rclone/fs/config/configmap/configmap.go
Nick Craig-Wood f111e0eaf8 fs: enable configmap to be able to tell values set vs config file values #4996
This adds AddOverrideGetter and GetOverride methods to config map and
uses them in fs.ConfigMap.

This enables us to tell which values have been set and which are just
read from the config file or at their defaults.

This also deletes the unused AddGetters method in configmap.
2021-03-15 19:22:07 +00:00

137 lines
3.2 KiB
Go

// Package configmap provides an abstraction for reading and writing config
package configmap
import (
"sort"
"strings"
)
// Getter provides an interface to get config items
type Getter interface {
// Get should get an item with the key passed in and return
// the value. If the item is found then it should return true,
// otherwise false.
Get(key string) (value string, ok bool)
}
// Setter provides an interface to set config items
type Setter interface {
// Set should set an item into persistent config store.
Set(key, value string)
}
// Mapper provides an interface to read and write config
type Mapper interface {
Getter
Setter
}
// Map provides a wrapper around multiple Setter and
// Getter interfaces.
type Map struct {
setters []Setter
getters []Getter
override []Getter
}
// New returns an empty Map
func New() *Map {
return &Map{}
}
// AddGetter appends a getter onto the end of the getters
func (c *Map) AddGetter(getter Getter) *Map {
c.getters = append(c.getters, getter)
return c
}
// AddOverrideGetter appends a getter onto the end of the getters
//
// It also appends it onto the override getters for GetOverride
func (c *Map) AddOverrideGetter(getter Getter) *Map {
c.getters = append(c.getters, getter)
c.override = append(c.override, getter)
return c
}
// AddSetter appends a setter onto the end of the setters
func (c *Map) AddSetter(setter Setter) *Map {
c.setters = append(c.setters, setter)
return c
}
// get gets an item with the key passed in and return the value from
// the first getter. If the item is found then it returns true,
// otherwise false.
func (c *Map) get(key string, getters []Getter) (value string, ok bool) {
for _, do := range getters {
value, ok = do.Get(key)
if ok {
return value, ok
}
}
return "", false
}
// Get gets an item with the key passed in and return the value from
// the first getter. If the item is found then it returns true,
// otherwise false.
func (c *Map) Get(key string) (value string, ok bool) {
return c.get(key, c.getters)
}
// GetOverride gets an item with the key passed in and return the
// value from the first override getter. If the item is found then it
// returns true, otherwise false.
func (c *Map) GetOverride(key string) (value string, ok bool) {
return c.get(key, c.override)
}
// Set sets an item into all the stored setters.
func (c *Map) Set(key, value string) {
for _, do := range c.setters {
do.Set(key, value)
}
}
// Simple is a simple Mapper for testing
type Simple map[string]string
// Get the value
func (c Simple) Get(key string) (value string, ok bool) {
value, ok = c[key]
return value, ok
}
// Set the value
func (c Simple) Set(key, value string) {
c[key] = value
}
// String the map value the same way the config parser does, but with
// sorted keys for reproducability.
func (c Simple) String() string {
var ks = make([]string, 0, len(c))
for k := range c {
ks = append(ks, k)
}
sort.Strings(ks)
var out strings.Builder
for _, k := range ks {
if out.Len() > 0 {
out.WriteRune(',')
}
out.WriteString(k)
out.WriteRune('=')
out.WriteRune('\'')
for _, ch := range c[k] {
out.WriteRune(ch)
// Escape ' as ''
if ch == '\'' {
out.WriteRune(ch)
}
}
out.WriteRune('\'')
}
return out.String()
}