node_internals.h

// 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.

#ifndef SRC_NODE_INTERNALS_H_
#define SRC_NODE_INTERNALS_H_

#if defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS

#include "env-inl.h"
#include "node.h"
#include "node_binding.h"
#include "node_mutex.h"
#include "node_persistent.h"
#include "tracing/trace_event.h"
#include "util-inl.h"
#include "uv.h"
#include "v8.h"

#include <stdint.h>
#include <stdlib.h>

#include <string>
#include <vector>

// Custom constants used by both node_constants.cc and node_zlib.cc
#define Z_MIN_WINDOWBITS 8
#define Z_MAX_WINDOWBITS 15
#define Z_DEFAULT_WINDOWBITS 15
// Fewer than 64 bytes per chunk is not recommended.
// Technically it could work with as few as 8, but even 64 bytes
// is low.  Usually a MB or more is best.
#define Z_MIN_CHUNK 64
#define Z_MAX_CHUNK std::numeric_limits<double>::infinity()
#define Z_DEFAULT_CHUNK (16 * 1024)
#define Z_MIN_MEMLEVEL 1
#define Z_MAX_MEMLEVEL 9
#define Z_DEFAULT_MEMLEVEL 8
#define Z_MIN_LEVEL -1
#define Z_MAX_LEVEL 9
#define Z_DEFAULT_LEVEL Z_DEFAULT_COMPRESSION

struct sockaddr;

// Variation on NODE_DEFINE_CONSTANT that sets a String value.
#define NODE_DEFINE_STRING_CONSTANT(target, name, constant)                   \
  do {                                                                        \
    v8::Isolate* isolate = target->GetIsolate();                              \
    v8::Local<v8::String> constant_name =                                     \
        v8::String::NewFromUtf8(isolate, name, v8::NewStringType::kNormal)    \
            .ToLocalChecked();                                                \
    v8::Local<v8::String> constant_value =                                    \
        v8::String::NewFromUtf8(isolate, constant, v8::NewStringType::kNormal)\
            .ToLocalChecked();                                                \
    v8::PropertyAttribute constant_attributes =                               \
        static_cast<v8::PropertyAttribute>(v8::ReadOnly | v8::DontDelete);    \
    target->DefineOwnProperty(isolate->GetCurrentContext(),                   \
                              constant_name,                                  \
                              constant_value,                                 \
                              constant_attributes).FromJust();                \
  } while (0)

namespace node {

namespace native_module {
class NativeModuleLoader;
}

extern Mutex process_mutex;
extern Mutex environ_mutex;

// Tells whether it is safe to call v8::Isolate::GetCurrent().
extern bool v8_initialized;

extern Mutex per_process_opts_mutex;
extern std::shared_ptr<PerProcessOptions> per_process_opts;

// Forward declaration
class Environment;

// Convert a struct sockaddr to a { address: '1.2.3.4', port: 1234 } JS object.
// Sets address and port properties on the info object and returns it.
// If |info| is omitted, a new object is returned.
v8::Local<v8::Object> AddressToJS(
    Environment* env,
    const sockaddr* addr,
    v8::Local<v8::Object> info = v8::Local<v8::Object>());

template <typename T, int (*F)(const typename T::HandleType*, sockaddr*, int*)>
void GetSockOrPeerName(const v8::FunctionCallbackInfo<v8::Value>& args) {
  T* wrap;
  ASSIGN_OR_RETURN_UNWRAP(&wrap,
                          args.Holder(),
                          args.GetReturnValue().Set(UV_EBADF));
  CHECK(args[0]->IsObject());
  sockaddr_storage storage;
  int addrlen = sizeof(storage);
  sockaddr* const addr = reinterpret_cast<sockaddr*>(&storage);
  const int err = F(&wrap->handle_, addr, &addrlen);
  if (err == 0)
    AddressToJS(wrap->env(), addr, args[0].As<v8::Object>());
  args.GetReturnValue().Set(err);
}

void Exit(const v8::FunctionCallbackInfo<v8::Value>& args);
void SignalExit(int signo);
#ifdef __POSIX__
void RegisterSignalHandler(int signal,
                           void (*handler)(int signal),
                           bool reset_handler = false);
#endif

v8::Local<v8::Object> CreateEnvVarProxy(v8::Local<v8::Context> context,
                                        v8::Isolate* isolate,
                                        v8::Local<v8::Value> data);

std::string GetHumanReadableProcessName();
void GetHumanReadableProcessName(char (*name)[1024]);

template <typename T, size_t N>
constexpr size_t arraysize(const T(&)[N]) { return N; }

#ifndef ROUND_UP
# define ROUND_UP(a, b) ((a) % (b) ? ((a) + (b)) - ((a) % (b)) : (a))
#endif

#ifdef __GNUC__
# define MUST_USE_RESULT __attribute__((warn_unused_result))
#else
# define MUST_USE_RESULT
#endif

class SlicedArguments {
 public:
  inline explicit SlicedArguments(
      const v8::FunctionCallbackInfo<v8::Value>& args,
      size_t start = 0);
  inline size_t size() const { return size_; }
  inline v8::Local<v8::Value>* data() { return data_; }

 private:
  size_t size_;
  v8::Local<v8::Value>* data_;
  v8::Local<v8::Value> fixed_[64];
  std::vector<v8::Local<v8::Value>> dynamic_;
};

SlicedArguments::SlicedArguments(
    const v8::FunctionCallbackInfo<v8::Value>& args,
    size_t start) : size_(0), data_(fixed_) {
  const size_t length = static_cast<size_t>(args.Length());
  if (start >= length) return;
  const size_t size = length - start;

  if (size > arraysize(fixed_)) {
    dynamic_.resize(size);
    data_ = dynamic_.data();
  }

  for (size_t i = 0; i < size; ++i)
    data_[i] = args[i + start];

  size_ = size;
}

namespace task_queue {
void PromiseRejectCallback(v8::PromiseRejectMessage message);
}  // namespace task_queue

v8::Maybe<bool> ProcessEmitWarning(Environment* env, const char* fmt, ...);
v8::Maybe<bool> ProcessEmitDeprecationWarning(Environment* env,
                                              const char* warning,
                                              const char* deprecation_code);

void SetupProcessObject(Environment* env,
                        const std::vector<std::string>& args,
                        const std::vector<std::string>& exec_args);

enum Endianness {
  kLittleEndian,  // _Not_ LITTLE_ENDIAN, clashes with endian.h.
  kBigEndian
};

inline enum Endianness GetEndianness() {
  // Constant-folded by the compiler.
  const union {
    uint8_t u8[2];
    uint16_t u16;
  } u = {
    { 1, 0 }
  };
  return u.u16 == 1 ? kLittleEndian : kBigEndian;
}

inline bool IsLittleEndian() {
  return GetEndianness() == kLittleEndian;
}

inline bool IsBigEndian() {
  return GetEndianness() == kBigEndian;
}

class ArrayBufferAllocator : public v8::ArrayBuffer::Allocator {
 public:
  inline uint32_t* zero_fill_field() { return &zero_fill_field_; }

  virtual void* Allocate(size_t size);  // Defined in src/node.cc
  virtual void* AllocateUninitialized(size_t size)
    { return node::UncheckedMalloc(size); }
  virtual void Free(void* data, size_t) { free(data); }

 private:
  uint32_t zero_fill_field_ = 1;  // Boolean but exposed as uint32 to JS land.
};

namespace Buffer {
v8::MaybeLocal<v8::Object> Copy(Environment* env, const char* data, size_t len);
v8::MaybeLocal<v8::Object> New(Environment* env, size_t size);
// Takes ownership of |data|.
v8::MaybeLocal<v8::Object> New(Environment* env,
                               char* data,
                               size_t length,
                               void (*callback)(char* data, void* hint),
                               void* hint);
// Takes ownership of |data|.  Must allocate |data| with malloc() or realloc()
// because ArrayBufferAllocator::Free() deallocates it again with free().
// Mixing operator new and free() is undefined behavior so don't do that.
v8::MaybeLocal<v8::Object> New(Environment* env, char* data, size_t length);

inline
v8::MaybeLocal<v8::Uint8Array> New(Environment* env,
                                   v8::Local<v8::ArrayBuffer> ab,
                                   size_t byte_offset,
                                   size_t length) {
  v8::Local<v8::Uint8Array> ui = v8::Uint8Array::New(ab, byte_offset, length);
  v8::Maybe<bool> mb =
      ui->SetPrototype(env->context(), env->buffer_prototype_object());
  if (mb.IsNothing())
    return v8::MaybeLocal<v8::Uint8Array>();
  return ui;
}

// Construct a Buffer from a MaybeStackBuffer (and also its subclasses like
// Utf8Value and TwoByteValue).
// If |buf| is invalidated, an empty MaybeLocal is returned, and nothing is
// changed.
// If |buf| contains actual data, this method takes ownership of |buf|'s
// underlying buffer. However, |buf| itself can be reused even after this call,
// but its capacity, if increased through AllocateSufficientStorage, is not
// guaranteed to stay the same.
template <typename T>
static v8::MaybeLocal<v8::Object> New(Environment* env,
                                      MaybeStackBuffer<T>* buf) {
  v8::MaybeLocal<v8::Object> ret;
  char* src = reinterpret_cast<char*>(buf->out());
  const size_t len_in_bytes = buf->length() * sizeof(buf->out()[0]);

  if (buf->IsAllocated())
    ret = New(env, src, len_in_bytes);
  else if (!buf->IsInvalidated())
    ret = Copy(env, src, len_in_bytes);

  if (ret.IsEmpty())
    return ret;

  if (buf->IsAllocated())
    buf->Release();

  return ret;
}
}  // namespace Buffer

v8::MaybeLocal<v8::Value> InternalMakeCallback(
    Environment* env,
    v8::Local<v8::Object> recv,
    const v8::Local<v8::Function> callback,
    int argc,
    v8::Local<v8::Value> argv[],
    async_context asyncContext);

class InternalCallbackScope {
 public:
  // Tell the constructor whether its `object` parameter may be empty or not.
  enum ResourceExpectation { kRequireResource, kAllowEmptyResource };
  InternalCallbackScope(Environment* env,
                        v8::Local<v8::Object> object,
                        const async_context& asyncContext,
                        ResourceExpectation expect = kRequireResource);
  // Utility that can be used by AsyncWrap classes.
  explicit InternalCallbackScope(AsyncWrap* async_wrap);
  ~InternalCallbackScope();
  void Close();

  inline bool Failed() const { return failed_; }
  inline void MarkAsFailed() { failed_ = true; }

 private:
  Environment* env_;
  async_context async_context_;
  v8::Local<v8::Object> object_;
  Environment::AsyncCallbackScope callback_scope_;
  bool failed_ = false;
  bool pushed_ids_ = false;
  bool closed_ = false;
};

class ThreadPoolWork {
 public:
  explicit inline ThreadPoolWork(Environment* env) : env_(env) {
    CHECK_NOT_NULL(env);
  }
  inline virtual ~ThreadPoolWork() = default;

  inline void ScheduleWork();
  inline int CancelWork();

  virtual void DoThreadPoolWork() = 0;
  virtual void AfterThreadPoolWork(int status) = 0;

 private:
  Environment* env_;
  uv_work_t work_req_;
};

void ThreadPoolWork::ScheduleWork() {
  env_->IncreaseWaitingRequestCounter();
  int status = uv_queue_work(
      env_->event_loop(),
      &work_req_,
      [](uv_work_t* req) {
        ThreadPoolWork* self = ContainerOf(&ThreadPoolWork::work_req_, req);
        self->DoThreadPoolWork();
      },
      [](uv_work_t* req, int status) {
        ThreadPoolWork* self = ContainerOf(&ThreadPoolWork::work_req_, req);
        self->env_->DecreaseWaitingRequestCounter();
        self->AfterThreadPoolWork(status);
      });
  CHECK_EQ(status, 0);
}

int ThreadPoolWork::CancelWork() {
  return uv_cancel(reinterpret_cast<uv_req_t*>(&work_req_));
}

tracing::AgentWriterHandle* GetTracingAgentWriter();
void DisposePlatform();

#define TRACING_CATEGORY_NODE "node"
#define TRACING_CATEGORY_NODE1(one)                                           \
    TRACING_CATEGORY_NODE ","                                                 \
    TRACING_CATEGORY_NODE "." #one
#define TRACING_CATEGORY_NODE2(one, two)                                      \
    TRACING_CATEGORY_NODE ","                                                 \
    TRACING_CATEGORY_NODE "." #one ","                                        \
    TRACING_CATEGORY_NODE "." #one "." #two

// Functions defined in node.cc that are exposed via the bootstrapper object

extern double prog_start_time;

void RawDebug(const v8::FunctionCallbackInfo<v8::Value>& args);

void DebugPortGetter(v8::Local<v8::Name> property,
                     const v8::PropertyCallbackInfo<v8::Value>& info);
void DebugPortSetter(v8::Local<v8::Name> property,
                     v8::Local<v8::Value> value,
                     const v8::PropertyCallbackInfo<void>& info);

void GetParentProcessId(v8::Local<v8::Name> property,
                        const v8::PropertyCallbackInfo<v8::Value>& info);

void ProcessTitleGetter(v8::Local<v8::Name> property,
                        const v8::PropertyCallbackInfo<v8::Value>& info);
void ProcessTitleSetter(v8::Local<v8::Name> property,
                        v8::Local<v8::Value> value,
                        const v8::PropertyCallbackInfo<void>& info);

#if defined(__POSIX__) && !defined(__ANDROID__) && !defined(__CloudABI__)
#define NODE_IMPLEMENTS_POSIX_CREDENTIALS 1
#endif  // __POSIX__ && !defined(__ANDROID__) && !defined(__CloudABI__)

namespace credentials {
bool SafeGetenv(const char* key, std::string* text);
}  // namespace credentials

void DefineZlibConstants(v8::Local<v8::Object> target);

}  // namespace node

#endif  // defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS

#endif  // SRC_NODE_INTERNALS_H_