[Bug] Loading bulk models is causing major delay in intellisense

Reproducible in vscode.dev or in VS Code Desktop?

• Not reproducible in vscode.dev or VS Code Desktop

Reproducible in the monaco editor playground?

• Not reproducible in the monaco editor playground

Monaco Editor Playground Code

// ========== Example #1: Loading .definition models instead of .ts ======================
monaco.languages.typescript.javascriptDefaults.setEagerModelSync(false);
monaco.languages.typescript.typescriptDefaults.setEagerModelSync(false);

monaco.languages.typescript.javascriptDefaults.setDiagnosticsOptions({
    noSemanticValidation: true,
    noSyntaxValidation: true,
    noSuggestionDiagnostics: true
});

monaco.languages.typescript.typescriptDefaults.setDiagnosticsOptions({
    noSemanticValidation: true,
    noSyntaxValidation: true,
    noSuggestionDiagnostics: true
});

monaco.languages.typescript.typescriptDefaults.setCompilerOptions({
    target: monaco.languages.typescript.ScriptTarget.ES2016,
    allowNonTsExtensions: true,
    moduleResolution: monaco.languages.typescript.ModuleResolutionKind.NodeJs,
    module: monaco.languages.typescript.ModuleKind.CommonJS,
    noEmit: true,
    typeRoots: ["node_modules/@types"]
});

// Case #1: Load 2000 .d.ts files with each having 1 function declaration
let extraLibs = []
for (let i = 0; i < 2000; i++) {
    extraLibs.push(
        {
        content: `export declare function next${i}() : string`,
        filePath:  monaco.Uri.file(`/node_modules/@types/external${i}/index.d.ts`).toString(true)
        }
    );
}

// Case #2: Load 1 .d.ts file with 2000 function declarations
/*let def = ''
for (let i = 0; i < 2000; i++) {
    def = def.concat(`export declare function next${i}() : string\n`);
}
let extraLibs = []
extraLibs.push(
    {
    content: def,
    filePath:  monaco.Uri.file(`/node_modules/@types/external1/index.d.ts`).toString(true)
    }
);*/

monaco.languages.typescript.typescriptDefaults.setExtraLibs(extraLibs);

extraLibs.forEach((lib) => monaco.editor.createModel(lib.content, "typescript", monaco.Uri.parse(lib.filePath)))


var jsCode = `import * as x from "external1"
const tt : string = x.next1();`;

monaco.editor.create(document.getElementById("container"), {
    model: monaco.editor.createModel(jsCode, "typescript", monaco.Uri.file("main.tsx")),
});



// ========== Example #2: Loading .ts models instead of definitions ======================
/*monaco.languages.typescript.javascriptDefaults.setEagerModelSync(true);
monaco.languages.typescript.typescriptDefaults.setEagerModelSync(true);

monaco.languages.typescript.javascriptDefaults.setDiagnosticsOptions({
    noSemanticValidation: true,
    noSyntaxValidation: true,
    noSuggestionDiagnostics: true
});

monaco.languages.typescript.typescriptDefaults.setDiagnosticsOptions({
    noSemanticValidation: true,
    noSyntaxValidation: true,
    noSuggestionDiagnostics: true
});

editor = monaco.editor.create(
    document.getElementById('container'),
    {
        minimap: { enabled: true },
        scrollBeyondLastLine: true,
        // model: null,
        language: 'typescript',
        theme: 'vs-dark',
        value: 'function () {}\n\n'
    }
);

// simulate 2000 .ts files
for (var fileIdx = 0; fileIdx < 2000; fileIdx++) {
    for (var fnIdx = 0; fnIdx < 1; fnIdx++) {
        monaco.editor.createModel(`
            function test_${fileIdx}_${fnIdx}() {}
            function fn_${fileIdx}_${fnIdx}() {}
            function foo_${fileIdx}_${fnIdx}() {}
            function bar_${fileIdx}_${fnIdx}() {}
            function out_${fileIdx}_${fnIdx}() {}
            `,
            'typescript'
        );
    }
}*/

Reproduction Steps

Press Ctrl + Space after x. in the playground output (in the 2nd line: const tt : string = x.next1();). Suggestions dialog shows 'Loading...' indicator for 12-15 seconds before showing the eligible candidates.

for (let i = 0; i < 2000; i++) {
    extraLibs.push(
        {
        content: `export declare function next${i}() : string`,
        filePath:  monaco.Uri.file(`/node_modules/@types/external${i}/index.d.ts`).toString(true)
        }
    );
}

Actual (Problematic) Behavior

Adding bulk of definition or ts file models is causing the 'Loading...' indicator for 12-15 seconds for every intellisense request. Not just the initial request.

Expected Behavior

Intellisense requests should complete with in reasonable time which otherwise directly impacts the developer experience

Additional Context

I posted this as a question in Stackoverflow (https://stackoverflow.com/questions/73936684/performant-way-to-load-2000-ts-models-into-monaco-editor-for-intellisense), but the solutions suggested (loading definition files) also didn't worked.

My observation: When I have bulk of files (ex: 2000), then the intellisense is taking longer time. But when I add 200K function declarations to 1 definition file, the perf is very good.