lib,src: split up big builtin scripts

Reduces the body of parsed source code from 210 kb to 80 kb for a null
program (`node -e 0`) and from 255 kb to 190 kb for a one-liner that
prints some output to the console.

It doesn't seem to have much impact on the size of the generated code
(on my system I see an 8% reduction with --nolazy and 3% without) but
hopefully it speeds up startup on slow systems because there is now
less source code to parse.

Author: bnoordhuis

lib/_stream_duplex.js

@@ -7,11 +7,11 @@
 
 module.exports = Duplex;
 
-const util = require('util');
 const Readable = require('_stream_readable');
 const Writable = require('_stream_writable');
+const inherits = require('internal/inherits');
 
-util.inherits(Duplex, Readable);
+inherits(Duplex, Readable);
 
 var keys = Object.keys(Writable.prototype);
 for (var v = 0; v < keys.length; v++) {

lib/_stream_passthrough.js

@@ -7,8 +7,8 @@
 module.exports = PassThrough;
 
 const Transform = require('_stream_transform');
-const util = require('util');
-util.inherits(PassThrough, Transform);
+const inherits = require('internal/inherits');
+inherits(PassThrough, Transform);
 
 function PassThrough(options) {
   if (!(this instanceof PassThrough))

lib/_stream_readable.js

@@ -3,14 +3,16 @@
 module.exports = Readable;
 Readable.ReadableState = ReadableState;
 
-const EE = require('events').EventEmitter;
-const Stream = require('stream');
 const Buffer = require('buffer').Buffer;
-const util = require('util');
-const debug = util.debuglog('stream');
+const EE = require('events').EventEmitter;
+const Stream = require('internal/stream');
+const debug = require('internal/debuglog')('stream');
+const inherits = require('internal/inherits');
+
+var Duplex;  // Break recursive dependency with _stream_duplex.js.
 var StringDecoder;
 
-util.inherits(Readable, Stream);
+inherits(Readable, Stream);
 
 function ReadableState(options, stream) {
   options = options || {};
@@ -19,7 +21,10 @@ function ReadableState(options, stream) {
   // make all the buffer merging and length checks go away
   this.objectMode = !!options.objectMode;
 
-  if (stream instanceof Stream.Duplex)
+  if (Duplex === undefined)
+    Duplex = require('_stream_duplex');
+
+  if (stream instanceof Duplex)
     this.objectMode = this.objectMode || !!options.readableObjectMode;
 
   // the point at which it stops calling _read() to fill the buffer

lib/_stream_transform.js

@@ -45,8 +45,8 @@
 module.exports = Transform;
 
 const Duplex = require('_stream_duplex');
-const util = require('util');
-util.inherits(Transform, Duplex);
+const inherits = require('internal/inherits');
+inherits(Transform, Duplex);
 
 
 function TransformState(stream) {

lib/_stream_wrap.js

@@ -1,11 +1,11 @@
 'use strict';
 
 const assert = require('assert');
-const util = require('util');
 const Socket = require('net').Socket;
 const JSStream = process.binding('js_stream').JSStream;
 const uv = process.binding('uv');
-const debug = util.debuglog('stream_wrap');
+const debug = require('internal/debuglog')('stream_wrap');
+const inherits = require('internal/inherits');
 
 function StreamWrap(stream) {
   const handle = new JSStream();
@@ -57,7 +57,7 @@ function StreamWrap(stream) {
     handle: handle
   });
 }
-util.inherits(StreamWrap, Socket);
+inherits(StreamWrap, Socket);
 module.exports = StreamWrap;
 
 // require('_stream_wrap').StreamWrap

lib/_stream_writable.js

@@ -7,12 +7,14 @@
 module.exports = Writable;
 Writable.WritableState = WritableState;
 
-const util = require('util');
-const internalUtil = require('internal/util');
-const Stream = require('stream');
 const Buffer = require('buffer').Buffer;
+const Stream = require('internal/stream');
+const inherits = require('internal/inherits');
+const internalUtil = require('internal/util');
+
+inherits(Writable, Stream);
 
-util.inherits(Writable, Stream);
+var Duplex;  // Break recursive dependency with _stream_duplex.js.
 
 function nop() {}
 
@@ -30,7 +32,10 @@ function WritableState(options, stream) {
   // contains buffers or objects.
   this.objectMode = !!options.objectMode;
 
-  if (stream instanceof Stream.Duplex)
+  if (Duplex === undefined)
+    Duplex = require('_stream_duplex');
+
+  if (stream instanceof Duplex)
     this.objectMode = this.objectMode || !!options.writableObjectMode;
 
   // the point at which write() starts returning false
@@ -130,8 +135,13 @@ Object.defineProperty(WritableState.prototype, 'buffer', {
 function Writable(options) {
   // Writable ctor is applied to Duplexes, though they're not
   // instanceof Writable, they're instanceof Readable.
-  if (!(this instanceof Writable) && !(this instanceof Stream.Duplex))
-    return new Writable(options);
+  if (!(this instanceof Writable)) {
+    if (Duplex === undefined)
+      Duplex = require('_stream_duplex');
+
+    if (!(this instanceof Duplex))
+      return new Writable(options);
+  }
 
   this._writableState = new WritableState(options, this);
 

lib/console.js

@@ -1,6 +1,7 @@
 'use strict';
 
-const util = require('util');
+const format = require('internal/format');
+
 
 function Console(stdout, stderr) {
   if (!(this instanceof Console)) {
@@ -33,23 +34,30 @@ function Console(stdout, stderr) {
 }
 
 Console.prototype.log = function() {
-  this._stdout.write(util.format.apply(this, arguments) + '\n');
+  this._stdout.write(format.apply(this, arguments) + '\n');
 };
 
 
 Console.prototype.info = Console.prototype.log;
 
 
 Console.prototype.warn = function() {
-  this._stderr.write(util.format.apply(this, arguments) + '\n');
+  this._stderr.write(format.apply(this, arguments) + '\n');
 };
 
 
 Console.prototype.error = Console.prototype.warn;
 
 
+var extend;
+var inspect;
+
 Console.prototype.dir = function(object, options) {
-  this._stdout.write(util.inspect(object, util._extend({
+  if (extend === undefined) {
+    extend = require('internal/extend');
+    inspect = require('util').inspect;
+  }
+  this._stdout.write(inspect(object, extend({
     customInspect: false
   }, options)) + '\n');
 };
@@ -75,7 +83,7 @@ Console.prototype.trace = function trace() {
   // exposed.
   var err = new Error();
   err.name = 'Trace';
-  err.message = util.format.apply(this, arguments);
+  err.message = format.apply(this, arguments);
   Error.captureStackTrace(err, trace);
   this.error(err.stack);
 };
@@ -84,7 +92,7 @@ Console.prototype.trace = function trace() {
 Console.prototype.assert = function(expression) {
   if (!expression) {
     var arr = Array.prototype.slice.call(arguments, 1);
-    require('assert').ok(false, util.format.apply(this, arr));
+    require('assert').ok(false, format.apply(this, arr));
   }
 };
 

lib/dgram.js

@@ -2,10 +2,13 @@
 
 const assert = require('assert');
 const Buffer = require('buffer').Buffer;
-const util = require('util');
 const events = require('events');
 const constants = require('constants');
 
+const errnoException = require('internal/errno_exception');
+const exceptionWithHostPort = require('internal/exception_with_host_port');
+const inherits = require('internal/inherits');
+
 const UDP = process.binding('udp_wrap').UDP;
 const SendWrap = process.binding('udp_wrap').SendWrap;
 
@@ -17,9 +20,6 @@ const BIND_STATE_BOUND = 2;
 var cluster = null;
 var dns = null;
 
-const errnoException = util._errnoException;
-const exceptionWithHostPort = util._exceptionWithHostPort;
-
 function lookup(address, family, callback) {
   if (!dns)
     dns = require('dns');
@@ -101,7 +101,7 @@ function Socket(type, listener) {
   if (typeof listener === 'function')
     this.on('message', listener);
 }
-util.inherits(Socket, events.EventEmitter);
+inherits(Socket, events.EventEmitter);
 exports.Socket = Socket;
 
 

lib/fs.js

@@ -4,7 +4,6 @@
 'use strict';
 
 const SlowBuffer = require('buffer').SlowBuffer;
-const util = require('util');
 const pathModule = require('path');
 
 const binding = process.binding('fs');
@@ -34,7 +33,9 @@ const O_WRONLY = constants.O_WRONLY || 0;
 const isWindows = process.platform === 'win32';
 
 const DEBUG = process.env.NODE_DEBUG && /fs/.test(process.env.NODE_DEBUG);
-const errnoException = util._errnoException;
+const errnoException = require('internal/errno_exception');
+const extend = require('internal/extend');
+const inherits = require('internal/inherits');
 
 function throwOptionsError(options) {
   throw new TypeError('Expected options to be either an object or a string, ' +
@@ -1048,7 +1049,7 @@ function toUnixTimestamp(time) {
   if (typeof time === 'number') {
     return time;
   }
-  if (util.isDate(time)) {
+  if (Object.prototype.toString.call(time) === '[object Date]') {
     // convert to 123.456 UNIX timestamp
     return time.getTime() / 1000;
   }
@@ -1185,7 +1186,7 @@ fs.appendFile = function(path, data, options, callback_) {
   }
 
   if (!options.flag)
-    options = util._extend({ flag: 'a' }, options);
+    options = extend({ flag: 'a' }, options);
   fs.writeFile(path, data, options, callback);
 };
 
@@ -1198,7 +1199,7 @@ fs.appendFileSync = function(path, data, options) {
     throwOptionsError(options);
   }
   if (!options.flag)
-    options = util._extend({ flag: 'a' }, options);
+    options = extend({ flag: 'a' }, options);
 
   fs.writeFileSync(path, data, options);
 };
@@ -1219,7 +1220,7 @@ function FSWatcher() {
     }
   };
 }
-util.inherits(FSWatcher, EventEmitter);
+inherits(FSWatcher, EventEmitter);
 
 FSWatcher.prototype.start = function(filename, persistent, recursive) {
   nullCheck(filename);
@@ -1289,7 +1290,7 @@ function StatWatcher() {
     self.emit('stop');
   };
 }
-util.inherits(StatWatcher, EventEmitter);
+inherits(StatWatcher, EventEmitter);
 
 
 StatWatcher.prototype.start = function(filename, persistent, interval) {
@@ -1319,7 +1320,7 @@ fs.watchFile = function(filename, options, listener) {
   };
 
   if (options !== null && typeof options === 'object') {
-    options = util._extend(defaults, options);
+    options = extend(defaults, options);
   } else {
     listener = options;
     options = defaults;
@@ -1607,7 +1608,7 @@ fs.createReadStream = function(path, options) {
   return new ReadStream(path, options);
 };
 
-util.inherits(ReadStream, Readable);
+inherits(ReadStream, Readable);
 fs.ReadStream = ReadStream;
 
 function ReadStream(path, options) {
@@ -1779,7 +1780,7 @@ fs.createWriteStream = function(path, options) {
   return new WriteStream(path, options);
 };
 
-util.inherits(WriteStream, Writable);
+inherits(WriteStream, Writable);
 fs.WriteStream = WriteStream;
 function WriteStream(path, options) {
   if (!(this instanceof WriteStream))
@@ -1887,7 +1888,7 @@ function SyncWriteStream(fd, options) {
   this.autoClose = options.autoClose === undefined ? true : options.autoClose;
 }
 
-util.inherits(SyncWriteStream, Stream);
+inherits(SyncWriteStream, Stream);
 
 
 // Export

lib/internal/assert.js

@@ -0,0 +1,6 @@
+'use strict';
+
+module.exports = function assert(expression, message) {
+  if (!expression)
+    throw new Error(`Internal assertion failed: ${message || 'no message'}`);
+};

lib/internal/debuglog.js

@@ -0,0 +1,25 @@
+'use strict';
+
+const debugs = {};
+var debugEnviron;
+var format;
+
+module.exports = function(set) {
+  if (debugEnviron === undefined)
+    debugEnviron = process.env.NODE_DEBUG || '';
+  set = set.toUpperCase();
+  if (!debugs[set]) {
+    if (new RegExp('\\b' + set + '\\b', 'i').test(debugEnviron)) {
+      var pid = process.pid;
+      debugs[set] = function() {
+        if (format === undefined)
+          format = require('internal/format');
+        const msg = format.apply(exports, arguments);
+        console.error('%s %d: %s', set, pid, msg);
+      };
+    } else {
+      debugs[set] = function() {};
+    }
+  }
+  return debugs[set];
+};

lib/internal/errno_exception.js

@@ -0,0 +1,17 @@
+'use strict';
+
+var uv;
+
+module.exports = function errnoException(err, syscall, original) {
+  if (uv === undefined)
+    uv = process.binding('uv');
+  var errname = uv.errname(err);
+  var message = syscall + ' ' + errname;
+  if (original)
+    message += ' ' + original;
+  var e = new Error(message);
+  e.code = errname;
+  e.errno = errname;
+  e.syscall = syscall;
+  return e;
+};