pub fn keyfile_settings_backend_new(
    filename: &str,
    root_path: &str,
    root_group: Option<&str>
) -> SettingsBackend
Expand description

Creates a keyfile-backed SettingsBackend.

The filename of the keyfile to use is given by filename.

All settings read to or written from the backend must fall under the path given in root_path (which must start and end with a slash and not contain two consecutive slashes). root_path may be “/”.

If root_group is non-None then it specifies the name of the keyfile group used for keys that are written directly below root_path. For example, if root_path is “/apps/example/” and root_group is “toplevel”, then settings the key “/apps/example/enabled” to a value of true will cause the following to appear in the keyfile:

  [toplevel]
  enabled=true

If root_group is None then it is not permitted to store keys directly below the root_path.

For keys not stored directly below root_path (ie: in a sub-path), the name of the subpath (with the final slash stripped) is used as the name of the keyfile group. To continue the example, if “/apps/example/profiles/default/font-size” were set to 12 then the following would appear in the keyfile:

  [profiles/default]
  font-size=12

The backend will refuse writes (and return writability as being false) for keys outside of root_path and, in the event that root_group is None, also for keys directly under root_path. Writes will also be refused if the backend detects that it has the inability to rewrite the keyfile (ie: the containing directory is not writable).

There is no checking done for your key namespace clashing with the syntax of the key file format. For example, if you have ‘[’ or ‘]’ characters in your path names or ‘=’ in your key names you may be in trouble.

The backend reads default values from a keyfile called defaults in the directory specified by the GKeyfileSettingsBackend:defaults-dir property, and a list of locked keys from a text file with the name locks in the same location.

filename

the filename of the keyfile

root_path

the path under which all settings keys appear

root_group

the group name corresponding to root_path, or None

Returns

a keyfile-backed SettingsBackend