fs: improve error performance for readSync

benchmark/fs/bench-readSync.js

@@ -0,0 +1,57 @@
+'use strict';
+
+const common = require('../common');
+const fs = require('fs');
+const tmpdir = require('../../test/common/tmpdir');
+tmpdir.refresh();
+
+const bufferSize = 1024;
+const sectorSize = 512;
+
+const bench = common.createBenchmark(main, {
+  type: ['existing', 'non-existing'],
+  n: [1e4],
+});
+
+function main({ n, type }) {
+  let fd;
+
+  const tmpfile = { name: tmpdir.resolve(`.existing-file-${process.pid}`),
+                    len: bufferSize * n };
+
+
+  tmpfile.contents = Buffer.allocUnsafe(tmpfile.len);
+
+  for (let offset = 0; offset < tmpfile.len; offset += sectorSize) {
+    const fillByte = 256 * Math.random();
+    const nBytesToFill = Math.min(sectorSize, tmpfile.len - offset);
+    tmpfile.contents.fill(fillByte, offset, offset + nBytesToFill);
+  }
+
+  fs.writeFileSync(tmpfile.name, tmpfile.contents);
+
+  switch (type) {
+    case 'existing':
+      fd = fs.openSync(tmpfile.name, 'r', 0o666);
+      break;
+    case 'non-existing':
+      fd = 1 << 30;
+      break;
+    default:
+      new Error('Invalid type');
+  }
+
+  const buffer = Buffer.alloc(bufferSize);
+
+  bench.start();
+  for (let i = 0; i < n; i++) {
+    try {
+      fs.readSync(fd, buffer);
+    } catch {
+      // Continue regardless of error.
+    }
+  }
+  bench.end(n);
+
+  if (type === 'existing') fs.closeSync(fd);
+}

lib/fs.js

@@ -751,11 +751,7 @@ function readSync(fd, buffer, offsetOrOptions, length, position) {
     validatePosition(position, 'position', length);
   }
 
-  const ctx = {};
-  const result = binding.read(fd, buffer, offset, length, position,
-                              undefined, ctx);
-  handleErrorFromBinding(ctx);
-  return result;
+  return binding.read(fd, buffer, offset, length, position);
 }
 
 /**

src/node_file.cc

@@ -2364,18 +2364,23 @@ static void Read(const FunctionCallbackInfo<Value>& args) {
   char* buf = buffer_data + off;
   uv_buf_t uvbuf = uv_buf_init(buf, len);
 
-  FSReqBase* req_wrap_async = GetReqWrap(args, 5);
-  if (req_wrap_async != nullptr) {  // read(fd, buffer, offset, len, pos, req)
+  if (argc > 5) {  // read(fd, buffer, offset, len, pos, req)
+    FSReqBase* req_wrap_async = GetReqWrap(args, 5);
+    CHECK_NOT_NULL(req_wrap_async);
     FS_ASYNC_TRACE_BEGIN0(UV_FS_READ, req_wrap_async)
     AsyncCall(env, req_wrap_async, args, "read", UTF8, AfterInteger,
               uv_fs_read, fd, &uvbuf, 1, pos);
-  } else {  // read(fd, buffer, offset, len, pos, undefined, ctx)
-    CHECK_EQ(argc, 7);
-    FSReqWrapSync req_wrap_sync;
+  } else {  // read(fd, buffer, offset, len, pos)
+    FSReqWrapSync req_wrap_sync("read");
     FS_SYNC_TRACE_BEGIN(read);
-    const int bytesRead = SyncCall(env, args[6], &req_wrap_sync, "read",
-                                   uv_fs_read, fd, &uvbuf, 1, pos);
+    const int bytesRead = SyncCallAndThrowOnError(
+        env, &req_wrap_sync, uv_fs_read, fd, &uvbuf, 1, pos);
     FS_SYNC_TRACE_END(read, "bytesRead", bytesRead);
+
+    if (is_uv_error(bytesRead)) {
+      return;
+    }
+
     args.GetReturnValue().Set(bytesRead);
   }
 }

typings/internalBinding/fs.d.ts

@@ -155,8 +155,8 @@ declare namespace InternalFSBinding {
   function openFileHandle(path: StringOrBuffer, flags: number, mode: number, usePromises: typeof kUsePromises): Promise<FileHandle>;
 
   function read(fd: number, buffer: ArrayBufferView, offset: number, length: number, position: number, req: FSReqCallback<number>): void;
-  function read(fd: number, buffer: ArrayBufferView, offset: number, length: number, position: number, req: undefined, ctx: FSSyncContext): number;
   function read(fd: number, buffer: ArrayBufferView, offset: number, length: number, position: number, usePromises: typeof kUsePromises): Promise<number>;
+  function read(fd: number, buffer: ArrayBufferView, offset: number, length: number, position: number): number;
 
   function readBuffers(fd: number, buffers: ArrayBufferView[], position: number, req: FSReqCallback<number>): void;
   function readBuffers(fd: number, buffers: ArrayBufferView[], position: number, req: undefined, ctx: FSSyncContext): number;