Use a cache with a key on subset of options

Author: jakebailey

src/compiler/checker.ts

@@ -111,10 +111,7 @@ import {
     createGetCanonicalFileName,
     createGetSymbolWalker,
     createModeAwareCacheKey,
-    createPrinterWithDefaults,
-    createPrinterWithRemoveComments,
-    createPrinterWithRemoveCommentsNeverAsciiEscape,
-    createPrinterWithRemoveCommentsOmitTrailingSemicolon,
+    createOrReusePrinter,
     createPropertyNameNodeForIdentifierOrLiteral,
     createSymbolTable,
     createTextWriter,
@@ -6127,8 +6124,8 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
             const entity = builder(symbol, meaning!, enclosingDeclaration, nodeFlags)!; // TODO: GH#18217
             // add neverAsciiEscape for GH#39027
             const printer = enclosingDeclaration?.kind === SyntaxKind.SourceFile
-                ? createPrinterWithRemoveCommentsNeverAsciiEscape()
-                : createPrinterWithRemoveComments();
+                ? createOrReusePrinter({ removeComments: true, neverAsciiEscape: true })
+                : createOrReusePrinter({ removeComments: true });
             const sourceFile = enclosingDeclaration && getSourceFileOfNode(enclosingDeclaration);
             printer.writeNode(EmitHint.Unspecified, entity, /*sourceFile*/ sourceFile, writer);
             return writer;
@@ -6147,7 +6144,7 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
                 sigOutput = kind === SignatureKind.Construct ? SyntaxKind.ConstructSignature : SyntaxKind.CallSignature;
             }
             const sig = nodeBuilder.signatureToSignatureDeclaration(signature, sigOutput, enclosingDeclaration, toNodeBuilderFlags(flags) | NodeBuilderFlags.IgnoreErrors | NodeBuilderFlags.WriteTypeParametersInQualifiedName);
-            const printer = createPrinterWithRemoveCommentsOmitTrailingSemicolon();
+            const printer = createOrReusePrinter({ removeComments: true, omitTrailingSemicolon: true });
             const sourceFile = enclosingDeclaration && getSourceFileOfNode(enclosingDeclaration);
             printer.writeNode(EmitHint.Unspecified, sig!, /*sourceFile*/ sourceFile, getTrailingSemicolonDeferringWriter(writer)); // TODO: GH#18217
             return writer;
@@ -6160,7 +6157,8 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
         if (typeNode === undefined) return Debug.fail("should always get typenode");
         // The unresolved type gets a synthesized comment on `any` to hint to users that it's not a plain `any`.
         // Otherwise, we always strip comments out.
-        const printer = type !== unresolvedType ? createPrinterWithRemoveComments() : createPrinterWithDefaults();
+        const options = { removeComments: type !== unresolvedType };
+        const printer = createOrReusePrinter(options);
         const sourceFile = enclosingDeclaration && getSourceFileOfNode(enclosingDeclaration);
         printer.writeNode(EmitHint.Unspecified, typeNode, /*sourceFile*/ sourceFile, writer);
         const result = writer.getText();
@@ -9640,7 +9638,7 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
                 typePredicate.kind === TypePredicateKind.Identifier || typePredicate.kind === TypePredicateKind.AssertsIdentifier ? factory.createIdentifier(typePredicate.parameterName) : factory.createThisTypeNode(),
                 typePredicate.type && nodeBuilder.typeToTypeNode(typePredicate.type, enclosingDeclaration, toNodeBuilderFlags(flags) | NodeBuilderFlags.IgnoreErrors | NodeBuilderFlags.WriteTypeParametersInQualifiedName)! // TODO: GH#18217
             );
-            const printer = createPrinterWithRemoveComments();
+            const printer = createOrReusePrinter({ removeComments: true });
             const sourceFile = enclosingDeclaration && getSourceFileOfNode(enclosingDeclaration);
             printer.writeNode(EmitHint.Unspecified, predicate, /*sourceFile*/ sourceFile, writer);
             return writer;

src/compiler/emitter.ts

@@ -1343,17 +1343,29 @@ const enum PipelinePhase {
     Emit,
 }
 
-/** @internal */
-export const createPrinterWithDefaults = memoize(() => createPrinter({}));
+const printerCache = new Map<string, Printer>();
 
+// If updating this, make sure the cache key is updated too.
 /** @internal */
-export const createPrinterWithRemoveComments = memoize(() => createPrinter({ removeComments: true }));
+export type ReusablePrinterOptions = Pick<PrinterOptions, "removeComments" | "neverAsciiEscape" | "omitTrailingSemicolon" | "module" | "target" | "newLine">;
 
 /** @internal */
-export const createPrinterWithRemoveCommentsNeverAsciiEscape = memoize(() => createPrinter({ removeComments: true, neverAsciiEscape: true }));
+export function createOrReusePrinter(o: ReusablePrinterOptions = {}) {
+    const key = `${keyBool(o.removeComments)}|${keyBool(o.neverAsciiEscape)}|${keyBool(o.omitTrailingSemicolon)}|${keyNum(o.module)}|${keyNum(o.target)}|${keyNum(o.newLine)}`;
+    let printer = printerCache.get(key);
+    if (!printer) {
+        printerCache.set(key, printer = createPrinter(o));
+    }
+    return printer;
 
-/** @internal */
-export const createPrinterWithRemoveCommentsOmitTrailingSemicolon = memoize(() => createPrinter({ removeComments: true, omitTrailingSemicolon: true }));
+    function keyBool(value: boolean | undefined) {
+        return value === undefined ? "u" : value ? 1 : 0;
+    }
+
+    function keyNum(value: number | undefined) {
+        return value === undefined ? "u" : `${value}`;
+    }
+}
 
 export function createPrinter(printerOptions: PrinterOptions = {}, handlers: PrintHandlers = {}): Printer {
     const {

src/services/callHierarchy.ts

@@ -14,7 +14,7 @@ import {
     ClassLikeDeclaration,
     ClassStaticBlockDeclaration,
     compareStringsCaseSensitive,
-    createPrinterWithRemoveCommentsOmitTrailingSemicolon,
+    createOrReusePrinter,
     createTextRangeFromNode,
     createTextSpanFromBounds,
     createTextSpanFromRange,
@@ -245,7 +245,7 @@ function getCallHierarchyItemName(program: Program, node: CallHierarchyDeclarati
     }
     if (text === undefined) {
         // get the text from printing the node on a single line without comments...
-        const printer = createPrinterWithRemoveCommentsOmitTrailingSemicolon();
+        const printer = createOrReusePrinter({ removeComments: true, omitTrailingSemicolon: true });
         text = usingSingleLineStringWriter(writer => printer.writeNode(EmitHint.Unspecified, node, node.getSourceFile(), writer));
     }
     return { text, pos: declName.getStart(), end: declName.getEnd() };

src/services/completions.ts

@@ -34,6 +34,7 @@ import {
     ConstructorDeclaration,
     ContextFlags,
     createModuleSpecifierResolutionHost,
+    createOrReusePrinter,
     createPackageJsonImportFilter,
     createPrinter,
     createSortedArray,
@@ -1747,7 +1748,7 @@ function getEntryForObjectLiteralMethodCompletion(
         insertText = printer.printSnippetList(ListFormat.CommaDelimited | ListFormat.AllowTrailingComma, factory.createNodeArray([method], /*hasTrailingComma*/ true), sourceFile);
     }
 
-    const signaturePrinter = createPrinter({
+    const signaturePrinter = createOrReusePrinter({
         removeComments: true,
         module: options.module,
         target: options.target,

src/services/inlayHints.ts

@@ -2,7 +2,7 @@ import {
     __String,
     ArrowFunction,
     CallExpression,
-    createPrinterWithRemoveComments,
+    createOrReusePrinter,
     Debug,
     EmitHint,
     EnumMember,
@@ -382,7 +382,7 @@ export function provideInlayHints(context: InlayHintsContext): InlayHint[] {
 
     function printTypeInSingleLine(type: Type) {
         const flags = NodeBuilderFlags.IgnoreErrors | TypeFormatFlags.AllowUniqueESSymbolType | TypeFormatFlags.UseAliasDefinedOutsideCurrentScope;
-        const printer = createPrinterWithRemoveComments();
+        const printer = createOrReusePrinter({ removeComments: true });
 
         return usingSingleLineStringWriter(writer => {
             const typeNode = checker.typeToTypeNode(type, /*enclosingDeclaration*/ undefined, flags);

src/services/signatureHelp.ts

@@ -7,7 +7,7 @@ import {
     CheckFlags,
     contains,
     countWhere,
-    createPrinterWithRemoveComments,
+    createOrReusePrinter,
     createTextSpan,
     createTextSpanFromBounds,
     createTextSpanFromNode,
@@ -659,7 +659,7 @@ function createTypeHelpItems(
 function getTypeHelpItem(symbol: Symbol, typeParameters: readonly TypeParameter[], checker: TypeChecker, enclosingDeclaration: Node, sourceFile: SourceFile): SignatureHelpItem {
     const typeSymbolDisplay = symbolToDisplayParts(checker, symbol);
 
-    const printer = createPrinterWithRemoveComments();
+    const printer = createOrReusePrinter({ removeComments: true });
     const parameters = typeParameters.map(t => createSignatureHelpParameterForTypeParameter(t, checker, enclosingDeclaration, sourceFile, printer));
 
     const documentation = symbol.getDocumentationComment(checker);
@@ -699,7 +699,7 @@ interface SignatureHelpItemInfo { readonly isVariadic: boolean; readonly paramet
 
 function itemInfoForTypeParameters(candidateSignature: Signature, checker: TypeChecker, enclosingDeclaration: Node, sourceFile: SourceFile): SignatureHelpItemInfo[] {
     const typeParameters = (candidateSignature.target || candidateSignature).typeParameters;
-    const printer = createPrinterWithRemoveComments();
+    const printer = createOrReusePrinter({ removeComments: true });
     const parameters = (typeParameters || emptyArray).map(t => createSignatureHelpParameterForTypeParameter(t, checker, enclosingDeclaration, sourceFile, printer));
     const thisParameter = candidateSignature.thisParameter ? [checker.symbolToParameterDeclaration(candidateSignature.thisParameter, enclosingDeclaration, signatureHelpNodeBuilderFlags)!] : [];
 
@@ -713,7 +713,7 @@ function itemInfoForTypeParameters(candidateSignature: Signature, checker: TypeC
 }
 
 function itemInfoForParameters(candidateSignature: Signature, checker: TypeChecker, enclosingDeclaration: Node, sourceFile: SourceFile): SignatureHelpItemInfo[] {
-    const printer = createPrinterWithRemoveComments();
+    const printer = createOrReusePrinter({ removeComments: true });
     const typeParameterParts = mapToDisplayParts(writer => {
         if (candidateSignature.typeParameters && candidateSignature.typeParameters.length) {
             const args = factory.createNodeArray(candidateSignature.typeParameters.map(p => checker.typeParameterToDeclaration(p, enclosingDeclaration, signatureHelpNodeBuilderFlags)!));

src/services/symbolDisplay.ts

@@ -5,7 +5,7 @@ import {
     CallExpression,
     CheckFlags,
     contains,
-    createPrinterWithRemoveComments,
+    createOrReusePrinter,
     Debug,
     displayPart,
     EmitHint,
@@ -728,7 +728,7 @@ export function getSymbolDisplayPartsDocumentationAndSymbolKind(typeChecker: Typ
     return { displayParts, documentation, symbolKind, tags: tags.length === 0 ? undefined : tags };
 
     function getPrinter() {
-        return createPrinterWithRemoveComments();
+        return createOrReusePrinter({ removeComments: true });
     }
 
     function prefixNextMeaning() {

src/services/utilities.ts

@@ -30,7 +30,7 @@ import {
     ConditionalExpression,
     contains,
     ContextFlags,
-    createPrinterWithRemoveCommentsOmitTrailingSemicolon,
+    createOrReusePrinter,
     createRange,
     createScanner,
     createTextSpan,
@@ -2984,7 +2984,7 @@ export function signatureToDisplayParts(typechecker: TypeChecker, signature: Sig
 export function nodeToDisplayParts(node: Node, enclosingDeclaration: Node): SymbolDisplayPart[] {
     const file = enclosingDeclaration.getSourceFile();
     return mapToDisplayParts(writer => {
-        const printer = createPrinterWithRemoveCommentsOmitTrailingSemicolon();
+        const printer = createOrReusePrinter({ removeComments: true, omitTrailingSemicolon: true });
         printer.writeNode(EmitHint.Unspecified, node, file, writer);
     });
 }