Added file system persistence

Collection.go

@@ -1,6 +1,11 @@
 package ocean
 
-import "sync"
+import (
+	"encoding/json"
+	"os"
+	"path"
+	"sync"
+)
 
 type Collection[T any] interface {
 	All() <-chan T
@@ -12,13 +17,32 @@ type Collection[T any] interface {
 
 // collection is a hash map of homogeneous data.
 type collection[T any] struct {
-	data sync.Map
-	name string
+	data      sync.Map
+	name      string
+	directory string
 }
 
 // NewCollection creates a new collection with the given name.
-func NewCollection[T any](name string) *collection[T] {
-	return &collection[T]{name: name}
+func NewCollection[T any](namespace string, name string) (*collection[T], error) {
+	home, err := os.UserHomeDir()
+
+	if err != nil {
+		return nil, err
+	}
+
+	directory := path.Join(home, ".ocean", namespace, name)
+	err = os.MkdirAll(directory, 0700)
+
+	if err != nil {
+		return nil, err
+	}
+
+	c := &collection[T]{
+		name:      name,
+		directory: directory,
+	}
+
+	return c, err
 }
 
 // Get returns the value for the given key.
@@ -30,6 +54,22 @@ func (c *collection[T]) Get(key string) (T, bool) {
 // 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.

Collection_test.go

@@ -8,7 +8,9 @@ import (
 )
 
 func TestCollectionGet(t *testing.T) {
-	users := ocean.NewCollection[string]("User")
+	users, err := ocean.NewCollection[string]("test", "User")
+	assert.Nil(t, err)
+
 	users.Set("1", "abc")
 	user, exists := users.Get("1")
 
@@ -17,7 +19,9 @@ func TestCollectionGet(t *testing.T) {
 }
 
 func TestCollectionAll(t *testing.T) {
-	users := ocean.NewCollection[string]("User")
+	users, err := ocean.NewCollection[string]("test", "User")
+	assert.Nil(t, err)
+
 	users.Set("1", "abc")
 	users.Set("2", "def")
 	count := 0
@@ -30,7 +34,8 @@ func TestCollectionAll(t *testing.T) {
 }
 
 func TestInteraction(t *testing.T) {
-	users := ocean.NewCollection[string]("User")
+	users, err := ocean.NewCollection[string]("test", "User")
+	assert.Nil(t, err)
 
 	assert.True(t, !users.Exists("1"))
 	assert.True(t, !users.Exists("2"))