lts/src/node_dir.cc
#include "node_dir.h"
#include "node_file-inl.h"
#include "node_process.h"
#include "memory_tracker-inl.h"
#include "util.h"
#include "tracing/trace_event.h"
#include "string_bytes.h"
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <cstring>
#include <cerrno>
#include <climits>
#include <memory>
namespace node {
namespace fs_dir {
using fs::FSReqAfterScope;
using fs::FSReqBase;
using fs::FSReqWrapSync;
using fs::GetReqWrap;
using v8::Array;
using v8::Context;
using v8::FunctionCallbackInfo;
using v8::FunctionTemplate;
using v8::HandleScope;
using v8::Integer;
using v8::Isolate;
using v8::Local;
using v8::MaybeLocal;
using v8::Null;
using v8::Number;
using v8::Object;
using v8::ObjectTemplate;
using v8::String;
using v8::Value;
#define TRACE_NAME(name) "fs_dir.sync." #name
#define GET_TRACE_ENABLED \
(*TRACE_EVENT_API_GET_CATEGORY_GROUP_ENABLED \
(TRACING_CATEGORY_NODE2(fs_dir, sync)) != 0)
#define FS_DIR_SYNC_TRACE_BEGIN(syscall, ...) \
if (GET_TRACE_ENABLED) \
TRACE_EVENT_BEGIN(TRACING_CATEGORY_NODE2(fs_dir, sync), TRACE_NAME(syscall), \
##__VA_ARGS__);
#define FS_DIR_SYNC_TRACE_END(syscall, ...) \
if (GET_TRACE_ENABLED) \
TRACE_EVENT_END(TRACING_CATEGORY_NODE2(fs_dir, sync), TRACE_NAME(syscall), \
##__VA_ARGS__);
DirHandle::DirHandle(Environment* env, Local<Object> obj, uv_dir_t* dir)
: AsyncWrap(env, obj, AsyncWrap::PROVIDER_DIRHANDLE),
dir_(dir) {
MakeWeak();
dir_->nentries = 0;
dir_->dirents = nullptr;
}
DirHandle* DirHandle::New(Environment* env, uv_dir_t* dir) {
Local<Object> obj;
if (!env->dir_instance_template()
->NewInstance(env->context())
.ToLocal(&obj)) {
return nullptr;
}
return new DirHandle(env, obj, dir);
}
void DirHandle::New(const FunctionCallbackInfo<Value>& args) {
CHECK(args.IsConstructCall());
}
DirHandle::~DirHandle() {
CHECK(!closing_); // We should not be deleting while explicitly closing!
GCClose(); // Close synchronously and emit warning
CHECK(closed_); // We have to be closed at the point
}
void DirHandle::MemoryInfo(MemoryTracker* tracker) const {
tracker->TrackFieldWithSize("dir", sizeof(*dir_));
}
// Close the directory handle if it hasn't already been closed. A process
// warning will be emitted using a SetImmediate to avoid calling back to
// JS during GC. If closing the fd fails at this point, a fatal exception
// will crash the process immediately.
inline void DirHandle::GCClose() {
if (closed_) return;
uv_fs_t req;
int ret = uv_fs_closedir(nullptr, &req, dir_, nullptr);
uv_fs_req_cleanup(&req);
closing_ = false;
closed_ = true;
struct err_detail { int ret; };
err_detail detail { ret };
if (ret < 0) {
// Do not unref this
env()->SetImmediate([detail](Environment* env) {
char msg[70];
snprintf(msg, arraysize(msg),
"Closing directory handle on garbage collection failed");
// This exception will end up being fatal for the process because
// it is being thrown from within the SetImmediate handler and
// there is no JS stack to bubble it to. In other words, tearing
// down the process is the only reasonable thing we can do here.
HandleScope handle_scope(env->isolate());
env->ThrowUVException(detail.ret, "close", msg);
});
return;
}
// If the close was successful, we still want to emit a process warning
// to notify that the file descriptor was gc'd. We want to be noisy about
// this because not explicitly closing the DirHandle is a bug.
env()->SetUnrefImmediate([](Environment* env) {
ProcessEmitWarning(env,
"Closing directory handle on garbage collection");
});
}
void AfterClose(uv_fs_t* req) {
FSReqBase* req_wrap = FSReqBase::from_req(req);
FSReqAfterScope after(req_wrap, req);
if (after.Proceed())
req_wrap->Resolve(Undefined(req_wrap->env()->isolate()));
}
void DirHandle::Close(const FunctionCallbackInfo<Value>& args) {
Environment* env = Environment::GetCurrent(args);
const int argc = args.Length();
CHECK_GE(argc, 1);
DirHandle* dir;
ASSIGN_OR_RETURN_UNWRAP(&dir, args.Holder());
dir->closing_ = false;
dir->closed_ = true;
FSReqBase* req_wrap_async = GetReqWrap(env, args[0]);
if (req_wrap_async != nullptr) { // close(req)
AsyncCall(env, req_wrap_async, args, "closedir", UTF8, AfterClose,
uv_fs_closedir, dir->dir());
} else { // close(undefined, ctx)
CHECK_EQ(argc, 2);
FSReqWrapSync req_wrap_sync;
FS_DIR_SYNC_TRACE_BEGIN(closedir);
SyncCall(env, args[1], &req_wrap_sync, "closedir", uv_fs_closedir,
dir->dir());
FS_DIR_SYNC_TRACE_END(closedir);
}
}
static MaybeLocal<Array> DirentListToArray(
Environment* env,
uv_dirent_t* ents,
int num,
enum encoding encoding,
Local<Value>* err_out) {
MaybeStackBuffer<Local<Value>, 64> entries(num * 2);
// Return an array of all read filenames.
int j = 0;
for (int i = 0; i < num; i++) {
Local<Value> filename;
Local<Value> error;
const size_t namelen = strlen(ents[i].name);
if (!StringBytes::Encode(env->isolate(),
ents[i].name,
namelen,
encoding,
&error).ToLocal(&filename)) {
*err_out = error;
return MaybeLocal<Array>();
}
entries[j++] = filename;
entries[j++] = Integer::New(env->isolate(), ents[i].type);
}
return Array::New(env->isolate(), entries.out(), j);
}
static void AfterDirRead(uv_fs_t* req) {
BaseObjectPtr<FSReqBase> req_wrap { FSReqBase::from_req(req) };
FSReqAfterScope after(req_wrap.get(), req);
if (!after.Proceed()) {
return;
}
Environment* env = req_wrap->env();
Isolate* isolate = env->isolate();
if (req->result == 0) {
// Done
Local<Value> done = Null(isolate);
after.Clear();
req_wrap->Resolve(done);
return;
}
uv_dir_t* dir = static_cast<uv_dir_t*>(req->ptr);
Local<Value> error;
Local<Array> js_array;
if (!DirentListToArray(env,
dir->dirents,
req->result,
req_wrap->encoding(),
&error).ToLocal(&js_array)) {
// Clear libuv resources *before* delivering results to JS land because
// that can schedule another operation on the same uv_dir_t. Ditto below.
after.Clear();
return req_wrap->Reject(error);
}
after.Clear();
req_wrap->Resolve(js_array);
}
void DirHandle::Read(const FunctionCallbackInfo<Value>& args) {
Environment* env = Environment::GetCurrent(args);
Isolate* isolate = env->isolate();
const int argc = args.Length();
CHECK_GE(argc, 3);
const enum encoding encoding = ParseEncoding(isolate, args[0], UTF8);
DirHandle* dir;
ASSIGN_OR_RETURN_UNWRAP(&dir, args.Holder());
CHECK(args[1]->IsNumber());
uint64_t buffer_size = args[1].As<Number>()->Value();
if (buffer_size != dir->dirents_.size()) {
dir->dirents_.resize(buffer_size);
dir->dir_->nentries = buffer_size;
dir->dir_->dirents = dir->dirents_.data();
}
FSReqBase* req_wrap_async = GetReqWrap(env, args[2]);
if (req_wrap_async != nullptr) { // dir.read(encoding, bufferSize, req)
AsyncCall(env, req_wrap_async, args, "readdir", encoding,
AfterDirRead, uv_fs_readdir, dir->dir());
} else { // dir.read(encoding, bufferSize, undefined, ctx)
CHECK_EQ(argc, 4);
FSReqWrapSync req_wrap_sync;
FS_DIR_SYNC_TRACE_BEGIN(readdir);
int err = SyncCall(env, args[3], &req_wrap_sync, "readdir", uv_fs_readdir,
dir->dir());
FS_DIR_SYNC_TRACE_END(readdir);
if (err < 0) {
return; // syscall failed, no need to continue, error info is in ctx
}
if (req_wrap_sync.req.result == 0) {
// Done
Local<Value> done = Null(isolate);
args.GetReturnValue().Set(done);
return;
}
CHECK_GE(req_wrap_sync.req.result, 0);
Local<Value> error;
Local<Array> js_array;
if (!DirentListToArray(env,
dir->dir()->dirents,
req_wrap_sync.req.result,
encoding,
&error).ToLocal(&js_array)) {
Local<Object> ctx = args[2].As<Object>();
USE(ctx->Set(env->context(), env->error_string(), error));
return;
}
args.GetReturnValue().Set(js_array);
}
}
void AfterOpenDir(uv_fs_t* req) {
FSReqBase* req_wrap = FSReqBase::from_req(req);
FSReqAfterScope after(req_wrap, req);
if (!after.Proceed()) {
return;
}
Environment* env = req_wrap->env();
uv_dir_t* dir = static_cast<uv_dir_t*>(req->ptr);
DirHandle* handle = DirHandle::New(env, dir);
req_wrap->Resolve(handle->object().As<Value>());
}
static void OpenDir(const FunctionCallbackInfo<Value>& args) {
Environment* env = Environment::GetCurrent(args);
Isolate* isolate = env->isolate();
const int argc = args.Length();
CHECK_GE(argc, 3);
BufferValue path(isolate, args[0]);
CHECK_NOT_NULL(*path);
const enum encoding encoding = ParseEncoding(isolate, args[1], UTF8);
FSReqBase* req_wrap_async = GetReqWrap(env, args[2]);
if (req_wrap_async != nullptr) { // openDir(path, encoding, req)
AsyncCall(env, req_wrap_async, args, "opendir", encoding, AfterOpenDir,
uv_fs_opendir, *path);
} else { // openDir(path, encoding, undefined, ctx)
CHECK_EQ(argc, 4);
FSReqWrapSync req_wrap_sync;
FS_DIR_SYNC_TRACE_BEGIN(opendir);
int result = SyncCall(env, args[3], &req_wrap_sync, "opendir",
uv_fs_opendir, *path);
FS_DIR_SYNC_TRACE_END(opendir);
if (result < 0) {
return; // syscall failed, no need to continue, error info is in ctx
}
uv_fs_t* req = &req_wrap_sync.req;
uv_dir_t* dir = static_cast<uv_dir_t*>(req->ptr);
DirHandle* handle = DirHandle::New(env, dir);
args.GetReturnValue().Set(handle->object().As<Value>());
}
}
void Initialize(Local<Object> target,
Local<Value> unused,
Local<Context> context,
void* priv) {
Environment* env = Environment::GetCurrent(context);
Isolate* isolate = env->isolate();
env->SetMethod(target, "opendir", OpenDir);
// Create FunctionTemplate for DirHandle
Local<FunctionTemplate> dir = env->NewFunctionTemplate(DirHandle::New);
dir->Inherit(AsyncWrap::GetConstructorTemplate(env));
env->SetProtoMethod(dir, "read", DirHandle::Read);
env->SetProtoMethod(dir, "close", DirHandle::Close);
Local<ObjectTemplate> dirt = dir->InstanceTemplate();
dirt->SetInternalFieldCount(DirHandle::kInternalFieldCount);
Local<String> handleString =
FIXED_ONE_BYTE_STRING(isolate, "DirHandle");
dir->SetClassName(handleString);
target
->Set(context, handleString,
dir->GetFunction(env->context()).ToLocalChecked())
.FromJust();
env->set_dir_instance_template(dirt);
}
} // namespace fs_dir
} // end namespace node
NODE_MODULE_CONTEXT_AWARE_INTERNAL(fs_dir, node::fs_dir::Initialize)