io.c

subversion-1.4.3-1.tar.gz 配置svn的源码

  const char *path_apr;
  apr_finfo_t finfo;
  apr_fileperms_t perms_to_set;

  SVN_ERR(svn_path_cstring_from_utf8(&path_apr, path, pool));

  /* Try to change only a minimal amount of the perms first 
     by getting the current perms and adding bits
     only on where read perms are granted.  If this fails
     fall through to just setting file attributes. */
  status = apr_stat(&finfo, path_apr, APR_FINFO_PROT, pool);
  if (status)
    {
      if (ignore_enoent && APR_STATUS_IS_ENOENT(status))
        return SVN_NO_ERROR;
      else if (status != APR_ENOTIMPL)
        return svn_error_wrap_apr(status,
                                  _("Can't change perms of file '%s'"),
                                  svn_path_local_style(path, pool));
      return SVN_NO_ERROR;
    }

  perms_to_set = finfo.protection;
  if (change_readwrite)
    {
      if (enable_write) /* Make read-write. */
        SVN_ERR(get_default_file_perms(path, &perms_to_set, pool));
      else
        {
          if (finfo.protection & APR_UREAD)
            perms_to_set &= ~APR_UWRITE;
          if (finfo.protection & APR_GREAD)
            perms_to_set &= ~APR_GWRITE;
          if (finfo.protection & APR_WREAD)
            perms_to_set &= ~APR_WWRITE;
        }
    }

  if (change_executable)
    {
      if (executable)
        {
          if (finfo.protection & APR_UREAD)
            perms_to_set |= APR_UEXECUTE;
          if (finfo.protection & APR_GREAD)
            perms_to_set |= APR_GEXECUTE;
          if (finfo.protection & APR_WREAD)
            perms_to_set |= APR_WEXECUTE;
        }
      else
        {
          if (finfo.protection & APR_UREAD)
            perms_to_set &= ~APR_UEXECUTE;
          if (finfo.protection & APR_GREAD)
            perms_to_set &= ~APR_GEXECUTE;
          if (finfo.protection & APR_WREAD)
            perms_to_set &= ~APR_WEXECUTE;
        }
    }

  /* If we aren't changing anything then just return, this saves
     some system calls and helps with shared working copies */
  if (perms_to_set == finfo.protection)
    return SVN_NO_ERROR;

  status = apr_file_perms_set(path_apr, perms_to_set);
  if (!status)
    return SVN_NO_ERROR;

  if (APR_STATUS_IS_EPERM(status))
    {
      /* We don't have permissions to change the
         permissions!  Try a move, copy, and delete
         workaround to see if we can get the file owned by
         us.  If these succeed, try the permissions set
         again.

         Note that we only attempt this in the
         stat-available path.  This assumes that the
         move-copy workaround will only be helpful on
         platforms that implement apr_stat. */
      SVN_ERR(reown_file(path_apr, pool));
      status = apr_file_perms_set(path_apr, perms_to_set);
    }

  if (!status)
    return SVN_NO_ERROR;

  if (ignore_enoent && APR_STATUS_IS_ENOENT(status))
    return SVN_NO_ERROR;
  else if (status == APR_ENOTIMPL)
    {
      /* At least try to set the attributes. */
      apr_fileattrs_t attrs = 0;
      apr_fileattrs_t attrs_values = 0;

      if (change_readwrite)
        {
          attrs = APR_FILE_ATTR_READONLY;
          if (!enable_write)
            attrs_values = APR_FILE_ATTR_READONLY;
        }
      if (change_executable)
        {
          attrs = APR_FILE_ATTR_EXECUTABLE;
          if (executable)
            attrs_values = APR_FILE_ATTR_EXECUTABLE;
        }
      status = apr_file_attrs_set(path_apr, attrs, attrs_values, pool);
    }

  return svn_error_wrap_apr(status,
                            _("Can't change perms of file '%s'"),
                            svn_path_local_style(path, pool));
}
#endif

svn_error_t *
svn_io_set_file_read_write_carefully(const char *path,
                                     svn_boolean_t enable_write,
                                     svn_boolean_t ignore_enoent,
                                     apr_pool_t *pool)
{
  if (enable_write)
    return svn_io_set_file_read_write(path, ignore_enoent, pool);
  return svn_io_set_file_read_only(path, ignore_enoent, pool);
}

svn_error_t *
svn_io_set_file_read_only(const char *path,
                          svn_boolean_t ignore_enoent,
                          apr_pool_t *pool)
{
  /* On Windows, just set the file attributes -- on unix call
     our internal function which attempts to honor the umask. */
#ifndef WIN32
  return io_set_file_perms(path, TRUE, FALSE, FALSE, FALSE,
                           ignore_enoent, pool);
#else
  apr_status_t status;
  const char *path_apr;

  SVN_ERR(svn_path_cstring_from_utf8(&path_apr, path, pool));

  status = apr_file_attrs_set(path_apr,
                              APR_FILE_ATTR_READONLY,
                              APR_FILE_ATTR_READONLY,
                              pool);

  if (status && status != APR_ENOTIMPL)
    if (!ignore_enoent || !APR_STATUS_IS_ENOENT(status))
      return svn_error_wrap_apr(status,
                                _("Can't set file '%s' read-only"),
                                svn_path_local_style(path, pool));

  return SVN_NO_ERROR;
#endif
}


svn_error_t *
svn_io_set_file_read_write(const char *path,
                           svn_boolean_t ignore_enoent,
                           apr_pool_t *pool)
{
  /* On Windows, just set the file attributes -- on unix call
     our internal function which attempts to honor the umask. */
#ifndef WIN32
  return io_set_file_perms(path, TRUE, TRUE, FALSE, FALSE,
                           ignore_enoent, pool);
#else
  apr_status_t status;
  const char *path_apr;

  SVN_ERR(svn_path_cstring_from_utf8(&path_apr, path, pool));

  status = apr_file_attrs_set(path_apr,
                              0,
                              APR_FILE_ATTR_READONLY,
                              pool);

  if (status && status != APR_ENOTIMPL)
    if (!ignore_enoent || !APR_STATUS_IS_ENOENT(status))
      return svn_error_wrap_apr(status,
                                _("Can't set file '%s' read-write"),
                                svn_path_local_style(path, pool));

  return SVN_NO_ERROR;
#endif
}

svn_error_t *
svn_io_set_file_executable(const char *path,
                           svn_boolean_t executable,
                           svn_boolean_t ignore_enoent,
                           apr_pool_t *pool)
{
  /* On Windows, just exit -- on unix call our internal function
  which attempts to honor the umask. */
#ifndef WIN32
  return io_set_file_perms(path, FALSE, FALSE, TRUE, executable,
                           ignore_enoent, pool);
#else
  return SVN_NO_ERROR;
#endif
}


svn_error_t *
svn_io_is_file_executable(svn_boolean_t *executable, 
                          const char *path, 
                          apr_pool_t *pool)
{
#if defined(APR_HAS_USER) && !defined(WIN32)
  apr_finfo_t file_info;
  apr_status_t apr_err;
  apr_uid_t uid;
  apr_gid_t gid;

  *executable = FALSE;
  
  /* Get file and user info. */
  SVN_ERR(svn_io_stat(&file_info, path, 
                      (APR_FINFO_PROT | APR_FINFO_OWNER), 
                      pool));
  apr_err = apr_uid_current(&uid, &gid, pool);

  if (apr_err)
    return svn_error_wrap_apr(apr_err, _("Error getting UID of process"));
    
  /* Check executable bit for current user. */
  if (apr_uid_compare(uid, file_info.user) == APR_SUCCESS)
    *executable = (file_info.protection & APR_UEXECUTE);

  else if (apr_gid_compare(gid, file_info.group) == APR_SUCCESS)
    *executable = (file_info.protection & APR_GEXECUTE);

  else
    *executable = (file_info.protection & APR_WEXECUTE);

#else  /* defined(WIN32) || !defined(APR_HAS_USER) */
  *executable = FALSE;
#endif

  return SVN_NO_ERROR;
}


/*** File locking. ***/
/* Clear all outstanding locks on ARG, an open apr_file_t *. */
static apr_status_t
svn_io__file_clear_and_close(void *arg)
{
  apr_status_t apr_err;
  apr_file_t *f = arg;

  /* Remove locks. */
  apr_err = apr_file_unlock(f);
  if (apr_err)
    return apr_err;

  /* Close the file. */
  apr_err = apr_file_close(f);
  if (apr_err)
    return apr_err;

  return 0;
}


svn_error_t *svn_io_file_lock(const char *lock_file,
                              svn_boolean_t exclusive,
                              apr_pool_t *pool)
{
  return svn_io_file_lock2(lock_file, exclusive, FALSE, pool);
}

svn_error_t *svn_io_file_lock2(const char *lock_file,
                               svn_boolean_t exclusive,
                               svn_boolean_t nonblocking,
                               apr_pool_t *pool)
{
  int locktype = APR_FLOCK_SHARED;
  apr_file_t *lockfile_handle;
  apr_int32_t flags;
  apr_status_t apr_err;

  if(exclusive == TRUE)
    locktype = APR_FLOCK_EXCLUSIVE;

  flags = APR_READ;
  if (locktype == APR_FLOCK_EXCLUSIVE)
    flags |= APR_WRITE;

  if (nonblocking == TRUE)
    locktype |= APR_FLOCK_NONBLOCK;

  SVN_ERR(svn_io_file_open(&lockfile_handle, lock_file, flags,
                           APR_OS_DEFAULT,
                           pool));

  /* Get lock on the filehandle. */
  apr_err = apr_file_lock(lockfile_handle, locktype);
  if (apr_err)
    {
      switch (locktype & APR_FLOCK_TYPEMASK)
        {
        case APR_FLOCK_SHARED:
          return svn_error_wrap_apr
            (apr_err, _("Can't get shared lock on file '%s'"),
             svn_path_local_style(lock_file, pool));
        case APR_FLOCK_EXCLUSIVE:
          return svn_error_wrap_apr
            (apr_err, _("Can't get exclusive lock on file '%s'"),
             svn_path_local_style(lock_file, pool));
        default:
          /* Cannot happen. */
          abort();
        }
    }
  
  apr_pool_cleanup_register(pool, lockfile_handle, 
                            svn_io__file_clear_and_close,
                            apr_pool_cleanup_null);
                             
  return SVN_NO_ERROR;
}



/* Data consistency/coherency operations. */

static svn_error_t *
do_io_file_wrapper_cleanup(apr_file_t *file, apr_status_t status, 
                           const char *msg, const char *msg_no_name,
                           apr_pool_t *pool);

svn_error_t *svn_io_file_flush_to_disk(apr_file_t *file,
                                       apr_pool_t *pool)
{
  apr_os_file_t filehand;

  /* First make sure that any user-space buffered data is flushed. */
  SVN_ERR(do_io_file_wrapper_cleanup(file, apr_file_flush(file),
                                     N_("Can't flush file '%s'"),
                                     N_("Can't flush stream"),
                                     pool));

  apr_os_file_get(&filehand, file);
    
  /* Call the operating system specific function to actually force the
     data to disk. */
  {
#ifdef WIN32
      
    if (! FlushFileBuffers(filehand))
        return svn_error_wrap_apr
          (apr_get_os_error(), _("Can't flush file to disk"));
      
#else
      int rv;

      do {
        rv = fsync(filehand);
      } while (rv == -1 && APR_STATUS_IS_EINTR(apr_get_os_error()));

      /* If the file is in a memory filesystem, fsync() may return
         EINVAL.  Presumably the user knows the risks, and we can just
         ignore the error. */
      if (rv == -1 && APR_STATUS_IS_EINVAL(apr_get_os_error()))
        return SVN_NO_ERROR;

      if (rv == -1)
        return svn_error_wrap_apr
          (apr_get_os_error(), _("Can't flush file to disk"));

#endif
  }
  return SVN_NO_ERROR;
}
    


/* TODO write test for these two functions, then refactor. */

svn_error_t *
svn_stringbuf_from_file(svn_stringbuf_t **result,
                        const char *filename,
                        apr_pool_t *pool)
{
  apr_file_t *f = NULL;

  if (filename[0] == '-' && filename[1] == '\0')
    return svn_error_create
        (SVN_ERR_UNSUPPORTED_FEATURE, NULL,
         _("Reading from stdin is currently broken, so disabled"));

  SVN_ERR(svn_io_file_open(&f, filename, APR_READ, APR_OS_DEFAULT, pool));

  SVN_ERR(svn_stringbuf_from_aprfile(result, f, pool));

  SVN_ERR(svn_io_file_close(f, pool));

  return SVN_NO_ERROR;
}