Alby's blog

世上没有巧合，只有巧合的假象。

0%

Libuv 源码分析(4):数据结构—枚举( enum )

发表于 更新于 分类于

一、概述

Libuv 定义了若干枚举，本文集中列出方便查询( 针对 Windows 平台的枚举未完全列出)。这些枚举主要定义在如下文件：
include/uv.h
include/uv-common.h
src/unix/internal.h
src/unix/fsevents.c ( Darwin )
src/win/tty.c ( Windows )
src/win/winapi.h ( Windows )

二、用于声明枚举的映射( Map )的宏

主要目的是方便维护、减少出错几率和减少代码量。
UV_ERRNO_MAP ：映射错误号和错误消息。用在 uv_strerror 和 uv_err_name 函数。
UV_HANDLE_TYPE_MAP ：映射 Handles 类型。
UV_REQ_TYPE_MAP ：映射 Requests 类型。

注：映射宏一般配合命名为 “XX” 的临时宏使用。

三、include/uv.h

1、uv_errno_t ：错误号

1
2
3
4
5
6
typedef enum {
#define XX(code, _) UV_ ## code = UV__ ## code,
  UV_ERRNO_MAP(XX)
#undef XX
  UV_ERRNO_MAX = UV__EOF - 1
} uv_errno_t;

2、uv_handle_type ：Handle 类型

1
2
3
4
5
6
7
8
typedef enum {
  UV_UNKNOWN_HANDLE = 0,
#define XX(uc, lc) UV_##uc,
  UV_HANDLE_TYPE_MAP(XX)
#undef XX
  UV_FILE,
  UV_HANDLE_TYPE_MAX
} uv_handle_type;

3、uv_req_type ：Request 类型

1
2
3
4
5
6
7
8
typedef enum {
  UV_UNKNOWN_REQ = 0,
#define XX(uc, lc) UV_##uc,
  UV_REQ_TYPE_MAP(XX)
#undef XX
  UV_REQ_TYPE_PRIVATE
  UV_REQ_TYPE_MAX
} uv_req_type;

4、uv_loop_option ：Loop 选项

1
2
3
typedef enum {
  UV_LOOP_BLOCK_SIGNAL
} uv_loop_option;

5、uv_run_mode ：Loop 运行模式

1
2
3
4
5
typedef enum {
  UV_RUN_DEFAULT = 0,
  UV_RUN_ONCE,
  UV_RUN_NOWAIT
} uv_run_mode;

6、uv_membership ：UDP socket 组播选项

1
2
3
4
typedef enum {
  UV_LEAVE_GROUP = 0,
  UV_JOIN_GROUP
} uv_membership;

7、uv_tcp_flags ：TCP socket 标记

1
2
3
4
enum uv_tcp_flags {
  /* Used with uv_tcp_bind, when an IPv6 address is used. */
  UV_TCP_IPV6ONLY = 1
};

8、uv_udp_flags ：UDP socket 标记

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
enum uv_udp_flags {
  /* Disables dual stack mode. */
  UV_UDP_IPV6ONLY = 1,
  /*
   * Indicates message was truncated because read buffer was too small. The
   * remainder was discarded by the OS. Used in uv_udp_recv_cb.
   */
  UV_UDP_PARTIAL = 2,
  /*
   * Indicates if SO_REUSEADDR will be set when binding the handle.
   * This sets the SO_REUSEPORT socket flag on the BSDs and OS X. On other
   * UNIX platforms, it sets the SO_REUSEADDR flag.  What that means is that
   * multiple threads or processes can bind to the same address without error
   * (provided they all set the flag) but only the last one to bind will receive
   * any traffic, in effect "stealing" the port from the previous listener.
   */
  UV_UDP_REUSEADDR = 4
};

9、uv_tty_mode_t ：tty 模式

1
2
3
4
5
6
7
8
typedef enum {
  /* Initial/normal terminal mode */
  UV_TTY_MODE_NORMAL,
  /* Raw input mode (On Windows, ENABLE_WINDOW_INPUT is also enabled) */
  UV_TTY_MODE_RAW,
  /* Binary-safe I/O mode for IPC (UNIX-only) */
  UV_TTY_MODE_IO
} uv_tty_mode_t;

10、poll 事件

1
2
3
4
5
enum uv_poll_event {
  UV_READABLE = 1,
  UV_WRITABLE = 2,
  UV_DISCONNECT = 4
};

11、uv_stdio_flags ：标准 IO 标记

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
/* uv_spawn() options. */
typedef enum {
  UV_IGNORE         = 0x00,
  UV_CREATE_PIPE    = 0x01,
  UV_INHERIT_FD     = 0x02,
  UV_INHERIT_STREAM = 0x04,

  /*
   * When UV_CREATE_PIPE is specified, UV_READABLE_PIPE and UV_WRITABLE_PIPE
   * determine the direction of flow, from the child process' perspective. Both
   * flags may be specified to create a duplex data stream.
   */
  UV_READABLE_PIPE  = 0x10,
  UV_WRITABLE_PIPE  = 0x20
} uv_stdio_flags;

12、uv_process_flags ：进程标记

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
/*
 * These are the flags that can be used for the uv_process_options.flags field.
 */
enum uv_process_flags {
  /*
   * Set the child process' user id. The user id is supplied in the `uid` field
   * of the options struct. This does not work on windows; setting this flag
   * will cause uv_spawn() to fail.
   */
  UV_PROCESS_SETUID = (1 << 0),
  /*
   * Set the child process' group id. The user id is supplied in the `gid`
   * field of the options struct. This does not work on windows; setting this
   * flag will cause uv_spawn() to fail.
   */
  UV_PROCESS_SETGID = (1 << 1),
  /*
   * Do not wrap any arguments in quotes, or perform any other escaping, when
   * converting the argument list into a command line string. This option is
   * only meaningful on Windows systems. On UNIX it is silently ignored.
   */
  UV_PROCESS_WINDOWS_VERBATIM_ARGUMENTS = (1 << 2),
  /*
   * Spawn the child process in a detached state - this will make it a process
   * group leader, and will effectively enable the child to keep running after
   * the parent exits.  Note that the child process will still keep the
   * parent's event loop alive unless the parent process calls uv_unref() on
   * the child's process handle.
   */
  UV_PROCESS_DETACHED = (1 << 3),
  /*
   * Hide the subprocess console window that would normally be created. This
   * option is only meaningful on Windows systems. On UNIX it is silently
   * ignored.
   */
  UV_PROCESS_WINDOWS_HIDE = (1 << 4)
};

13、uv_dirent_type_t ：dirent 结构中的文件类型字段映射

1
2
3
4
5
6
7
8
9
10
typedef enum {
  UV_DIRENT_UNKNOWN,
  UV_DIRENT_FILE,
  UV_DIRENT_DIR,
  UV_DIRENT_LINK,
  UV_DIRENT_FIFO,
  UV_DIRENT_SOCKET,
  UV_DIRENT_CHAR,
  UV_DIRENT_BLOCK
} uv_dirent_type_t;

14、uv_fs_type ：文件系统操作类型

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
typedef enum {
  UV_FS_UNKNOWN = -1,
  UV_FS_CUSTOM,
  UV_FS_OPEN,
  UV_FS_CLOSE,
  UV_FS_READ,
  UV_FS_WRITE,
  UV_FS_SENDFILE,
  UV_FS_STAT,
  UV_FS_LSTAT,
  UV_FS_FSTAT,
  UV_FS_FTRUNCATE,
  UV_FS_UTIME,
  UV_FS_FUTIME,
  UV_FS_ACCESS,
  UV_FS_CHMOD,
  UV_FS_FCHMOD,
  UV_FS_FSYNC,
  UV_FS_FDATASYNC,
  UV_FS_UNLINK,
  UV_FS_RMDIR,
  UV_FS_MKDIR,
  UV_FS_MKDTEMP,
  UV_FS_RENAME,
  UV_FS_SCANDIR,
  UV_FS_LINK,
  UV_FS_SYMLINK,
  UV_FS_READLINK,
  UV_FS_CHOWN,
  UV_FS_FCHOWN,
  UV_FS_REALPATH
} uv_fs_type;

15、uv_fs_event ：文件系统事件

1
2
3
4
enum uv_fs_event {
  UV_RENAME = 1,
  UV_CHANGE = 2
};

16、uv_fs_event_flags ：文件系统事件处理标记

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
/*
 * Flags to be passed to uv_fs_event_start().
 */
enum uv_fs_event_flags {
  /*
   * By default, if the fs event watcher is given a directory name, we will
   * watch for all events in that directory. This flags overrides this behavior
   * and makes fs_event report only changes to the directory entry itself. This
   * flag does not affect individual files watched.
   * This flag is currently not implemented yet on any backend.
   */
  UV_FS_EVENT_WATCH_ENTRY = 1,

  /*
   * By default uv_fs_event will try to use a kernel interface such as inotify
   * or kqueue to detect events. This may not work on remote filesystems such
   * as NFS mounts. This flag makes fs_event fall back to calling stat() on a
   * regular interval.
   * This flag is currently not implemented yet on any backend.
   */
  UV_FS_EVENT_STAT = 2,

  /*
   * By default, event watcher, when watching directory, is not registering
   * (is ignoring) changes in it's subdirectories.
   * This flag will override this behaviour on platforms that support it.
   */
  UV_FS_EVENT_RECURSIVE = 4
};

目前仅在 macOS 和 Windows 使用了 UV_FS_EVENT_RECURSIVE 标记。

四、include/uv-common.h

1、Handle 标记

1
2
3
4
5
6
7
8
9
10
11
12
13
#ifndef _WIN32
enum {
  UV__HANDLE_INTERNAL = 0x8000,
  UV__HANDLE_ACTIVE   = 0x4000,
  UV__HANDLE_REF      = 0x2000,
  UV__HANDLE_CLOSING  = 0 /* no-op on unix */
};
#else
# define UV__HANDLE_INTERNAL  0x80
# define UV__HANDLE_ACTIVE    0x40
# define UV__HANDLE_REF       0x20
# define UV__HANDLE_CLOSING   0x01
#endif

五、src/unix/internal.h

1、Handle 标记

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
/* handle flags */
enum {
  UV_CLOSING              = 0x01,   /* uv_close() called but not finished. */
  UV_CLOSED               = 0x02,   /* close(2) finished. */
  UV_STREAM_READING       = 0x04,   /* uv_read_start() called. */
  UV_STREAM_SHUTTING      = 0x08,   /* uv_shutdown() called but not complete. */
  UV_STREAM_SHUT          = 0x10,   /* Write side closed. */
  UV_STREAM_READABLE      = 0x20,   /* The stream is readable */
  UV_STREAM_WRITABLE      = 0x40,   /* The stream is writable */
  UV_STREAM_BLOCKING      = 0x80,   /* Synchronous writes. */
  UV_STREAM_READ_PARTIAL  = 0x100,  /* read(2) read less than requested. */
  UV_STREAM_READ_EOF      = 0x200,  /* read(2) read EOF. */
  UV_TCP_NODELAY          = 0x400,  /* Disable Nagle. */
  UV_TCP_KEEPALIVE        = 0x800,  /* Turn on keep-alive. */
  UV_TCP_SINGLE_ACCEPT    = 0x1000, /* Only accept() when idle. */
  UV_HANDLE_IPV6          = 0x10000, /* Handle is bound to a IPv6 socket. */
  UV_UDP_PROCESSING       = 0x20000  /* Handle is running the send callback queue. */
};

2、Loop 标记

1
2
3
4
/* loop flags */
enum {
  UV_LOOP_BLOCK_SIGPROF = 1
};

3、uv_clocktype_t ：时钟类型

1
2
3
4
typedef enum {
  UV_CLOCK_PRECISE = 0,  /* Use the highest resolution clock available. */
  UV_CLOCK_FAST = 1      /* Use the fastest clock with <= 1ms granularity. */
} uv_clocktype_t;

六、include/fsevents.c ( Darwin )

1、uv__cf_loop_signal_type_t ：Core Foundation 事件循环信号类型

1
2
3
4
5
enum uv__cf_loop_signal_type_e {
  kUVCFLoopSignalRegular,
  kUVCFLoopSignalClosing
};
typedef enum uv__cf_loop_signal_type_e uv__cf_loop_signal_type_t;

七、Windows

1、_FS_INFORMATION_CLASS

1
2
3
4
5
6
7
8
9
10
11
12
13
typedef enum _FS_INFORMATION_CLASS {
  FileFsVolumeInformation       = 1,
  FileFsLabelInformation        = 2,
  FileFsSizeInformation         = 3,
  FileFsDeviceInformation       = 4,
  FileFsAttributeInformation    = 5,
  FileFsControlInformation      = 6,
  FileFsFullSizeInformation     = 7,
  FileFsObjectIdInformation     = 8,
  FileFsDriverPathInformation   = 9,
  FileFsVolumeFlagsInformation  = 10,
  FileFsSectorSizeInformation   = 11
} FS_INFORMATION_CLASS, *PFS_INFORMATION_CLASS;

2、uv__read_console_status_e

1
2
3
4
5
6
enum uv__read_console_status_e {
  NOT_STARTED,
  IN_PROGRESS,
  TRAP_REQUESTED,
  COMPLETED
};