mswindows.c

Wget很好的处理了http和ftp的下载,很值得学习的经典代码

{
  xfree_null (title_buf);
  xfree_null (curr_url);
  title_buf = xmalloc (strlen (url) + 20);
  curr_url = xstrdup (url);
  old_percentage = -1;
  sprintf (title_buf, "Wget %s", curr_url);
  SetConsoleTitle (title_buf);
}

/* Updates the console title with the percentage of the current file
   transferred.  */
void
ws_percenttitle (double percentage_float)
{
  int percentage;

  if (!title_buf || !curr_url)
    return;

  percentage = (int) percentage_float;

  /* Clamp percentage value.  */
  if (percentage < 0)
    percentage = 0;
  if (percentage > 100)
    percentage = 100;

  /* Only update the title when the percentage has changed.  */
  if (percentage == old_percentage)
    return;

  old_percentage = percentage;

  sprintf (title_buf, "Wget [%d%%] %s", percentage, curr_url);
  SetConsoleTitle (title_buf);
}

/* Returns a pointer to the fully qualified name of the directory that
   contains the Wget binary (wget.exe).  The returned path does not have a
   trailing path separator.  Returns NULL on failure.  */
char *
ws_mypath (void)
{
  static char *wspathsave = NULL;

  if (!wspathsave)
    {
      char buf[MAX_PATH + 1];
      char *p;
      DWORD len;

      len = GetModuleFileName (GetModuleHandle (NULL), buf, sizeof (buf));
      if (!len || (len >= sizeof (buf)))
        return NULL;

      p = strrchr (buf, PATH_SEPARATOR);
      if (!p)
        return NULL;

      *p = '\0';
      wspathsave = xstrdup (buf);
    }

  return wspathsave;
}

/* Prevent Windows entering sleep/hibernation-mode while Wget is doing
   a lengthy transfer.  Windows does not, by default, consider network
   activity in console-programs as activity!  Works on Win-98/ME/2K
   and up.  */
static void
set_sleep_mode (void)
{
  typedef DWORD (WINAPI *func_t) (DWORD);
  func_t set_exec_state;

  set_exec_state =
      (func_t) GetProcAddress (GetModuleHandle ("KERNEL32.DLL"),
                               "SetThreadExecutionState");

  if (set_exec_state)
    set_exec_state (ES_SYSTEM_REQUIRED | ES_CONTINUOUS);
}

/* Perform Windows specific initialization.  */
void
ws_startup (void)
{
  WSADATA data;
  WORD requested = MAKEWORD (1, 1);
  int err = WSAStartup (requested, &data);
  if (err != 0)
    {
      fprintf (stderr, _("%s: Couldn't find usable socket driver.\n"),
               exec_name);
      exit (1);
    }

  if (data.wVersion < requested)
    {
      fprintf (stderr, _("%s: Couldn't find usable socket driver.\n"),
               exec_name);
      WSACleanup ();
      exit (1);
    }

  atexit (ws_cleanup);
  set_sleep_mode ();
  SetConsoleCtrlHandler (ws_handler, TRUE);
}

/* run_with_timeout Windows implementation.  */

/* Stack size 0 uses default thread stack-size (reserve+commit).
   Determined by what's in the PE header.  */
#define THREAD_STACK_SIZE  0

struct thread_data
{
  void (*fun) (void *);
  void *arg;
  DWORD ws_error;
};

/* The callback that runs FUN(ARG) in a separate thread.  This
   function exists for two reasons: a) to not require FUN to be
   declared WINAPI/__stdcall[1], and b) to retrieve Winsock errors,
   which are per-thread.  The latter is useful when FUN calls Winsock
   functions, which is how run_with_timeout is used in Wget.

   [1] MSVC can use __fastcall globally (cl /Gr) and on Watcom this is
   the default (wcc386 -3r).  */

static DWORD WINAPI
thread_helper (void *arg)
{
  struct thread_data *td = (struct thread_data *) arg;

  /* Initialize Winsock error to what it was in the parent.  That way
     the subsequent call to WSAGetLastError will return the same value
     if td->fun doesn't change Winsock error state.  */
  WSASetLastError (td->ws_error);

  td->fun (td->arg);

  /* Return Winsock error to the caller, in case FUN ran Winsock
     code.  */
  td->ws_error = WSAGetLastError ();
  return 0;
}

/* Call FUN(ARG), but don't allow it to run for more than TIMEOUT
   seconds.  Returns true if the function was interrupted with a
   timeout, false otherwise.

   This works by running FUN in a separate thread and terminating the
   thread if it doesn't finish in the specified time.  */

bool
run_with_timeout (double seconds, void (*fun) (void *), void *arg)
{
  HANDLE thread_hnd;
  struct thread_data thread_arg;
  DWORD thread_id;
  bool rc;

  DEBUGP (("seconds %.2f, ", seconds));

  if (seconds == 0)
    {
    blocking_fallback:
      fun (arg);
      return false;
    }

  thread_arg.fun = fun;
  thread_arg.arg = arg;
  thread_arg.ws_error = WSAGetLastError ();
  thread_hnd = CreateThread (NULL, THREAD_STACK_SIZE, thread_helper,
                             &thread_arg, 0, &thread_id);
  if (!thread_hnd)
    {
      DEBUGP (("CreateThread() failed; [%#lx]\n",
               (unsigned long) GetLastError ()));
      goto blocking_fallback;
    }

  if (WaitForSingleObject (thread_hnd, (DWORD)(1000 * seconds))
      == WAIT_OBJECT_0)
    {
      /* Propagate error state (which is per-thread) to this thread,
         so the caller can inspect it.  */
      WSASetLastError (thread_arg.ws_error);
      DEBUGP (("Winsock error: %d\n", WSAGetLastError ()));
      rc = false;
    }
  else
    {
      TerminateThread (thread_hnd, 1);
      rc = true;
    }

  CloseHandle (thread_hnd);     /* Clear-up after TerminateThread().  */
  thread_hnd = NULL;
  return rc;
}

/* Wget expects network calls such as connect, recv, send, etc., to set
   errno on failure.  To achieve that, Winsock calls are wrapped with code
   that, in case of error, sets errno to the value of WSAGetLastError().
   In addition, we provide a wrapper around strerror, which recognizes
   Winsock errors and prints the appropriate error message. */

/* Define a macro that creates a function definition that wraps FUN into
   a function that sets errno the way the rest of the code expects. */

#define WRAP(fun, decl, call) int wrapped_##fun decl {  \
  int retval = fun call;                                \
  if (retval < 0)                                       \
    errno = WSAGetLastError ();                         \
  return retval;                                        \
}

WRAP (socket, (int domain, int type, int protocol), (domain, type, protocol))
WRAP (bind, (int s, struct sockaddr *a, int alen), (s, a, alen))
WRAP (connect, (int s, const struct sockaddr *a, int alen), (s, a, alen))
WRAP (listen, (int s, int backlog), (s, backlog))
WRAP (accept, (int s, struct sockaddr *a, int *alen), (s, a, alen))
WRAP (recv, (int s, void *buf, int len, int flags), (s, buf, len, flags))
WRAP (send, (int s, const void *buf, int len, int flags), (s, buf, len, flags))
WRAP (select, (int n, fd_set *r, fd_set *w, fd_set *e, const struct timeval *tm),
              (n, r, w, e, tm))
WRAP (getsockname, (int s, struct sockaddr *n, int *nlen), (s, n, nlen))
WRAP (getpeername, (int s, struct sockaddr *n, int *nlen), (s, n, nlen))
WRAP (setsockopt, (int s, int level, int opt, const void *val, int len),
                  (s, level, opt, val, len))
WRAP (closesocket, (int s), (s))

/* Return the text of the error message for Winsock error WSERR. */

static const char *
get_winsock_error (int wserr)
{
  switch (wserr) {
  case WSAEINTR:           return "Interrupted system call";
  case WSAEBADF:           return "Bad file number";
  case WSAEACCES:          return "Permission denied";
  case WSAEFAULT:          return "Bad address";
  case WSAEINVAL:          return "Invalid argument";
  case WSAEMFILE:          return "Too many open files";
  case WSAEWOULDBLOCK:     return "Resource temporarily unavailable";
  case WSAEINPROGRESS:     return "Operation now in progress";
  case WSAEALREADY:        return "Operation already in progress";
  case WSAENOTSOCK:        return "Socket operation on nonsocket";
  case WSAEDESTADDRREQ:    return "Destination address required";
  case WSAEMSGSIZE:        return "Message too long";
  case WSAEPROTOTYPE:      return "Protocol wrong type for socket";
  case WSAENOPROTOOPT:     return "Bad protocol option";
  case WSAEPROTONOSUPPORT: return "Protocol not supported";
  case WSAESOCKTNOSUPPORT: return "Socket type not supported";
  case WSAEOPNOTSUPP:      return "Operation not supported";
  case WSAEPFNOSUPPORT:    return "Protocol family not supported";
  case WSAEAFNOSUPPORT:    return "Address family not supported by protocol family";
  case WSAEADDRINUSE:      return "Address already in use";
  case WSAEADDRNOTAVAIL:   return "Cannot assign requested address";
  case WSAENETDOWN:        return "Network is down";
  case WSAENETUNREACH:     return "Network is unreachable";
  case WSAENETRESET:       return "Network dropped connection on reset";
  case WSAECONNABORTED:    return "Software caused connection abort";
  case WSAECONNRESET:      return "Connection reset by peer";
  case WSAENOBUFS:         return "No buffer space available";
  case WSAEISCONN:         return "Socket is already connected";
  case WSAENOTCONN:        return "Socket is not connected";
  case WSAESHUTDOWN:       return "Cannot send after socket shutdown";
  case WSAETOOMANYREFS:    return "Too many references";
  case WSAETIMEDOUT:       return "Connection timed out";
  case WSAECONNREFUSED:    return "Connection refused";
  case WSAELOOP:           return "Too many levels of symbolic links";
  case WSAENAMETOOLONG:    return "File name too long";
  case WSAEHOSTDOWN:       return "Host is down";
  case WSAEHOSTUNREACH:    return "No route to host";
  case WSAENOTEMPTY:       return "Not empty";
  case WSAEPROCLIM:        return "Too many processes";
  case WSAEUSERS:          return "Too many users";
  case WSAEDQUOT:          return "Bad quota";
  case WSAESTALE:          return "Something is stale";
  case WSAEREMOTE:         return "Remote error";
  case WSAEDISCON:         return "Disconnected";

  /* Extended Winsock errors */
  case WSASYSNOTREADY:     return "Winsock library is not ready";
  case WSANOTINITIALISED:  return "Winsock library not initalised";
  case WSAVERNOTSUPPORTED: return "Winsock version not supported";

  case WSAHOST_NOT_FOUND: return "Host not found";
  case WSATRY_AGAIN:      return "Host not found, try again";
  case WSANO_RECOVERY:    return "Unrecoverable error in call to nameserver";
  case WSANO_DATA:        return "No data record of requested type";

  default:
    return NULL;
  }
}

/* Return the error message corresponding to ERR.  This is different
   from Windows libc strerror() in that it handles Winsock errors
   correctly.  */

const char *
windows_strerror (int err)
{
  const char *p;
  if (err >= 0 && err < sys_nerr)
    return strerror (err);
  else if ((p = get_winsock_error (err)) != NULL)
    return p;
  else
    {
      static char buf[32];
      snprintf (buf, sizeof (buf), "Unknown error %d (%#x)", err, err);
      return buf;
    }
}

#ifdef ENABLE_IPV6
/* An inet_ntop implementation that uses WSAAddressToString.
   Prototype complies with POSIX 1003.1-2004.  This is only used under
   IPv6 because Wget prints IPv4 addresses using inet_ntoa.  */

const char *
inet_ntop (int af, const void *src, char *dst, socklen_t cnt)
{
  /* struct sockaddr can't accomodate struct sockaddr_in6. */
  union {
    struct sockaddr_in6 sin6;
    struct sockaddr_in sin;
  } sa;
  DWORD dstlen = cnt;
  size_t srcsize;

  xzero (sa);
  switch (af)
    {
    case AF_INET:
      sa.sin.sin_family = AF_INET;
      sa.sin.sin_addr = *(struct in_addr *) src;
      srcsize = sizeof (sa.sin);
      break;
    case AF_INET6:
      sa.sin6.sin6_family = AF_INET6;
      sa.sin6.sin6_addr = *(struct in6_addr *) src;
      srcsize = sizeof (sa.sin6);
      break;
    default:
      abort ();
    }

  if (WSAAddressToString ((struct sockaddr *) &sa, srcsize, NULL, dst, &dstlen) != 0)
    {
      errno = WSAGetLastError();
      return NULL;
    }
  return (const char *) dst;
}
#endif