init

.gitignore

@@ -0,0 +1 @@
+.idea

Readme.md

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+# State
+From time to time i need some small state persistens like e.g. for a bot how count the numbers of messages with a special value. I want to store them somewhere to not cound double without thin king about it so i store a struct as json.
+
+This pkg will provice Methodes to store (read and write) structs to the hdd.
+
+Idear for later:
+* Store in S3 as well
+* Function for dealing with lists on store. Like add to list, chcik if exists in list and so on
+
+# Working with State
+
+## Write State to HDD
+```
+state, err := NewLocaleFilesystem("data/")
+if err != nil {
+    panic(err)
+}
+```

error.go

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+package state
+
+import "errors"
+
+var ErrLocaleFilesystemCantCreateFolder = errors.New("cant create folder for state")
+var ErrLocaleFilesystemCantStoreState = errors.New("cant store state")
+var ErrLocaleFilesystemCantReadState = errors.New("cant read state")

go.mod

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+module state
+
+go 1.21
+
+require (
+	github.com/google/uuid v1.6.0
+	github.com/stretchr/testify v1.8.4
+)
+
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)

go.sum

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+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
+github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
+github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

state.go

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+package state
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+)
+
+type StateStore interface {
+	StoreState(key string, object interface{}) error
+	GetState(key string, object any) error
+}
+
+func NewLocaleFilesystem(path string) (StateStore, error) {
+	l := localeFilesystem{}
+	l.path = path
+
+	if _, err := os.Stat(l.path); os.IsNotExist(err) {
+		err = os.MkdirAll(l.path, 0744)
+		if err != nil {
+			return nil, fmt.Errorf("%e: %s", ErrLocaleFilesystemCantCreateFolder, err)
+		}
+	}
+	return l, nil
+}
+
+type localeFilesystem struct {
+	path string
+}
+
+func (s localeFilesystem) GetState(key string, object any) error {
+	data, err := os.ReadFile(fmt.Sprintf("%v/%v.json", s.path, key))
+	if err != nil {
+		return fmt.Errorf("%e: %v", ErrLocaleFilesystemCantReadState, err)
+	}
+
+	err = json.Unmarshal(data, object)
+
+	if err != nil {
+		return fmt.Errorf("%e: %v", ErrLocaleFilesystemCantReadState, err)
+	}
+
+	return nil
+}
+
+func (s localeFilesystem) StoreState(key string, object any) error {
+	data, err := json.Marshal(object)
+	if err != nil {
+		return fmt.Errorf("%e: %v", ErrLocaleFilesystemCantStoreState, err)
+	}
+
+	err = os.WriteFile(fmt.Sprintf("%v/%v.json", s.path, key), data, 0644)
+	if err != nil {
+		return fmt.Errorf("%e: %v", ErrLocaleFilesystemCantStoreState, err)
+	}
+
+	return nil
+}

state_test.go

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+package state
+
+import (
+	"github.com/google/uuid"
+	"github.com/stretchr/testify/assert"
+	"os"
+	"testing"
+)
+
+func TestStoreStateAsJsonToHDD(t *testing.T) {
+	data := struct {
+		Name      string
+		Test      string `json:"-"`
+		Age       int
+		something string
+	}{
+		Name:      "Max",
+		Test:      "foo",
+		Age:       1337,
+		something: "nothing",
+	}
+
+	store, err := NewLocaleFilesystem("/tmp/statetest")
+	defer os.RemoveAll("/tmp/statetest")
+	assert.Nil(t, err, "should be able to create filesystem store without error")
+
+	err = store.StoreState("geheim", data)
+	assert.Nil(t, err, "should be store data without error")
+
+	if _, err := os.Stat("/tmp/statetest/geheim.json"); os.IsNotExist(err) {
+		t.Error("state file does not exists")
+	}
+
+	databyte, err := os.ReadFile("/tmp/statetest/geheim.json")
+	assert.Nil(t, err, "should be able to read file without error")
+
+	assert.Equal(t, "{\"Name\":\"Max\",\"Age\":1337}", string(databyte), "json should match")
+}
+
+func TestStoreStateFromHDD(t *testing.T) {
+	data := struct {
+		Name      string
+		Test      string `json:"-"`
+		Age       int
+		something string
+	}{}
+
+	result := struct {
+		Name      string
+		Test      string `json:"-"`
+		Age       int
+		something string
+	}{
+		Name:      "Max",
+		Test:      "",
+		Age:       1337,
+		something: "",
+	}
+
+	store, err := NewLocaleFilesystem("/tmp/statetest")
+	defer os.RemoveAll("/tmp/statetest")
+	assert.Nil(t, err, "should be able to create filesystem store without error")
+
+	key := uuid.NewString()
+
+	os.WriteFile("/tmp/statetest/"+key+".json", []byte("{\"Name\":\"Max\",\"Age\":1337}"), 0744)
+
+	store.GetState(key, &data)
+
+	assert.Equal(t, result, data, "should get same data from hdd")
+}