lts/src/fs_event_wrap.cc
// 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.
#include "async_wrap-inl.h"
#include "env-inl.h"
#include "node.h"
#include "handle_wrap.h"
#include "string_bytes.h"
namespace node {
using v8::Context;
using v8::DontDelete;
using v8::DontEnum;
using v8::FunctionCallbackInfo;
using v8::FunctionTemplate;
using v8::HandleScope;
using v8::Integer;
using v8::Local;
using v8::MaybeLocal;
using v8::Object;
using v8::PropertyAttribute;
using v8::ReadOnly;
using v8::Signature;
using v8::String;
using v8::Value;
namespace {
class FSEventWrap: public HandleWrap {
public:
static void Initialize(Local<Object> target,
Local<Value> unused,
Local<Context> context,
void* priv);
static void New(const FunctionCallbackInfo<Value>& args);
static void Start(const FunctionCallbackInfo<Value>& args);
static void GetInitialized(const FunctionCallbackInfo<Value>& args);
SET_NO_MEMORY_INFO()
SET_MEMORY_INFO_NAME(FSEventWrap)
SET_SELF_SIZE(FSEventWrap)
private:
static const encoding kDefaultEncoding = UTF8;
FSEventWrap(Environment* env, Local<Object> object);
~FSEventWrap() override = default;
static void OnEvent(uv_fs_event_t* handle, const char* filename, int events,
int status);
uv_fs_event_t handle_;
enum encoding encoding_ = kDefaultEncoding;
};
FSEventWrap::FSEventWrap(Environment* env, Local<Object> object)
: HandleWrap(env,
object,
reinterpret_cast<uv_handle_t*>(&handle_),
AsyncWrap::PROVIDER_FSEVENTWRAP) {
MarkAsUninitialized();
}
void FSEventWrap::GetInitialized(const FunctionCallbackInfo<Value>& args) {
FSEventWrap* wrap = Unwrap<FSEventWrap>(args.This());
CHECK_NOT_NULL(wrap);
args.GetReturnValue().Set(!wrap->IsHandleClosing());
}
void FSEventWrap::Initialize(Local<Object> target,
Local<Value> unused,
Local<Context> context,
void* priv) {
Environment* env = Environment::GetCurrent(context);
auto fsevent_string = FIXED_ONE_BYTE_STRING(env->isolate(), "FSEvent");
Local<FunctionTemplate> t = env->NewFunctionTemplate(New);
t->InstanceTemplate()->SetInternalFieldCount(
FSEventWrap::kInternalFieldCount);
t->SetClassName(fsevent_string);
t->Inherit(AsyncWrap::GetConstructorTemplate(env));
env->SetProtoMethod(t, "start", Start);
env->SetProtoMethod(t, "close", Close);
Local<FunctionTemplate> get_initialized_templ =
FunctionTemplate::New(env->isolate(),
GetInitialized,
env->as_callback_data(),
Signature::New(env->isolate(), t));
t->PrototypeTemplate()->SetAccessorProperty(
FIXED_ONE_BYTE_STRING(env->isolate(), "initialized"),
get_initialized_templ,
Local<FunctionTemplate>(),
static_cast<PropertyAttribute>(ReadOnly | DontDelete | DontEnum));
target->Set(env->context(),
fsevent_string,
t->GetFunction(context).ToLocalChecked()).Check();
}
void FSEventWrap::New(const FunctionCallbackInfo<Value>& args) {
CHECK(args.IsConstructCall());
Environment* env = Environment::GetCurrent(args);
new FSEventWrap(env, args.This());
}
// wrap.start(filename, persistent, recursive, encoding)
void FSEventWrap::Start(const FunctionCallbackInfo<Value>& args) {
Environment* env = Environment::GetCurrent(args);
FSEventWrap* wrap = Unwrap<FSEventWrap>(args.This());
CHECK_NOT_NULL(wrap);
CHECK(wrap->IsHandleClosing()); // Check that Start() has not been called.
const int argc = args.Length();
CHECK_GE(argc, 4);
BufferValue path(env->isolate(), args[0]);
CHECK_NOT_NULL(*path);
unsigned int flags = 0;
if (args[2]->IsTrue())
flags |= UV_FS_EVENT_RECURSIVE;
wrap->encoding_ = ParseEncoding(env->isolate(), args[3], kDefaultEncoding);
int err = uv_fs_event_init(wrap->env()->event_loop(), &wrap->handle_);
if (err != 0) {
return args.GetReturnValue().Set(err);
}
err = uv_fs_event_start(&wrap->handle_, OnEvent, *path, flags);
wrap->MarkAsInitialized();
if (err != 0) {
FSEventWrap::Close(args);
return args.GetReturnValue().Set(err);
}
// Check for persistent argument
if (!args[1]->IsTrue()) {
uv_unref(reinterpret_cast<uv_handle_t*>(&wrap->handle_));
}
args.GetReturnValue().Set(err);
}
void FSEventWrap::OnEvent(uv_fs_event_t* handle, const char* filename,
int events, int status) {
FSEventWrap* wrap = static_cast<FSEventWrap*>(handle->data);
Environment* env = wrap->env();
HandleScope handle_scope(env->isolate());
Context::Scope context_scope(env->context());
CHECK_EQ(wrap->persistent().IsEmpty(), false);
// We're in a bind here. libuv can set both UV_RENAME and UV_CHANGE but
// the Node API only lets us pass a single event to JS land.
//
// The obvious solution is to run the callback twice, once for each event.
// However, since the second event is not allowed to fire if the handle is
// closed after the first event, and since there is no good way to detect
// closed handles, that option is out.
//
// For now, ignore the UV_CHANGE event if UV_RENAME is also set. Make the
// assumption that a rename implicitly means an attribute change. Not too
// unreasonable, right? Still, we should revisit this before v1.0.
Local<String> event_string;
if (status) {
event_string = String::Empty(env->isolate());
} else if (events & UV_RENAME) {
event_string = env->rename_string();
} else if (events & UV_CHANGE) {
event_string = env->change_string();
} else {
CHECK(0 && "bad fs events flag");
}
Local<Value> argv[] = {
Integer::New(env->isolate(), status),
event_string,
Null(env->isolate())
};
if (filename != nullptr) {
Local<Value> error;
MaybeLocal<Value> fn = StringBytes::Encode(env->isolate(),
filename,
wrap->encoding_,
&error);
if (fn.IsEmpty()) {
argv[0] = Integer::New(env->isolate(), UV_EINVAL);
argv[2] = StringBytes::Encode(env->isolate(),
filename,
strlen(filename),
BUFFER,
&error).ToLocalChecked();
} else {
argv[2] = fn.ToLocalChecked();
}
}
wrap->MakeCallback(env->onchange_string(), arraysize(argv), argv);
}
} // anonymous namespace
} // namespace node
NODE_MODULE_CONTEXT_AWARE_INTERNAL(fs_event_wrap, node::FSEventWrap::Initialize)