fix(exthost/#3009): Call '$release*' APIs to clean-up extension host cache

CHANGES_CURRENT.md

@@ -5,6 +5,7 @@
 - #3008 - SCM: Fix index-out-of-bound exception when rendering diff markers
 - #3007 - Extensions: Show 'missing dependency' activation error to user
 - #3011 - Vim: Visual Block - Handle 'I' and 'A' in visual block mode (fixes #1633)
+- #3016 - Extensions: Fix memory leak in extension host language features (fixes #3009)
 
 ### Performance
 

src/Exthost/CodeLens.re

@@ -1,5 +1,5 @@
 [@deriving show]
-type t = {
+type lens = {
   cacheId: option(list(int)),
   range: OneBasedRange.t,
   command: option(Command.t),
@@ -33,12 +33,29 @@ let decode = Decode.decode;
 let encode = Encode.encode;
 
 module List = {
+  [@deriving show]
+  type cacheId = int;
+
+  [@deriving show]
+  type t = {
+    cacheId: option(cacheId),
+    lenses: list(lens),
+  };
+
+  let default = {cacheId: None, lenses: []};
+
   module Decode = {
     open Oni_Core.Json.Decode;
 
-    let simple = list(decode);
+    let simple = list(decode) |> map(lenses => {cacheId: None, lenses});
 
-    let nested = field("lenses", simple);
+    let nested =
+      obj(({field, _}) =>
+        {
+          lenses: field.required("lenses", list(decode)),
+          cacheId: field.optional("cacheId", int),
+        }
+      );
 
     let decode = one_of([("nested", nested), ("simple", simple)]);
   };

src/Exthost/Exthost.rei

@@ -100,15 +100,26 @@ module OneBasedRange: {
 
 module CodeLens: {
   [@deriving show]
-  type t = {
+  type lens = {
     cacheId: option(list(int)),
     range: OneBasedRange.t,
     command: option(Command.t),
   };
 
-  let decode: Json.decoder(t);
+  module List: {
+    [@deriving show]
+    type cacheId;
 
-  module List: {let decode: Json.decoder(list(t));};
+    [@deriving show]
+    type t = {
+      cacheId: option(cacheId),
+      lenses: list(lens),
+    };
+
+    let default: t;
+
+    let decode: Json.decoder(t);
+  };
 };
 
 module Location: {
@@ -593,9 +604,11 @@ module SignatureHelp: {
     let decode: Json.decoder(t);
   };
 
+  type cacheId;
+
   module Response: {
     type t = {
-      id: int,
+      cacheId,
       signatures: list(Signature.t),
       activeSignature: int,
       activeParameter: int,
@@ -606,10 +619,15 @@ module SignatureHelp: {
 };
 
 module SuggestResult: {
+  [@deriving show];
+
+  type cacheId;
+
   [@deriving show]
   type t = {
     completions: list(SuggestItem.t),
     isIncomplete: bool,
+    cacheId: option(cacheId),
   };
 
   let empty: t;
@@ -1758,11 +1776,14 @@ module Request: {
   module LanguageFeatures: {
     let provideCodeLenses:
       (~handle: int, ~resource: Uri.t, Client.t) =>
-      Lwt.t(option(list(CodeLens.t)));
+      Lwt.t(option(CodeLens.List.t));
 
     let resolveCodeLens:
-      (~handle: int, ~codeLens: CodeLens.t, Client.t) =>
-      Lwt.t(option(CodeLens.t));
+      (~handle: int, ~codeLens: CodeLens.lens, Client.t) =>
+      Lwt.t(option(CodeLens.lens));
+
+    let releaseCodeLenses:
+      (~handle: int, ~cacheId: CodeLens.List.cacheId, Client.t) => unit;
 
     let provideCompletionItems:
       (
@@ -1778,6 +1799,9 @@ module Request: {
       (~handle: int, ~chainedCacheId: ChainedCacheId.t, Client.t) =>
       Lwt.t(SuggestItem.t);
 
+    let releaseCompletionItems:
+      (~handle: int, ~cacheId: SuggestResult.cacheId, Client.t) => unit;
+
     let provideDocumentHighlights:
       (
         ~handle: int,
@@ -1875,6 +1899,9 @@ module Request: {
       ) =>
       Lwt.t(option(SignatureHelp.Response.t));
 
+    let releaseSignatureHelp:
+      (~handle: int, ~cacheId: SignatureHelp.cacheId, Client.t) => unit;
+
     let provideDocumentFormattingEdits:
       (
         ~handle: int,
@@ -1904,8 +1931,6 @@ module Request: {
         Client.t
       ) =>
       Lwt.t(option(list(Edit.SingleEditOperation.t)));
-
-    let releaseSignatureHelp: (~handle: int, ~id: int, Client.t) => unit;
   };
 
   module SCM: {

src/Exthost/Request.re

@@ -251,7 +251,7 @@ module LanguageFeatures = {
     );
   };
 
-  let resolveCodeLens = (~handle: int, ~codeLens: CodeLens.t, client) => {
+  let resolveCodeLens = (~handle: int, ~codeLens: CodeLens.lens, client) => {
     let decoder = Json.Decode.(nullable(CodeLens.decode));
     Client.request(
       ~decoder,
@@ -266,6 +266,17 @@ module LanguageFeatures = {
       client,
     );
   };
+
+  let releaseCodeLenses = (~handle: int, ~cacheId, client) => {
+    Client.notify(
+      ~usesCancellationToken=false,
+      ~rpcName="ExtHostLanguageFeatures",
+      ~method="$releaseCodeLenses",
+      ~args=`List([`Int(handle), `Int(cacheId)]),
+      client,
+    );
+  };
+
   let provideCompletionItems =
       (
         ~handle: int,
@@ -319,6 +330,16 @@ module LanguageFeatures = {
     );
   };
 
+  let releaseCompletionItems = (~handle: int, ~cacheId, client) => {
+    Client.notify(
+      ~usesCancellationToken=false,
+      ~rpcName="ExtHostLanguageFeatures",
+      ~method="$releaseCompletionItems",
+      ~args=`List([`Int(handle), `Int(cacheId)]),
+      client,
+    );
+  };
+
   module Internal = {
     let provideDefinitionLink =
         (~handle, ~resource, ~position, method, client) => {
@@ -448,15 +469,15 @@ module LanguageFeatures = {
     );
   };
 
-  let releaseSignatureHelp = (~handle, ~id, client) =>
+  let releaseSignatureHelp = (~handle, ~cacheId, client) =>
     Client.notify(
       ~rpcName="ExtHostLanguageFeatures",
       ~method="$releaseSignatureHelp",
       ~args=
         `List(
           Json.Encode.[
             handle |> encode_value(int),
-            id |> encode_value(int),
+            cacheId |> encode_value(int),
           ],
         ),
       client,

src/Exthost/SignatureHelp.re

@@ -122,10 +122,13 @@ module Signature = {
     );
 };
 
+[@deriving show]
+type cacheId = int;
+
 module Response = {
   [@deriving show]
   type t = {
-    id: int,
+    cacheId,
     signatures: list(Signature.t),
     activeSignature: int,
     activeParameter: int,
@@ -135,7 +138,7 @@ module Response = {
     Json.Decode.(
       obj(({field, _}) =>
         {
-          id: field.required("id", int),
+          cacheId: field.required("id", int),
           signatures: field.required("signatures", list(Signature.decode)),
           activeSignature: field.required("activeSignature", int),
           activeParameter: field.required("activeParameter", int),

src/Exthost/SuggestResult.re

@@ -1,12 +1,16 @@
 open Oni_Core;
 
+[@deriving show]
+type cacheId = int;
+
 [@deriving show]
 type t = {
   completions: list(SuggestItem.t),
   isIncomplete: bool,
+  cacheId: option(cacheId),
 };
 
-let empty = {completions: [], isIncomplete: false};
+let empty = {completions: [], isIncomplete: false, cacheId: None};
 
 module Dto = {
   let decode = {
@@ -17,6 +21,7 @@ module Dto = {
           // https://github.com/onivim/vscode-exthost/blob/50bef147f7bbd250015361a4e3cad3305f65bc27/src/vs/workbench/api/common/extHost.protocol.ts#L1129
           completions: field.required("b", list(SuggestItem.Dto.decode)),
           isIncomplete: field.withDefault("c", false, bool),
+          cacheId: field.optional("x", int),
         }
       )
     );

src/Feature/LanguageSupport/CodeLens.re

@@ -7,12 +7,12 @@ module Log = (
 
 // MODEL
 
-type codeLens = Exthost.CodeLens.t;
+type codeLens = Exthost.CodeLens.lens;
 
-let lineNumber = (lens: Exthost.CodeLens.t) =>
+let lineNumber = (lens: Exthost.CodeLens.lens) =>
   Exthost.OneBasedRange.(lens.range.startLineNumber - 1);
 
-let textFromExthost = (lens: Exthost.CodeLens.t) => {
+let textFromExthost = (lens: Exthost.CodeLens.lens) => {
   Exthost.Command.(
     lens.command
     |> OptionEx.flatMap(command => command.label)
@@ -21,7 +21,7 @@ let textFromExthost = (lens: Exthost.CodeLens.t) => {
   );
 };
 
-let text = (lens: Exthost.CodeLens.t) => textFromExthost(lens);
+let text = (lens: Exthost.CodeLens.lens) => textFromExthost(lens);
 
 type provider = {
   handle: int,
@@ -55,7 +55,7 @@ type msg =
       bufferId: int,
       startLine: EditorCoreTypes.LineNumber.t,
       stopLine: EditorCoreTypes.LineNumber.t,
-      lenses: list(Exthost.CodeLens.t),
+      lenses: list(Exthost.CodeLens.lens),
     });
 
 let register = (~handle: int, ~selector, ~maybeEventHandle, model) => {

src/Feature/LanguageSupport/Feature_LanguageSupport.rei

@@ -32,7 +32,7 @@ module Msg: {
 };
 
 module CodeLens: {
-  type t = Exthost.CodeLens.t;
+  type t = Exthost.CodeLens.lens;
 
   let lineNumber: t => int;
   let text: t => string;