本文針對go 1.11版本，路徑src/container/list/list.go

資料結構

Element結構體

• Value
• 前驅
• 後繼

// Element is an element of a linked list.
type Element struct {
	// Next and previous pointers in the doubly-linked list of elements.
	// To simplify the implementation, internally a list l is implemented
	// as a ring, such that &l.root is both the next element of the last
	// list element (l.Back()) and the previous element of the first list
	// element (l.Front()).
	next, prev *Element

	// The list to which this element belongs.
	list *List

	// The value stored with this element.
	Value interface{}
}
 

List結構體

雙向列表，包括連結串列節點個數

// List represents a doubly linked list.
// The zero value for List is an empty list ready to use.
type List struct {
	root Element // sentinel list element, only &root, root.prev, and root.next are used
	len  int     // current list length excluding (this) sentinel element
}
 

1. 雙向連結串列初始化

     節點個數為0，前驅後前繼都指向root節點

// Init initializes or clears list l.
func (l *List) Init() *List {
	l.root.next = &l.root
	l.root.prev = &l.root
	l.len = 0
	return l
}

// New returns an initialized list.
func New() *List { return new(List).Init() }

2. insert函式

  程式碼簡單明瞭，就是改變prev next指標，注意別指丟了就行

// insert inserts e after at, increments l.len, and returns e.
func (l *List) insert(e, at *Element) *Element {
	n := at.next
	at.next = e
	e.prev = at
	e.next = n
	n.prev = e
	e.list = l
	l.len++
	return e
}

3. remove函式

   刪除操作，避免記憶體洩露，等待gc回收

// remove removes e from its list, decrements l.len, and returns e.
func (l *List) remove(e *Element) *Element {
	e.prev.next = e.next
	e.next.prev = e.prev
	e.next = nil // avoid memory leaks
	e.prev = nil // avoid memory leaks
	e.list = nil
	l.len--
	return e
}