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redis3 using redis native sorted set

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This commit is contained in:
Chris Lu
2021-10-06 18:18:24 -07:00
parent 8668d49c9d
commit 371fead8a5
10 changed files with 817 additions and 205 deletions
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181
weed/util/skiplist/skiplist.go
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@@ -17,12 +17,12 @@ const (
)
type SkipList struct {
startLevels [maxLevel]*SkipListElementReference
endLevels [maxLevel]*SkipListElementReference
maxNewLevel int
maxLevel int
listStore ListStore
hasChanges bool
StartLevels [maxLevel]*SkipListElementReference
EndLevels [maxLevel]*SkipListElementReference
MaxNewLevel int
MaxLevel int
ListStore ListStore
HasChanges bool
// elementCount int
}
@@ -36,9 +36,9 @@ func NewSeed(seed int64, listStore ListStore) *SkipList {
//fmt.Printf("SkipList seed: %v\n", seed)
list := &SkipList{
maxNewLevel: maxLevel,
maxLevel: 0,
listStore: listStore,
MaxNewLevel: maxLevel,
MaxLevel: 0,
ListStore: listStore,
// elementCount: 0,
}
@@ -52,7 +52,7 @@ func New(listStore ListStore) *SkipList {
// IsEmpty checks, if the skiplist is empty.
func (t *SkipList) IsEmpty() bool {
return t.startLevels[0] == nil
return t.StartLevels[0] == nil
}
func (t *SkipList) generateLevel(maxLevel int) int {
@@ -70,8 +70,8 @@ func (t *SkipList) generateLevel(maxLevel int) int {
func (t *SkipList) findEntryIndex(key []byte, minLevel int) int {
// Find good entry point so we don't accidentally skip half the list.
for i := t.maxLevel; i >= 0; i-- {
if t.startLevels[i] != nil && bytes.Compare(t.startLevels[i].Key, key) < 0 || i <= minLevel {
for i := t.MaxLevel; i >= 0; i-- {
if t.StartLevels[i] != nil && bytes.Compare(t.StartLevels[i].Key, key) < 0 || i <= minLevel {
return i
}
}
@@ -90,7 +90,7 @@ func (t *SkipList) findExtended(key []byte, findGreaterOrEqual bool) (prevElemen
index := t.findEntryIndex(key, 0)
var currentNode *SkipListElement
currentNode, err = t.loadElement(t.startLevels[index])
currentNode, err = t.LoadElement(t.StartLevels[index])
if err != nil {
return
}
@@ -115,7 +115,7 @@ func (t *SkipList) findExtended(key []byte, findGreaterOrEqual bool) (prevElemen
// Which direction are we continuing next time?
if currentNode.Next[index] != nil && bytes.Compare(currentNode.Next[index].Key, key) <= 0 {
// Go right
currentNode, err = t.loadElement(currentNode.Next[index])
currentNode, err = t.LoadElement(currentNode.Next[index])
if err != nil {
return
}
@@ -129,7 +129,7 @@ func (t *SkipList) findExtended(key []byte, findGreaterOrEqual bool) (prevElemen
if currentNode.Next[0] != nil && bytes.Compare(currentNode.Next[0].Key, key) == 0 {
prevElementIfVisited = currentNode
var currentNodeNext *SkipListElement
currentNodeNext, err = t.loadElement(currentNode.Next[0])
currentNodeNext, err = t.LoadElement(currentNode.Next[0])
if err != nil {
return
}
@@ -145,7 +145,7 @@ func (t *SkipList) findExtended(key []byte, findGreaterOrEqual bool) (prevElemen
} else {
// Element is not found and we reached the bottom.
if findGreaterOrEqual {
foundElem, err = t.loadElement(currentNode.Next[index])
foundElem, err = t.LoadElement(currentNode.Next[index])
if err != nil {
return
}
@@ -188,13 +188,13 @@ func (t *SkipList) FindGreaterOrEqual(key []byte) (prevIfVisited *SkipListElemen
// If there are multiple entries with the same value, Delete will remove one of them
// (Which one will change based on the actual skiplist layout)
// Delete runs in approx. O(log(n))
func (t *SkipList) Delete(key []byte) (err error) {
func (t *SkipList) DeleteByKey(key []byte) (id int64, err error) {
if t == nil || t.IsEmpty() || key == nil {
return
}
index := t.findEntryIndex(key, t.maxLevel)
index := t.findEntryIndex(key, t.MaxLevel)
var currentNode *SkipListElement
var nextNode *SkipListElement
@@ -202,12 +202,12 @@ func (t *SkipList) Delete(key []byte) (err error) {
for {
if currentNode == nil {
nextNode, err = t.loadElement(t.startLevels[index])
nextNode, err = t.LoadElement(t.StartLevels[index])
} else {
nextNode, err = t.loadElement(currentNode.Next[index])
nextNode, err = t.LoadElement(currentNode.Next[index])
}
if err != nil {
return err
return id, err
}
// Found and remove!
@@ -215,45 +215,46 @@ func (t *SkipList) Delete(key []byte) (err error) {
if currentNode != nil {
currentNode.Next[index] = nextNode.Next[index]
if err = t.saveElement(currentNode); err != nil {
return err
if err = t.SaveElement(currentNode); err != nil {
return id, err
}
}
if index == 0 {
if nextNode.Next[index] != nil {
nextNextNode, err := t.loadElement(nextNode.Next[index])
nextNextNode, err := t.LoadElement(nextNode.Next[index])
if err != nil {
return err
return id, err
}
if nextNextNode != nil {
nextNextNode.Prev = currentNode.Reference()
if err = t.saveElement(nextNextNode); err != nil {
return err
if err = t.SaveElement(nextNextNode); err != nil {
return id, err
}
}
}
// t.elementCount--
if err = t.deleteElement(nextNode); err != nil {
return err
id = nextNode.Id
if err = t.DeleteElement(nextNode); err != nil {
return id, err
}
}
// Link from start needs readjustments.
startNextKey := t.startLevels[index].Key
startNextKey := t.StartLevels[index].Key
if compareElement(nextNode, startNextKey) == 0 {
t.hasChanges = true
t.startLevels[index] = nextNode.Next[index]
t.HasChanges = true
t.StartLevels[index] = nextNode.Next[index]
// This was our currently highest node!
if t.startLevels[index] == nil {
t.maxLevel = index - 1
if t.StartLevels[index] == nil {
t.MaxLevel = index - 1
}
}
// Link from end needs readjustments.
if nextNode.Next[index] == nil {
t.endLevels[index] = currentNode.Reference()
t.hasChanges = true
t.EndLevels[index] = currentNode.Reference()
t.HasChanges = true
}
nextNode.Next[index] = nil
}
@@ -274,24 +275,28 @@ func (t *SkipList) Delete(key []byte) (err error) {
// Insert inserts the given ListElement into the skiplist.
// Insert runs in approx. O(log(n))
func (t *SkipList) Insert(key, value []byte) (err error) {
func (t *SkipList) InsertByKey(key []byte, idIfKnown int64, value []byte) (id int64, err error) {
if t == nil || key == nil {
return
}
level := t.generateLevel(t.maxNewLevel)
level := t.generateLevel(t.MaxNewLevel)
// Only grow the height of the skiplist by one at a time!
if level > t.maxLevel {
level = t.maxLevel + 1
t.maxLevel = level
t.hasChanges = true
if level > t.MaxLevel {
level = t.MaxLevel + 1
t.MaxLevel = level
t.HasChanges = true
}
id = idIfKnown
if id == 0 {
id = rand.Int63()
}
elem := &SkipListElement{
Id: rand.Int63(),
Next: make([]*SkipListElementReference, t.maxNewLevel, t.maxNewLevel),
Id: id,
Next: make([]*SkipListElementReference, t.MaxNewLevel, t.MaxNewLevel),
Level: int32(level),
Key: key,
Value: value,
@@ -302,8 +307,8 @@ func (t *SkipList) Insert(key, value []byte) (err error) {
newFirst := true
newLast := true
if !t.IsEmpty() {
newFirst = compareElement(elem, t.startLevels[0].Key) < 0
newLast = compareElement(elem, t.endLevels[0].Key) > 0
newFirst = compareElement(elem, t.StartLevels[0].Key) < 0
newLast = compareElement(elem, t.EndLevels[0].Key) > 0
}
normallyInserted := false
@@ -319,7 +324,7 @@ func (t *SkipList) Insert(key, value []byte) (err error) {
for {
if currentNode == nil {
nextNodeRef = t.startLevels[index]
nextNodeRef = t.StartLevels[index]
} else {
nextNodeRef = currentNode.Next[index]
}
@@ -331,19 +336,19 @@ func (t *SkipList) Insert(key, value []byte) (err error) {
elem.Next[index] = nextNodeRef
if currentNode != nil {
currentNode.Next[index] = elem.Reference()
if err = t.saveElement(currentNode); err != nil {
if err = t.SaveElement(currentNode); err != nil {
return
}
}
if index == 0 {
elem.Prev = currentNode.Reference()
if nextNodeRef != nil {
if nextNode, err = t.loadElement(nextNodeRef); err != nil {
if nextNode, err = t.LoadElement(nextNodeRef); err != nil {
return
}
if nextNode != nil {
nextNode.Prev = elem.Reference()
if err = t.saveElement(nextNode); err != nil {
if err = t.SaveElement(nextNode); err != nil {
return
}
}
@@ -355,7 +360,7 @@ func (t *SkipList) Insert(key, value []byte) (err error) {
// Go right
if nextNode == nil {
// reuse nextNode when index == 0
if nextNode, err = t.loadElement(nextNodeRef); err != nil {
if nextNode, err = t.LoadElement(nextNodeRef); err != nil {
return
}
}
@@ -380,28 +385,28 @@ func (t *SkipList) Insert(key, value []byte) (err error) {
if newFirst || normallyInserted {
if t.startLevels[i] == nil || bytes.Compare(t.startLevels[i].Key, key) > 0 {
if i == 0 && t.startLevels[i] != nil {
startLevelElement, err := t.loadElement(t.startLevels[i])
if t.StartLevels[i] == nil || bytes.Compare(t.StartLevels[i].Key, key) > 0 {
if i == 0 && t.StartLevels[i] != nil {
startLevelElement, err := t.LoadElement(t.StartLevels[i])
if err != nil {
return err
return id, err
}
if startLevelElement != nil {
startLevelElement.Prev = elem.Reference()
if err = t.saveElement(startLevelElement); err != nil {
return err
if err = t.SaveElement(startLevelElement); err != nil {
return id, err
}
}
}
elem.Next[i] = t.startLevels[i]
t.startLevels[i] = elem.Reference()
t.hasChanges = true
elem.Next[i] = t.StartLevels[i]
t.StartLevels[i] = elem.Reference()
t.HasChanges = true
}
// link the endLevels to this element!
// link the EndLevels to this element!
if elem.Next[i] == nil {
t.endLevels[i] = elem.Reference()
t.hasChanges = true
t.EndLevels[i] = elem.Reference()
t.HasChanges = true
}
didSomething = true
@@ -411,29 +416,29 @@ func (t *SkipList) Insert(key, value []byte) (err error) {
// Places the element after the very last element on this level!
// This is very important, so we are not linking the very first element (newFirst AND newLast) to itself!
if !newFirst {
if t.endLevels[i] != nil {
endLevelElement, err := t.loadElement(t.endLevels[i])
if t.EndLevels[i] != nil {
endLevelElement, err := t.LoadElement(t.EndLevels[i])
if err != nil {
return err
return id, err
}
if endLevelElement != nil {
endLevelElement.Next[i] = elem.Reference()
if err = t.saveElement(endLevelElement); err != nil {
return err
if err = t.SaveElement(endLevelElement); err != nil {
return id, err
}
}
}
if i == 0 {
elem.Prev = t.endLevels[i]
elem.Prev = t.EndLevels[i]
}
t.endLevels[i] = elem.Reference()
t.hasChanges = true
t.EndLevels[i] = elem.Reference()
t.HasChanges = true
}
// Link the startLevels to this element!
if t.startLevels[i] == nil || bytes.Compare(t.startLevels[i].Key, key) > 0 {
t.startLevels[i] = elem.Reference()
t.hasChanges = true
if t.StartLevels[i] == nil || bytes.Compare(t.StartLevels[i].Key, key) > 0 {
t.StartLevels[i] = elem.Reference()
t.HasChanges = true
}
didSomething = true
@@ -444,41 +449,41 @@ func (t *SkipList) Insert(key, value []byte) (err error) {
}
}
if err = t.saveElement(elem); err != nil {
return err
if err = t.SaveElement(elem); err != nil {
return id, err
}
return nil
return id, nil
}
// GetSmallestNode returns the very first/smallest node in the skiplist.
// GetSmallestNode runs in O(1)
func (t *SkipList) GetSmallestNode() (*SkipListElement, error) {
return t.loadElement(t.startLevels[0])
return t.LoadElement(t.StartLevels[0])
}
// GetLargestNode returns the very last/largest node in the skiplist.
// GetLargestNode runs in O(1)
func (t *SkipList) GetLargestNode() (*SkipListElement, error) {
return t.loadElement(t.endLevels[0])
return t.LoadElement(t.EndLevels[0])
}
// Next returns the next element based on the given node.
// Next will loop around to the first node, if you call it on the last!
func (t *SkipList) Next(e *SkipListElement) (*SkipListElement, error) {
if e.Next[0] == nil {
return t.loadElement(t.startLevels[0])
return t.LoadElement(t.StartLevels[0])
}
return t.loadElement(e.Next[0])
return t.LoadElement(e.Next[0])
}
// Prev returns the previous element based on the given node.
// Prev will loop around to the last node, if you call it on the first!
func (t *SkipList) Prev(e *SkipListElement) (*SkipListElement, error) {
if e.Prev == nil {
return t.loadElement(t.endLevels[0])
return t.LoadElement(t.EndLevels[0])
}
return t.loadElement(e.Prev)
return t.LoadElement(e.Prev)
}
// ChangeValue can be used to change the actual value of a node in the skiplist
@@ -488,14 +493,14 @@ func (t *SkipList) Prev(e *SkipListElement) (*SkipListElement, error) {
func (t *SkipList) ChangeValue(e *SkipListElement, newValue []byte) (err error) {
// The key needs to stay correct, so this is very important!
e.Value = newValue
return t.saveElement(e)
return t.SaveElement(e)
}
// String returns a string format of the skiplist. Useful to get a graphical overview and/or debugging.
func (t *SkipList) println() {
print("start --> ")
for i, l := range t.startLevels {
for i, l := range t.StartLevels {
if l == nil {
break
}
@@ -510,10 +515,10 @@ func (t *SkipList) println() {
}
println()
nodeRef := t.startLevels[0]
nodeRef := t.StartLevels[0]
for nodeRef != nil {
print(fmt.Sprintf("%v: ", string(nodeRef.Key)))
node, _ := t.loadElement(nodeRef)
node, _ := t.LoadElement(nodeRef)
if node == nil {
break
}
@@ -546,7 +551,7 @@ func (t *SkipList) println() {
}
print("end --> ")
for i, l := range t.endLevels {
for i, l := range t.EndLevels {
if l == nil {
break
}