fs: improve error performance of readlinkSync

PR-URL: #49962
Refs: nodejs/performance#106
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Stephen Belanger <admin@stephenbelanger.com>
Reviewed-By: Vinícius Lourenço Claro Cardoso <contact@viniciusl.com.br>

Author: anonrig

benchmark/fs/bench-readlinkSync.js

@@ -0,0 +1,54 @@
+'use strict';
+
+constcommon=require('../common');
+constfs=require('fs');
+constassert=require('assert');
+consttmpdir=require('../../test/common/tmpdir');
+
+if(process.platform==='win32'){
+console.log('Skipping: Windows does not play well with `symlinkSync`');
+process.exit(0);
+}
+
+constbench=common.createBenchmark(main,{
+type: ['valid','invalid'],
+n: [1e3],
+});
+
+functionmain({ n, type }){
+switch(type){
+case'valid': {
+tmpdir.refresh();
+consttmpfile=tmpdir.resolve(`.readlink-file-${process.pid}`);
+fs.writeFileSync(tmpfile,'data','utf8');
+letreturnValue;
+for(leti=0;i<n;i++){
+fs.symlinkSync(tmpfile,tmpdir.resolve(`.readlink-sync-${i}`),'file');
+}
+bench.start();
+for(leti=0;i<n;i++){
+returnValue=fs.readlinkSync(tmpdir.resolve(`.readlink-sync-${i}`),{encoding: 'utf8'});
+}
+bench.end(n);
+assert(returnValue);
+break;
+}
+
+case'invalid': {
+lethasError=false;
+bench.start();
+for(leti=0;i<n;i++){
+try{
+fs.readlinkSync(tmpdir.resolve('.non-existing-file-for-readlinkSync'));
+}catch{
+hasError=true;
+}
+}
+bench.end(n);
+assert(hasError);
+break;
+}
+default:
+newError('Invalid type');
+}
+}

lib/fs.js

@@ -1728,11 +1728,10 @@ function readlink(path, options, callback) {
 functionreadlinkSync(path,options){
 options=getOptions(options);
 path=getValidatedPath(path,'oldPath');
-constctx={ path };
-constresult=binding.readlink(pathModule.toNamespacedPath(path),
-options.encoding,undefined,ctx);
-handleErrorFromBinding(ctx);
-returnresult;
+returnbinding.readlink(
+pathModule.toNamespacedPath(path),
+options.encoding,
+);
 }
 
 /**
@@ -2714,10 +2713,8 @@ function realpathSync(p, options) {
 }
 }
 if(linkTarget===null){
-constctx={path: base};
 binding.stat(baseLong,false,undefined,true);
-linkTarget=binding.readlink(baseLong,undefined,undefined,ctx);
-handleErrorFromBinding(ctx);
+linkTarget=binding.readlink(baseLong,undefined);
 }
 resolvedLink=pathModule.resolve(previous,linkTarget);
 

src/node_file.cc

@@ -1383,7 +1383,7 @@ static void ReadLink(const FunctionCallbackInfo<Value>& args) {
  Isolate* isolate = env->isolate();
 
 constint argc = args.Length();
-CHECK_GE(argc, 3);
+CHECK_GE(argc, 2);
 
  BufferValue path(isolate, args[0]);
 CHECK_NOT_NULL(*path);
@@ -1392,21 +1392,20 @@ static void ReadLink(const FunctionCallbackInfo<Value>& args) {
 
 constenum encoding encoding = ParseEncoding(isolate, args[1], UTF8);
 
-FSReqBase* req_wrap_async = GetReqWrap(args, 2);
-if (req_wrap_async != nullptr) { // readlink(path, encoding, req)
+if (argc > 2) { // readlink(path, encoding, req)
+ FSReqBase* req_wrap_async = GetReqWrap(args, 2);
 FS_ASYNC_TRACE_BEGIN1(
 UV_FS_READLINK, req_wrap_async, "path", TRACE_STR_COPY(*path))
 AsyncCall(env, req_wrap_async, args, "readlink", encoding, AfterStringPtr,
  uv_fs_readlink, *path);
- } else {
-CHECK_EQ(argc, 4);
- FSReqWrapSync req_wrap_sync;
+ } else { // readlink(path, encoding)
+ FSReqWrapSync req_wrap_sync("readlink", *path);
 FS_SYNC_TRACE_BEGIN(readlink);
-int err =SyncCall(env, args[3], &req_wrap_sync, "readlink",
- uv_fs_readlink, *path);
+int err =
+SyncCallAndThrowOnError(env, &req_wrap_sync, uv_fs_readlink, *path);
 FS_SYNC_TRACE_END(readlink);
 if (err < 0) {
-return;// syscall failed, no need to continue, error info is in ctx
+return;
  }
 constchar* link_path = static_cast<constchar*>(req_wrap_sync.req.ptr);
 
@@ -1416,8 +1415,7 @@ static void ReadLink(const FunctionCallbackInfo<Value>& args) {
  encoding,
  &error);
 if (rc.IsEmpty()) {
- Local<Object> ctx = args[3].As<Object>();
- ctx->Set(env->context(), env->error_string(), error).Check();
+ env->isolate()->ThrowException(error);
 return;
  }
 

typings/internalBinding/fs.d.ts

@@ -178,6 +178,7 @@ declare namespace InternalFSBinding {
 functionreadlink(path: StringOrBuffer,encoding: unknown,req: FSReqCallback<string|Buffer>): void;
 functionreadlink(path: StringOrBuffer,encoding: unknown,req: undefined,ctx: FSSyncContext): string|Buffer;
 functionreadlink(path: StringOrBuffer,encoding: unknown,usePromises: typeofkUsePromises): Promise<string|Buffer>;
+functionreadlink(path: StringOrBuffer,encoding: unknown): StringOrBuffer;
 
 functionrealpath(path: StringOrBuffer,encoding: unknown,req: FSReqCallback<string|Buffer>): void;
 functionrealpath(path: StringOrBuffer,encoding: unknown,req: undefined,ctx: FSSyncContext): string|Buffer;