diff options
Diffstat (limited to 'vendor/codeberg.org/gruf/go-structr/list.go')
-rw-r--r-- | vendor/codeberg.org/gruf/go-structr/list.go | 151 |
1 files changed, 0 insertions, 151 deletions
diff --git a/vendor/codeberg.org/gruf/go-structr/list.go b/vendor/codeberg.org/gruf/go-structr/list.go deleted file mode 100644 index bf380aa26..000000000 --- a/vendor/codeberg.org/gruf/go-structr/list.go +++ /dev/null @@ -1,151 +0,0 @@ -package structr - -import ( - "sync" - "unsafe" -) - -// elem represents an elem -// in a doubly-linked list. -type list_elem struct { - next *list_elem - prev *list_elem - - // data is a ptr to the - // value this linked list - // element is embedded-in. - data unsafe.Pointer -} - -// list implements a doubly-linked list, where: -// - head = index 0 (i.e. the front) -// - tail = index n-1 (i.e. the back) -type list struct { - head *list_elem - tail *list_elem - len int -} - -var list_pool sync.Pool - -// new_list returns a new prepared list. -func new_list() *list { - v := list_pool.Get() - if v == nil { - v = new(list) - } - list := v.(*list) - return list -} - -// free_list releases the list. -func free_list(list *list) { - if list.head != nil || - list.tail != nil || - list.len != 0 { - should_not_reach() - return - } - list_pool.Put(list) -} - -// push_front will push the given elem to front (head) of list. -func (l *list) push_front(elem *list_elem) { - // Set new head. - oldHead := l.head - l.head = elem - - if oldHead != nil { - // Link to old head - elem.next = oldHead - oldHead.prev = elem - } else { - // First in list. - l.tail = elem - } - - // Incr count - l.len++ -} - -// push_back will push the given elem to back (tail) of list. -func (l *list) push_back(elem *list_elem) { - // Set new tail. - oldTail := l.tail - l.tail = elem - - if oldTail != nil { - // Link to old tail - elem.prev = oldTail - oldTail.next = elem - } else { - // First in list. - l.head = elem - } - - // Incr count - l.len++ -} - -// move_front will move given elem to front (head) of list. -// if it is already at front this call is a no-op. -func (l *list) move_front(elem *list_elem) { - if elem == l.head { - return - } - l.remove(elem) - l.push_front(elem) -} - -// move_back will move given elem to back (tail) of list, -// if it is already at back this call is a no-op. -func (l *list) move_back(elem *list_elem) { - if elem == l.tail { - return - } - l.remove(elem) - l.push_back(elem) -} - -// remove will remove given elem from list. -func (l *list) remove(elem *list_elem) { - // Get linked elems. - next := elem.next - prev := elem.prev - - // Unset elem. - elem.next = nil - elem.prev = nil - - switch { - case next == nil: - if prev == nil { - // next == nil && prev == nil - // - // elem is ONLY one in list. - l.head = nil - l.tail = nil - } else { - // next == nil && prev != nil - // - // elem is last in list. - l.tail = prev - prev.next = nil - } - - case prev == nil: - // next != nil && prev == nil - // - // elem is front in list. - l.head = next - next.prev = nil - - // elem in middle of list. - default: - next.prev = prev - prev.next = next - } - - // Decr count - l.len-- -} |