Merge pull request #6657 from unclejack/refactor_truncindex

refactor TruncIndex to use a trie & vendor deps
This commit is contained in:
Michael Crosby 2014-06-26 16:53:49 -07:00
commit cab7894808
14 changed files with 1795 additions and 58 deletions

View file

@ -182,11 +182,7 @@ func (daemon *Daemon) register(container *Container, updateSuffixarray bool, con
// don't update the Suffixarray if we're starting up
// we'll waste time if we update it for every container
if updateSuffixarray {
daemon.idIndex.Add(container.ID)
} else {
daemon.idIndex.AddWithoutSuffixarrayUpdate(container.ID)
}
daemon.idIndex.Add(container.ID)
// FIXME: if the container is supposed to be running but is not, auto restart it?
// if so, then we need to restart monitor and init a new lock
@ -377,8 +373,6 @@ func (daemon *Daemon) restore() error {
}
}
daemon.idIndex.UpdateSuffixarray()
for _, container := range containersToStart {
utils.Debugf("Starting container %d", container.ID)
if err := container.Start(); err != nil {

View file

@ -47,6 +47,8 @@ clone git github.com/gorilla/mux 136d54f81f
clone git github.com/syndtr/gocapability 3c85049eae
clone git github.com/tchap/go-patricia v1.0.0
clone hg code.google.com/p/go.net 84a4013f96e0
clone hg code.google.com/p/gosqlite 74691fb6f837

View file

@ -1,31 +1,34 @@
package truncindex
import (
"errors"
"fmt"
"index/suffixarray"
"strings"
"sync"
"github.com/tchap/go-patricia/patricia"
)
var (
ErrNoID = errors.New("prefix can't be empty")
)
// TruncIndex allows the retrieval of string identifiers by any of their unique prefixes.
// This is used to retrieve image and container IDs by more convenient shorthand prefixes.
type TruncIndex struct {
sync.RWMutex
index *suffixarray.Index
ids map[string]bool
bytes []byte
trie *patricia.Trie
ids map[string]struct{}
}
func NewTruncIndex(ids []string) (idx *TruncIndex) {
idx = &TruncIndex{
ids: make(map[string]bool),
bytes: []byte{' '},
ids: make(map[string]struct{}),
trie: patricia.NewTrie(),
}
for _, id := range ids {
idx.ids[id] = true
idx.bytes = append(idx.bytes, []byte(id+" ")...)
idx.addId(id)
}
idx.index = suffixarray.New(idx.bytes)
return
}
@ -33,11 +36,16 @@ func (idx *TruncIndex) addId(id string) error {
if strings.Contains(id, " ") {
return fmt.Errorf("Illegal character: ' '")
}
if _, exists := idx.ids[id]; exists {
return fmt.Errorf("Id already exists: %s", id)
if id == "" {
return ErrNoID
}
if _, exists := idx.ids[id]; exists {
return fmt.Errorf("Id already exists: '%s'", id)
}
idx.ids[id] = struct{}{}
if inserted := idx.trie.Insert(patricia.Prefix(id), struct{}{}); !inserted {
return fmt.Errorf("Failed to insert id: %s", id)
}
idx.ids[id] = true
idx.bytes = append(idx.bytes, []byte(id+" ")...)
return nil
}
@ -47,56 +55,46 @@ func (idx *TruncIndex) Add(id string) error {
if err := idx.addId(id); err != nil {
return err
}
idx.index = suffixarray.New(idx.bytes)
return nil
}
func (idx *TruncIndex) AddWithoutSuffixarrayUpdate(id string) error {
idx.Lock()
defer idx.Unlock()
return idx.addId(id)
}
func (idx *TruncIndex) UpdateSuffixarray() {
idx.Lock()
defer idx.Unlock()
idx.index = suffixarray.New(idx.bytes)
}
func (idx *TruncIndex) Delete(id string) error {
idx.Lock()
defer idx.Unlock()
if _, exists := idx.ids[id]; !exists {
return fmt.Errorf("No such id: %s", id)
}
before, after, err := idx.lookup(id)
if err != nil {
return err
if _, exists := idx.ids[id]; !exists || id == "" {
return fmt.Errorf("No such id: '%s'", id)
}
delete(idx.ids, id)
idx.bytes = append(idx.bytes[:before], idx.bytes[after:]...)
idx.index = suffixarray.New(idx.bytes)
return nil
}
func (idx *TruncIndex) lookup(s string) (int, int, error) {
offsets := idx.index.Lookup([]byte(" "+s), -1)
//log.Printf("lookup(%s): %v (index bytes: '%s')\n", s, offsets, idx.index.Bytes())
if offsets == nil || len(offsets) == 0 || len(offsets) > 1 {
return -1, -1, fmt.Errorf("No such id: %s", s)
if deleted := idx.trie.Delete(patricia.Prefix(id)); !deleted {
return fmt.Errorf("No such id: '%s'", id)
}
offsetBefore := offsets[0] + 1
offsetAfter := offsetBefore + strings.Index(string(idx.bytes[offsetBefore:]), " ")
return offsetBefore, offsetAfter, nil
return nil
}
func (idx *TruncIndex) Get(s string) (string, error) {
idx.RLock()
defer idx.RUnlock()
before, after, err := idx.lookup(s)
//log.Printf("Get(%s) bytes=|%s| before=|%d| after=|%d|\n", s, idx.bytes, before, after)
if err != nil {
return "", err
var (
id string
)
if s == "" {
return "", ErrNoID
}
return string(idx.bytes[before:after]), err
subTreeVisitFunc := func(prefix patricia.Prefix, item patricia.Item) error {
if id != "" {
// we haven't found the ID if there are two or more IDs
id = ""
return fmt.Errorf("we've found two entries")
}
id = string(prefix)
return nil
}
if err := idx.trie.VisitSubtree(patricia.Prefix(s), subTreeVisitFunc); err != nil {
return "", fmt.Errorf("No such id: %s", s)
}
if id != "" {
return id, nil
}
return "", fmt.Errorf("No such id: %s", s)
}

View file

@ -26,8 +26,16 @@ func TestTruncIndex(t *testing.T) {
if err := index.Add(id); err != nil {
t.Fatal(err)
}
// Add an empty id (should fail)
if err := index.Add(""); err == nil {
t.Fatalf("Adding an empty id should return an error")
}
// Get a non-existing id
assertIndexGet(t, index, "abracadabra", "", true)
// Get an empty id
assertIndexGet(t, index, "", "", true)
// Get the exact id
assertIndexGet(t, index, id, id, false)
// The first letter should match
@ -60,6 +68,11 @@ func TestTruncIndex(t *testing.T) {
t.Fatalf("Deleting a non-existing id should return an error")
}
// Deleting an empty id should return an error
if err := index.Delete(""); err == nil {
t.Fatal("Deleting an empty id should return an error")
}
// Deleting id2 should remove conflicts
if err := index.Delete(id2); err != nil {
t.Fatal(err)
@ -84,7 +97,7 @@ func assertIndexGet(t *testing.T, index *TruncIndex, input, expectedResult strin
if result, err := index.Get(input); err != nil && !expectError {
t.Fatalf("Unexpected error getting '%s': %s", input, err)
} else if err == nil && expectError {
t.Fatalf("Getting '%s' should return an error", input)
t.Fatalf("Getting '%s' should return an error, not '%s'", input, result)
} else if result != expectedResult {
t.Fatalf("Getting '%s' returned '%s' instead of '%s'", input, result, expectedResult)
}

View file

@ -0,0 +1,25 @@
# Swap files.
*.swp
# Compiled Object files, Static and Dynamic libs (Shared Objects)
*.o
*.a
*.so
# Folders
_obj
_test
# Architecture specific extensions/prefixes
*.[568vq]
[568vq].out
*.cgo1.go
*.cgo2.c
_cgo_defun.c
_cgo_gotypes.go
_cgo_export.*
_testmain.go
*.exe

View file

@ -0,0 +1,9 @@
language: go
go:
- 1.2
- tip
branches:
exclude:
- wip

View file

@ -0,0 +1,3 @@
This is the complete list of go-patricia copyright holders:
Ondřej Kupka <ondra.cap@gmail.com>

View file

@ -0,0 +1,20 @@
The MIT License (MIT)
Copyright (c) 2014 The AUTHORS
Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the "Software"), to deal in
the Software without restriction, including without limitation the rights to
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
the Software, and to permit persons to whom the Software is furnished to do so,
subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

View file

@ -0,0 +1,112 @@
# go-patricia #
**Documentation**: [GoDoc](http://godoc.org/github.com/tchap/go-patricia/patricia)<br />
**Build Status**: [![Build Status](https://travis-ci.org/tchap/go-patricia.png?branch=master)](https://travis-ci.org/tchap/go-patricia)<br >
**Test Coverage**: Comming as soon as Drone.io people update their Go.
## About ##
A generic patricia trie (also called radix tree) implemented in Go (Golang).
The patricia trie as implemented in this library enables fast visiting of items
in some particular ways:
1. visit all items saved in the tree,
2. visit all items matching particular prefix (visit subtree), or
3. given a string, visit all items matching some prefix of that string.
`[]byte` type is used for keys, `interface{}` for values.
`Trie` is not thread safe. Synchronize the access yourself.
### State of the Project ###
Apparently some people are using this, so the API should not change often.
Any ideas on how to make the library better are still welcome.
More (unit) testing would be cool as well...
## Usage ##
Import the package from GitHub first.
```go
import "github.com/tchap/go-patricia/patricia"
```
Then you can start having fun.
```go
printItem := func(prefix patricia.Prefix, item patricia.Item) error {
fmt.Printf("%q: %v\n", prefix, item)
return nil
}
// Create a new tree.
trie := NewTrie()
// Insert some items.
trie.Insert(Prefix("Pepa Novak"), 1)
trie.Insert(Prefix("Pepa Sindelar"), 2)
trie.Insert(Prefix("Karel Macha"), 3)
trie.Insert(Prefix("Karel Hynek Macha"), 4)
// Just check if some things are present in the tree.
key := Prefix("Pepa Novak")
fmt.Printf("%q present? %v\n", key, trie.Match(key))
// "Pepa Novak" present? true
key = Prefix("Karel")
fmt.Printf("Anybody called %q here? %v\n", key, trie.MatchSubtree(key))
// Anybody called "Karel" here? true
// Walk the tree.
trie.Visit(printItem)
// "Pepa Novak": 1
// "Pepa Sindelar": 2
// "Karel Macha": 3
// "Karel Hynek Macha": 4
// Walk a subtree.
trie.VisitSubtree(Prefix("Pepa"), printItem)
// "Pepa Novak": 1
// "Pepa Sindelar": 2
// Modify an item, then fetch it from the tree.
trie.Set(Prefix("Karel Hynek Macha"), 10)
key = Prefix("Karel Hynek Macha")
fmt.Printf("%q: %v\n", key, trie.Get(key))
// "Karel Hynek Macha": 10
// Walk prefixes.
prefix := Prefix("Karel Hynek Macha je kouzelnik")
trie.VisitPrefixes(prefix, printItem)
// "Karel Hynek Macha": 10
// Delete some items.
trie.Delete(Prefix("Pepa Novak"))
trie.Delete(Prefix("Karel Macha"))
// Walk again.
trie.Visit(printItem)
// "Pepa Sindelar": 2
// "Karel Hynek Macha": 10
// Delete a subtree.
trie.DeleteSubtree(Prefix("Pepa"))
// Print what is left.
trie.Visit(printItem)
// "Karel Hynek Macha": 10
```
## License ##
MIT, check the `LICENSE` file.
[![Gittip
Badge](http://img.shields.io/gittip/alanhamlett.png)](https://www.gittip.com/tchap/
"Gittip Badge")
[![Bitdeli
Badge](https://d2weczhvl823v0.cloudfront.net/tchap/go-patricia/trend.png)](https://bitdeli.com/free
"Bitdeli Badge")

View file

@ -0,0 +1,231 @@
// Copyright (c) 2014 The go-patricia AUTHORS
//
// Use of this source code is governed by The MIT License
// that can be found in the LICENSE file.
package patricia
const (
// Max prefix length that is kept in a single trie node.
MaxPrefixPerNode = 10
// Max children to keep in a node in the sparse mode.
MaxChildrenPerSparseNode = 8
)
type childList interface {
length() int
head() *Trie
add(child *Trie) childList
replace(b byte, child *Trie)
remove(child *Trie)
next(b byte) *Trie
walk(prefix *Prefix, visitor VisitorFunc) error
}
type sparseChildList struct {
children []*Trie
}
func newSparseChildList() childList {
return &sparseChildList{
children: make([]*Trie, 0, MaxChildrenPerSparseNode),
}
}
func (list *sparseChildList) length() int {
return len(list.children)
}
func (list *sparseChildList) head() *Trie {
return list.children[0]
}
func (list *sparseChildList) add(child *Trie) childList {
// Search for an empty spot and insert the child if possible.
if len(list.children) != cap(list.children) {
list.children = append(list.children, child)
return list
}
// Otherwise we have to transform to the dense list type.
return newDenseChildList(list, child)
}
func (list *sparseChildList) replace(b byte, child *Trie) {
// Seek the child and replace it.
for i, node := range list.children {
if node.prefix[0] == b {
list.children[i] = child
return
}
}
}
func (list *sparseChildList) remove(child *Trie) {
for i, node := range list.children {
if node.prefix[0] == child.prefix[0] {
list.children = append(list.children[:i], list.children[i+1:]...)
return
}
}
// This is not supposed to be reached.
panic("removing non-existent child")
}
func (list *sparseChildList) next(b byte) *Trie {
for _, child := range list.children {
if child.prefix[0] == b {
return child
}
}
return nil
}
func (list *sparseChildList) walk(prefix *Prefix, visitor VisitorFunc) error {
for _, child := range list.children {
*prefix = append(*prefix, child.prefix...)
if child.item != nil {
err := visitor(*prefix, child.item)
if err != nil {
if err == SkipSubtree {
*prefix = (*prefix)[:len(*prefix)-len(child.prefix)]
continue
}
*prefix = (*prefix)[:len(*prefix)-len(child.prefix)]
return err
}
}
err := child.children.walk(prefix, visitor)
*prefix = (*prefix)[:len(*prefix)-len(child.prefix)]
if err != nil {
return err
}
}
return nil
}
type denseChildList struct {
min int
max int
children []*Trie
}
func newDenseChildList(list *sparseChildList, child *Trie) childList {
var (
min int = 255
max int = 0
)
for _, child := range list.children {
b := int(child.prefix[0])
if b < min {
min = b
}
if b > max {
max = b
}
}
b := int(child.prefix[0])
if b < min {
min = b
}
if b > max {
max = b
}
children := make([]*Trie, max-min+1)
for _, child := range list.children {
children[int(child.prefix[0])-min] = child
}
children[int(child.prefix[0])-min] = child
return &denseChildList{min, max, children}
}
func (list *denseChildList) length() int {
return list.max - list.min + 1
}
func (list *denseChildList) head() *Trie {
return list.children[0]
}
func (list *denseChildList) add(child *Trie) childList {
b := int(child.prefix[0])
switch {
case list.min <= b && b <= list.max:
if list.children[b-list.min] != nil {
panic("dense child list collision detected")
}
list.children[b-list.min] = child
case b < list.min:
children := make([]*Trie, list.max-b+1)
children[0] = child
copy(children[list.min-b:], list.children)
list.children = children
list.min = b
default: // b > list.max
children := make([]*Trie, b-list.min+1)
children[b-list.min] = child
copy(children, list.children)
list.children = children
list.max = b
}
return list
}
func (list *denseChildList) replace(b byte, child *Trie) {
list.children[int(b)-list.min] = nil
list.children[int(child.prefix[0])-list.min] = child
}
func (list *denseChildList) remove(child *Trie) {
i := int(child.prefix[0]) - list.min
if list.children[i] == nil {
// This is not supposed to be reached.
panic("removing non-existent child")
}
list.children[i] = nil
}
func (list *denseChildList) next(b byte) *Trie {
i := int(b)
if i < list.min || list.max < i {
return nil
}
return list.children[i-list.min]
}
func (list *denseChildList) walk(prefix *Prefix, visitor VisitorFunc) error {
for _, child := range list.children {
if child == nil {
continue
}
*prefix = append(*prefix, child.prefix...)
if child.item != nil {
if err := visitor(*prefix, child.item); err != nil {
if err == SkipSubtree {
*prefix = (*prefix)[:len(*prefix)-len(child.prefix)]
continue
}
*prefix = (*prefix)[:len(*prefix)-len(child.prefix)]
return err
}
}
err := child.children.walk(prefix, visitor)
*prefix = (*prefix)[:len(*prefix)-len(child.prefix)]
if err != nil {
return err
}
}
return nil
}

View file

@ -0,0 +1,432 @@
// Copyright (c) 2014 The go-patricia AUTHORS
//
// Use of this source code is governed by The MIT License
// that can be found in the LICENSE file.
package patricia
import (
"errors"
)
//------------------------------------------------------------------------------
// Trie
//------------------------------------------------------------------------------
type (
Prefix []byte
Item interface{}
VisitorFunc func(prefix Prefix, item Item) error
)
// Trie is a generic patricia trie that allows fast retrieval of items by prefix.
// and other funky stuff.
//
// Trie is not thread-safe.
type Trie struct {
prefix Prefix
item Item
children childList
}
// Public API ------------------------------------------------------------------
// Trie constructor.
func NewTrie() *Trie {
return &Trie{
children: newSparseChildList(),
}
}
// Item returns the item stored in the root of this trie.
func (trie *Trie) Item() Item {
return trie.item
}
// Insert inserts a new item into the trie using the given prefix. Insert does
// not replace existing items. It returns false if an item was already in place.
func (trie *Trie) Insert(key Prefix, item Item) (inserted bool) {
return trie.put(key, item, false)
}
// Set works much like Insert, but it always sets the item, possibly replacing
// the item previously inserted.
func (trie *Trie) Set(key Prefix, item Item) {
trie.put(key, item, true)
}
// Get returns the item located at key.
//
// This method is a bit dangerous, because Get can as well end up in an internal
// node that is not really representing any user-defined value. So when nil is
// a valid value being used, it is not possible to tell if the value was inserted
// into the tree by the user or not. A possible workaround for this is not to use
// nil interface as a valid value, even using zero value of any type is enough
// to prevent this bad behaviour.
func (trie *Trie) Get(key Prefix) (item Item) {
_, node, found, leftover := trie.findSubtree(key)
if !found || len(leftover) != 0 {
return nil
}
return node.item
}
// Match returns what Get(prefix) != nil would return. The same warning as for
// Get applies here as well.
func (trie *Trie) Match(prefix Prefix) (matchedExactly bool) {
return trie.Get(prefix) != nil
}
// MatchSubtree returns true when there is a subtree representing extensions
// to key, that is if there are any keys in the tree which have key as prefix.
func (trie *Trie) MatchSubtree(key Prefix) (matched bool) {
_, _, matched, _ = trie.findSubtree(key)
return
}
// Visit calls visitor on every node containing a non-nil item.
//
// If an error is returned from visitor, the function stops visiting the tree
// and returns that error, unless it is a special error - SkipSubtree. In that
// case Visit skips the subtree represented by the current node and continues
// elsewhere.
func (trie *Trie) Visit(visitor VisitorFunc) error {
return trie.walk(nil, visitor)
}
// VisitSubtree works much like Visit, but it only visits nodes matching prefix.
func (trie *Trie) VisitSubtree(prefix Prefix, visitor VisitorFunc) error {
// Nil prefix not allowed.
if prefix == nil {
panic(ErrNilPrefix)
}
// Empty trie must be handled explicitly.
if trie.prefix == nil {
return nil
}
// Locate the relevant subtree.
_, root, found, leftover := trie.findSubtree(prefix)
if !found {
return nil
}
prefix = append(prefix, leftover...)
// Visit it.
return root.walk(prefix, visitor)
}
// VisitPrefixes visits only nodes that represent prefixes of key.
// To say the obvious, returning SkipSubtree from visitor makes no sense here.
func (trie *Trie) VisitPrefixes(key Prefix, visitor VisitorFunc) error {
// Nil key not allowed.
if key == nil {
panic(ErrNilPrefix)
}
// Empty trie must be handled explicitly.
if trie.prefix == nil {
return nil
}
// Walk the path matching key prefixes.
node := trie
prefix := key
offset := 0
for {
// Compute what part of prefix matches.
common := node.longestCommonPrefixLength(key)
key = key[common:]
offset += common
// Partial match means that there is no subtree matching prefix.
if common < len(node.prefix) {
return nil
}
// Call the visitor.
if item := node.item; item != nil {
if err := visitor(prefix[:offset], item); err != nil {
return err
}
}
if len(key) == 0 {
// This node represents key, we are finished.
return nil
}
// There is some key suffix left, move to the children.
child := node.children.next(key[0])
if child == nil {
// There is nowhere to continue, return.
return nil
}
node = child
}
}
// Delete deletes the item represented by the given prefix.
//
// True is returned if the matching node was found and deleted.
func (trie *Trie) Delete(key Prefix) (deleted bool) {
// Nil prefix not allowed.
if key == nil {
panic(ErrNilPrefix)
}
// Empty trie must be handled explicitly.
if trie.prefix == nil {
return false
}
// Find the relevant node.
parent, node, _, leftover := trie.findSubtree(key)
if len(leftover) != 0 {
return false
}
// If the item is already set to nil, there is nothing to do.
if node.item == nil {
return false
}
// Delete the item.
node.item = nil
// Compact since that might be possible now.
if compacted := node.compact(); compacted != node {
if parent == nil {
*node = *compacted
} else {
parent.children.replace(node.prefix[0], compacted)
*parent = *parent.compact()
}
}
return true
}
// DeleteSubtree finds the subtree exactly matching prefix and deletes it.
//
// True is returned if the subtree was found and deleted.
func (trie *Trie) DeleteSubtree(prefix Prefix) (deleted bool) {
// Nil prefix not allowed.
if prefix == nil {
panic(ErrNilPrefix)
}
// Empty trie must be handled explicitly.
if trie.prefix == nil {
return false
}
// Locate the relevant subtree.
parent, root, found, _ := trie.findSubtree(prefix)
if !found {
return false
}
// If we are in the root of the trie, reset the trie.
if parent == nil {
root.prefix = nil
root.children = newSparseChildList()
return true
}
// Otherwise remove the root node from its parent.
parent.children.remove(root)
return true
}
// Internal helper methods -----------------------------------------------------
func (trie *Trie) put(key Prefix, item Item, replace bool) (inserted bool) {
// Nil prefix not allowed.
if key == nil {
panic(ErrNilPrefix)
}
var (
common int
node *Trie = trie
child *Trie
)
if node.prefix == nil {
if len(key) <= MaxPrefixPerNode {
node.prefix = key
goto InsertItem
}
node.prefix = key[:MaxPrefixPerNode]
key = key[MaxPrefixPerNode:]
goto AppendChild
}
for {
// Compute the longest common prefix length.
common = node.longestCommonPrefixLength(key)
key = key[common:]
// Only a part matches, split.
if common < len(node.prefix) {
goto SplitPrefix
}
// common == len(node.prefix) since never (common > len(node.prefix))
// common == len(former key) <-> 0 == len(key)
// -> former key == node.prefix
if len(key) == 0 {
goto InsertItem
}
// Check children for matching prefix.
child = node.children.next(key[0])
if child == nil {
goto AppendChild
}
node = child
}
SplitPrefix:
// Split the prefix if necessary.
child = new(Trie)
*child = *node
*node = *NewTrie()
node.prefix = child.prefix[:common]
child.prefix = child.prefix[common:]
child = child.compact()
node.children = node.children.add(child)
AppendChild:
// Keep appending children until whole prefix is inserted.
// This loop starts with empty node.prefix that needs to be filled.
for len(key) != 0 {
child := NewTrie()
if len(key) <= MaxPrefixPerNode {
child.prefix = key
node.children = node.children.add(child)
node = child
goto InsertItem
} else {
child.prefix = key[:MaxPrefixPerNode]
key = key[MaxPrefixPerNode:]
node.children = node.children.add(child)
node = child
}
}
InsertItem:
// Try to insert the item if possible.
if replace || node.item == nil {
node.item = item
return true
}
return false
}
func (trie *Trie) compact() *Trie {
// Only a node with a single child can be compacted.
if trie.children.length() != 1 {
return trie
}
child := trie.children.head()
// If any item is set, we cannot compact since we want to retain
// the ability to do searching by key. This makes compaction less usable,
// but that simply cannot be avoided.
if trie.item != nil || child.item != nil {
return trie
}
// Make sure the combined prefixes fit into a single node.
if len(trie.prefix)+len(child.prefix) > MaxPrefixPerNode {
return trie
}
// Concatenate the prefixes, move the items.
child.prefix = append(trie.prefix, child.prefix...)
if trie.item != nil {
child.item = trie.item
}
return child
}
func (trie *Trie) findSubtree(prefix Prefix) (parent *Trie, root *Trie, found bool, leftover Prefix) {
// Find the subtree matching prefix.
root = trie
for {
// Compute what part of prefix matches.
common := root.longestCommonPrefixLength(prefix)
prefix = prefix[common:]
// We used up the whole prefix, subtree found.
if len(prefix) == 0 {
found = true
leftover = root.prefix[common:]
return
}
// Partial match means that there is no subtree matching prefix.
if common < len(root.prefix) {
leftover = root.prefix[common:]
return
}
// There is some prefix left, move to the children.
child := root.children.next(prefix[0])
if child == nil {
// There is nowhere to continue, there is no subtree matching prefix.
return
}
parent = root
root = child
}
}
func (trie *Trie) walk(actualRootPrefix Prefix, visitor VisitorFunc) error {
var prefix Prefix
// Allocate a bit more space for prefix at the beginning.
if actualRootPrefix == nil {
prefix = make(Prefix, 32+len(trie.prefix))
copy(prefix, trie.prefix)
prefix = prefix[:len(trie.prefix)]
} else {
prefix = make(Prefix, 32+len(actualRootPrefix))
copy(prefix, actualRootPrefix)
prefix = prefix[:len(actualRootPrefix)]
}
// Visit the root first. Not that this works for empty trie as well since
// in that case item == nil && len(children) == 0.
if trie.item != nil {
if err := visitor(prefix, trie.item); err != nil {
if err == SkipSubtree {
return nil
}
return err
}
}
// Then continue to the children.
return trie.children.walk(&prefix, visitor)
}
func (trie *Trie) longestCommonPrefixLength(prefix Prefix) (i int) {
for ; i < len(prefix) && i < len(trie.prefix) && prefix[i] == trie.prefix[i]; i++ {
}
return
}
// Errors ----------------------------------------------------------------------
var (
SkipSubtree = errors.New("Skip this subtree")
ErrNilPrefix = errors.New("Nil prefix passed into a method call")
)

View file

@ -0,0 +1,161 @@
// Copyright (c) 2014 The go-patricia AUTHORS
//
// Use of this source code is governed by The MIT License
// that can be found in the LICENSE file.
package patricia
import (
"testing"
)
// Tests -----------------------------------------------------------------------
func TestTrie_InsertDense(t *testing.T) {
trie := NewTrie()
data := []testData{
{"aba", 0, success},
{"abb", 1, success},
{"abc", 2, success},
{"abd", 3, success},
{"abe", 4, success},
{"abf", 5, success},
{"abg", 6, success},
{"abh", 7, success},
{"abi", 8, success},
{"abj", 9, success},
{"abk", 0, success},
{"abl", 1, success},
{"abm", 2, success},
{"abn", 3, success},
{"abo", 4, success},
{"abp", 5, success},
{"abq", 6, success},
{"abr", 7, success},
{"abs", 8, success},
{"abt", 9, success},
{"abu", 0, success},
{"abv", 1, success},
{"abw", 2, success},
{"abx", 3, success},
{"aby", 4, success},
{"abz", 5, success},
}
for _, v := range data {
t.Logf("INSERT prefix=%v, item=%v, success=%v", v.key, v.value, v.retVal)
if ok := trie.Insert(Prefix(v.key), v.value); ok != v.retVal {
t.Errorf("Unexpected return value, expected=%v, got=%v", v.retVal, ok)
}
}
}
func TestTrie_InsertDensePreceeding(t *testing.T) {
trie := NewTrie()
start := byte(70)
// create a dense node
for i := byte(0); i <= MaxChildrenPerSparseNode; i++ {
if !trie.Insert(Prefix([]byte{start + i}), true) {
t.Errorf("insert failed, prefix=%v", start+i)
}
}
// insert some preceeding keys
for i := byte(1); i < start; i *= i + 1 {
if !trie.Insert(Prefix([]byte{start - i}), true) {
t.Errorf("insert failed, prefix=%v", start-i)
}
}
}
func TestTrie_InsertDenseDuplicatePrefixes(t *testing.T) {
trie := NewTrie()
data := []testData{
{"aba", 0, success},
{"abb", 1, success},
{"abc", 2, success},
{"abd", 3, success},
{"abe", 4, success},
{"abf", 5, success},
{"abg", 6, success},
{"abh", 7, success},
{"abi", 8, success},
{"abj", 9, success},
{"abk", 0, success},
{"abl", 1, success},
{"abm", 2, success},
{"abn", 3, success},
{"abo", 4, success},
{"abp", 5, success},
{"abq", 6, success},
{"abr", 7, success},
{"abs", 8, success},
{"abt", 9, success},
{"abu", 0, success},
{"abv", 1, success},
{"abw", 2, success},
{"abx", 3, success},
{"aby", 4, success},
{"abz", 5, success},
{"aba", 0, failure},
{"abb", 1, failure},
{"abc", 2, failure},
{"abd", 3, failure},
{"abe", 4, failure},
}
for _, v := range data {
t.Logf("INSERT prefix=%v, item=%v, success=%v", v.key, v.value, v.retVal)
if ok := trie.Insert(Prefix(v.key), v.value); ok != v.retVal {
t.Errorf("Unexpected return value, expected=%v, got=%v", v.retVal, ok)
}
}
}
func TestTrie_DeleteDense(t *testing.T) {
trie := NewTrie()
data := []testData{
{"aba", 0, success},
{"abb", 1, success},
{"abc", 2, success},
{"abd", 3, success},
{"abe", 4, success},
{"abf", 5, success},
{"abg", 6, success},
{"abh", 7, success},
{"abi", 8, success},
{"abj", 9, success},
{"abk", 0, success},
{"abl", 1, success},
{"abm", 2, success},
{"abn", 3, success},
{"abo", 4, success},
{"abp", 5, success},
{"abq", 6, success},
{"abr", 7, success},
{"abs", 8, success},
{"abt", 9, success},
{"abu", 0, success},
{"abv", 1, success},
{"abw", 2, success},
{"abx", 3, success},
{"aby", 4, success},
{"abz", 5, success},
}
for _, v := range data {
t.Logf("INSERT prefix=%v, item=%v, success=%v", v.key, v.value, v.retVal)
if ok := trie.Insert(Prefix(v.key), v.value); ok != v.retVal {
t.Errorf("Unexpected return value, expected=%v, got=%v", v.retVal, ok)
}
}
for _, v := range data {
t.Logf("DELETE word=%v, success=%v", v.key, v.retVal)
if ok := trie.Delete([]byte(v.key)); ok != v.retVal {
t.Errorf("Unexpected return value, expected=%v, got=%v", v.retVal, ok)
}
}
}

View file

@ -0,0 +1,659 @@
// Copyright (c) 2014 The go-patricia AUTHORS
//
// Use of this source code is governed by The MIT License
// that can be found in the LICENSE file.
package patricia
import (
"bytes"
"errors"
"fmt"
"strings"
"testing"
)
const (
success = true
failure = false
)
type testData struct {
key string
value interface{}
retVal bool
}
// Tests -----------------------------------------------------------------------
func TestTrie_InsertDifferentPrefixes(t *testing.T) {
trie := NewTrie()
data := []testData{
{"Pepaneeeeeeeeeeeeee", "Pepan Zdepan", success},
{"Honzooooooooooooooo", "Honza Novak", success},
{"Jenikuuuuuuuuuuuuuu", "Jenik Poustevnicek", success},
}
for _, v := range data {
t.Logf("INSERT prefix=%v, item=%v, success=%v", v.key, v.value, v.retVal)
if ok := trie.Insert(Prefix(v.key), v.value); ok != v.retVal {
t.Errorf("Unexpected return value, expected=%v, got=%v", v.retVal, ok)
}
}
}
func TestTrie_InsertDuplicatePrefixes(t *testing.T) {
trie := NewTrie()
data := []testData{
{"Pepan", "Pepan Zdepan", success},
{"Pepan", "Pepan Zdepan", failure},
}
for _, v := range data {
t.Logf("INSERT prefix=%v, item=%v, success=%v", v.key, v.value, v.retVal)
if ok := trie.Insert(Prefix(v.key), v.value); ok != v.retVal {
t.Errorf("Unexpected return value, expected=%v, got=%v", v.retVal, ok)
}
}
}
func TestTrie_InsertVariousPrefixes(t *testing.T) {
trie := NewTrie()
data := []testData{
{"Pepan", "Pepan Zdepan", success},
{"Pepin", "Pepin Omacka", success},
{"Honza", "Honza Novak", success},
{"Jenik", "Jenik Poustevnicek", success},
{"Pepan", "Pepan Dupan", failure},
{"Karel", "Karel Pekar", success},
{"Jenik", "Jenik Poustevnicek", failure},
{"Pepanek", "Pepanek Zemlicka", success},
}
for _, v := range data {
t.Logf("INSERT prefix=%v, item=%v, success=%v", v.key, v.value, v.retVal)
if ok := trie.Insert(Prefix(v.key), v.value); ok != v.retVal {
t.Errorf("Unexpected return value, expected=%v, got=%v", v.retVal, ok)
}
}
}
func TestTrie_InsertAndMatchPrefix(t *testing.T) {
trie := NewTrie()
t.Log("INSERT prefix=by week")
trie.Insert(Prefix("by week"), 2)
t.Log("INSERT prefix=by")
trie.Insert(Prefix("by"), 1)
if !trie.Match(Prefix("by")) {
t.Error("MATCH prefix=by, expected=true, got=false")
}
}
func TestTrie_SetGet(t *testing.T) {
trie := NewTrie()
data := []testData{
{"Pepan", "Pepan Zdepan", success},
{"Pepin", "Pepin Omacka", success},
{"Honza", "Honza Novak", success},
{"Jenik", "Jenik Poustevnicek", success},
{"Pepan", "Pepan Dupan", failure},
{"Karel", "Karel Pekar", success},
{"Jenik", "Jenik Poustevnicek", failure},
{"Pepanek", "Pepanek Zemlicka", success},
}
for _, v := range data {
t.Logf("INSERT prefix=%v, item=%v, success=%v", v.key, v.value, v.retVal)
if ok := trie.Insert(Prefix(v.key), v.value); ok != v.retVal {
t.Errorf("Unexpected return value, expected=%v, got=%v", v.retVal, ok)
}
}
for _, v := range data {
t.Logf("SET %q to 10", v.key)
trie.Set(Prefix(v.key), 10)
}
for _, v := range data {
value := trie.Get(Prefix(v.key))
t.Logf("GET %q => %v", v.key, value)
if value.(int) != 10 {
t.Errorf("Unexpected return value, != 10", value)
}
}
if value := trie.Get(Prefix("random crap")); value != nil {
t.Errorf("Unexpected return value, %v != <nil>", value)
}
}
func TestTrie_Match(t *testing.T) {
trie := NewTrie()
data := []testData{
{"Pepan", "Pepan Zdepan", success},
{"Pepin", "Pepin Omacka", success},
{"Honza", "Honza Novak", success},
{"Jenik", "Jenik Poustevnicek", success},
{"Pepan", "Pepan Dupan", failure},
{"Karel", "Karel Pekar", success},
{"Jenik", "Jenik Poustevnicek", failure},
{"Pepanek", "Pepanek Zemlicka", success},
}
for _, v := range data {
t.Logf("INSERT prefix=%v, item=%v, success=%v", v.key, v.value, v.retVal)
if ok := trie.Insert(Prefix(v.key), v.value); ok != v.retVal {
t.Errorf("Unexpected return value, expected=%v, got=%v", v.retVal, ok)
}
}
for _, v := range data {
matched := trie.Match(Prefix(v.key))
t.Logf("MATCH %q => %v", v.key, matched)
if !matched {
t.Errorf("Inserted key %q was not matched", v.key)
}
}
if trie.Match(Prefix("random crap")) {
t.Errorf("Key that was not inserted matched: %q", "random crap")
}
}
func TestTrie_MatchFalsePositive(t *testing.T) {
trie := NewTrie()
if ok := trie.Insert(Prefix("A"), 1); !ok {
t.Fatal("INSERT prefix=A, item=1 not ok")
}
resultMatchSubtree := trie.MatchSubtree(Prefix("A extra"))
resultMatch := trie.Match(Prefix("A extra"))
if resultMatchSubtree != false {
t.Error("MatchSubtree returned false positive")
}
if resultMatch != false {
t.Error("Match returned false positive")
}
}
func TestTrie_MatchSubtree(t *testing.T) {
trie := NewTrie()
data := []testData{
{"Pepan", "Pepan Zdepan", success},
{"Pepin", "Pepin Omacka", success},
{"Honza", "Honza Novak", success},
{"Jenik", "Jenik Poustevnicek", success},
{"Pepan", "Pepan Dupan", failure},
{"Karel", "Karel Pekar", success},
{"Jenik", "Jenik Poustevnicek", failure},
{"Pepanek", "Pepanek Zemlicka", success},
}
for _, v := range data {
t.Logf("INSERT prefix=%v, item=%v, success=%v", v.key, v.value, v.retVal)
if ok := trie.Insert(Prefix(v.key), v.value); ok != v.retVal {
t.Errorf("Unexpected return value, expected=%v, got=%v", v.retVal, ok)
}
}
for _, v := range data {
key := Prefix(v.key[:3])
matched := trie.MatchSubtree(key)
t.Logf("MATCH_SUBTREE %q => %v", key, matched)
if !matched {
t.Errorf("Subtree %q was not matched", v.key)
}
}
}
func TestTrie_Visit(t *testing.T) {
trie := NewTrie()
data := []testData{
{"Pepa", 0, success},
{"Pepa Zdepa", 1, success},
{"Pepa Kuchar", 2, success},
{"Honza", 3, success},
{"Jenik", 4, success},
}
for _, v := range data {
t.Logf("INSERT prefix=%v, item=%v, success=%v", v.key, v.value, v.retVal)
if ok := trie.Insert([]byte(v.key), v.value); ok != v.retVal {
t.Fatalf("Unexpected return value, expected=%v, got=%v", v.retVal, ok)
}
}
if err := trie.Visit(func(prefix Prefix, item Item) error {
name := data[item.(int)].key
t.Logf("VISITING prefix=%q, item=%v", prefix, item)
if !strings.HasPrefix(string(prefix), name) {
t.Errorf("Unexpected prefix encountered, %q not a prefix of %q", prefix, name)
}
return nil
}); err != nil {
t.Fatal(err)
}
}
func TestTrie_VisitSkipSubtree(t *testing.T) {
trie := NewTrie()
data := []testData{
{"Pepa", 0, success},
{"Pepa Zdepa", 1, success},
{"Pepa Kuchar", 2, success},
{"Honza", 3, success},
{"Jenik", 4, success},
}
for _, v := range data {
t.Logf("INSERT prefix=%v, item=%v, success=%v", v.key, v.value, v.retVal)
if ok := trie.Insert([]byte(v.key), v.value); ok != v.retVal {
t.Fatalf("Unexpected return value, expected=%v, got=%v", v.retVal, ok)
}
}
if err := trie.Visit(func(prefix Prefix, item Item) error {
t.Logf("VISITING prefix=%q, item=%v", prefix, item)
if item.(int) == 0 {
t.Logf("SKIP %q", prefix)
return SkipSubtree
}
if strings.HasPrefix(string(prefix), "Pepa") {
t.Errorf("Unexpected prefix encountered, %q", prefix)
}
return nil
}); err != nil {
t.Fatal(err)
}
}
func TestTrie_VisitReturnError(t *testing.T) {
trie := NewTrie()
data := []testData{
{"Pepa", 0, success},
{"Pepa Zdepa", 1, success},
{"Pepa Kuchar", 2, success},
{"Honza", 3, success},
{"Jenik", 4, success},
}
for _, v := range data {
t.Logf("INSERT prefix=%v, item=%v, success=%v", v.key, v.value, v.retVal)
if ok := trie.Insert([]byte(v.key), v.value); ok != v.retVal {
t.Fatalf("Unexpected return value, expected=%v, got=%v", v.retVal, ok)
}
}
someErr := errors.New("Something exploded")
if err := trie.Visit(func(prefix Prefix, item Item) error {
t.Logf("VISITING prefix=%q, item=%v", prefix, item)
if item.(int) == 0 {
return someErr
}
if item.(int) != 0 {
t.Errorf("Unexpected prefix encountered, %q", prefix)
}
return nil
}); err != nil && err != someErr {
t.Fatal(err)
}
}
func TestTrie_VisitSubtree(t *testing.T) {
trie := NewTrie()
data := []testData{
{"Pepa", 0, success},
{"Pepa Zdepa", 1, success},
{"Pepa Kuchar", 2, success},
{"Honza", 3, success},
{"Jenik", 4, success},
}
for _, v := range data {
t.Logf("INSERT prefix=%v, item=%v, success=%v", v.key, v.value, v.retVal)
if ok := trie.Insert([]byte(v.key), v.value); ok != v.retVal {
t.Fatalf("Unexpected return value, expected=%v, got=%v", v.retVal, ok)
}
}
var counter int
subtreePrefix := []byte("Pep")
t.Log("VISIT Pep")
if err := trie.VisitSubtree(subtreePrefix, func(prefix Prefix, item Item) error {
t.Logf("VISITING prefix=%q, item=%v", prefix, item)
if !bytes.HasPrefix(prefix, subtreePrefix) {
t.Errorf("Unexpected prefix encountered, %q does not extend %q",
prefix, subtreePrefix)
}
if len(prefix) > len(data[item.(int)].key) {
t.Fatalf("Something is rather fishy here, prefix=%q", prefix)
}
counter++
return nil
}); err != nil {
t.Fatal(err)
}
if counter != 3 {
t.Error("Unexpected number of nodes visited")
}
}
func TestTrie_VisitPrefixes(t *testing.T) {
trie := NewTrie()
data := []testData{
{"P", 0, success},
{"Pe", 1, success},
{"Pep", 2, success},
{"Pepa", 3, success},
{"Pepa Zdepa", 4, success},
{"Pepa Kuchar", 5, success},
{"Honza", 6, success},
{"Jenik", 7, success},
}
for _, v := range data {
t.Logf("INSERT prefix=%v, item=%v, success=%v", v.key, v.value, v.retVal)
if ok := trie.Insert([]byte(v.key), v.value); ok != v.retVal {
t.Fatalf("Unexpected return value, expected=%v, got=%v", v.retVal, ok)
}
}
var counter int
word := []byte("Pepa")
if err := trie.VisitPrefixes(word, func(prefix Prefix, item Item) error {
t.Logf("VISITING prefix=%q, item=%v", prefix, item)
if !bytes.HasPrefix(word, prefix) {
t.Errorf("Unexpected prefix encountered, %q is not a prefix of %q",
prefix, word)
}
counter++
return nil
}); err != nil {
t.Fatal(err)
}
if counter != 4 {
t.Error("Unexpected number of nodes visited")
}
}
func TestParticiaTrie_Delete(t *testing.T) {
trie := NewTrie()
data := []testData{
{"Pepan", "Pepan Zdepan", success},
{"Honza", "Honza Novak", success},
{"Jenik", "Jenik Poustevnicek", success},
}
for _, v := range data {
t.Logf("INSERT prefix=%v, item=%v, success=%v", v.key, v.value, v.retVal)
if ok := trie.Insert([]byte(v.key), v.value); ok != v.retVal {
t.Fatalf("Unexpected return value, expected=%v, got=%v", v.retVal, ok)
}
}
for _, v := range data {
t.Logf("DELETE word=%v, success=%v", v.key, v.retVal)
if ok := trie.Delete([]byte(v.key)); ok != v.retVal {
t.Errorf("Unexpected return value, expected=%v, got=%v", v.retVal, ok)
}
}
}
func TestParticiaTrie_DeleteNonExistent(t *testing.T) {
trie := NewTrie()
insertData := []testData{
{"Pepan", "Pepan Zdepan", success},
{"Honza", "Honza Novak", success},
{"Jenik", "Jenik Poustevnicek", success},
}
deleteData := []testData{
{"Pepan", "Pepan Zdepan", success},
{"Honza", "Honza Novak", success},
{"Pepan", "Pepan Zdepan", failure},
{"Jenik", "Jenik Poustevnicek", success},
{"Honza", "Honza Novak", failure},
}
for _, v := range insertData {
t.Logf("INSERT prefix=%v, item=%v, success=%v", v.key, v.value, v.retVal)
if ok := trie.Insert([]byte(v.key), v.value); ok != v.retVal {
t.Fatalf("Unexpected return value, expected=%v, got=%v", v.retVal, ok)
}
}
for _, v := range deleteData {
t.Logf("DELETE word=%v, success=%v", v.key, v.retVal)
if ok := trie.Delete([]byte(v.key)); ok != v.retVal {
t.Errorf("Unexpected return value, expected=%v, got=%v", v.retVal, ok)
}
}
}
func TestParticiaTrie_DeleteSubtree(t *testing.T) {
trie := NewTrie()
insertData := []testData{
{"P", 0, success},
{"Pe", 1, success},
{"Pep", 2, success},
{"Pepa", 3, success},
{"Pepa Zdepa", 4, success},
{"Pepa Kuchar", 5, success},
{"Honza", 6, success},
{"Jenik", 7, success},
}
deleteData := []testData{
{"Pe", -1, success},
{"Pe", -1, failure},
{"Honzik", -1, failure},
{"Honza", -1, success},
{"Honza", -1, failure},
{"Pep", -1, failure},
{"P", -1, success},
{"Nobody", -1, failure},
{"", -1, success},
}
for _, v := range insertData {
t.Logf("INSERT prefix=%v, item=%v, success=%v", v.key, v.value, v.retVal)
if ok := trie.Insert([]byte(v.key), v.value); ok != v.retVal {
t.Fatalf("Unexpected return value, expected=%v, got=%v", v.retVal, ok)
}
}
for _, v := range deleteData {
t.Logf("DELETE_SUBTREE prefix=%v, success=%v", v.key, v.retVal)
if ok := trie.DeleteSubtree([]byte(v.key)); ok != v.retVal {
t.Errorf("Unexpected return value, expected=%v, got=%v", v.retVal, ok)
}
}
}
/*
func TestTrie_Dump(t *testing.T) {
trie := NewTrie()
data := []testData{
{"Honda", nil, success},
{"Honza", nil, success},
{"Jenik", nil, success},
{"Pepan", nil, success},
{"Pepin", nil, success},
}
for i, v := range data {
if _, ok := trie.Insert([]byte(v.key), v.value); ok != v.retVal {
t.Logf("INSERT %v %v", v.key, v.value)
t.Fatalf("Unexpected return value, expected=%v, got=%v", i, ok)
}
}
dump := `
+--+--+ Hon +--+--+ da
| |
| +--+ za
|
+--+ Jenik
|
+--+ Pep +--+--+ an
|
+--+ in
`
var buf bytes.Buffer
trie.Dump(buf)
if !bytes.Equal(buf.Bytes(), dump) {
t.Logf("DUMP")
t.Fatalf("Unexpected dump generated, expected\n\n%v\ngot\n\n%v", dump, buf.String())
}
}
*/
func TestTrie_compact(t *testing.T) {
trie := NewTrie()
trie.Insert(Prefix("a"), 0)
trie.Insert(Prefix("ab"), 0)
trie.Insert(Prefix("abc"), 0)
trie.Insert(Prefix("abcd"), 0)
trie.Insert(Prefix("abcde"), 0)
trie.Insert(Prefix("abcdef"), 0)
trie.Insert(Prefix("abcdefg"), 0)
trie.Insert(Prefix("abcdefgi"), 0)
trie.Insert(Prefix("abcdefgij"), 0)
trie.Insert(Prefix("abcdefgijk"), 0)
trie.Delete(Prefix("abcdef"))
trie.Delete(Prefix("abcde"))
trie.Delete(Prefix("abcdefg"))
trie.Delete(Prefix("a"))
trie.Delete(Prefix("abc"))
trie.Delete(Prefix("ab"))
trie.Visit(func(prefix Prefix, item Item) error {
// 97 ~~ 'a',
for ch := byte(97); ch <= 107; ch++ {
if c := bytes.Count(prefix, []byte{ch}); c > 1 {
t.Errorf("%q appeared in %q %v times", ch, prefix, c)
}
}
return nil
})
}
func TestTrie_longestCommonPrefixLenght(t *testing.T) {
trie := NewTrie()
trie.prefix = []byte("1234567890")
switch {
case trie.longestCommonPrefixLength([]byte("")) != 0:
t.Fail()
case trie.longestCommonPrefixLength([]byte("12345")) != 5:
t.Fail()
case trie.longestCommonPrefixLength([]byte("123789")) != 3:
t.Fail()
case trie.longestCommonPrefixLength([]byte("12345678901")) != 10:
t.Fail()
}
}
// Examples --------------------------------------------------------------------
func ExampleTrie() {
// Create a new tree.
trie := NewTrie()
// Insert some items.
trie.Insert(Prefix("Pepa Novak"), 1)
trie.Insert(Prefix("Pepa Sindelar"), 2)
trie.Insert(Prefix("Karel Macha"), 3)
trie.Insert(Prefix("Karel Hynek Macha"), 4)
// Just check if some things are present in the tree.
key := Prefix("Pepa Novak")
fmt.Printf("%q present? %v\n", key, trie.Match(key))
key = Prefix("Karel")
fmt.Printf("Anybody called %q here? %v\n", key, trie.MatchSubtree(key))
// Walk the tree.
trie.Visit(printItem)
// "Pepa Novak": 1
// "Pepa Sindelar": 2
// "Karel Macha": 3
// "Karel Hynek Macha": 4
// Walk a subtree.
trie.VisitSubtree(Prefix("Pepa"), printItem)
// "Pepa Novak": 1
// "Pepa Sindelar": 2
// Modify an item, then fetch it from the tree.
trie.Set(Prefix("Karel Hynek Macha"), 10)
key = Prefix("Karel Hynek Macha")
fmt.Printf("%q: %v\n", key, trie.Get(key))
// "Karel Hynek Macha": 10
// Walk prefixes.
prefix := Prefix("Karel Hynek Macha je kouzelnik")
trie.VisitPrefixes(prefix, printItem)
// "Karel Hynek Macha": 10
// Delete some items.
trie.Delete(Prefix("Pepa Novak"))
trie.Delete(Prefix("Karel Macha"))
// Walk again.
trie.Visit(printItem)
// "Pepa Sindelar": 2
// "Karel Hynek Macha": 10
// Delete a subtree.
trie.DeleteSubtree(Prefix("Pepa"))
// Print what is left.
trie.Visit(printItem)
// "Karel Hynek Macha": 10
// Output:
// "Pepa Novak" present? true
// Anybody called "Karel" here? true
// "Pepa Novak": 1
// "Pepa Sindelar": 2
// "Karel Macha": 3
// "Karel Hynek Macha": 4
// "Pepa Novak": 1
// "Pepa Sindelar": 2
// "Karel Hynek Macha": 10
// "Karel Hynek Macha": 10
// "Pepa Sindelar": 2
// "Karel Hynek Macha": 10
// "Karel Hynek Macha": 10
}
// Helpers ---------------------------------------------------------------------
func printItem(prefix Prefix, item Item) error {
fmt.Printf("%q: %v\n", prefix, item)
return nil
}

View file

@ -0,0 +1,78 @@
// Copyright (c) 2014 The go-patricia AUTHORS
//
// Use of this source code is governed by The MIT License
// that can be found in the LICENSE file.
package patricia
import (
"crypto/rand"
"reflect"
"testing"
)
// Tests -----------------------------------------------------------------------
func TestTrie_GetNonexistentPrefix(t *testing.T) {
trie := NewTrie()
data := []testData{
{"aba", 0, success},
}
for _, v := range data {
t.Logf("INSERT prefix=%v, item=%v, success=%v", v.key, v.value, v.retVal)
if ok := trie.Insert(Prefix(v.key), v.value); ok != v.retVal {
t.Errorf("Unexpected return value, expected=%v, got=%v", v.retVal, ok)
}
}
t.Logf("GET prefix=baa, expect item=nil")
if item := trie.Get(Prefix("baa")); item != nil {
t.Errorf("Unexpected return value, expected=<nil>, got=%v", item)
}
}
func TestTrie_RandomKitchenSink(t *testing.T) {
if testing.Short() {
t.Skip()
}
const count, size = 750000, 16
b := make([]byte, count+size+1)
if _, err := rand.Read(b); err != nil {
t.Fatal("error generating random bytes", err)
}
m := make(map[string]string)
for i := 0; i < count; i++ {
m[string(b[i:i+size])] = string(b[i+1 : i+size+1])
}
trie := NewTrie()
getAndDelete := func(k, v string) {
i := trie.Get(Prefix(k))
if i == nil {
t.Fatalf("item not found, prefix=%v", []byte(k))
} else if s, ok := i.(string); !ok {
t.Fatalf("unexpected item type, expecting=%v, got=%v", reflect.TypeOf(k), reflect.TypeOf(i))
} else if s != v {
t.Fatalf("unexpected item, expecting=%v, got=%v", []byte(k), []byte(s))
} else if !trie.Delete(Prefix(k)) {
t.Fatalf("delete failed, prefix=%v", []byte(k))
} else if i = trie.Get(Prefix(k)); i != nil {
t.Fatalf("unexpected item, expecting=<nil>, got=%v", i)
} else if trie.Delete(Prefix(k)) {
t.Fatalf("extra delete succeeded, prefix=%v", []byte(k))
}
}
for k, v := range m {
if !trie.Insert(Prefix(k), v) {
t.Fatalf("insert failed, prefix=%v", []byte(k))
}
if byte(k[size/2]) < 128 {
getAndDelete(k, v)
delete(m, k)
}
}
for k, v := range m {
getAndDelete(k, v)
}
}