*: godep btree

Godeps/Godeps.json

@@ -20,14 +20,14 @@
 			"Comment": "v0.2.0-rc1-130-g6aa2da5",
 			"Rev": "6aa2da5a7a905609c93036b9307185a04a5a84a5"
 		},
-		{
-			"ImportPath": "github.com/coreos/pkg/capnslog",
-			"Rev": "9d5dd4632f9ece71bdf83d31253593a633e73df5"
-		},
 		{
 			"ImportPath": "github.com/coreos/go-semver/semver",
 			"Rev": "568e959cd89871e61434c1143528d9162da89ef2"
 		},
+		{
+			"ImportPath": "github.com/coreos/pkg/capnslog",
+			"Rev": "9d5dd4632f9ece71bdf83d31253593a633e73df5"
+		},
 		{
 			"ImportPath": "github.com/gogo/protobuf/proto",
 			"Rev": "bc946d07d1016848dfd2507f90f0859c9471681e"
@@ -36,6 +36,10 @@
 			"ImportPath": "github.com/golang/protobuf/proto",
 			"Rev": "5677a0e3d5e89854c9974e1256839ee23f8233ca"
 		},
+		{
+			"ImportPath": "github.com/google/btree",
+			"Rev": "cc6329d4279e3f025a53a83c397d2339b5705c45"
+		},
 		{
 			"ImportPath": "github.com/jonboulle/clockwork",
 			"Rev": "72f9bd7c4e0c2a40055ab3d0f09654f730cce982"

Godeps/_workspace/src/github.com/google/btree/.travis.yml

@@ -0,0 +1 @@
+language: go

Godeps/_workspace/src/github.com/google/btree/LICENSE

@@ -0,0 +1,202 @@
+
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Godeps/_workspace/src/github.com/google/btree/README.md

@@ -0,0 +1,12 @@
+# BTree implementation for Go
+
+![Travis CI Build Status](https://api.travis-ci.org/google/btree.svg?branch=master)
+
+This package provides an in-memory B-Tree implementation for Go, useful as a
+an ordered, mutable data structure.
+
+The API is based off of the wonderful
+http://godoc.org/github.com/petar/GoLLRB/llrb, and is meant to allow btree to
+act as a drop-in replacement for gollrb trees.
+
+See http://godoc.org/github.com/google/btree for documentation.

Godeps/_workspace/src/github.com/google/btree/btree.go

@@ -0,0 +1,571 @@
+// Copyright 2014 Google Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package btree implements in-memory B-Trees of arbitrary degree.
+//
+// btree implements an in-memory B-Tree for use as an ordered data structure.
+// It is not meant for persistent storage solutions.
+//
+// It has a flatter structure than an equivalent red-black or other binary tree,
+// which in some cases yields better memory usage and/or performance.
+// See some discussion on the matter here:
+//   http://google-opensource.blogspot.com/2013/01/c-containers-that-save-memory-and-time.html
+// Note, though, that this project is in no way related to the C++ B-Tree
+// implmentation written about there.
+//
+// Within this tree, each node contains a slice of items and a (possibly nil)
+// slice of children.  For basic numeric values or raw structs, this can cause
+// efficiency differences when compared to equivalent C++ template code that
+// stores values in arrays within the node:
+//   * Due to the overhead of storing values as interfaces (each
+//     value needs to be stored as the value itself, then 2 words for the
+//     interface pointing to that value and its type), resulting in higher
+//     memory use.
+//   * Since interfaces can point to values anywhere in memory, values are
+//     most likely not stored in contiguous blocks, resulting in a higher
+//     number of cache misses.
+// These issues don't tend to matter, though, when working with strings or other
+// heap-allocated structures, since C++-equivalent structures also must store
+// pointers and also distribute their values across the heap.
+//
+// This implementation is designed to be a drop-in replacement to gollrb.LLRB
+// trees, (http://github.com/petar/gollrb), an excellent and probably the most
+// widely used ordered tree implementation in the Go ecosystem currently.
+// Its functions, therefore, exactly mirror those of
+// llrb.LLRB where possible.  Unlike gollrb, though, we currently don't
+// support storing multiple equivalent values or backwards iteration.
+package btree
+
+import (
+	"fmt"
+	"io"
+	"sort"
+	"strings"
+)
+
+// Item represents a single object in the tree.
+type Item interface {
+	// Less tests whether the current item is less than the given argument.
+	//
+	// This must provide a strict weak ordering.
+	// If !a.Less(b) && !b.Less(a), we treat this to mean a == b (i.e. we can only
+	// hold one of either a or b in the tree).
+	Less(than Item) bool
+}
+
+// ItemIterator allows callers of Ascend* to iterate in-order over portions of
+// the tree.  When this function returns false, iteration will stop and the
+// associated Ascend* function will immediately return.
+type ItemIterator func(i Item) bool
+
+// New creates a new B-Tree with the given degree.
+//
+// New(2), for example, will create a 2-3-4 tree (each node contains 1-3 items
+// and 2-4 children).
+func New(degree int) *BTree {
+	if degree <= 1 {
+		panic("bad degree")
+	}
+	return &BTree{
+		degree:   degree,
+		freelist: make([]*node, 0, 32),
+	}
+}
+
+// items stores items in a node.
+type items []Item
+
+// insertAt inserts a value into the given index, pushing all subsequent values
+// forward.
+func (s *items) insertAt(index int, item Item) {
+	*s = append(*s, nil)
+	if index < len(*s) {
+		copy((*s)[index+1:], (*s)[index:])
+	}
+	(*s)[index] = item
+}
+
+// removeAt removes a value at a given index, pulling all subsequent values
+// back.
+func (s *items) removeAt(index int) Item {
+	item := (*s)[index]
+	copy((*s)[index:], (*s)[index+1:])
+	*s = (*s)[:len(*s)-1]
+	return item
+}
+
+// pop removes and returns the last element in the list.
+func (s *items) pop() (out Item) {
+	index := len(*s) - 1
+	out, *s = (*s)[index], (*s)[:index]
+	return
+}
+
+// find returns the index where the given item should be inserted into this
+// list.  'found' is true if the item already exists in the list at the given
+// index.
+func (s items) find(item Item) (index int, found bool) {
+	i := sort.Search(len(s), func(i int) bool {
+		return item.Less(s[i])
+	})
+	if i > 0 && !s[i-1].Less(item) {
+		return i - 1, true
+	}
+	return i, false
+}
+
+// children stores child nodes in a node.
+type children []*node
+
+// insertAt inserts a value into the given index, pushing all subsequent values
+// forward.
+func (s *children) insertAt(index int, n *node) {
+	*s = append(*s, nil)
+	if index < len(*s) {
+		copy((*s)[index+1:], (*s)[index:])
+	}
+	(*s)[index] = n
+}
+
+// removeAt removes a value at a given index, pulling all subsequent values
+// back.
+func (s *children) removeAt(index int) *node {
+	n := (*s)[index]
+	copy((*s)[index:], (*s)[index+1:])
+	*s = (*s)[:len(*s)-1]
+	return n
+}
+
+// pop removes and returns the last element in the list.
+func (s *children) pop() (out *node) {
+	index := len(*s) - 1
+	out, *s = (*s)[index], (*s)[:index]
+	return
+}
+
+// node is an internal node in a tree.
+//
+// It must at all times maintain the invariant that either
+//   * len(children) == 0, len(items) unconstrained
+//   * len(children) == len(items) + 1
+type node struct {
+	items    items
+	children children
+	t        *BTree
+}
+
+// split splits the given node at the given index.  The current node shrinks,
+// and this function returns the item that existed at that index and a new node
+// containing all items/children after it.
+func (n *node) split(i int) (Item, *node) {
+	item := n.items[i]
+	next := n.t.newNode()
+	next.items = append(next.items, n.items[i+1:]...)
+	n.items = n.items[:i]
+	if len(n.children) > 0 {
+		next.children = append(next.children, n.children[i+1:]...)
+		n.children = n.children[:i+1]
+	}
+	return item, next
+}
+
+// maybeSplitChild checks if a child should be split, and if so splits it.
+// Returns whether or not a split occurred.
+func (n *node) maybeSplitChild(i, maxItems int) bool {
+	if len(n.children[i].items) < maxItems {
+		return false
+	}
+	first := n.children[i]
+	item, second := first.split(maxItems / 2)
+	n.items.insertAt(i, item)
+	n.children.insertAt(i+1, second)
+	return true
+}
+
+// insert inserts an item into the subtree rooted at this node, making sure
+// no nodes in the subtree exceed maxItems items.  Should an equivalent item be
+// be found/replaced by insert, it will be returned.
+func (n *node) insert(item Item, maxItems int) Item {
+	i, found := n.items.find(item)
+	if found {
+		out := n.items[i]
+		n.items[i] = item
+		return out
+	}
+	if len(n.children) == 0 {
+		n.items.insertAt(i, item)
+		return nil
+	}
+	if n.maybeSplitChild(i, maxItems) {
+		inTree := n.items[i]
+		switch {
+		case item.Less(inTree):
+			// no change, we want first split node
+		case inTree.Less(item):
+			i++ // we want second split node
+		default:
+			out := n.items[i]
+			n.items[i] = item
+			return out
+		}
+	}
+	return n.children[i].insert(item, maxItems)
+}
+
+// get finds the given key in the subtree and returns it.
+func (n *node) get(key Item) Item {
+	i, found := n.items.find(key)
+	if found {
+		return n.items[i]
+	} else if len(n.children) > 0 {
+		return n.children[i].get(key)
+	}
+	return nil
+}
+
+// toRemove details what item to remove in a node.remove call.
+type toRemove int
+
+const (
+	removeItem toRemove = iota // removes the given item
+	removeMin                  // removes smallest item in the subtree
+	removeMax                  // removes largest item in the subtree
+)
+
+// remove removes an item from the subtree rooted at this node.
+func (n *node) remove(item Item, minItems int, typ toRemove) Item {
+	var i int
+	var found bool
+	switch typ {
+	case removeMax:
+		if len(n.children) == 0 {
+			return n.items.pop()
+		}
+		i = len(n.items)
+	case removeMin:
+		if len(n.children) == 0 {
+			return n.items.removeAt(0)
+		}
+		i = 0
+	case removeItem:
+		i, found = n.items.find(item)
+		if len(n.children) == 0 {
+			if found {
+				return n.items.removeAt(i)
+			}
+			return nil
+		}
+	default:
+		panic("invalid type")
+	}
+	// If we get to here, we have children.
+	child := n.children[i]
+	if len(child.items) <= minItems {
+		return n.growChildAndRemove(i, item, minItems, typ)
+	}
+	// Either we had enough items to begin with, or we've done some
+	// merging/stealing, because we've got enough now and we're ready to return
+	// stuff.
+	if found {
+		// The item exists at index 'i', and the child we've selected can give us a
+		// predecessor, since if we've gotten here it's got > minItems items in it.
+		out := n.items[i]
+		// We use our special-case 'remove' call with typ=maxItem to pull the
+		// predecessor of item i (the rightmost leaf of our immediate left child)
+		// and set it into where we pulled the item from.
+		n.items[i] = child.remove(nil, minItems, removeMax)
+		return out
+	}
+	// Final recursive call.  Once we're here, we know that the item isn't in this
+	// node and that the child is big enough to remove from.
+	return child.remove(item, minItems, typ)
+}
+
+// growChildAndRemove grows child 'i' to make sure it's possible to remove an
+// item from it while keeping it at minItems, then calls remove to actually
+// remove it.
+//
+// Most documentation says we have to do two sets of special casing:
+//   1) item is in this node
+//   2) item is in child
+// In both cases, we need to handle the two subcases:
+//   A) node has enough values that it can spare one
+//   B) node doesn't have enough values
+// For the latter, we have to check:
+//   a) left sibling has node to spare
+//   b) right sibling has node to spare
+//   c) we must merge
+// To simplify our code here, we handle cases #1 and #2 the same:
+// If a node doesn't have enough items, we make sure it does (using a,b,c).
+// We then simply redo our remove call, and the second time (regardless of
+// whether we're in case 1 or 2), we'll have enough items and can guarantee
+// that we hit case A.
+func (n *node) growChildAndRemove(i int, item Item, minItems int, typ toRemove) Item {
+	child := n.children[i]
+	if i > 0 && len(n.children[i-1].items) > minItems {
+		// Steal from left child
+		stealFrom := n.children[i-1]
+		stolenItem := stealFrom.items.pop()
+		child.items.insertAt(0, n.items[i-1])
+		n.items[i-1] = stolenItem
+		if len(stealFrom.children) > 0 {
+			child.children.insertAt(0, stealFrom.children.pop())
+		}
+	} else if i < len(n.items) && len(n.children[i+1].items) > minItems {
+		// steal from right child
+		stealFrom := n.children[i+1]
+		stolenItem := stealFrom.items.removeAt(0)
+		child.items = append(child.items, n.items[i])
+		n.items[i] = stolenItem
+		if len(stealFrom.children) > 0 {
+			child.children = append(child.children, stealFrom.children.removeAt(0))
+		}
+	} else {
+		if i >= len(n.items) {
+			i--
+			child = n.children[i]
+		}
+		// merge with right child
+		mergeItem := n.items.removeAt(i)
+		mergeChild := n.children.removeAt(i + 1)
+		child.items = append(child.items, mergeItem)
+		child.items = append(child.items, mergeChild.items...)
+		child.children = append(child.children, mergeChild.children...)
+		n.t.freeNode(mergeChild)
+	}
+	return n.remove(item, minItems, typ)
+}
+
+// iterate provides a simple method for iterating over elements in the tree.
+// It could probably use some work to be extra-efficient (it calls from() a
+// little more than it should), but it works pretty well for now.
+//
+// It requires that 'from' and 'to' both return true for values we should hit
+// with the iterator.  It should also be the case that 'from' returns true for
+// values less than or equal to values 'to' returns true for, and 'to'
+// returns true for values greater than or equal to those that 'from'
+// does.
+func (n *node) iterate(from, to func(Item) bool, iter ItemIterator) bool {
+	for i, item := range n.items {
+		if !from(item) {
+			continue
+		}
+		if len(n.children) > 0 && !n.children[i].iterate(from, to, iter) {
+			return false
+		}
+		if !to(item) {
+			return false
+		}
+		if !iter(item) {
+			return false
+		}
+	}
+	if len(n.children) > 0 {
+		return n.children[len(n.children)-1].iterate(from, to, iter)
+	}
+	return true
+}
+
+// Used for testing/debugging purposes.
+func (n *node) print(w io.Writer, level int) {
+	fmt.Fprintf(w, "%sNODE:%v\n", strings.Repeat("  ", level), n.items)
+	for _, c := range n.children {
+		c.print(w, level+1)
+	}
+}
+
+// BTree is an implementation of a B-Tree.
+//
+// BTree stores Item instances in an ordered structure, allowing easy insertion,
+// removal, and iteration.
+//
+// Write operations are not safe for concurrent mutation by multiple
+// goroutines, but Read operations are.
+type BTree struct {
+	degree   int
+	length   int
+	root     *node
+	freelist []*node
+}
+
+// maxItems returns the max number of items to allow per node.
+func (t *BTree) maxItems() int {
+	return t.degree*2 - 1
+}
+
+// minItems returns the min number of items to allow per node (ignored for the
+// root node).
+func (t *BTree) minItems() int {
+	return t.degree - 1
+}
+
+func (t *BTree) newNode() (n *node) {
+	index := len(t.freelist) - 1
+	if index < 0 {
+		return &node{t: t}
+	}
+	t.freelist, n = t.freelist[:index], t.freelist[index]
+	return
+}
+
+func (t *BTree) freeNode(n *node) {
+	if len(t.freelist) < cap(t.freelist) {
+    for i := range n.items {
+      n.items[i] = nil  // clear to allow GC
+    }
+		n.items = n.items[:0]
+    for i := range n.children {
+      n.children[i] = nil  // clear to allow GC
+    }
+		n.children = n.children[:0]
+		t.freelist = append(t.freelist, n)
+	}
+}
+
+// ReplaceOrInsert adds the given item to the tree.  If an item in the tree
+// already equals the given one, it is removed from the tree and returned.
+// Otherwise, nil is returned.
+//
+// nil cannot be added to the tree (will panic).
+func (t *BTree) ReplaceOrInsert(item Item) Item {
+	if item == nil {
+		panic("nil item being added to BTree")
+	}
+	if t.root == nil {
+		t.root = t.newNode()
+		t.root.items = append(t.root.items, item)
+		t.length++
+		return nil
+	} else if len(t.root.items) >= t.maxItems() {
+		item2, second := t.root.split(t.maxItems() / 2)
+		oldroot := t.root
+		t.root = t.newNode()
+		t.root.items = append(t.root.items, item2)
+		t.root.children = append(t.root.children, oldroot, second)
+	}
+	out := t.root.insert(item, t.maxItems())
+	if out == nil {
+		t.length++
+	}
+	return out
+}
+
+// Delete removes an item equal to the passed in item from the tree, returning
+// it.  If no such item exists, returns nil.
+func (t *BTree) Delete(item Item) Item {
+	return t.deleteItem(item, removeItem)
+}
+
+// DeleteMin removes the smallest item in the tree and returns it.
+// If no such item exists, returns nil.
+func (t *BTree) DeleteMin() Item {
+	return t.deleteItem(nil, removeMin)
+}
+
+// DeleteMax removes the largest item in the tree and returns it.
+// If no such item exists, returns nil.
+func (t *BTree) DeleteMax() Item {
+	return t.deleteItem(nil, removeMax)
+}
+
+func (t *BTree) deleteItem(item Item, typ toRemove) Item {
+	if t.root == nil || len(t.root.items) == 0 {
+		return nil
+	}
+	out := t.root.remove(item, t.minItems(), typ)
+	if len(t.root.items) == 0 && len(t.root.children) > 0 {
+		oldroot := t.root
+		t.root = t.root.children[0]
+		t.freeNode(oldroot)
+	}
+	if out != nil {
+		t.length--
+	}
+	return out
+}
+
+// AscendRange calls the iterator for every value in the tree within the range
+// [greaterOrEqual, lessThan), until iterator returns false.
+func (t *BTree) AscendRange(greaterOrEqual, lessThan Item, iterator ItemIterator) {
+	if t.root == nil {
+		return
+	}
+	t.root.iterate(
+		func(a Item) bool { return !a.Less(greaterOrEqual) },
+		func(a Item) bool { return a.Less(lessThan) },
+		iterator)
+}
+
+// AscendLessThan calls the iterator for every value in the tree within the range
+// [first, pivot), until iterator returns false.
+func (t *BTree) AscendLessThan(pivot Item, iterator ItemIterator) {
+	if t.root == nil {
+		return
+	}
+	t.root.iterate(
+		func(a Item) bool { return true },
+		func(a Item) bool { return a.Less(pivot) },
+		iterator)
+}
+
+// AscendGreaterOrEqual calls the iterator for every value in the tree within
+// the range [pivot, last], until iterator returns false.
+func (t *BTree) AscendGreaterOrEqual(pivot Item, iterator ItemIterator) {
+	if t.root == nil {
+		return
+	}
+	t.root.iterate(
+		func(a Item) bool { return !a.Less(pivot) },
+		func(a Item) bool { return true },
+		iterator)
+}
+
+// Ascend calls the iterator for every value in the tree within the range
+// [first, last], until iterator returns false.
+func (t *BTree) Ascend(iterator ItemIterator) {
+	if t.root == nil {
+		return
+	}
+	t.root.iterate(
+		func(a Item) bool { return true },
+		func(a Item) bool { return true },
+		iterator)
+}
+
+// Get looks for the key item in the tree, returning it.  It returns nil if
+// unable to find that item.
+func (t *BTree) Get(key Item) Item {
+	if t.root == nil {
+		return nil
+	}
+	return t.root.get(key)
+}
+
+// Has returns true if the given key is in the tree.
+func (t *BTree) Has(key Item) bool {
+	return t.Get(key) != nil
+}
+
+// Len returns the number of items currently in the tree.
+func (t *BTree) Len() int {
+	return t.length
+}
+
+// Int implements the Item interface for integers.
+type Int int
+
+// Less returns true if int(a) < int(b).
+func (a Int) Less(b Item) bool {
+	return a < b.(Int)
+}

Godeps/_workspace/src/github.com/google/btree/btree_mem.go

@@ -0,0 +1,76 @@
+// Copyright 2014 Google Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build ignore
+
+// This binary compares memory usage between btree and gollrb.
+package main
+
+import (
+	"flag"
+	"fmt"
+	"math/rand"
+	"runtime"
+	"time"
+
+	"github.com/coreos/etcd/Godeps/_workspace/src/github.com/google/btree"
+	"github.com/petar/GoLLRB/llrb"
+)
+
+var (
+	size   = flag.Int("size", 1000000, "size of the tree to build")
+	degree = flag.Int("degree", 8, "degree of btree")
+	gollrb = flag.Bool("llrb", false, "use llrb instead of btree")
+)
+
+func main() {
+	flag.Parse()
+	vals := rand.Perm(*size)
+	var t, v interface{}
+	v = vals
+	var stats runtime.MemStats
+	for i := 0; i < 10; i++ {
+		runtime.GC()
+	}
+	fmt.Println("-------- BEFORE ----------")
+	runtime.ReadMemStats(&stats)
+	fmt.Printf("%+v\n", stats)
+	start := time.Now()
+	if *gollrb {
+		tr := llrb.New()
+		for _, v := range vals {
+			tr.ReplaceOrInsert(llrb.Int(v))
+		}
+		t = tr // keep it around
+	} else {
+		tr := btree.New(*degree)
+		for _, v := range vals {
+			tr.ReplaceOrInsert(btree.Int(v))
+		}
+		t = tr // keep it around
+	}
+	fmt.Printf("%v inserts in %v\n", *size, time.Since(start))
+	fmt.Println("-------- AFTER ----------")
+	runtime.ReadMemStats(&stats)
+	fmt.Printf("%+v\n", stats)
+	for i := 0; i < 10; i++ {
+		runtime.GC()
+	}
+	fmt.Println("-------- AFTER GC ----------")
+	runtime.ReadMemStats(&stats)
+	fmt.Printf("%+v\n", stats)
+	if t == v {
+		fmt.Println("to make sure vals and tree aren't GC'd")
+	}
+}

Godeps/_workspace/src/github.com/google/btree/btree_test.go

@@ -0,0 +1,293 @@
+// Copyright 2014 Google Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package btree
+
+import (
+	"flag"
+	"fmt"
+	"math/rand"
+	"reflect"
+	"testing"
+	"time"
+)
+
+func init() {
+	seed := time.Now().Unix()
+	fmt.Println(seed)
+	rand.Seed(seed)
+}
+
+// perm returns a random permutation of n Int items in the range [0, n).
+func perm(n int) (out []Item) {
+	for _, v := range rand.Perm(n) {
+		out = append(out, Int(v))
+	}
+	return
+}
+
+// rang returns an ordered list of Int items in the range [0, n).
+func rang(n int) (out []Item) {
+	for i := 0; i < n; i++ {
+		out = append(out, Int(i))
+	}
+	return
+}
+
+// all extracts all items from a tree in order as a slice.
+func all(t *BTree) (out []Item) {
+	t.Ascend(func(a Item) bool {
+		out = append(out, a)
+		return true
+	})
+	return
+}
+
+var btreeDegree = flag.Int("degree", 32, "B-Tree degree")
+
+func TestBTree(t *testing.T) {
+	tr := New(*btreeDegree)
+	const treeSize = 10000
+	for i := 0; i < 10; i++ {
+		for _, item := range perm(treeSize) {
+			if x := tr.ReplaceOrInsert(item); x != nil {
+				t.Fatal("insert found item", item)
+			}
+		}
+		for _, item := range perm(treeSize) {
+			if x := tr.ReplaceOrInsert(item); x == nil {
+				t.Fatal("insert didn't find item", item)
+			}
+		}
+		got := all(tr)
+		want := rang(treeSize)
+		if !reflect.DeepEqual(got, want) {
+			t.Fatalf("mismatch:\n got: %v\nwant: %v", got, want)
+		}
+		for _, item := range perm(treeSize) {
+			if x := tr.Delete(item); x == nil {
+				t.Fatalf("didn't find %v", item)
+			}
+		}
+		if got = all(tr); len(got) > 0 {
+			t.Fatalf("some left!: %v", got)
+		}
+	}
+}
+
+func ExampleBTree() {
+	tr := New(*btreeDegree)
+	for i := Int(0); i < 10; i++ {
+		tr.ReplaceOrInsert(i)
+	}
+	fmt.Println("len:       ", tr.Len())
+	fmt.Println("get3:      ", tr.Get(Int(3)))
+	fmt.Println("get100:    ", tr.Get(Int(100)))
+	fmt.Println("del4:      ", tr.Delete(Int(4)))
+	fmt.Println("del100:    ", tr.Delete(Int(100)))
+	fmt.Println("replace5:  ", tr.ReplaceOrInsert(Int(5)))
+	fmt.Println("replace100:", tr.ReplaceOrInsert(Int(100)))
+	fmt.Println("delmin:    ", tr.DeleteMin())
+	fmt.Println("delmax:    ", tr.DeleteMax())
+	fmt.Println("len:       ", tr.Len())
+	// Output:
+	// len:        10
+	// get3:       3
+	// get100:     <nil>
+	// del4:       4
+	// del100:     <nil>
+	// replace5:   5
+	// replace100: <nil>
+	// delmin:     0
+	// delmax:     100
+	// len:        8
+}
+
+func TestDeleteMin(t *testing.T) {
+	tr := New(3)
+	for _, v := range perm(100) {
+		tr.ReplaceOrInsert(v)
+	}
+	var got []Item
+	for v := tr.DeleteMin(); v != nil; v = tr.DeleteMin() {
+		got = append(got, v)
+	}
+	if want := rang(100); !reflect.DeepEqual(got, want) {
+		t.Fatalf("ascendrange:\n got: %v\nwant: %v", got, want)
+	}
+}
+
+func TestDeleteMax(t *testing.T) {
+	tr := New(3)
+	for _, v := range perm(100) {
+		tr.ReplaceOrInsert(v)
+	}
+	var got []Item
+	for v := tr.DeleteMax(); v != nil; v = tr.DeleteMax() {
+		got = append(got, v)
+	}
+	// Reverse our list.
+	for i := 0; i < len(got)/2; i++ {
+		got[i], got[len(got)-i-1] = got[len(got)-i-1], got[i]
+	}
+	if want := rang(100); !reflect.DeepEqual(got, want) {
+		t.Fatalf("ascendrange:\n got: %v\nwant: %v", got, want)
+	}
+}
+
+func TestAscendRange(t *testing.T) {
+	tr := New(2)
+	for _, v := range perm(100) {
+		tr.ReplaceOrInsert(v)
+	}
+	var got []Item
+	tr.AscendRange(Int(40), Int(60), func(a Item) bool {
+		got = append(got, a)
+		return true
+	})
+	if want := rang(100)[40:60]; !reflect.DeepEqual(got, want) {
+		t.Fatalf("ascendrange:\n got: %v\nwant: %v", got, want)
+	}
+	got = got[:0]
+	tr.AscendRange(Int(40), Int(60), func(a Item) bool {
+		if a.(Int) > 50 {
+			return false
+		}
+		got = append(got, a)
+		return true
+	})
+	if want := rang(100)[40:51]; !reflect.DeepEqual(got, want) {
+		t.Fatalf("ascendrange:\n got: %v\nwant: %v", got, want)
+	}
+}
+
+func TestAscendLessThan(t *testing.T) {
+	tr := New(*btreeDegree)
+	for _, v := range perm(100) {
+		tr.ReplaceOrInsert(v)
+	}
+	var got []Item
+	tr.AscendLessThan(Int(60), func(a Item) bool {
+		got = append(got, a)
+		return true
+	})
+	if want := rang(100)[:60]; !reflect.DeepEqual(got, want) {
+		t.Fatalf("ascendrange:\n got: %v\nwant: %v", got, want)
+	}
+	got = got[:0]
+	tr.AscendLessThan(Int(60), func(a Item) bool {
+		if a.(Int) > 50 {
+			return false
+		}
+		got = append(got, a)
+		return true
+	})
+	if want := rang(100)[:51]; !reflect.DeepEqual(got, want) {
+		t.Fatalf("ascendrange:\n got: %v\nwant: %v", got, want)
+	}
+}
+
+func TestAscendGreaterOrEqual(t *testing.T) {
+	tr := New(*btreeDegree)
+	for _, v := range perm(100) {
+		tr.ReplaceOrInsert(v)
+	}
+	var got []Item
+	tr.AscendGreaterOrEqual(Int(40), func(a Item) bool {
+		got = append(got, a)
+		return true
+	})
+	if want := rang(100)[40:]; !reflect.DeepEqual(got, want) {
+		t.Fatalf("ascendrange:\n got: %v\nwant: %v", got, want)
+	}
+	got = got[:0]
+	tr.AscendGreaterOrEqual(Int(40), func(a Item) bool {
+		if a.(Int) > 50 {
+			return false
+		}
+		got = append(got, a)
+		return true
+	})
+	if want := rang(100)[40:51]; !reflect.DeepEqual(got, want) {
+		t.Fatalf("ascendrange:\n got: %v\nwant: %v", got, want)
+	}
+}
+
+const benchmarkTreeSize = 10000
+
+func BenchmarkInsert(b *testing.B) {
+	b.StopTimer()
+	insertP := perm(benchmarkTreeSize)
+	b.StartTimer()
+	i := 0
+	for i < b.N {
+		tr := New(*btreeDegree)
+		for _, item := range insertP {
+			tr.ReplaceOrInsert(item)
+			i++
+			if i >= b.N {
+				return
+			}
+		}
+	}
+}
+
+func BenchmarkDelete(b *testing.B) {
+	b.StopTimer()
+	insertP := perm(benchmarkTreeSize)
+	removeP := perm(benchmarkTreeSize)
+	b.StartTimer()
+	i := 0
+	for i < b.N {
+		b.StopTimer()
+		tr := New(*btreeDegree)
+		for _, v := range insertP {
+			tr.ReplaceOrInsert(v)
+		}
+		b.StartTimer()
+		for _, item := range removeP {
+			tr.Delete(item)
+			i++
+			if i >= b.N {
+				return
+			}
+		}
+		if tr.Len() > 0 {
+			panic(tr.Len())
+		}
+	}
+}
+
+func BenchmarkGet(b *testing.B) {
+	b.StopTimer()
+	insertP := perm(benchmarkTreeSize)
+	removeP := perm(benchmarkTreeSize)
+	b.StartTimer()
+	i := 0
+	for i < b.N {
+		b.StopTimer()
+		tr := New(*btreeDegree)
+		for _, v := range insertP {
+			tr.ReplaceOrInsert(v)
+		}
+		b.StartTimer()
+		for _, item := range removeP {
+			tr.Get(item)
+			i++
+			if i >= b.N {
+				return
+			}
+		}
+	}
+}

storage/index.go

@@ -4,7 +4,7 @@ import (
 	"log"
 	"sync"
 
-	"github.com/google/btree"
+	"github.com/coreos/etcd/Godeps/_workspace/src/github.com/google/btree"
 )
 
 type index interface {

storage/key_index.go

@@ -5,7 +5,7 @@ import (
 	"errors"
 	"log"
 
-	"github.com/google/btree"
+	"github.com/coreos/etcd/Godeps/_workspace/src/github.com/google/btree"
 )
 
 var (