static const unsigned int kBufferSize = 65536;

public:

inline SyncProcessOutputBuffer();

inline void OnAlloc(size_t suggested_size, uv_buf_t* buf) const;

inline void OnRead(const uv_buf_t* buf, size_t nread);

inline size_t Copy(char* dest) const;

inline unsigned int available() const;

inline unsigned int used() const;

inline SyncProcessOutputBuffer* next() const;

inline void set_next(SyncProcessOutputBuffer* next);

private:

// Use unsigned int because that's what `uv_buf_init` takes.

mutable char data_[kBufferSize];

unsigned int used_;

SyncProcessOutputBuffer* next_;

enum Lifecycle {

kUninitialized = 0,

kInitialized,

kStarted,

kClosing,

kClosed

};

public:

SyncProcessStdioPipe(SyncProcessRunner* process_handler,

bool readable,

bool writable,

uv_buf_t input_buffer);

~SyncProcessStdioPipe();

int Initialize(uv_loop_t* loop);

int Start();

void Close();

Local<Object> GetOutputAsBuffer(Environment* env) const;

inline bool readable() const;

inline bool writable() const;

inline uv_stdio_flags uv_flags() const;

inline uv_pipe_t* uv_pipe() const;

inline uv_stream_t* uv_stream() const;

inline uv_handle_t* uv_handle() const;

private:

inline size_t OutputLength() const;

inline void CopyOutput(char* dest) const;

inline void OnAlloc(size_t suggested_size, uv_buf_t* buf);

inline void OnRead(const uv_buf_t* buf, ssize_t nread);

inline void OnWriteDone(int result);

inline void OnShutdownDone(int result);

inline void OnClose();

inline void SetError(int error);

static void AllocCallback(uv_handle_t* handle,

size_t suggested_size,

uv_buf_t* buf);

static void ReadCallback(uv_stream_t* stream,

ssize_t nread,

const uv_buf_t* buf);

static void WriteCallback(uv_write_t* req, int result);

static void ShutdownCallback(uv_shutdown_t* req, int result);

static void CloseCallback(uv_handle_t* handle);

SyncProcessRunner* process_handler_;

bool readable_;

bool writable_;

uv_buf_t input_buffer_;

SyncProcessOutputBuffer* first_output_buffer_;

SyncProcessOutputBuffer* last_output_buffer_;

mutable uv_pipe_t uv_pipe_;

uv_write_t write_req_;

uv_shutdown_t shutdown_req_;

Lifecycle lifecycle_;

enum Lifecycle {

kUninitialized = 0,

kInitialized,

kHandlesClosed

};

public:

static void Initialize(Local<Object> target,

Local<Value> unused,

Local<Context> context);

static void Spawn(const FunctionCallbackInfo<Value>& args);

private:

friend class SyncProcessStdioPipe;

explicit SyncProcessRunner(Environment* env_);

~SyncProcessRunner();

inline Environment* env() const;

Local<Object> Run(Local<Value> options);

void TryInitializeAndRunLoop(Local<Value> options);

void CloseHandlesAndDeleteLoop();

void CloseStdioPipes();

void CloseKillTimer();

void Kill();

void IncrementBufferSizeAndCheckOverflow(ssize_t length);

void OnExit(int64_t exit_status, int term_signal);

void OnKillTimerTimeout();

int GetError();

void SetError(int error);

void SetPipeError(int pipe_error);

Local<Object> BuildResultObject();

Local<Array> BuildOutputArray();

int ParseOptions(Local<Value> js_value);

int ParseStdioOptions(Local<Value> js_value);

int ParseStdioOption(int child_fd, Local<Object> js_stdio_option);

inline int AddStdioIgnore(uint32_t child_fd);

inline int AddStdioPipe(uint32_t child_fd,

bool readable,

bool writable,

uv_buf_t input_buffer);

inline int AddStdioInheritFD(uint32_t child_fd, int inherit_fd);

static bool IsSet(Local<Value> value);

template <typename t> static bool CheckRange(Local<Value> js_value);

int CopyJsString(Local<Value> js_value, const char** target);

int CopyJsStringArray(Local<Value> js_value, char** target);

static void ExitCallback(uv_process_t* handle,

int64_t exit_status,

int term_signal);

static void KillTimerCallback(uv_timer_t* handle);

static void KillTimerCloseCallback(uv_handle_t* handle);

size_t max_buffer_;

uint64_t timeout_;

int kill_signal_;

uv_loop_t* uv_loop_;

uint32_t stdio_count_;

uv_stdio_container_t* uv_stdio_containers_;

SyncProcessStdioPipe** stdio_pipes_;

bool stdio_pipes_initialized_;

uv_process_options_t uv_process_options_;

const char* file_buffer_;

char* args_buffer_;

char* env_buffer_;

const char* cwd_buffer_;

uv_process_t uv_process_;

bool killed_;

size_t buffered_output_size_;

int64_t exit_status_;

int term_signal_;

uv_timer_t uv_timer_;

bool kill_timer_initialized_;

// Errors that happen in one of the pipe handlers are stored in the

// `pipe_error` field. They are treated as "low-priority", only to be

// reported if no more serious errors happened.

int error_;

int pipe_error_;

Lifecycle lifecycle_;

Environment* env_;