You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
515 lines
13 KiB
515 lines
13 KiB
/*
|
|
This tree is not concurrency safe.
|
|
If you want to use it from multiple goroutines, you need to wrap all calls to *IAVLTree
|
|
with a mutex.
|
|
*/
|
|
|
|
package merkle
|
|
|
|
import (
|
|
. "github.com/tendermint/tendermint/binary"
|
|
"bytes"
|
|
"io"
|
|
"crypto/sha256"
|
|
)
|
|
|
|
const HASH_BYTE_SIZE int = 4+32
|
|
|
|
// Immutable AVL Tree (wraps the Node root)
|
|
|
|
type IAVLTree struct {
|
|
db Db
|
|
root *IAVLNode
|
|
}
|
|
|
|
func NewIAVLTree(db Db) *IAVLTree {
|
|
return &IAVLTree{db:db, root:nil}
|
|
}
|
|
|
|
func NewIAVLTreeFromHash(db Db, hash ByteSlice) *IAVLTree {
|
|
root := &IAVLNode{
|
|
hash: hash,
|
|
flags: IAVLNODE_FLAG_PERSISTED | IAVLNODE_FLAG_PLACEHOLDER,
|
|
}
|
|
root.fill(db)
|
|
return &IAVLTree{db:db, root:root}
|
|
}
|
|
|
|
func (t *IAVLTree) Root() Node {
|
|
return t.root
|
|
}
|
|
|
|
func (t *IAVLTree) Size() uint64 {
|
|
if t.root == nil { return 0 }
|
|
return t.root.Size()
|
|
}
|
|
|
|
func (t *IAVLTree) Height() uint8 {
|
|
if t.root == nil { return 0 }
|
|
return t.root.Height()
|
|
}
|
|
|
|
func (t *IAVLTree) Has(key Key) bool {
|
|
if t.root == nil { return false }
|
|
return t.root.has(t.db, key)
|
|
}
|
|
|
|
func (t *IAVLTree) Put(key Key, value Value) (updated bool) {
|
|
if t.root == nil {
|
|
t.root = NewIAVLNode(key, value)
|
|
return false
|
|
}
|
|
t.root, updated = t.root.put(t.db, key, value)
|
|
return updated
|
|
}
|
|
|
|
func (t *IAVLTree) Hash() (ByteSlice, uint64) {
|
|
if t.root == nil { return nil, 0 }
|
|
return t.root.Hash()
|
|
}
|
|
|
|
func (t *IAVLTree) Save() {
|
|
if t.root == nil { return }
|
|
if t.root.hash == nil {
|
|
t.root.Hash()
|
|
}
|
|
t.root.Save(t.db)
|
|
}
|
|
|
|
func (t *IAVLTree) Get(key Key) (value Value) {
|
|
if t.root == nil { return nil }
|
|
return t.root.get(t.db, key)
|
|
}
|
|
|
|
func (t *IAVLTree) Remove(key Key) (value Value, err error) {
|
|
if t.root == nil { return nil, NotFound(key) }
|
|
newRoot, _, value, err := t.root.remove(t.db, key)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
t.root = newRoot
|
|
return value, nil
|
|
}
|
|
|
|
func (t *IAVLTree) Copy() Tree {
|
|
return &IAVLTree{db:t.db, root:t.root}
|
|
}
|
|
|
|
// Traverses all the nodes of the tree in prefix order.
|
|
// return true from cb to halt iteration.
|
|
// node.Height() == 0 if you just want a value node.
|
|
func (t *IAVLTree) Traverse(cb func(Node) bool) {
|
|
if t.root == nil { return }
|
|
t.root.traverse(t.db, cb)
|
|
}
|
|
|
|
func (t *IAVLTree) Values() <-chan Value {
|
|
root := t.root
|
|
ch := make(chan Value)
|
|
go func() {
|
|
root.traverse(t.db, func(n Node) bool {
|
|
if n.Height() == 0 { ch <- n.Value() }
|
|
return true
|
|
})
|
|
close(ch)
|
|
}()
|
|
return ch
|
|
}
|
|
|
|
|
|
// Node
|
|
|
|
type IAVLNode struct {
|
|
key Key
|
|
value Value
|
|
size uint64
|
|
height uint8
|
|
hash ByteSlice
|
|
left *IAVLNode
|
|
right *IAVLNode
|
|
|
|
// volatile
|
|
flags byte
|
|
}
|
|
|
|
const (
|
|
IAVLNODE_FLAG_PERSISTED = byte(0x01)
|
|
IAVLNODE_FLAG_PLACEHOLDER = byte(0x02)
|
|
)
|
|
|
|
func NewIAVLNode(key Key, value Value) *IAVLNode {
|
|
return &IAVLNode{
|
|
key: key,
|
|
value: value,
|
|
size: 1,
|
|
}
|
|
}
|
|
|
|
func (self *IAVLNode) Copy() *IAVLNode {
|
|
if self.height == 0 {
|
|
panic("Why are you copying a value node?")
|
|
}
|
|
return &IAVLNode{
|
|
key: self.key,
|
|
size: self.size,
|
|
height: self.height,
|
|
left: self.left,
|
|
right: self.right,
|
|
hash: nil,
|
|
flags: byte(0),
|
|
}
|
|
}
|
|
|
|
func (self *IAVLNode) Key() Key {
|
|
return self.key
|
|
}
|
|
|
|
func (self *IAVLNode) Value() Value {
|
|
return self.value
|
|
}
|
|
|
|
func (self *IAVLNode) Size() uint64 {
|
|
return self.size
|
|
}
|
|
|
|
func (self *IAVLNode) Height() uint8 {
|
|
return self.height
|
|
}
|
|
|
|
func (self *IAVLNode) has(db Db, key Key) (has bool) {
|
|
if self.key.Equals(key) {
|
|
return true
|
|
}
|
|
if self.height == 0 {
|
|
return false
|
|
} else {
|
|
if key.Less(self.key) {
|
|
return self.leftFilled(db).has(db, key)
|
|
} else {
|
|
return self.rightFilled(db).has(db, key)
|
|
}
|
|
}
|
|
}
|
|
|
|
func (self *IAVLNode) get(db Db, key Key) (value Value) {
|
|
if self.height == 0 {
|
|
if self.key.Equals(key) {
|
|
return self.value
|
|
} else {
|
|
return nil
|
|
}
|
|
} else {
|
|
if key.Less(self.key) {
|
|
return self.leftFilled(db).get(db, key)
|
|
} else {
|
|
return self.rightFilled(db).get(db, key)
|
|
}
|
|
}
|
|
}
|
|
|
|
func (self *IAVLNode) Hash() (ByteSlice, uint64) {
|
|
if self.hash != nil {
|
|
return self.hash, 0
|
|
}
|
|
|
|
hasher := sha256.New()
|
|
_, hashCount, err := self.saveToCountHashes(hasher, false)
|
|
if err != nil { panic(err) }
|
|
self.hash = hasher.Sum(nil)
|
|
|
|
return self.hash, hashCount+1
|
|
}
|
|
|
|
func (self *IAVLNode) Save(db Db) {
|
|
if self.hash == nil {
|
|
panic("savee.hash can't be nil")
|
|
}
|
|
if self.flags & IAVLNODE_FLAG_PERSISTED > 0 ||
|
|
self.flags & IAVLNODE_FLAG_PLACEHOLDER > 0 {
|
|
return
|
|
}
|
|
|
|
// children
|
|
if self.height > 0 {
|
|
self.left.Save(db)
|
|
self.right.Save(db)
|
|
}
|
|
|
|
// save self
|
|
buf := bytes.NewBuffer(nil)
|
|
_, err := self.WriteTo(buf)
|
|
if err != nil { panic(err) }
|
|
db.Put([]byte(self.hash), buf.Bytes())
|
|
|
|
self.flags |= IAVLNODE_FLAG_PERSISTED
|
|
}
|
|
|
|
func (self *IAVLNode) put(db Db, key Key, value Value) (_ *IAVLNode, updated bool) {
|
|
if self.height == 0 {
|
|
if key.Less(self.key) {
|
|
return &IAVLNode{
|
|
key: self.key,
|
|
height: 1,
|
|
size: 2,
|
|
left: NewIAVLNode(key, value),
|
|
right: self,
|
|
}, false
|
|
} else if self.key.Equals(key) {
|
|
return NewIAVLNode(key, value), true
|
|
} else {
|
|
return &IAVLNode{
|
|
key: key,
|
|
height: 1,
|
|
size: 2,
|
|
left: self,
|
|
right: NewIAVLNode(key, value),
|
|
}, false
|
|
}
|
|
} else {
|
|
self = self.Copy()
|
|
if key.Less(self.key) {
|
|
self.left, updated = self.leftFilled(db).put(db, key, value)
|
|
} else {
|
|
self.right, updated = self.rightFilled(db).put(db, key, value)
|
|
}
|
|
if updated {
|
|
return self, updated
|
|
} else {
|
|
self.calcHeightAndSize(db)
|
|
return self.balance(db), updated
|
|
}
|
|
}
|
|
}
|
|
|
|
// newKey: new leftmost leaf key for tree after successfully removing 'key' if changed.
|
|
func (self *IAVLNode) remove(db Db, key Key) (newSelf *IAVLNode, newKey Key, value Value, err error) {
|
|
if self.height == 0 {
|
|
if self.key.Equals(key) {
|
|
return nil, nil, self.value, nil
|
|
} else {
|
|
return self, nil, nil, NotFound(key)
|
|
}
|
|
} else {
|
|
if key.Less(self.key) {
|
|
var newLeft *IAVLNode
|
|
newLeft, newKey, value, err = self.leftFilled(db).remove(db, key)
|
|
if err != nil {
|
|
return self, nil, value, err
|
|
} else if newLeft == nil { // left node held value, was removed
|
|
return self.right, self.key, value, nil
|
|
}
|
|
self = self.Copy()
|
|
self.left = newLeft
|
|
} else {
|
|
var newRight *IAVLNode
|
|
newRight, newKey, value, err = self.rightFilled(db).remove(db, key)
|
|
if err != nil {
|
|
return self, nil, value, err
|
|
} else if newRight == nil { // right node held value, was removed
|
|
return self.left, nil, value, nil
|
|
}
|
|
self = self.Copy()
|
|
self.right = newRight
|
|
if newKey != nil {
|
|
self.key = newKey
|
|
newKey = nil
|
|
}
|
|
}
|
|
self.calcHeightAndSize(db)
|
|
return self.balance(db), newKey, value, err
|
|
}
|
|
}
|
|
|
|
func (self *IAVLNode) WriteTo(w io.Writer) (n int64, err error) {
|
|
n, _, err = self.saveToCountHashes(w, true)
|
|
return
|
|
}
|
|
|
|
func (self *IAVLNode) saveToCountHashes(w io.Writer, meta bool) (n int64, hashCount uint64, err error) {
|
|
var _n int64
|
|
|
|
if meta {
|
|
// height & size
|
|
_n, err = UInt8(self.height).WriteTo(w)
|
|
if err != nil { return } else { n += _n }
|
|
_n, err = UInt64(self.size).WriteTo(w)
|
|
if err != nil { return } else { n += _n }
|
|
|
|
// key
|
|
_n, err = Byte(GetBinaryType(self.key)).WriteTo(w)
|
|
if err != nil { return } else { n += _n }
|
|
_n, err = self.key.WriteTo(w)
|
|
if err != nil { return } else { n += _n }
|
|
}
|
|
|
|
if self.height == 0 {
|
|
// value
|
|
_n, err = Byte(GetBinaryType(self.value)).WriteTo(w)
|
|
if err != nil { return } else { n += _n }
|
|
if self.value != nil {
|
|
_n, err = self.value.WriteTo(w)
|
|
if err != nil { return } else { n += _n }
|
|
}
|
|
} else {
|
|
// left
|
|
leftHash, leftCount := self.left.Hash()
|
|
hashCount += leftCount
|
|
_n, err = leftHash.WriteTo(w)
|
|
if err != nil { return } else { n += _n }
|
|
// right
|
|
rightHash, rightCount := self.right.Hash()
|
|
hashCount += rightCount
|
|
_n, err = rightHash.WriteTo(w)
|
|
if err != nil { return } else { n += _n }
|
|
}
|
|
|
|
return
|
|
}
|
|
|
|
// Given a placeholder node which has only the hash set,
|
|
// load the rest of the data from db.
|
|
// Not threadsafe.
|
|
func (self *IAVLNode) fill(db Db) {
|
|
if self.hash == nil {
|
|
panic("placeholder.hash can't be nil")
|
|
}
|
|
buf := db.Get(self.hash)
|
|
r := bytes.NewReader(buf)
|
|
// node header
|
|
self.height = uint8(ReadUInt8(r))
|
|
self.size = uint64(ReadUInt64(r))
|
|
// key
|
|
key := ReadBinary(r)
|
|
self.key = key.(Key)
|
|
|
|
if self.height == 0 {
|
|
// value
|
|
self.value = ReadBinary(r)
|
|
} else {
|
|
// left
|
|
var leftHash ByteSlice
|
|
leftHash = ReadByteSlice(r)
|
|
self.left = &IAVLNode{
|
|
hash: leftHash,
|
|
flags: IAVLNODE_FLAG_PERSISTED | IAVLNODE_FLAG_PLACEHOLDER,
|
|
}
|
|
// right
|
|
var rightHash ByteSlice
|
|
rightHash = ReadByteSlice(r)
|
|
self.right = &IAVLNode{
|
|
hash: rightHash,
|
|
flags: IAVLNODE_FLAG_PERSISTED | IAVLNODE_FLAG_PLACEHOLDER,
|
|
}
|
|
if r.Len() != 0 {
|
|
panic("buf not all consumed")
|
|
}
|
|
}
|
|
self.flags &= ^IAVLNODE_FLAG_PLACEHOLDER
|
|
}
|
|
|
|
func (self *IAVLNode) leftFilled(db Db) *IAVLNode {
|
|
if self.left.flags & IAVLNODE_FLAG_PLACEHOLDER > 0 {
|
|
self.left.fill(db)
|
|
}
|
|
return self.left
|
|
}
|
|
|
|
func (self *IAVLNode) rightFilled(db Db) *IAVLNode {
|
|
if self.right.flags & IAVLNODE_FLAG_PLACEHOLDER > 0 {
|
|
self.right.fill(db)
|
|
}
|
|
return self.right
|
|
}
|
|
|
|
func (self *IAVLNode) rotateRight(db Db) *IAVLNode {
|
|
self = self.Copy()
|
|
sl := self.leftFilled(db).Copy()
|
|
slr := sl.right
|
|
|
|
sl.right = self
|
|
self.left = slr
|
|
|
|
self.calcHeightAndSize(db)
|
|
sl.calcHeightAndSize(db)
|
|
|
|
return sl
|
|
}
|
|
|
|
func (self *IAVLNode) rotateLeft(db Db) *IAVLNode {
|
|
self = self.Copy()
|
|
sr := self.rightFilled(db).Copy()
|
|
srl := sr.left
|
|
|
|
sr.left = self
|
|
self.right = srl
|
|
|
|
self.calcHeightAndSize(db)
|
|
sr.calcHeightAndSize(db)
|
|
|
|
return sr
|
|
}
|
|
|
|
func (self *IAVLNode) calcHeightAndSize(db Db) {
|
|
self.height = maxUint8(self.leftFilled(db).Height(), self.rightFilled(db).Height()) + 1
|
|
self.size = self.leftFilled(db).Size() + self.rightFilled(db).Size()
|
|
}
|
|
|
|
func (self *IAVLNode) calcBalance(db Db) int {
|
|
return int(self.leftFilled(db).Height()) - int(self.rightFilled(db).Height())
|
|
}
|
|
|
|
func (self *IAVLNode) balance(db Db) (newSelf *IAVLNode) {
|
|
balance := self.calcBalance(db)
|
|
if (balance > 1) {
|
|
if (self.leftFilled(db).calcBalance(db) >= 0) {
|
|
// Left Left Case
|
|
return self.rotateRight(db)
|
|
} else {
|
|
// Left Right Case
|
|
self = self.Copy()
|
|
self.left = self.leftFilled(db).rotateLeft(db)
|
|
//self.calcHeightAndSize()
|
|
return self.rotateRight(db)
|
|
}
|
|
}
|
|
if (balance < -1) {
|
|
if (self.rightFilled(db).calcBalance(db) <= 0) {
|
|
// Right Right Case
|
|
return self.rotateLeft(db)
|
|
} else {
|
|
// Right Left Case
|
|
self = self.Copy()
|
|
self.right = self.rightFilled(db).rotateRight(db)
|
|
//self.calcHeightAndSize()
|
|
return self.rotateLeft(db)
|
|
}
|
|
}
|
|
// Nothing changed
|
|
return self
|
|
}
|
|
|
|
func (self *IAVLNode) lmd(db Db) (*IAVLNode) {
|
|
if self.height == 0 {
|
|
return self
|
|
}
|
|
return self.leftFilled(db).lmd(db)
|
|
}
|
|
|
|
func (self *IAVLNode) rmd(db Db) (*IAVLNode) {
|
|
if self.height == 0 {
|
|
return self
|
|
}
|
|
return self.rightFilled(db).rmd(db)
|
|
}
|
|
|
|
func (self *IAVLNode) traverse(db Db, cb func(Node)bool) bool {
|
|
stop := cb(self)
|
|
if stop { return stop }
|
|
if self.height > 0 {
|
|
stop = self.leftFilled(db).traverse(db, cb)
|
|
if stop { return stop }
|
|
stop = self.rightFilled(db).traverse(db, cb)
|
|
if stop { return stop }
|
|
}
|
|
return false
|
|
}
|