appsettings

README

AppSettings

A hierarchical key value store for persisting simple runtime options in Go applications.

Example

s := appsettings.NewAppSettings("settings.json")

t := s.GetTree("user-settings")

//set
t.SetString("pizza", "pie")
t.SetInt("how-many-pugs", 349)

//read
if v, err := t.GetInt("how-many-pugs"); err == nil {
	log.Println(v)
}

if v, err = t.GetString("pizza"); err == nil {
	log.Println(v)
}

s.Persist()

Installation

go get -u -v github.com/donatj/appsettings

Migration from v0.0.1

The JSON format for the early Alpha changed. To migrate your existing data compatibly to the more modern format, you can use jq and execute the following command, first replacing {your-file} with the path to your actual database file.

jq '.Tree |= with_entries(.value = {Leaves: .value} ) | . + {Branches: .Tree} | del(.Tree)' < {your-file} > tmp && mv tmp {your-fie}

Documentation

Documentation can be found a godoc:

https://godoc.org/github.com/donatj/appsettings

Documentation

Overview

Package appsettings provides simple key/value store functionality designed to be used for easily storing and recalling application runtime settings

Index

• Variables
• func OptionPrettyPrint(app *AppSettings)
• type AppSettings
  • func NewAppSettings(dbFilename string, options ...Option) (*AppSettings, error)
  • func (a AppSettings) DecrInt64(key string) int64
  • func (a AppSettings) Delete(key string)
  • func (a AppSettings) DeleteTree(key string)
  • func (a AppSettings) GetInt(key string) (int, error)
  • func (a AppSettings) GetInt64(key string) (int64, error)
  • func (a AppSettings) GetLeaves() map[string]string
  • func (a AppSettings) GetString(key string) (string, error)
  • func (a AppSettings) GetTree(key string) DataTree
  • func (a AppSettings) GetTrees() map[string]DataTree
  • func (a AppSettings) HasLeaf(key string) bool
  • func (a AppSettings) HasTree(key string) bool
  • func (a AppSettings) IncrInt64(key string) int64
  • func (a *AppSettings) Persist() error
  • func (a AppSettings) SetInt(key string, val int)
  • func (a AppSettings) SetInt64(key string, val int64)
  • func (a AppSettings) SetString(key string, val string)
• type DataTree
• type Option

Variables

var ErrUndefinedKey = errors.New("undefined key")

ErrUndefinedKey is returned when the key requested from get is undefined.

Functions

func OptionPrettyPrint

func OptionPrettyPrint(app *AppSettings)

OptionPrettyPrint configures AppSettings to pretty print the saved json

Types

type AppSettings

type AppSettings struct {
	// contains filtered or unexported fields
}

AppSettings is the root most DataTree

func NewAppSettings

func NewAppSettings(dbFilename string, options ...Option) (*AppSettings, error)

NewAppSettings gets a new AppSettings struct

func (AppSettings) DecrInt64

func (a AppSettings) DecrInt64(key string) int64

DecrInt64 decrements an int or int64 leaf and returns the new value as int64.

If the key is undefined or non-integer, this will initialize it to 0 and decrements it to -1

func (AppSettings) Delete

func (a AppSettings) Delete(key string)

Delete removes the given leaf from the branch.

func (AppSettings) DeleteTree

func (a AppSettings) DeleteTree(key string)

DeleteTree removes the given tree from the branch.

func (AppSettings) GetInt

func (a AppSettings) GetInt(key string) (int, error)

GetInt gets the give keys leaf as an int.

Returns an ErrUndefinedKey if the key is not defined.

Will return an error if ParseInt of the value of the leaf fails.

func (AppSettings) GetInt64

func (a AppSettings) GetInt64(key string) (int64, error)

GetInt64 gets the give keys leaf as an int64.

Returns an ErrUndefinedKey if the key is not defined.

Will return an error if ParseInt(...,10, 64) of the value of the leaf fails.

func (AppSettings) GetLeaves

func (a AppSettings) GetLeaves() map[string]string

func (AppSettings) GetString

func (a AppSettings) GetString(key string) (string, error)

GetString gets the give keys leaf as a string.

Returns an ErrUndefinedKey if the key is not defined

func (AppSettings) GetTree

func (a AppSettings) GetTree(key string) DataTree

GetTree fetches a tree for app setting storage

func (AppSettings) GetTrees

func (a AppSettings) GetTrees() map[string]DataTree

func (AppSettings) HasLeaf

func (a AppSettings) HasLeaf(key string) bool

HasLeaf checks if the given key is defined as a leaf value

func (AppSettings) HasTree

func (a AppSettings) HasTree(key string) bool

HasTree checks if the given key is defined as a tree

func (AppSettings) IncrInt64

func (a AppSettings) IncrInt64(key string) int64

IncrInt64 increments an int or int64 leaf and returns the new value as int64.

If the key is undefined or non-integer, this will initialize it to 0 and increment it to 1

func (*AppSettings) Persist

func (a *AppSettings) Persist() error

Persist causes the current state of the app settings to be persisted.

func (AppSettings) SetInt

func (a AppSettings) SetInt(key string, val int)

SetInt sets the give key leaf as a int.

func (AppSettings) SetInt64

func (a AppSettings) SetInt64(key string, val int64)

SetInt64 sets the give key leaf as a int64.

func (AppSettings) SetString

func (a AppSettings) SetString(key string, val string)

SetString sets the give key leaf as a string.

type DataTree

type DataTree interface {
	GetString(key string) (string, error)
	SetString(key string, val string)

	GetInt(key string) (int, error)
	SetInt(key string, val int)

	GetInt64(key string) (int64, error)
	SetInt64(key string, val int64)
	IncrInt64(key string) int64
	DecrInt64(key string) int64

	Delete(key string)
	DeleteTree(key string)
	GetTree(key string) DataTree

	HasTree(key string) bool
	HasLeaf(key string) bool

	GetTrees() map[string]DataTree
	GetLeaves() map[string]string
}

DataTree is the host of key and branches of values

type Option

type Option func(*AppSettings)

Option sets an option of the passed AppSettings