, IO, etc.

impl Clone for DiskCache

fn clone(&self) -> DiskCache

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for DiskCache

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

Formats the value using the given formatter.