text: // 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.h"
  #include "node.h"
  #include "node_binding.h"
  #include "node_mutex.h"
  #include "tracing/trace_event.h"
  #include "util.h"
  #include "uv.h"
  #include "v8.h"
  
  #include <cstdint>
  #include <cstdlib>
  
  #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
  
  struct sockaddr;
  
  namespace node {
  
  namespace native_module {
  class NativeModuleLoader;
  }
  
  namespace per_process {
  extern Mutex env_var_mutex;
  extern uint64_t node_start_time;
  }  // namespace per_process
  
  // 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 PrintStackTrace(v8::Isolate* isolate, v8::Local<v8::StackTrace> stack);
  void PrintCaughtException(v8::Isolate* isolate,
                            v8::Local<v8::Context> context,
                            const v8::TryCatch& try_catch);
  
  void ResetStdio();  // Safe to call more than once and from signal handlers.
  #ifdef __POSIX__
  void SignalExit(int signal, siginfo_t* info, void* ucontext);
  #endif
  
  std::string GetProcessTitle(const char* default_title);
  std::string GetHumanReadableProcessName();
  
  void InitializeContextRuntime(v8::Local<v8::Context>);
  bool InitializePrimordials(v8::Local<v8::Context> context);
  
  class NodeArrayBufferAllocator : public ArrayBufferAllocator {
   public:
    inline uint32_t* zero_fill_field() { return &zero_fill_field_; }
  
    void* Allocate(size_t size) override;  // Defined in src/node.cc
    void* AllocateUninitialized(size_t size) override;
    void Free(void* data, size_t size) override;
    void* Reallocate(void* data, size_t old_size, size_t size) override;
    virtual void RegisterPointer(void* data, size_t size) {
      total_mem_usage_.fetch_add(size, std::memory_order_relaxed);
    }
    virtual void UnregisterPointer(void* data, size_t size) {
      total_mem_usage_.fetch_sub(size, std::memory_order_relaxed);
    }
  
    NodeArrayBufferAllocator* GetImpl() final { return this; }
    inline uint64_t total_mem_usage() const {
      return total_mem_usage_.load(std::memory_order_relaxed);
    }
  
   private:
    uint32_t zero_fill_field_ = 1;  // Boolean but exposed as uint32 to JS land.
    std::atomic<size_t> total_mem_usage_ {0};
  };
  
  class DebuggingArrayBufferAllocator final : public NodeArrayBufferAllocator {
   public:
    ~DebuggingArrayBufferAllocator() override;
    void* Allocate(size_t size) override;
    void* AllocateUninitialized(size_t size) override;
    void Free(void* data, size_t size) override;
    void* Reallocate(void* data, size_t old_size, size_t size) override;
    void RegisterPointer(void* data, size_t size) override;
    void UnregisterPointer(void* data, size_t size) override;
  
   private:
    void RegisterPointerInternal(void* data, size_t size);
    void UnregisterPointerInternal(void* data, size_t size);
    Mutex mutex_;
    std::unordered_map<void*, size_t> allocations_;
  };
  
  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 the current Isolate's
  // ArrayBuffer::Allocator().
  v8::MaybeLocal<v8::Object> New(Environment* env,
                                 char* data,
                                 size_t length);
  // Creates a Buffer instance over an existing ArrayBuffer.
  v8::MaybeLocal<v8::Uint8Array> New(Environment* env,
                                     v8::Local<v8::ArrayBuffer> ab,
                                     size_t byte_offset,
                                     size_t length);
  // 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> resource,
      v8::Local<v8::Object> recv,
      const v8::Local<v8::Function> callback,
      int argc,
      v8::Local<v8::Value> argv[],
      async_context asyncContext);
  
  v8::MaybeLocal<v8::Value> MakeSyncCallback(v8::Isolate* isolate,
                                             v8::Local<v8::Object> recv,
                                             v8::Local<v8::Function> callback,
                                             int argc,
                                             v8::Local<v8::Value> argv[]);
  
  class InternalCallbackScope {
   public:
    enum Flags {
      kNoFlags = 0,
      // Indicates whether 'before' and 'after' hooks should be skipped.
      kSkipAsyncHooks = 1,
      // Indicates whether nextTick and microtask queues should be skipped.
      // This should only be used when there is no call into JS in this scope.
      // (The HTTP parser also uses it for some weird backwards
      // compatibility issues, but it shouldn't.)
      kSkipTaskQueues = 2
    };
    InternalCallbackScope(Environment* env,
                          v8::Local<v8::Object> object,
                          const async_context& asyncContext,
                          int flags = kNoFlags);
    // Utility that can be used by AsyncWrap classes.
    explicit InternalCallbackScope(AsyncWrap* async_wrap, int flags = 0);
    ~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_;
    bool skip_hooks_;
    bool skip_task_queues_;
    bool failed_ = false;
    bool pushed_ids_ = false;
    bool closed_ = false;
  };
  
  class DebugSealHandleScope {
   public:
    explicit inline DebugSealHandleScope(v8::Isolate* isolate = nullptr)
  #ifdef DEBUG
      : actual_scope_(isolate != nullptr ? isolate : v8::Isolate::GetCurrent())
  #endif
    {}
  
   private:
  #ifdef DEBUG
    v8::SealHandleScope actual_scope_;
  #endif
  };
  
  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;
  
    Environment* env() const { return env_; }
  
   private:
    Environment* env_;
    uv_work_t work_req_;
  };
  
  #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
  
  #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, Environment* env = nullptr);
  }  // namespace credentials
  
  void DefineZlibConstants(v8::Local<v8::Object> target);
  v8::Isolate* NewIsolate(v8::Isolate::CreateParams* params,
                          uv_loop_t* event_loop,
                          MultiIsolatePlatform* platform);
  // This overload automatically picks the right 'main_script_id' if no callback
  // was provided by the embedder.
  v8::MaybeLocal<v8::Value> StartExecution(Environment* env,
                                           StartExecutionCallback cb = nullptr);
  v8::MaybeLocal<v8::Object> GetPerContextExports(v8::Local<v8::Context> context);
  v8::MaybeLocal<v8::Value> ExecuteBootstrapper(
      Environment* env,
      const char* id,
      std::vector<v8::Local<v8::String>>* parameters,
      std::vector<v8::Local<v8::Value>>* arguments);
  void MarkBootstrapComplete(const v8::FunctionCallbackInfo<v8::Value>& args);
  
  struct InitializationResult {
    int exit_code = 0;
    std::vector<std::string> args;
    std::vector<std::string> exec_args;
    bool early_return = false;
  };
  InitializationResult InitializeOncePerProcess(int argc, char** argv);
  void TearDownOncePerProcess();
  void SetIsolateErrorHandlers(v8::Isolate* isolate, const IsolateSettings& s);
  void SetIsolateMiscHandlers(v8::Isolate* isolate, const IsolateSettings& s);
  void SetIsolateCreateParamsForNode(v8::Isolate::CreateParams* params);
  
  #if HAVE_INSPECTOR
  namespace profiler {
  void StartProfilers(Environment* env);
  }
  #endif  // HAVE_INSPECTOR
  
  #ifdef __POSIX__
  static constexpr unsigned kMaxSignal = 32;
  #endif
  
  bool HasSignalJSHandler(int signum);
  
  #ifdef _WIN32
  typedef SYSTEMTIME TIME_TYPE;
  #else  // UNIX, OSX
  typedef struct tm TIME_TYPE;
  #endif
  
  double GetCurrentTimeInMicroseconds();
  int WriteFileSync(const char* path, uv_buf_t buf);
  int WriteFileSync(v8::Isolate* isolate,
                    const char* path,
                    v8::Local<v8::String> string);
  
  class DiagnosticFilename {
   public:
    static void LocalTime(TIME_TYPE* tm_struct);
  
    inline DiagnosticFilename(Environment* env,
                              const char* prefix,
                              const char* ext);
  
    inline DiagnosticFilename(uint64_t thread_id,
                              const char* prefix,
                              const char* ext);
  
    inline const char* operator*() const;
  
   private:
    static std::string MakeFilename(
        uint64_t thread_id,
        const char* prefix,
        const char* ext);
  
    std::string filename_;
  };
  
  namespace heap {
  bool WriteSnapshot(v8::Isolate* isolate, const char* filename);
  }
  
  class TraceEventScope {
   public:
    TraceEventScope(const char* category,
                    const char* name,
                    void* id) : category_(category), name_(name), id_(id) {
      TRACE_EVENT_NESTABLE_ASYNC_BEGIN0(category_, name_, id_);
    }
    ~TraceEventScope() {
      TRACE_EVENT_NESTABLE_ASYNC_END0(category_, name_, id_);
    }
  
   private:
    const char* category_;
    const char* name_;
    void* id_;
  };
  
  namespace heap {
  
  void DeleteHeapSnapshot(const v8::HeapSnapshot* snapshot);
  using HeapSnapshotPointer =
    DeleteFnPtr<const v8::HeapSnapshot, DeleteHeapSnapshot>;
  
  BaseObjectPtr<AsyncWrap> CreateHeapSnapshotStream(
      Environment* env, HeapSnapshotPointer&& snapshot);
  }  // namespace heap
  
  namespace fs {
  std::string Basename(const std::string& str, const std::string& extension);
  }  // namespace fs
  
  node_module napi_module_to_node_module(const napi_module* mod);
  
  }  // namespace node
  
  #endif  // defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS
  
  #endif  // SRC_NODE_INTERNALS_H_
  