Struct ra_ap_hir_expand::db::InternMacroCallLookupQuery [−][src]
pub struct InternMacroCallLookupQuery;
Implementations
Get access to extra methods pertaining to this query. You can also use it to invoke this query, though it’s more common to use the trait method on the database itself.
Like in_db
, but gives access to methods for setting the
value of an input. Not applicable to derived queries.
Threads, cancellation, and blocking
Mutating the value of a query cannot be done while there are
still other queries executing. If you are using your database
within a single thread, this is not a problem: you only have
&self
access to the database, but this method requires &mut self
.
However, if you have used snapshot
to create other threads,
then attempts to set
will block the current thread until
those snapshots are dropped (usually when those threads
complete). This also implies that if you create a snapshot but
do not send it to another thread, then invoking set
will
deadlock.
Before blocking, the thread that is attempting to set
will
also set a cancellation flag. This will cause any query
invocations in other threads to unwind with a Cancelled
sentinel value and eventually let the set
succeed once all
threads have unwound past the salsa invocation.
If your query implementations are performing expensive
operations without invoking another query, you can also use
the Runtime::unwind_if_cancelled
method to check for an
ongoing cancellation and bring those operations to a close,
thus allowing the set
to succeed. Otherwise, long-running
computations may lead to “starvation”, meaning that the
thread attempting to set
has to wait a long, long time. =)
Trait Implementations
Returns the “default value” for a type. Read more
type Key = MacroCallId
type Key = MacroCallId
Type that you you give as a parameter – for queries with zero or more than one input, this will be a tuple. Read more
type Value = MacroCallLoc
type Value = MacroCallLoc
What value does the query return?
type Storage = LookupInternedStorage<Self, InternMacroCallQuery>
type Storage = LookupInternedStorage<Self, InternMacroCallQuery>
Internal struct storing the values for the query.
A unique index identifying this query within the group.
Name of the query method (e.g., foo
)
fn query_storage<'a>(
group_storage: &'a <Self as QueryDb<'_>>::GroupStorage
) -> &'a Arc<Self::Storage>
fn query_storage<'a>(
group_storage: &'a <Self as QueryDb<'_>>::GroupStorage
) -> &'a Arc<Self::Storage>
Extact storage for this query from the storage for its group.
type DynDb = dyn AstDatabase + 'd
type DynDb = dyn AstDatabase + 'd
Dyn version of the associated trait for this query group.
type Group = AstDatabaseStorage
type Group = AstDatabaseStorage
Associate query group struct.
Generated struct that contains storage for all queries in a group.
Auto Trait Implementations
impl RefUnwindSafe for InternMacroCallLookupQuery
impl Send for InternMacroCallLookupQuery
impl Sync for InternMacroCallLookupQuery
impl Unpin for InternMacroCallLookupQuery
impl UnwindSafe for InternMacroCallLookupQuery
Blanket Implementations
Mutably borrows from an owned value. Read more
Attaches the provided Subscriber
to this type, returning a
WithDispatch
wrapper. Read more
Attaches the current default Subscriber
to this type, returning a
WithDispatch
wrapper. Read more