M README.md → README.md

@@ -91,16 +91,6 @@
 Functions
 ---------
 
-### func Collect
-
-	func Collect()
-	
-Collect deletes expired or used captchas from the internal storage. It is
-called automatically by New function every CollectNum generated captchas,
-but still exported to enable freeing memory manually if needed.
-
-Collection is launched in a new goroutine.
-
 ### func New
 
 	func New(length int) (id string)
@@ -248,18 +238,16 @@
     // Get returns stored digits for the captcha id. Clear indicates
     // whether the captcha must be deleted from the store.
     Get(id string, clear bool) (digits []byte)
-
-    // Collect deletes expired captchas from the store.  For custom stores
-    // this method is not called automatically, it is only wired to the
-    // package's Collect function.  Custom stores must implement their own
-    // procedure for calling Collect, for example, in Set method.
-    Collect()
 }
 ```
 
 An object implementing Store interface can be registered with SetCustomStore
 function to handle storage and retrieval of captcha ids and solutions for
 them, replacing the default memory store.
+
+It is the responsibility of an object to delete expired and used captchas
+when necessary (for example, the default memory store collects them in Set
+method after the certain amount of captchas has been stored.)
 
 ### func NewMemoryStore
 

M captcha.go → captcha.go

@@ -166,12 +166,3 @@ }
 	}
 	return Verify(id, ns)
 }
-
-// Collect deletes expired or used captchas from the internal storage. It is
-// called automatically by New function every CollectNum generated captchas,
-// but still exported to enable freeing memory manually if needed.
-//
-// Collection is launched in a new goroutine.
-func Collect() {
-	go globalStore.Collect()
-}

M store.go → store.go

@@ -9,6 +9,10 @@
 // An object implementing Store interface can be registered with SetCustomStore
 // function to handle storage and retrieval of captcha ids and solutions for
 // them, replacing the default memory store.
+//
+// It is the responsibility of an object to delete expired and used captchas
+// when necessary (for example, the default memory store collects them in Set
+// method after the certain amount of captchas has been stored.)
 type Store interface {
 	// Set sets the digits for the captcha id.
 	Set(id string, digits []byte)
@@ -16,12 +20,6 @@
 	// Get returns stored digits for the captcha id. Clear indicates
 	// whether the captcha must be deleted from the store.
 	Get(id string, clear bool) (digits []byte)
-
-	// Collect deletes expired captchas from the store.  For custom stores
-	// this method is not called automatically, it is only wired to the
-	// package's Collect function.  Custom stores must implement their own
-	// procedure for calling Collect, for example, in Set method.
-	Collect()
 }
 
 // expValue stores timestamp and id of captchas. It is used in the list inside
@@ -67,7 +65,7 @@ s.mu.Unlock()
 		return
 	}
 	s.mu.Unlock()
-	go s.Collect()
+	go s.collect()
 }
 
 func (s *memoryStore) Get(id string, clear bool) (digits []byte) {
@@ -93,7 +91,7 @@ }
 	return
 }
 
-func (s *memoryStore) Collect() {
+func (s *memoryStore) collect() {
 	now := time.Seconds()
 	s.mu.Lock()
 	defer s.mu.Unlock()