Add autoClose=true option to fs.createWrireStream #20880

doc/api/fs.markdown

@@ -822,13 +822,20 @@ Returns a new WriteStream object (See `Writable Stream`).
     { flags: 'w',
       encoding: null,
       fd: null,
-      mode: 0666 }
+      mode: 0666,
+      autoClose: true }
 
 `options` may also include a `start` option to allow writing data at
 some position past the beginning of the file.  Modifying a file rather
 than replacing it may require a `flags` mode of `r+` rather than the
 default mode `w`.
 
+If `autoClose` is false, then the file descriptor won't be closed, even if
+there's an error. It is your responsiblity to close it and make sure
+there's no file descriptor leak. If `autoClose` is set to true (default
+behavior) on `error` or `end` the file descriptor will be closed
+automatically.
+
 Like `ReadStream` above, if `fd` is specified, `WriteStream` will ignore the
 `path` argument and will use the specified file descriptor. This means that no
 `open` event will be emitted.

lib/fs.js

@@ -1742,6 +1742,9 @@ function WriteStream(path, options) {
   this.mode = options.hasOwnProperty('mode') ? options.mode : 438; /*=0666*/
 
   this.start = options.hasOwnProperty('start') ? options.start : undefined;
+  this.autoClose = options.hasOwnProperty('autoClose') ?
+                       options.autoClose : true;
+
   this.pos = undefined;
   this.bytesWritten = 0;
 
@@ -1760,7 +1763,11 @@ function WriteStream(path, options) {
     this.open();
 
   // dispose on finish.
-  this.once('finish', this.close);
+  this.once('finish', function() {
+    if (this.autoClose) {
+      this.close();
+    }
+  });
 }
 
 fs.FileWriteStream = fs.WriteStream; // support the legacy name
@@ -1769,7 +1776,9 @@ fs.FileWriteStream = fs.WriteStream; // support the legacy name
 WriteStream.prototype.open = function() {
   fs.open(this.path, this.flags, this.mode, function(er, fd) {
     if (er) {
-      this.destroy();
+      if (this.autoClose) {
+        this.destroy();
+      }
       this.emit('error', er);
       return;
     }
@@ -1792,7 +1801,9 @@ WriteStream.prototype._write = function(data, encoding, cb) {
   var self = this;
   fs.write(this.fd, data, 0, data.length, this.pos, function(er, bytes) {
     if (er) {
-      self.destroy();
+      if (this.autoClose) {
+        self.destroy();
+      }
       return cb(er);
     }
     self.bytesWritten += bytes;

test/simple/test-fs-write-stream-autoclose-option.js

@@ -0,0 +1,70 @@
+// Copyright Joyent, Inc. and other Node contributors.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a
+// copy of this software and associated documentation files (the
+// "Software"), to deal in the Software without restriction, including
+// without limitation the rights to use, copy, modify, merge, publish,
+// distribute, sublicense, and/or sell copies of the Software, and to permit
+// persons to whom the Software is furnished to do so, subject to the
+// following conditions:
+//
+// The above copyright notice and this permission notice shall be included
+// in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
+// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+// USE OR OTHER DEALINGS IN THE SOFTWARE.
+var common = require('../common');
+var assert = require('assert');
+var path = require('path');
+var fs = require('fs');
+
+var file = path.join(common.tmpDir, 'write-autoclose-opt1.txt');
+var stream = fs.createWriteStream(file, {flags: 'w+', autoClose: false});
+stream.write('Test1');
+stream.end();
+stream.on('finish', function() {
+  process.nextTick(function() {
+    assert(!stream.closed);
+    assert(stream.fd);
+    next();
+  });
+});
+
+function next() {
+  // This will tell us if the fd is usable again or not
+  stream = fs.createWriteStream(null, {fd: stream.fd, start:0 });
+  stream.write('Test2');
+  stream.end();
+  stream.on('finish', function() {
+    assert(stream.closed);
+    assert(!stream.fd);
+    process.nextTick(next2);
+  });
+}
+
+function next2() {
+  //This will test if after reusing the fd data is written properly
+  fs.readFile(file, function(err, data) {
+    assert(!err);
+    assert.equal(data, 'Test2');
+    process.nextTick(next3);
+  });
+}
+
+function next3() {
+  //This is to test success scenario where autoClose is true
+  var stream = fs.createWriteStream(file, {autoClose: true});
+  stream.write('Test3');
+  stream.end();
+  stream.on('finish', function() {
+    process.nextTick(function() {
+      assert(stream.closed);
+      assert(!stream.fd);
+    });
+  });
+}