Introduce a LanguageServerId wrapper type

Clarify the meaning of all the usizes in use in all of these
struct fields an method signatures.

crates/language/src/buffer.rs

@@ -17,6 +17,7 @@ use collections::HashMap;
 use fs::LineEnding;
 use futures::FutureExt as _;
 use gpui::{fonts::HighlightStyle, AppContext, Entity, ModelContext, Task};
+use lsp::LanguageServerId;
 use parking_lot::Mutex;
 use settings::Settings;
 use similar::{ChangeTag, TextDiff};
@@ -72,7 +73,7 @@ pub struct Buffer {
     syntax_map: Mutex<SyntaxMap>,
     parsing_in_background: bool,
     parse_count: usize,
-    diagnostics: HashMap<usize, DiagnosticSet>, // server_id -> diagnostic set
+    diagnostics: HashMap<LanguageServerId, DiagnosticSet>,
     remote_selections: TreeMap<ReplicaId, SelectionSet>,
     selections_update_count: usize,
     diagnostics_update_count: usize,
@@ -89,7 +90,7 @@ pub struct BufferSnapshot {
     pub git_diff: git::diff::BufferDiff,
     pub(crate) syntax: SyntaxSnapshot,
     file: Option<Arc<dyn File>>,
-    diagnostics: HashMap<usize, DiagnosticSet>, // server_id -> diagnostic set
+    diagnostics: HashMap<LanguageServerId, DiagnosticSet>,
     diagnostics_update_count: usize,
     file_update_count: usize,
     git_diff_update_count: usize,
@@ -157,7 +158,7 @@ pub struct Completion {
 
 #[derive(Clone, Debug)]
 pub struct CodeAction {
-    pub server_id: usize,
+    pub server_id: LanguageServerId,
     pub range: Range<Anchor>,
     pub lsp_action: lsp::CodeAction,
 }
@@ -167,7 +168,7 @@ pub enum Operation {
     Buffer(text::Operation),
 
     UpdateDiagnostics {
-        server_id: usize,
+        server_id: LanguageServerId,
         diagnostics: Arc<[DiagnosticEntry<Anchor>]>,
         lamport_timestamp: clock::Lamport,
     },
@@ -879,7 +880,7 @@ impl Buffer {
 
     pub fn update_diagnostics(
         &mut self,
-        server_id: usize,
+        server_id: LanguageServerId,
         diagnostics: DiagnosticSet,
         cx: &mut ModelContext<Self>,
     ) {
@@ -1645,7 +1646,7 @@ impl Buffer {
 
     fn apply_diagnostic_update(
         &mut self,
-        server_id: usize,
+        server_id: LanguageServerId,
         diagnostics: DiagnosticSet,
         lamport_timestamp: clock::Lamport,
         cx: &mut ModelContext<Self>,

crates/language/src/buffer_tests.rs

@@ -1866,7 +1866,7 @@ fn test_random_collaboration(cx: &mut AppContext, mut rng: StdRng) {
                         buffer,
                     );
                     log::info!("peer {} setting diagnostics: {:?}", replica_id, diagnostics);
-                    buffer.update_diagnostics(0, diagnostics, cx);
+                    buffer.update_diagnostics(LanguageServerId(0), diagnostics, cx);
                 });
                 mutation_count -= 1;
             }

crates/language/src/language.rs

@@ -54,6 +54,7 @@ use futures::channel::mpsc;
 pub use buffer::Operation;
 pub use buffer::*;
 pub use diagnostic_set::DiagnosticEntry;
+pub use lsp::LanguageServerId;
 pub use outline::{Outline, OutlineItem};
 pub use tree_sitter::{Parser, Tree};
 
@@ -524,7 +525,7 @@ struct LanguageRegistryState {
 }
 
 pub struct PendingLanguageServer {
-    pub server_id: usize,
+    pub server_id: LanguageServerId,
     pub task: Task<Result<lsp::LanguageServer>>,
 }
 
@@ -819,7 +820,7 @@ impl LanguageRegistry {
                 Ok(server)
             });
 
-            let server_id = post_inc(&mut self.state.write().next_language_server_id);
+            let server_id = self.state.write().next_language_server_id();
             return Some(PendingLanguageServer { server_id, task });
         }
 
@@ -837,7 +838,7 @@ impl LanguageRegistry {
         let adapter = adapter.clone();
         let lsp_binary_statuses = self.lsp_binary_statuses_tx.clone();
         let login_shell_env_loaded = self.login_shell_env_loaded.clone();
-        let server_id = post_inc(&mut self.state.write().next_language_server_id);
+        let server_id = self.state.write().next_language_server_id();
 
         let task = cx.spawn(|cx| async move {
             login_shell_env_loaded.await;
@@ -884,6 +885,10 @@ impl LanguageRegistry {
 }
 
 impl LanguageRegistryState {
+    fn next_language_server_id(&mut self) -> LanguageServerId {
+        LanguageServerId(post_inc(&mut self.next_language_server_id))
+    }
+
     fn add(&mut self, language: Arc<Language>) {
         if let Some(theme) = self.theme.as_ref() {
             language.set_theme(&theme.editor.syntax);

crates/language/src/proto.rs

@@ -4,7 +4,7 @@ use crate::{
 };
 use anyhow::{anyhow, Result};
 use clock::ReplicaId;
-use lsp::DiagnosticSeverity;
+use lsp::{DiagnosticSeverity, LanguageServerId};
 use rpc::proto;
 use std::{ops::Range, sync::Arc};
 use text::*;
@@ -80,7 +80,7 @@ pub fn serialize_operation(operation: &crate::Operation) -> proto::Operation {
             } => proto::operation::Variant::UpdateDiagnostics(proto::UpdateDiagnostics {
                 replica_id: lamport_timestamp.replica_id as u32,
                 lamport_timestamp: lamport_timestamp.value,
-                server_id: *server_id as u64,
+                server_id: server_id.0 as u64,
                 diagnostics: serialize_diagnostics(diagnostics.iter()),
             }),
 
@@ -277,7 +277,7 @@ pub fn deserialize_operation(message: proto::Operation) -> Result<crate::Operati
                         replica_id: message.replica_id as ReplicaId,
                         value: message.lamport_timestamp,
                     },
-                    server_id: message.server_id as usize,
+                    server_id: LanguageServerId(message.server_id as usize),
                     diagnostics: deserialize_diagnostics(message.diagnostics),
                 }
             }
@@ -469,7 +469,7 @@ pub async fn deserialize_completion(
 
 pub fn serialize_code_action(action: &CodeAction) -> proto::CodeAction {
     proto::CodeAction {
-        server_id: action.server_id as u64,
+        server_id: action.server_id.0 as u64,
         start: Some(serialize_anchor(&action.range.start)),
         end: Some(serialize_anchor(&action.range.end)),
         lsp_action: serde_json::to_vec(&action.lsp_action).unwrap(),
@@ -487,7 +487,7 @@ pub fn deserialize_code_action(action: proto::CodeAction) -> Result<CodeAction>
         .ok_or_else(|| anyhow!("invalid end"))?;
     let lsp_action = serde_json::from_slice(&action.lsp_action)?;
     Ok(CodeAction {
-        server_id: action.server_id as usize,
+        server_id: LanguageServerId(action.server_id as usize),
         range: start..end,
         lsp_action,
     })