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1 // Copyright Joyent, Inc. and other Node contributors.
2 //
3 // Permission is hereby granted, free of charge, to any person obtaining a
4 // copy of this software and associated documentation files (the
5 // "Software"), to deal in the Software without restriction, including
6 // without limitation the rights to use, copy, modify, merge, publish,
7 // distribute, sublicense, and/or sell copies of the Software, and to permit
8 // persons to whom the Software is furnished to do so, subject to the
9 // following conditions:
10 //
11 // The above copyright notice and this permission notice shall be included
12 // in all copies or substantial portions of the Software.
13 //
14 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
15 // OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
16 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
17 // NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
18 // DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
19 // OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
20 // USE OR OTHER DEALINGS IN THE SOFTWARE.
21 
22 #include "async_wrap-inl.h"
23 #include "env-inl.h"
24 #include "node.h"
25 #include "handle_wrap.h"
26 #include "string_bytes.h"
27 
28 
29 namespace node {
30 
31 using v8::Context;
32 using v8::DontDelete;
33 using v8::DontEnum;
34 using v8::FunctionCallbackInfo;
35 using v8::FunctionTemplate;
36 using v8::HandleScope;
37 using v8::Integer;
38 using v8::Local;
39 using v8::MaybeLocal;
40 using v8::Object;
41 using v8::PropertyAttribute;
42 using v8::ReadOnly;
43 using v8::Signature;
44 using v8::String;
45 using v8::Value;
46 
47 namespace {
48 
49 class FSEventWrap: public HandleWrap {
50  public:
51   static void Initialize(Local<Object> target,
52                          Local<Value> unused,
53                          Local<Context> context,
54                          void* priv);
55   static void New(const FunctionCallbackInfo<Value>& args);
56   static void Start(const FunctionCallbackInfo<Value>& args);
57   static void GetInitialized(const FunctionCallbackInfo<Value>& args);
58 
59   SET_NO_MEMORY_INFO()
60   SET_MEMORY_INFO_NAME(FSEventWrap)
61   SET_SELF_SIZE(FSEventWrap)
62 
63  private:
64   static const encoding kDefaultEncoding = UTF8;
65 
66   FSEventWrap(Environment* env, Local<Object> object);
67   ~FSEventWrap() override = default;
68 
69   static void OnEvent(uv_fs_event_t* handle, const char* filename, int events,
70     int status);
71 
72   uv_fs_event_t handle_;
73   enum encoding encoding_ = kDefaultEncoding;
74 };
75 
76 
FSEventWrap(Environment * env,Local<Object> object)77 FSEventWrap::FSEventWrap(Environment* env, Local<Object> object)
78     : HandleWrap(env,
79                  object,
80                  reinterpret_cast<uv_handle_t*>(&handle_),
81                  AsyncWrap::PROVIDER_FSEVENTWRAP) {
82   MarkAsUninitialized();
83 }
84 
85 
GetInitialized(const FunctionCallbackInfo<Value> & args)86 void FSEventWrap::GetInitialized(const FunctionCallbackInfo<Value>& args) {
87   FSEventWrap* wrap = Unwrap<FSEventWrap>(args.This());
88   CHECK_NOT_NULL(wrap);
89   args.GetReturnValue().Set(!wrap->IsHandleClosing());
90 }
91 
Initialize(Local<Object> target,Local<Value> unused,Local<Context> context,void * priv)92 void FSEventWrap::Initialize(Local<Object> target,
93                              Local<Value> unused,
94                              Local<Context> context,
95                              void* priv) {
96   Environment* env = Environment::GetCurrent(context);
97 
98   auto fsevent_string = FIXED_ONE_BYTE_STRING(env->isolate(), "FSEvent");
99   Local<FunctionTemplate> t = env->NewFunctionTemplate(New);
100   t->InstanceTemplate()->SetInternalFieldCount(
101       FSEventWrap::kInternalFieldCount);
102   t->SetClassName(fsevent_string);
103 
104   t->Inherit(HandleWrap::GetConstructorTemplate(env));
105   env->SetProtoMethod(t, "start", Start);
106 
107   Local<FunctionTemplate> get_initialized_templ =
108       FunctionTemplate::New(env->isolate(),
109                             GetInitialized,
110                             env->as_callback_data(),
111                             Signature::New(env->isolate(), t));
112 
113   t->PrototypeTemplate()->SetAccessorProperty(
114       FIXED_ONE_BYTE_STRING(env->isolate(), "initialized"),
115       get_initialized_templ,
116       Local<FunctionTemplate>(),
117       static_cast<PropertyAttribute>(ReadOnly | DontDelete | DontEnum));
118 
119   target->Set(env->context(),
120               fsevent_string,
121               t->GetFunction(context).ToLocalChecked()).Check();
122 }
123 
124 
New(const FunctionCallbackInfo<Value> & args)125 void FSEventWrap::New(const FunctionCallbackInfo<Value>& args) {
126   CHECK(args.IsConstructCall());
127   Environment* env = Environment::GetCurrent(args);
128   new FSEventWrap(env, args.This());
129 }
130 
131 // wrap.start(filename, persistent, recursive, encoding)
Start(const FunctionCallbackInfo<Value> & args)132 void FSEventWrap::Start(const FunctionCallbackInfo<Value>& args) {
133   Environment* env = Environment::GetCurrent(args);
134 
135   FSEventWrap* wrap = Unwrap<FSEventWrap>(args.This());
136   CHECK_NOT_NULL(wrap);
137   CHECK(wrap->IsHandleClosing());  // Check that Start() has not been called.
138 
139   const int argc = args.Length();
140   CHECK_GE(argc, 4);
141 
142   BufferValue path(env->isolate(), args[0]);
143   CHECK_NOT_NULL(*path);
144 
145   unsigned int flags = 0;
146   if (args[2]->IsTrue())
147     flags |= UV_FS_EVENT_RECURSIVE;
148 
149   wrap->encoding_ = ParseEncoding(env->isolate(), args[3], kDefaultEncoding);
150 
151   int err = uv_fs_event_init(wrap->env()->event_loop(), &wrap->handle_);
152   if (err != 0) {
153     return args.GetReturnValue().Set(err);
154   }
155 
156   err = uv_fs_event_start(&wrap->handle_, OnEvent, *path, flags);
157   wrap->MarkAsInitialized();
158 
159   if (err != 0) {
160     FSEventWrap::Close(args);
161     return args.GetReturnValue().Set(err);
162   }
163 
164   // Check for persistent argument
165   if (!args[1]->IsTrue()) {
166     uv_unref(reinterpret_cast<uv_handle_t*>(&wrap->handle_));
167   }
168 
169   args.GetReturnValue().Set(err);
170 }
171 
172 
OnEvent(uv_fs_event_t * handle,const char * filename,int events,int status)173 void FSEventWrap::OnEvent(uv_fs_event_t* handle, const char* filename,
174     int events, int status) {
175   FSEventWrap* wrap = static_cast<FSEventWrap*>(handle->data);
176   Environment* env = wrap->env();
177 
178   HandleScope handle_scope(env->isolate());
179   Context::Scope context_scope(env->context());
180 
181   CHECK_EQ(wrap->persistent().IsEmpty(), false);
182 
183   // We're in a bind here. libuv can set both UV_RENAME and UV_CHANGE but
184   // the Node API only lets us pass a single event to JS land.
185   //
186   // The obvious solution is to run the callback twice, once for each event.
187   // However, since the second event is not allowed to fire if the handle is
188   // closed after the first event, and since there is no good way to detect
189   // closed handles, that option is out.
190   //
191   // For now, ignore the UV_CHANGE event if UV_RENAME is also set. Make the
192   // assumption that a rename implicitly means an attribute change. Not too
193   // unreasonable, right? Still, we should revisit this before v1.0.
194   Local<String> event_string;
195   if (status) {
196     event_string = String::Empty(env->isolate());
197   } else if (events & UV_RENAME) {
198     event_string = env->rename_string();
199   } else if (events & UV_CHANGE) {
200     event_string = env->change_string();
201   } else {
202     CHECK(0 && "bad fs events flag");
203   }
204 
205   Local<Value> argv[] = {
206     Integer::New(env->isolate(), status),
207     event_string,
208     Null(env->isolate())
209   };
210 
211   if (filename != nullptr) {
212     Local<Value> error;
213     MaybeLocal<Value> fn = StringBytes::Encode(env->isolate(),
214                                                filename,
215                                                wrap->encoding_,
216                                                &error);
217     if (fn.IsEmpty()) {
218       argv[0] = Integer::New(env->isolate(), UV_EINVAL);
219       argv[2] = StringBytes::Encode(env->isolate(),
220                                     filename,
221                                     strlen(filename),
222                                     BUFFER,
223                                     &error).ToLocalChecked();
224     } else {
225       argv[2] = fn.ToLocalChecked();
226     }
227   }
228 
229   wrap->MakeCallback(env->onchange_string(), arraysize(argv), argv);
230 }
231 
232 }  // anonymous namespace
233 }  // namespace node
234 
235 NODE_MODULE_CONTEXT_AWARE_INTERNAL(fs_event_wrap, node::FSEventWrap::Initialize)
236