Need a config system

sashakoshka commented

2024-06-08 21:30:22 +00:00

Owner

It could just be a wrapper around dconf, but dconf is owned by GNOME. Not only is this not cross platform (we'd need another implementation for other systems), but depending on anything GNOME related is a horrible idea. Additionally, holding all settings within a single file is kind of a bad idea.

The configuration system should:

Categorize application configurations by application ID
Have system and user-level configurations for each application
- System level configurations specify default values
- User level configurations override system level values
Be able to handle multiple locations for system-level config dirs to support XDG base dirs
- Just one location for the user-level config
- Each dir contains a single config file
Have a user-readable, editable file format
Preserve unused values
Store values losslessly in all cases
Be primarily key/value structured
Alert the application when a setting has changed, either by use of an API, or by the user or an external program
- Watch all files
- When a file gets changed, reload it and find out what value(s) were altered
Have some global Nasin settings that apply to all applications, possibly with the ID xyz.holanet.Nasin
- This would be read by Nasin itself and used to read things like the theme, scaling, etc.
- The handle to this must be made available through a function
Ideally not depend on dbus

It could just be a wrapper around dconf, but dconf is owned by GNOME. Not only is this not cross platform (we'd need another implementation for other systems), but depending on anything GNOME related is a horrible idea. Additionally, holding all settings within a single file is kind of a bad idea. The configuration system should: - Categorize application configurations by application ID - Have system and user-level configurations for each application - System level configurations specify default values - User level configurations override system level values - Be able to handle multiple locations for system-level config dirs to support XDG base dirs - Just one location for the user-level config - Each dir contains a single config file - Have a user-readable, editable file format - Preserve unused values - Store values losslessly in all cases - Be primarily key/value structured - Alert the application when a setting has changed, either by use of an API, or by the user or an external program - Watch all files - When a file gets changed, reload it and find out what value(s) were altered - Have some global Nasin settings that apply to all applications, possibly with the ID xyz.holanet.Nasin - This would be read by Nasin itself and used to read things like the theme, scaling, etc. - The handle to this must be made available through a function - Ideally not depend on dbus

sashakoshka commented

2024-06-08 21:34:08 +00:00

Author

Owner

The API could look like:

type Config struct { ... }

// Set sets a value in the user-level config file.
func (*Config) Set (key string, value any) error
// Get gets a value, considering all config files.
func (*Config) Get (key string, fallback any) (any, error)
// Reset removes the value from the user-level config file, resetting it to
// what is described by the system-level config files.
func (*Config) Reset (key string) error
// OnChange specifies a function to be called whenever a value is changed.
// The callback is always run within the backend's event loop using tomo.Do.
func (*Config) OnChange (func (key string))
// Close closes the config, causing it to stop watching for changes. Reads
// or writes to the config after this will return an error.
func (*Config) Close () error

// ApplicationConfig returns a new config for the application in question.
// It must be closed after use unless it is supposed to remain open for the
// entire duration the application is running.
func ApplicationConfig (ApplicationDescription) *Config
// ApplicationConfig returns the global config. This should not be closed.
func GlobalConfig () *Config

The API could look like: ```go type Config struct { ... } // Set sets a value in the user-level config file. func (*Config) Set (key string, value any) error // Get gets a value, considering all config files. func (*Config) Get (key string, fallback any) (any, error) // Reset removes the value from the user-level config file, resetting it to // what is described by the system-level config files. func (*Config) Reset (key string) error // OnChange specifies a function to be called whenever a value is changed. // The callback is always run within the backend's event loop using tomo.Do. func (*Config) OnChange (func (key string)) // Close closes the config, causing it to stop watching for changes. Reads // or writes to the config after this will return an error. func (*Config) Close () error // ApplicationConfig returns a new config for the application in question. // It must be closed after use unless it is supposed to remain open for the // entire duration the application is running. func ApplicationConfig (ApplicationDescription) *Config // ApplicationConfig returns the global config. This should not be closed. func GlobalConfig () *Config ```

sashakoshka commented

2024-06-08 21:52:14 +00:00

Author

Owner

Alternatively, the pattern used for canvases and textures could be used, providing more explicit ownership of resources (in this case a goroutine):

type Config interface {
        Set (key string, value any) error
        Get (key string, fallback any) (any, error)
        Reset (key string) error
        OnChange (func (key string))
}

type ConfigCloser interface {
        Config
        io.Closer
}

func ApplicationConfig (ApplicationDescription) Config
func GlobalConfig () ConfigCloser

Alternatively, the pattern used for canvases and textures could be used, providing more explicit ownership of resources (in this case a goroutine): ```go type Config interface { Set (key string, value any) error Get (key string, fallback any) (any, error) Reset (key string) error OnChange (func (key string)) } type ConfigCloser interface { Config io.Closer } func ApplicationConfig (ApplicationDescription) Config func GlobalConfig () ConfigCloser ```

Need a config system #3