Trait Database 

pub trait Database:
    Send
    + ZalsaDatabase
    + AsDynDatabase {
    // Provided methods
    fn trigger_lru_eviction(&mut self) { ... }
    fn synthetic_write(&mut self, durability: Durability) { ... }
    fn trigger_cancellation(&mut self) { ... }
    fn cancellation_token(&self) -> CancellationToken { ... }
    fn report_untracked_read(&self) { ... }
    fn ingredient_debug_name(
        &self,
        ingredient_index: IngredientIndex,
    ) -> Cow<'_, str> { ... }
    fn unwind_if_revision_cancelled(&self) { ... }
    fn attach<R>(&self, op: impl FnOnce(&Self) -> R) -> R
       where Self: Sized { ... }
}

The trait implemented by all Salsa databases. You can create your own subtraits of this trait using the #[salsa::db](crate::db) procedural macro.

Provided Methods

fn trigger_lru_eviction(&mut self)

Enforces current LRU limits, evicting entries if necessary.

WARNING: Just like an ordinary write, this method triggers cancellation. If you invoke it while a snapshot exists, it will block until that snapshot is dropped – if that snapshot is owned by the current thread, this could trigger deadlock.

fn synthetic_write(&mut self, durability: Durability)

A “synthetic write” causes the system to act as though some input of durability durability has changed, triggering a new revision. This is mostly useful for profiling scenarios.

WARNING: Just like an ordinary write, this method triggers cancellation. If you invoke it while a snapshot exists, it will block until that snapshot is dropped – if that snapshot is owned by the current thread, this could trigger deadlock.

Panics

Panics if durability is Durability::NEVER_CHANGE.

fn trigger_cancellation(&mut self)

This method cancels all outstanding computations. If you invoke it while a snapshot exists, it will block until that snapshot is dropped – if that snapshot is owned by the current thread, this could trigger deadlock.

fn cancellation_token(&self) -> CancellationToken

Retrieves a CancellationToken for the current database handle.

fn report_untracked_read(&self)

Reports that the query depends on some state unknown to salsa.

Queries which report untracked reads will be re-executed in the next revision.

fn ingredient_debug_name( &self, ingredient_index: IngredientIndex, ) -> Cow<'_, str>

Return the “debug name” (i.e., the struct name, etc) for an “ingredient”, which are the fine-grained components we use to track data. This is intended for debugging and the contents of the returned string are not semver-guaranteed.

Ingredient indices can be extracted from DatabaseKeyIndex values.

fn unwind_if_revision_cancelled(&self)

Starts unwinding the stack if the current revision is cancelled.

This method can be called by query implementations that perform potentially expensive computations, in order to speed up propagation of cancellation.

Cancellation will automatically be triggered by salsa on any query invocation.

This method should not be overridden by Database implementors. A salsa_event is emitted when this method is called, so that should be used instead.

fn attach<R>(&self, op: impl FnOnce(&Self) -> R) -> R

where Self: Sized,

Execute op with the database in thread-local storage for debug print-outs.

Implementations

impl dyn Database

pub fn memory_usage(&self) -> DatabaseInfo

Returns memory usage information about ingredients in the database.

Dyn Compatibility

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors

impl Database for DatabaseImpl