diff --git a/store/cachekv/memiterator.go b/store/cachekv/memiterator.go index 675494b8f..b197ac141 100644 --- a/store/cachekv/memiterator.go +++ b/store/cachekv/memiterator.go @@ -1,7 +1,6 @@ package cachekv import ( - "container/list" "errors" dbm "github.com/tendermint/tm-db" @@ -18,13 +17,13 @@ type memIterator struct { ascending bool } -func newMemIterator(start, end []byte, items *list.List, ascending bool) *memIterator { +func newMemIterator(start, end []byte, items *kv.List, ascending bool) *memIterator { itemsInDomain := make([]*kv.Pair, 0, items.Len()) var entered bool for e := items.Front(); e != nil; e = e.Next() { - item := e.Value.(*kv.Pair) + item := e.Value if !dbm.IsKeyInDomain(item.Key, start, end) { if entered { break diff --git a/store/cachekv/store.go b/store/cachekv/store.go index a953d4436..af5d75f9c 100644 --- a/store/cachekv/store.go +++ b/store/cachekv/store.go @@ -2,7 +2,6 @@ package cachekv import ( "bytes" - "container/list" "io" "sort" "sync" @@ -30,7 +29,7 @@ type Store struct { mtx sync.Mutex cache map[string]*cValue unsortedCache map[string]struct{} - sortedCache *list.List // always ascending sorted + sortedCache *kv.List // always ascending sorted parent types.KVStore } @@ -41,7 +40,7 @@ func NewStore(parent types.KVStore) *Store { return &Store{ cache: make(map[string]*cValue), unsortedCache: make(map[string]struct{}), - sortedCache: list.New(), + sortedCache: kv.NewList(), parent: parent, } } @@ -134,7 +133,7 @@ func (store *Store) Write() { // Clear the cache store.cache = make(map[string]*cValue) store.unsortedCache = make(map[string]struct{}) - store.sortedCache = list.New() + store.sortedCache = kv.NewList() } // CacheWrap implements CacheWrapper. @@ -206,7 +205,7 @@ func (store *Store) dirtyItems(start, end []byte) { for e := store.sortedCache.Front(); e != nil && len(unsorted) != 0; { uitem := unsorted[0] - sitem := e.Value.(*kv.Pair) + sitem := e.Value comp := bytes.Compare(uitem.Key, sitem.Key) switch comp { diff --git a/types/kv/kv.go b/types/kv/kv.go index a0aab3f47..1f3da91cc 100644 --- a/types/kv/kv.go +++ b/types/kv/kv.go @@ -23,4 +23,6 @@ func (kvs Pairs) Less(i, j int) bool { } func (kvs Pairs) Swap(i, j int) { kvs.Pairs[i], kvs.Pairs[j] = kvs.Pairs[j], kvs.Pairs[i] } -func (kvs Pairs) Sort() { sort.Sort(kvs) } + +// Sort invokes sort.Sort on kvs. +func (kvs Pairs) Sort() { sort.Sort(kvs) } diff --git a/types/kv/list.go b/types/kv/list.go new file mode 100644 index 000000000..9e928c849 --- /dev/null +++ b/types/kv/list.go @@ -0,0 +1,236 @@ +package kv + +// This code was copied from golang.org/pkg/container/list, but specially adapted +// for use with kv.Pair to avoid the type assertion CPU expense of using Value with +// an interface, per https://github.com/cosmos/cosmos-sdk/issues/8810 +// +// Copyright 2009 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// 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 *Pair +} + +// Next returns the next list element or nil. +func (e *Element) Next() *Element { + if p := e.next; e.list != nil && p != &e.list.root { + return p + } + return nil +} + +// Prev returns the previous list element or nil. +func (e *Element) Prev() *Element { + if p := e.prev; e.list != nil && p != &e.list.root { + return p + } + return nil +} + +// 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 +} + +// 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 +} + +// NewList returns an initialized list. +func NewList() *List { return new(List).Init() } + +// Len returns the number of elements of list l. +// The complexity is O(1). +func (l *List) Len() int { return l.len } + +// Front returns the first element of list l or nil if the list is empty. +func (l *List) Front() *Element { + if l.len == 0 { + return nil + } + return l.root.next +} + +// Back returns the last element of list l or nil if the list is empty. +func (l *List) Back() *Element { + if l.len == 0 { + return nil + } + return l.root.prev +} + +// lazyInit lazily initializes a zero List value. +func (l *List) lazyInit() { + if l.root.next == nil { + l.Init() + } +} + +// insert inserts e after at, increments l.len, and returns e. +func (l *List) insert(e, at *Element) *Element { + e.prev = at + e.next = at.next + e.prev.next = e + e.next.prev = e + e.list = l + l.len++ + return e +} + +// insertValue is a convenience wrapper for insert(&Element{Value: v}, at). +func (l *List) insertValue(v *Pair, at *Element) *Element { + return l.insert(&Element{Value: v}, at) +} + +// 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 +} + +// move moves e to next to at and returns e. +// nolint: unparam +func (l *List) move(e, at *Element) *Element { + if e == at { + return e + } + e.prev.next = e.next + e.next.prev = e.prev + + e.prev = at + e.next = at.next + e.prev.next = e + e.next.prev = e + + return e +} + +// Remove removes e from l if e is an element of list l. +// It returns the element value e.Value. +// The element must not be nil. +func (l *List) Remove(e *Element) *Pair { + if e.list == l { + // if e.list == l, l must have been initialized when e was inserted + // in l or l == nil (e is a zero Element) and l.remove will crash + l.remove(e) + } + return e.Value +} + +// PushFront inserts a new element e with value v at the front of list l and returns e. +func (l *List) PushFront(v *Pair) *Element { + l.lazyInit() + return l.insertValue(v, &l.root) +} + +// PushBack inserts a new element e with value v at the back of list l and returns e. +func (l *List) PushBack(v *Pair) *Element { + l.lazyInit() + return l.insertValue(v, l.root.prev) +} + +// InsertBefore inserts a new element e with value v immediately before mark and returns e. +// If mark is not an element of l, the list is not modified. +// The mark must not be nil. +func (l *List) InsertBefore(v *Pair, mark *Element) *Element { + if mark.list != l { + return nil + } + // see comment in List.Remove about initialization of l + return l.insertValue(v, mark.prev) +} + +// InsertAfter inserts a new element e with value v immediately after mark and returns e. +// If mark is not an element of l, the list is not modified. +// The mark must not be nil. +func (l *List) InsertAfter(v *Pair, mark *Element) *Element { + if mark.list != l { + return nil + } + // see comment in List.Remove about initialization of l + return l.insertValue(v, mark) +} + +// MoveToFront moves element e to the front of list l. +// If e is not an element of l, the list is not modified. +// The element must not be nil. +func (l *List) MoveToFront(e *Element) { + if e.list != l || l.root.next == e { + return + } + // see comment in List.Remove about initialization of l + l.move(e, &l.root) +} + +// MoveToBack moves element e to the back of list l. +// If e is not an element of l, the list is not modified. +// The element must not be nil. +func (l *List) MoveToBack(e *Element) { + if e.list != l || l.root.prev == e { + return + } + // see comment in List.Remove about initialization of l + l.move(e, l.root.prev) +} + +// MoveBefore moves element e to its new position before mark. +// If e or mark is not an element of l, or e == mark, the list is not modified. +// The element and mark must not be nil. +func (l *List) MoveBefore(e, mark *Element) { + if e.list != l || e == mark || mark.list != l { + return + } + l.move(e, mark.prev) +} + +// MoveAfter moves element e to its new position after mark. +// If e or mark is not an element of l, or e == mark, the list is not modified. +// The element and mark must not be nil. +func (l *List) MoveAfter(e, mark *Element) { + if e.list != l || e == mark || mark.list != l { + return + } + l.move(e, mark) +} + +// PushBackList inserts a copy of another list at the back of list l. +// The lists l and other may be the same. They must not be nil. +func (l *List) PushBackList(other *List) { + l.lazyInit() + for i, e := other.Len(), other.Front(); i > 0; i, e = i-1, e.Next() { + l.insertValue(e.Value, l.root.prev) + } +} + +// PushFrontList inserts a copy of another list at the front of list l. +// The lists l and other may be the same. They must not be nil. +func (l *List) PushFrontList(other *List) { + l.lazyInit() + for i, e := other.Len(), other.Back(); i > 0; i, e = i-1, e.Prev() { + l.insertValue(e.Value, &l.root) + } +}