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//! ra_db defines basic database traits. The concrete DB is defined by ra_ide_api.
mod cancellation;
mod syntax_ptr;
mod input;
mod loc2id;
pub mod mock;
use std::panic;
use ra_syntax::{TextUnit, TextRange, SourceFile, TreeArc};
pub use crate::{
cancellation::Canceled,
syntax_ptr::LocalSyntaxPtr,
input::{
FilesDatabase, FileId, CrateId, SourceRoot, SourceRootId, CrateGraph, Dependency,
FileTextQuery, FileSourceRootQuery, SourceRootQuery, LocalRootsQuery, LibraryRootsQuery, CrateGraphQuery,
FileRelativePathQuery
},
loc2id::LocationIntener,
};
pub trait BaseDatabase: salsa::Database + panic::RefUnwindSafe {
/// Aborts current query if there are pending changes.
///
/// rust-analyzer needs to be able to answer semantic questions about the
/// code while the code is being modified. A common problem is that a
/// long-running query is being calculated when a new change arrives.
///
/// We can't just apply the change immediately: this will cause the pending
/// query to see inconsistent state (it will observe an absence of
/// repeatable read). So what we do is we **cancel** all pending queries
/// before applying the change.
///
/// We implement cancellation by panicking with a special value and catching
/// it on the API boundary. Salsa explicitly supports this use-case.
fn check_canceled(&self) {
if self.salsa_runtime().is_current_revision_canceled() {
Canceled::throw()
}
}
fn catch_canceled<F: FnOnce(&Self) -> T + panic::UnwindSafe, T>(
&self,
f: F,
) -> Result<T, Canceled> {
panic::catch_unwind(|| f(self)).map_err(|err| match err.downcast::<Canceled>() {
Ok(canceled) => *canceled,
Err(payload) => panic::resume_unwind(payload),
})
}
}
salsa::query_group! {
pub trait SyntaxDatabase: crate::input::FilesDatabase + BaseDatabase {
fn source_file(file_id: FileId) -> TreeArc<SourceFile> {
type SourceFileQuery;
}
}
}
fn source_file(db: &impl SyntaxDatabase, file_id: FileId) -> TreeArc<SourceFile> {
let text = db.file_text(file_id);
SourceFile::parse(&*text)
}
#[derive(Clone, Copy, Debug)]
pub struct FilePosition {
pub file_id: FileId,
pub offset: TextUnit,
}
#[derive(Clone, Copy, Debug)]
pub struct FileRange {
pub file_id: FileId,
pub range: TextRange,
}
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