Improved file persistence

Collection.go

@@ -4,15 +4,18 @@ import (
 	"encoding/json"
 	"os"
 	"path"
+	"path/filepath"
+	"strings"
 	"sync"
 )
 
 type Collection[T any] interface {
-	All() <-chan T
+	All() <-chan *T
+	Clear()
 	Delete(key string)
 	Exists(key string) bool
-	Get(key string) (value T, ok bool)
-	Set(key string, value T)
+	Get(key string) (value *T, ok bool)
+	Set(key string, value *T)
 }
 
 // collection is a hash map of homogeneous data.
@@ -42,54 +45,16 @@ func NewCollection[T any](namespace string, name string) (*collection[T], error)
 		directory: directory,
 	}
 
-	return c, err
-}
-
-// Get returns the value for the given key.
-func (c *collection[T]) Get(key string) (T, bool) {
-	value, exists := c.data.Load(key)
-	return value.(T), exists
-}
-
-// Set sets the value for the given key.
-func (c *collection[T]) Set(key string, value T) {
-	c.data.Store(key, value)
-
-	fileName := path.Join(c.directory, key+".json")
-	file, err := os.Create(fileName)
-
-	if err != nil {
-		panic(err)
-	}
-
-	encoder := json.NewEncoder(file)
-	encoder.Encode(value)
-
-	err = file.Close()
-
-	if err != nil {
-		panic(err)
-	}
-}
-
-// Delete deletes a key from the collection.
-func (c *collection[T]) Delete(key string) {
-	c.data.Delete(key)
-}
-
-// Exists returns whether or not the key exists.
-func (c *collection[T]) Exists(key string) bool {
-	_, exists := c.data.Load(key)
-	return exists
+	return c, c.loadFromDisk()
 }
 
 // All returns a channel of all objects in the collection.
-func (c *collection[T]) All() <-chan T {
-	channel := make(chan T)
+func (c *collection[T]) All() <-chan *T {
+	channel := make(chan *T)
 
 	go func() {
 		c.data.Range(func(key, value any) bool {
-			channel <- value.(T)
+			channel <- value.(*T)
 			return true
 		})
 
@@ -98,3 +63,109 @@ func (c *collection[T]) All() <-chan T {
 
 	return channel
 }
+
+// Get returns the value for the given key.
+func (c *collection[T]) Get(key string) (*T, bool) {
+	value, exists := c.data.Load(key)
+	return value.(*T), exists
+}
+
+// Set sets the value for the given key.
+func (c *collection[T]) Set(key string, value *T) {
+	c.data.Store(key, value)
+	c.writeFileToDisk(key, value)
+}
+
+// Delete deletes a key from the collection.
+func (c *collection[T]) Delete(key string) {
+	c.data.Delete(key)
+	os.Remove(c.keyFile(key))
+}
+
+// Exists returns whether or not the key exists.
+func (c *collection[T]) Exists(key string) bool {
+	_, exists := c.data.Load(key)
+	return exists
+}
+
+// Clear deletes all objects from the collection.
+func (c *collection[T]) Clear() {
+	c.data.Range(func(key, value any) bool {
+		c.Delete(key.(string))
+		return true
+	})
+}
+
+// keyFile returns the file path for the given key.
+func (c *collection[T]) keyFile(key string) string {
+	return filepath.Join(c.directory, key+".json")
+}
+
+// loadFromDisk loads the collection data from the disk.
+func (c *collection[T]) loadFromDisk() error {
+	file, err := os.Open(c.directory)
+
+	if err != nil {
+		return err
+	}
+
+	files, err := file.Readdirnames(0)
+
+	for _, name := range files {
+		fileError := c.loadFileFromDisk(name)
+
+		if fileError != nil {
+			return fileError
+		}
+	}
+
+	if err != nil {
+		return err
+	}
+
+	return file.Close()
+}
+
+// loadFileFromDisk loads a single file from the disk.
+func (c *collection[T]) loadFileFromDisk(name string) error {
+	file, err := os.Open(filepath.Join(c.directory, name))
+
+	if err != nil {
+		return err
+	}
+
+	value := new(T)
+	decoder := json.NewDecoder(file)
+	err = decoder.Decode(value)
+
+	if err != nil {
+		return err
+	}
+
+	key := strings.TrimSuffix(name, filepath.Ext(name))
+	c.data.Store(key, value)
+	return file.Close()
+}
+
+// writeFileToDisk writes the value for the key to disk as a JSON file.
+func (c *collection[T]) writeFileToDisk(key string, value *T) {
+	fileName := c.keyFile(key)
+	file, err := os.Create(fileName)
+
+	if err != nil {
+		panic(err)
+	}
+
+	encoder := json.NewEncoder(file)
+	err = encoder.Encode(value)
+
+	if err != nil {
+		panic(err)
+	}
+
+	err = file.Close()
+
+	if err != nil {
+		panic(err)
+	}
+}

Collection_test.go

@@ -7,45 +7,36 @@ import (
 	"git.akyoto.dev/go/ocean"
 )
 
-func TestCollectionGet(t *testing.T) {
-	users, err := ocean.NewCollection[string]("test", "User")
-	assert.Nil(t, err)
+type User struct {
+	Name string `json:"name"`
+}
 
-	users.Set("1", "abc")
+func TestCollectionGet(t *testing.T) {
+	users, err := ocean.NewCollection[User]("test", "User")
+	assert.Nil(t, err)
+	defer users.Clear()
+
+	users.Set("1", &User{Name: "User 1"})
 	user, exists := users.Get("1")
 
 	assert.True(t, exists)
 	assert.NotNil(t, user)
 }
 
-func TestCollectionAll(t *testing.T) {
-	users, err := ocean.NewCollection[string]("test", "User")
-	assert.Nil(t, err)
-
-	users.Set("1", "abc")
-	users.Set("2", "def")
-	count := 0
-
-	for range users.All() {
-		count++
-	}
-
-	assert.Equal(t, count, 2)
-}
-
 func TestInteraction(t *testing.T) {
-	users, err := ocean.NewCollection[string]("test", "User")
+	users, err := ocean.NewCollection[User]("test", "User")
 	assert.Nil(t, err)
+	defer users.Clear()
 
 	assert.True(t, !users.Exists("1"))
 	assert.True(t, !users.Exists("2"))
 
-	users.Set("1", "abc")
+	users.Set("1", &User{Name: "User 1"})
 
 	assert.True(t, users.Exists("1"))
 	assert.True(t, !users.Exists("2"))
 
-	users.Set("2", "def")
+	users.Set("2", &User{Name: "User 1"})
 
 	assert.True(t, users.Exists("1"))
 	assert.True(t, users.Exists("2"))
@@ -60,3 +51,19 @@ func TestInteraction(t *testing.T) {
 	assert.True(t, !users.Exists("1"))
 	assert.True(t, !users.Exists("2"))
 }
+
+func TestCollectionAll(t *testing.T) {
+	users, err := ocean.NewCollection[User]("test", "User")
+	assert.Nil(t, err)
+	defer users.Clear()
+
+	users.Set("1", &User{Name: "User 1"})
+	users.Set("2", &User{Name: "User 2"})
+	count := 0
+
+	for range users.All() {
+		count++
+	}
+
+	assert.Equal(t, count, 2)
+}

README.md

@@ -4,4 +4,7 @@ In-memory key value store that saves your data to plain old JSON files.
 
 If you like, you can operate on your entire data with classic UNIX tools.
 
-Writing to disk is async, so the performance of your code is only limited by your CPU and RAM speed.
+```go
+users := ocean.NewCollection("namespace", "User")
+users.Set("1", &User{Name: "User 1"})
+```