Map the new interface

# Conflicts:
#	crates/project/src/lsp_store.rs

# Conflicts:
#	crates/project/src/lsp_store.rs

# Conflicts:
#	crates/editor/src/editor.rs
#	crates/project/src/lsp_store.rs

crates/project/src/lsp_store/inlay_hint_cache.rs

@@ -0,0 +1,56 @@
+use std::{collections::BTreeMap, ops::Range};
+
+use clock::Global;
+use collections::HashMap;
+use futures::future::Shared;
+use gpui::{Context, Entity, Task};
+use language::BufferRow;
+use lsp::LanguageServerId;
+use text::BufferId;
+
+use crate::{InlayHint, buffer_store::BufferStore};
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub struct InlayHintId(usize);
+
+#[derive(Debug)]
+pub struct InlayHintCache {
+    buffer_store: Entity<BufferStore>,
+    hints_for_version: Global,
+    hints: HashMap<LanguageServerId, Hints>,
+    cache_version: usize,
+}
+
+#[derive(Debug, Default)]
+struct Hints {
+    hints: HashMap<InlayHintId, InlayHint>,
+    hints_by_chunks: BTreeMap<Range<BufferRow>, Option<Vec<InlayHintId>>>,
+    hint_updates: HashMap<Range<BufferRow>, Shared<Task<InlayHints>>>,
+}
+
+pub struct InlayHints {
+    pub cache_version: usize,
+    pub hints: Vec<InlayHint>,
+}
+
+impl InlayHintCache {
+    pub fn remove_server_data(&mut self, for_server: LanguageServerId) -> bool {
+        let removed = self.hints.remove(&for_server).is_some();
+        if removed {
+            self.cache_version += 1;
+        }
+        removed
+    }
+
+    pub fn hints(
+        &self,
+        buffer: BufferId,
+        range: Range<usize>,
+        known_cache_version: Option<usize>,
+        cx: &mut Context<Self>,
+    ) -> Option<Shared<Task<InlayHints>>> {
+        todo!("TODO kb")
+    }
+    // we want to store the cache version outbound, so they can query with it: we can return nothing (`Option`) if the version matches
+    // we can get a new server up/down, so we want to re-query for them things, ignoring the cache version
+}