fs watcher binding

lib/fs.js

@@ -589,6 +589,73 @@ fs.writeFileSync = function(path, data, encoding) {
   fs.closeSync(fd);
 };
 
+
+function errnoException(errorno, syscall) {
+  // TODO make this more compatible with ErrnoException from src/node.cc
+  // Once all of Node is using this function the ErrnoException from
+  // src/node.cc should be removed.
+  var e = new Error(syscall + ' ' + errorno);
+  e.errno = e.code = errorno;
+  e.syscall = syscall;
+  return e;
+}
+
+
+function FSWather() {
+  var self = this;
+  var FSEvent = process.binding('fs_event_wrap').FSEvent;
+  this._handle = new FSEvent();
+
+  this._handle.onchange = function(status, event, filename) {
+    if (status) {
+      self.emit('error', errnoException(errno, 'watch'));
+    } else {
+      self.emit('change', event, filename);
+    }
+  };
+}
+util.inherits(FSWather, EventEmitter);
+
+FSWather.prototype.start = function(filename, persistent) {
+  var r = this._handle.start(filename, persistent);
+
+  if (r) {
+    this._handle.close();
+    throw errnoException(errno, "watch")
+  }
+};
+
+FSWather.prototype.close = function() {
+  this._handle.close();
+};
+
+fs.watch = function(filename) {
+  var watcher;
+  var options;
+  var listener;
+
+  if ('object' == typeof arguments[1]) {
+    options = arguments[1];
+    listener = arguments[2];
+  } else {
+    options = {};
+    listener = arguments[1];
+  }
+
+  if (!listener) {
+    throw new Error('watch requires a listener function');
+  }
+
+  if (options.persistent === undefined) options.persistent = true;
+
+  watcher = new FSWather();
+  watcher.start(filename, options.persistent);
+
+  watcher.addListener('change', listener);
+  return watcher;
+};
+
+
 // Stat Change Watchers
 
 function StatWatcher() {
@@ -623,6 +690,10 @@ function inStatWatchers(filename) {
 
 
 fs.watchFile = function(filename) {
+  if (isWindows) {
+    throw new Error('use fs.watch api instead');
+  }
+
   var stat;
   var options;
   var listener;

node.gyp

@@ -73,6 +73,7 @@
       ],
 
       'sources': [
+        'src/fs_event_wrap.cc',
         'src/cares_wrap.cc',
         'src/handle_wrap.cc',
         'src/node.cc',

src/fs_event_wrap.cc

@@ -0,0 +1,132 @@
+#include <node.h>
+#include <handle_wrap.h>
+
+#include <stdlib.h>
+
+using namespace v8;
+
+namespace node {
+
+#define UNWRAP                                                              \
+  assert(!args.Holder().IsEmpty());                                         \
+  assert(args.Holder()->InternalFieldCount() > 0);                          \
+  FSEventWrap* wrap =                                                       \
+      static_cast<FSEventWrap*>(args.Holder()->GetPointerFromInternalField(0)); \
+  if (!wrap) {                                                              \
+    SetErrno(UV_EBADF);                                                     \
+    return scope.Close(Integer::New(-1));                                   \
+  }
+
+class FSEventWrap: public HandleWrap {
+public:
+  static void Initialize(Handle<Object> target);
+  static Handle<Value> New(const Arguments& args);
+  static Handle<Value> Start(const Arguments& args);
+
+private:
+  FSEventWrap(Handle<Object> object);
+  virtual ~FSEventWrap();
+
+  static void OnEvent(uv_fs_event_t* handle, const char* filename, int events,
+    int status);
+
+  uv_fs_event_t handle_;
+};
+
+
+FSEventWrap::FSEventWrap(Handle<Object> object): HandleWrap(object,
+                                                    (uv_handle_t*)&handle_) {
+  handle_.data = reinterpret_cast<void*>(this);
+}
+
+
+FSEventWrap::~FSEventWrap() {
+}
+
+
+void FSEventWrap::Initialize(Handle<Object> target) {
+  HandleWrap::Initialize(target);
+
+  HandleScope scope;
+
+  Local<FunctionTemplate> t = FunctionTemplate::New(New);
+  t->InstanceTemplate()->SetInternalFieldCount(1);
+  t->SetClassName(String::NewSymbol("FSEvent"));
+
+  NODE_SET_PROTOTYPE_METHOD(t, "start", Start);
+  NODE_SET_PROTOTYPE_METHOD(t, "close", Close);
+
+  target->Set(String::NewSymbol("FSEvent"),
+              Persistent<FunctionTemplate>::New(t)->GetFunction());
+}
+
+
+Handle<Value> FSEventWrap::New(const Arguments& args) {
+  HandleScope scope;
+
+  assert(args.IsConstructCall());
+  new FSEventWrap(args.This());
+
+  return scope.Close(args.This());
+}
+
+
+Handle<Value> FSEventWrap::Start(const Arguments& args) {
+  HandleScope scope;
+
+  UNWRAP
+
+  if (args.Length() < 1 || !args[0]->IsString()) {
+    return ThrowException(Exception::TypeError(String::New("Bad arguments")));
+  }
+
+  String::Utf8Value path(args[0]->ToString());
+
+  int r = uv_fs_event_init(uv_default_loop(), &wrap->handle_, *path, OnEvent);
+  if (r == 0) {
+    // Check for persistent argument
+    if (!args[1]->IsTrue()) {
+      uv_unref(uv_default_loop());
+    }
+  } else { 
+    SetErrno(uv_last_error(uv_default_loop()).code);
+  }
+
+  return scope.Close(Integer::New(r));
+}
+
+
+void FSEventWrap::OnEvent(uv_fs_event_t* handle, const char* filename,
+    int events, int status) {
+  HandleScope scope;
+  Local<String> eventStr;
+
+  FSEventWrap* wrap = reinterpret_cast<FSEventWrap*>(handle->data);
+
+  assert(wrap->object_.IsEmpty() == false);
+
+  if (status) {
+    SetErrno(uv_last_error(uv_default_loop()).code);
+    eventStr = String::Empty();
+  } else {
+    switch (events) {
+      case UV_RENAME:
+        eventStr = String::New("rename");
+        break;
+      case UV_CHANGE:
+        eventStr = String::New("change");
+        break;
+    }
+  }
+
+  Local<Value> argv[3] = {
+    Integer::New(status),
+    eventStr,
+    filename ? (Local<Value>)String::New(filename) : Local<Value>::New(v8::Null())
+  };
+
+  MakeCallback(wrap->object_, "onchange", 3, argv);
+}
+} // namespace node
+
+NODE_MODULE(node_fs_event_wrap, node::FSEventWrap::Initialize);

src/node_extensions.h

@@ -51,6 +51,7 @@ NODE_EXT_LIST_ITEM(node_cares_wrap)
 NODE_EXT_LIST_ITEM(node_stdio_wrap)
 NODE_EXT_LIST_ITEM(node_tty_wrap)
 NODE_EXT_LIST_ITEM(node_process_wrap)
+NODE_EXT_LIST_ITEM(node_fs_event_wrap)
 
 NODE_EXT_LIST_END
 

test/simple/test-fs-watch.js

@@ -0,0 +1,143 @@
+// 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 expectFilePath = process.platform == 'win32' || process.platform == 'linux';
+
+var watchSeenOne = 0;
+var watchSeenTwo = 0;
+var watchSeenThree = 0;
+
+var startDir = process.cwd();
+var testDir = common.fixturesDir;
+
+var filenameOne = 'watch.txt';
+var filepathOne = path.join(testDir, filenameOne);
+
+var filenameTwo = 'hasOwnProperty';
+var filepathTwo = filenameTwo;
+var filepathTwoAbs = path.join(testDir, filenameTwo);
+
+var filenameThree = 'newfile.txt';
+var testsubdir = path.join(testDir, 'testsubdir');
+var filepathThree = path.join(testsubdir, filenameThree);
+
+
+process.addListener('exit', function() {
+  fs.unlinkSync(filepathOne);
+  fs.unlinkSync(filepathTwoAbs);
+  fs.unlinkSync(filepathThree);
+  fs.rmdirSync(testsubdir);
+  assert.ok(watchSeenOne > 0);
+  assert.ok(watchSeenTwo > 0);
+  assert.ok(watchSeenThree > 0);
+});
+
+
+fs.writeFileSync(filepathOne, "hello");
+
+assert.throws(
+  function() {
+    fs.watch(filepathOne);
+  },
+  function(e) {
+    return e.message === 'watch requires a listener function';
+  }
+);
+
+assert.doesNotThrow(
+  function() {
+    var watcher = fs.watch(filepathOne, function(event, filename) {
+      assert.equal('change', event);
+      if (expectFilePath) {
+        assert.equal('watch.txt', filename);
+      } else {
+        assert.equal(null, filename);
+      }
+      watcher.close();
+      ++watchSeenOne;
+    });
+  }
+);
+
+setTimeout(function() {
+  fs.writeFileSync(filepathOne, "world");
+}, 1000);
+
+
+process.chdir(testDir);
+
+fs.writeFileSync(filepathTwoAbs, "howdy");
+
+assert.throws(
+  function() {
+    fs.watch(filepathTwo);
+  },
+  function(e) {
+    return e.message === 'watch requires a listener function';
+  }
+);
+
+assert.doesNotThrow(
+  function() {
+    var watcher = fs.watch(filepathTwo, function(event, filename) {
+      assert.equal('change', event);
+      if (expectFilePath) {
+        assert.equal('hasOwnProperty', filename);
+      } else {
+        assert.equal(null, filename);
+      }
+      watcher.close();
+      ++watchSeenTwo;
+    });
+  }
+);
+
+setTimeout(function() {
+  fs.writeFileSync(filepathTwoAbs, "pardner");
+}, 1000);
+
+try { fs.unlinkSync(filepathThree); } catch(e) {}
+try { fs.mkdirSync(testsubdir, 0700); } catch(e) {}
+
+assert.doesNotThrow(
+  function() {
+    var watcher = fs.watch(testsubdir, function(event, filename) {
+      assert.equal('rename', event);
+      if (expectFilePath) {
+        assert.equal('newfile.txt', filename);
+      } else {
+        assert.equal(null, filename);
+      }
+      watcher.close();
+      ++watchSeenThree;
+    });
+  }
+);
+
+setTimeout(function() {
+  var fd = fs.openSync(filepathThree, 'w');
+  fs.closeSync(fd);
+}, 1000);

wscript

@@ -890,6 +890,7 @@ def build(bld):
     src/cares_wrap.cc
     src/stdio_wrap.cc
     src/tty_wrap.cc
+    src/fs_event_wrap.cc
     src/process_wrap.cc
     src/v8_typed_array.cc
   """