Struct CacheSnapshot 

pub struct CacheSnapshot {
    pub version: u32,
    pub toolchain_version: String,
    pub dependency_hash: u64,
    pub cells: HashMap<String, CachedCell>,
    pub created_at: u64,
}

Snapshot of Salsa DB state that can be persisted to disk.

This captures the essential compilation state needed for instant resume:

• Which cells have been compiled
• Where their dylibs are located
• What source code produced them (via hash)

Note: This does NOT store Salsa’s internal memoization state. Salsa queries will be recomputed on load, but since compiled dylibs are preserved, compilation (the slow part) is skipped.

Fields

version: u32

Cache format version for compatibility checking.

toolchain_version: String

Rust toolchain version string (e.g., “rustc 1.76.0-nightly (abc123 2024-01-15)”).

Cache is invalidated if toolchain changes, since compiled dylibs may have ABI incompatibilities.

dependency_hash: u64

Hash of external dependencies from //! [dependencies] block.

If this changes, the universe dylib needs recompilation and all cells must be recompiled against the new universe.

cells: HashMap<String, CachedCell>

Compilation results keyed by cell name.

created_at: u64

Unix timestamp when cache was created.

Implementations

impl CacheSnapshot

pub fn new(toolchain_version: String, dependency_hash: u64) -> Self

Create a new cache snapshot.

pub fn add_cell(&mut self, cell: CachedCell)

Add a compiled cell to the snapshot.

pub fn get_cell(&self, name: &str) -> Option<&CachedCell>

Get a cached cell by name.

pub fn is_cell_valid(&self, name: &str, current_source_hash: u64) -> bool

Check if a cell’s source has changed.

Returns true if the cell exists in cache with the same source hash.

pub fn is_dependency_valid(&self, current_hash: u64) -> bool

Check if dependency hash matches.

Trait Implementations

impl Archive for CacheSnapshot

where u32: Archive, String: Archive, u64: Archive, HashMap<String, CachedCell>: Archive,

const COPY_OPTIMIZATION: CopyOptimization<Self>

An optimization flag that allows the bytes of this type to be copied directly to a writer instead of calling serialize.

type Archived = ArchivedCacheSnapshot

The archived representation of this type.

type Resolver = CacheSnapshotResolver

The resolver for this type. It must contain all the additional information from serializing needed to make the archived type from the normal type.

fn resolve(&self, resolver: Self::Resolver, out: Place<Self::Archived>)

Creates the archived version of this value at the given position and writes it to the given output.

impl Clone for CacheSnapshot

fn clone(&self) -> CacheSnapshot

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for CacheSnapshot

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

Formats the value using the given formatter.

impl<__D: Fallible + ?Sized> Deserialize<CacheSnapshot, __D> for Archived<CacheSnapshot>

where u32: Archive, <u32 as Archive>::Archived: Deserialize<u32, __D>, String: Archive, <String as Archive>::Archived: Deserialize<String, __D>, u64: Archive, <u64 as Archive>::Archived: Deserialize<u64, __D>, HashMap<String, CachedCell>: Archive, <HashMap<String, CachedCell> as Archive>::Archived: Deserialize<HashMap<String, CachedCell>, __D>,

fn deserialize( &self, deserializer: &mut __D, ) -> Result<CacheSnapshot, <__D as Fallible>::Error>

Deserializes using the given deserializer

impl<__S: Fallible + ?Sized> Serialize<__S> for CacheSnapshot

where u32: Serialize<__S>, String: Serialize<__S>, u64: Serialize<__S>, HashMap<String, CachedCell>: Serialize<__S>,

fn serialize( &self, serializer: &mut __S, ) -> Result<<Self as Archive>::Resolver, <__S as Fallible>::Error>

Writes the dependencies for the object and returns a resolver that can create the archived type.