diff --git a/go.mod b/go.mod index 5da10f61..b832ceb6 100644 --- a/go.mod +++ b/go.mod @@ -50,6 +50,7 @@ require ( github.com/opencontainers/image-spec v1.0.1 github.com/otiai10/copy v1.2.1-0.20200916181228-26f84a0b1578 github.com/pelletier/go-toml v1.9.4 // indirect + github.com/peterbourgon/diskv v2.0.1+incompatible github.com/philopon/go-toposort v0.0.0-20170620085441-9be86dbd762f github.com/pkg/errors v0.9.1 github.com/pterm/pterm v0.12.32-0.20211002183613-ada9ef6790c3 diff --git a/go.sum b/go.sum index 9f457080..2329916d 100644 --- a/go.sum +++ b/go.sum @@ -537,6 +537,7 @@ github.com/golangplus/bytes v0.0.0-20160111154220-45c989fe5450/go.mod h1:Bk6SMAO github.com/golangplus/fmt v0.0.0-20150411045040-2a5d6d7d2995/go.mod h1:lJgMEyOkYFkPcDKwRXegd+iM6E7matEszMG5HhwytU8= github.com/golangplus/testing v0.0.0-20180327235837-af21d9c3145e/go.mod h1:0AA//k/eakGydO4jKRoRL2j92ZKSzTgj9tclaCrvXHk= github.com/google/btree v0.0.0-20180813153112-4030bb1f1f0c/go.mod h1:lNA+9X1NB3Zf8V7Ke586lFgjr2dZNuvo3lPJSGZ5JPQ= +github.com/google/btree v1.0.0 h1:0udJVsspx3VBr5FwtLhQQtuAsVc79tTq0ocGIPAU6qo= github.com/google/btree v1.0.0/go.mod h1:lNA+9X1NB3Zf8V7Ke586lFgjr2dZNuvo3lPJSGZ5JPQ= github.com/google/certificate-transparency-go v1.0.10-0.20180222191210-5ab67e519c93 h1:jc2UWq7CbdszqeH6qu1ougXMIUBfSy8Pbh/anURYbGI= github.com/google/certificate-transparency-go v1.0.10-0.20180222191210-5ab67e519c93/go.mod h1:QeJfpSbVSfYc7RgB3gJFj9cbuQMMchQxrWXz8Ruopmg= @@ -809,8 +810,6 @@ github.com/morikuni/aec v1.0.0/go.mod h1:BbKIizmSmc5MMPqRYbxO4ZU0S0+P200+tUnFx7P github.com/mrunalp/fileutils v0.5.0/go.mod h1:M1WthSahJixYnrXQl/DFQuteStB1weuxD2QJNHXfbSQ= github.com/mudler/cobra-extensions v0.0.0-20200612154940-31a47105fe3d h1:fKh+rvwZQCA+TPzK0EMwwbqhjvRHaQ6H8AsVU1Wt+NQ= github.com/mudler/cobra-extensions v0.0.0-20200612154940-31a47105fe3d/go.mod h1:puRUWSwyecW2V355tKncwPVPRAjQBduPsFjG0mrV/Nw= -github.com/mudler/go-pluggable v0.0.0-20210513155700-54c6443073af h1:jixIxEgLSqu24eMiyzfCI+roa5IaOUhF546ePSFyHeY= -github.com/mudler/go-pluggable v0.0.0-20210513155700-54c6443073af/go.mod h1:WmKcT8ONmhDQIqQ+HxU+tkGWjzBEyY/KFO8LTGCu4AI= github.com/mudler/go-pluggable v0.0.0-20211022125509-94dbf124830d h1:NKvvf/q1dWDde+yg5cMiU5EuYZ2jNuKs/9hb8xod8A0= github.com/mudler/go-pluggable v0.0.0-20211022125509-94dbf124830d/go.mod h1:WmKcT8ONmhDQIqQ+HxU+tkGWjzBEyY/KFO8LTGCu4AI= github.com/mudler/topsort v0.0.0-20201103161459-db5c7901c290 h1:426hFyXMpXeqIeGJn2cGAW9ogvM2Jf+Jv23gtVPvBLM= @@ -909,6 +908,7 @@ github.com/pelletier/go-toml v1.9.3/go.mod h1:u1nR/EPcESfeI/szUZKdtJ0xRNbUoANCko github.com/pelletier/go-toml v1.9.4 h1:tjENF6MfZAg8e4ZmZTeWaWiT2vXtsoO6+iuOjFhECwM= github.com/pelletier/go-toml v1.9.4/go.mod h1:u1nR/EPcESfeI/szUZKdtJ0xRNbUoANCkoOuaOx1Y+c= github.com/performancecopilot/speed v3.0.0+incompatible/go.mod h1:/CLtqpZ5gBg1M9iaPbIdPPGyKcA8hKdoy6hAWba7Yac= +github.com/peterbourgon/diskv v2.0.1+incompatible h1:UBdAOUP5p4RWqPBg048CAvpKN+vxiaj6gdUUzhl4XmI= github.com/peterbourgon/diskv v2.0.1+incompatible/go.mod h1:uqqh8zWWbv1HBMNONnaR/tNboyR3/BZd58JJSHlUSCU= github.com/phayes/freeport v0.0.0-20180830031419-95f893ade6f2/go.mod h1:iIss55rKnNBTvrwdmkUpLnDpZoAHvWaiq5+iMmen4AE= github.com/philopon/go-toposort v0.0.0-20170620085441-9be86dbd762f h1:WyCn68lTiytVSkk7W1K9nBiSGTSRlUOdyTnSjwrIlok= diff --git a/vendor/github.com/google/btree/.travis.yml b/vendor/github.com/google/btree/.travis.yml new file mode 100644 index 00000000..4f2ee4d9 --- /dev/null +++ b/vendor/github.com/google/btree/.travis.yml @@ -0,0 +1 @@ +language: go diff --git a/vendor/github.com/google/btree/LICENSE b/vendor/github.com/google/btree/LICENSE new file mode 100644 index 00000000..d6456956 --- /dev/null +++ b/vendor/github.com/google/btree/LICENSE @@ -0,0 +1,202 @@ + + Apache License + Version 2.0, January 2004 + http://www.apache.org/licenses/ + + TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION + + 1. 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We also recommend that a + file or class name and description of purpose be included on the + same "printed page" as the copyright notice for easier + identification within third-party archives. + + Copyright [yyyy] [name of copyright owner] + + 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. diff --git a/vendor/github.com/google/btree/README.md b/vendor/github.com/google/btree/README.md new file mode 100644 index 00000000..6062a4da --- /dev/null +++ b/vendor/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 +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. diff --git a/vendor/github.com/google/btree/btree.go b/vendor/github.com/google/btree/btree.go new file mode 100644 index 00000000..6ff062f9 --- /dev/null +++ b/vendor/github.com/google/btree/btree.go @@ -0,0 +1,890 @@ +// 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 +// implementation 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. +package btree + +import ( + "fmt" + "io" + "sort" + "strings" + "sync" +) + +// 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 +} + +const ( + DefaultFreeListSize = 32 +) + +var ( + nilItems = make(items, 16) + nilChildren = make(children, 16) +) + +// FreeList represents a free list of btree nodes. By default each +// BTree has its own FreeList, but multiple BTrees can share the same +// FreeList. +// Two Btrees using the same freelist are safe for concurrent write access. +type FreeList struct { + mu sync.Mutex + freelist []*node +} + +// NewFreeList creates a new free list. +// size is the maximum size of the returned free list. +func NewFreeList(size int) *FreeList { + return &FreeList{freelist: make([]*node, 0, size)} +} + +func (f *FreeList) newNode() (n *node) { + f.mu.Lock() + index := len(f.freelist) - 1 + if index < 0 { + f.mu.Unlock() + return new(node) + } + n = f.freelist[index] + f.freelist[index] = nil + f.freelist = f.freelist[:index] + f.mu.Unlock() + return +} + +// freeNode adds the given node to the list, returning true if it was added +// and false if it was discarded. +func (f *FreeList) freeNode(n *node) (out bool) { + f.mu.Lock() + if len(f.freelist) < cap(f.freelist) { + f.freelist = append(f.freelist, n) + out = true + } + f.mu.Unlock() + return +} + +// 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 { + return NewWithFreeList(degree, NewFreeList(DefaultFreeListSize)) +} + +// NewWithFreeList creates a new B-Tree that uses the given node free list. +func NewWithFreeList(degree int, f *FreeList) *BTree { + if degree <= 1 { + panic("bad degree") + } + return &BTree{ + degree: degree, + cow: ©OnWriteContext{freelist: f}, + } +} + +// 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)[len(*s)-1] = nil + *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)[index] + (*s)[index] = nil + *s = (*s)[:index] + return +} + +// truncate truncates this instance at index so that it contains only the +// first index items. index must be less than or equal to length. +func (s *items) truncate(index int) { + var toClear items + *s, toClear = (*s)[:index], (*s)[index:] + for len(toClear) > 0 { + toClear = toClear[copy(toClear, nilItems):] + } +} + +// 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)[len(*s)-1] = nil + *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)[index] + (*s)[index] = nil + *s = (*s)[:index] + return +} + +// truncate truncates this instance at index so that it contains only the +// first index children. index must be less than or equal to length. +func (s *children) truncate(index int) { + var toClear children + *s, toClear = (*s)[:index], (*s)[index:] + for len(toClear) > 0 { + toClear = toClear[copy(toClear, nilChildren):] + } +} + +// 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 + cow *copyOnWriteContext +} + +func (n *node) mutableFor(cow *copyOnWriteContext) *node { + if n.cow == cow { + return n + } + out := cow.newNode() + if cap(out.items) >= len(n.items) { + out.items = out.items[:len(n.items)] + } else { + out.items = make(items, len(n.items), cap(n.items)) + } + copy(out.items, n.items) + // Copy children + if cap(out.children) >= len(n.children) { + out.children = out.children[:len(n.children)] + } else { + out.children = make(children, len(n.children), cap(n.children)) + } + copy(out.children, n.children) + return out +} + +func (n *node) mutableChild(i int) *node { + c := n.children[i].mutableFor(n.cow) + n.children[i] = c + return c +} + +// 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.cow.newNode() + next.items = append(next.items, n.items[i+1:]...) + n.items.truncate(i) + if len(n.children) > 0 { + next.children = append(next.children, n.children[i+1:]...) + n.children.truncate(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.mutableChild(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.mutableChild(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 +} + +// min returns the first item in the subtree. +func min(n *node) Item { + if n == nil { + return nil + } + for len(n.children) > 0 { + n = n.children[0] + } + if len(n.items) == 0 { + return nil + } + return n.items[0] +} + +// max returns the last item in the subtree. +func max(n *node) Item { + if n == nil { + return nil + } + for len(n.children) > 0 { + n = n.children[len(n.children)-1] + } + if len(n.items) == 0 { + return nil + } + return n.items[len(n.items)-1] +} + +// 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. + if len(n.children[i].items) <= minItems { + return n.growChildAndRemove(i, item, minItems, typ) + } + child := n.mutableChild(i) + // 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 { + if i > 0 && len(n.children[i-1].items) > minItems { + // Steal from left child + child := n.mutableChild(i) + stealFrom := n.mutableChild(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 + child := n.mutableChild(i) + stealFrom := n.mutableChild(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.mutableChild(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.cow.freeNode(mergeChild) + } + return n.remove(item, minItems, typ) +} + +type direction int + +const ( + descend = direction(-1) + ascend = direction(+1) +) + +// iterate provides a simple method for iterating over elements in the tree. +// +// When ascending, the 'start' should be less than 'stop' and when descending, +// the 'start' should be greater than 'stop'. Setting 'includeStart' to true +// will force the iterator to include the first item when it equals 'start', +// thus creating a "greaterOrEqual" or "lessThanEqual" rather than just a +// "greaterThan" or "lessThan" queries. +func (n *node) iterate(dir direction, start, stop Item, includeStart bool, hit bool, iter ItemIterator) (bool, bool) { + var ok, found bool + var index int + switch dir { + case ascend: + if start != nil { + index, _ = n.items.find(start) + } + for i := index; i < len(n.items); i++ { + if len(n.children) > 0 { + if hit, ok = n.children[i].iterate(dir, start, stop, includeStart, hit, iter); !ok { + return hit, false + } + } + if !includeStart && !hit && start != nil && !start.Less(n.items[i]) { + hit = true + continue + } + hit = true + if stop != nil && !n.items[i].Less(stop) { + return hit, false + } + if !iter(n.items[i]) { + return hit, false + } + } + if len(n.children) > 0 { + if hit, ok = n.children[len(n.children)-1].iterate(dir, start, stop, includeStart, hit, iter); !ok { + return hit, false + } + } + case descend: + if start != nil { + index, found = n.items.find(start) + if !found { + index = index - 1 + } + } else { + index = len(n.items) - 1 + } + for i := index; i >= 0; i-- { + if start != nil && !n.items[i].Less(start) { + if !includeStart || hit || start.Less(n.items[i]) { + continue + } + } + if len(n.children) > 0 { + if hit, ok = n.children[i+1].iterate(dir, start, stop, includeStart, hit, iter); !ok { + return hit, false + } + } + if stop != nil && !stop.Less(n.items[i]) { + return hit, false // continue + } + hit = true + if !iter(n.items[i]) { + return hit, false + } + } + if len(n.children) > 0 { + if hit, ok = n.children[0].iterate(dir, start, stop, includeStart, hit, iter); !ok { + return hit, false + } + } + } + return hit, 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 + cow *copyOnWriteContext +} + +// copyOnWriteContext pointers determine node ownership... a tree with a write +// context equivalent to a node's write context is allowed to modify that node. +// A tree whose write context does not match a node's is not allowed to modify +// it, and must create a new, writable copy (IE: it's a Clone). +// +// When doing any write operation, we maintain the invariant that the current +// node's context is equal to the context of the tree that requested the write. +// We do this by, before we descend into any node, creating a copy with the +// correct context if the contexts don't match. +// +// Since the node we're currently visiting on any write has the requesting +// tree's context, that node is modifiable in place. Children of that node may +// not share context, but before we descend into them, we'll make a mutable +// copy. +type copyOnWriteContext struct { + freelist *FreeList +} + +// Clone clones the btree, lazily. Clone should not be called concurrently, +// but the original tree (t) and the new tree (t2) can be used concurrently +// once the Clone call completes. +// +// The internal tree structure of b is marked read-only and shared between t and +// t2. Writes to both t and t2 use copy-on-write logic, creating new nodes +// whenever one of b's original nodes would have been modified. Read operations +// should have no performance degredation. Write operations for both t and t2 +// will initially experience minor slow-downs caused by additional allocs and +// copies due to the aforementioned copy-on-write logic, but should converge to +// the original performance characteristics of the original tree. +func (t *BTree) Clone() (t2 *BTree) { + // Create two entirely new copy-on-write contexts. + // This operation effectively creates three trees: + // the original, shared nodes (old b.cow) + // the new b.cow nodes + // the new out.cow nodes + cow1, cow2 := *t.cow, *t.cow + out := *t + t.cow = &cow1 + out.cow = &cow2 + return &out +} + +// 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 (c *copyOnWriteContext) newNode() (n *node) { + n = c.freelist.newNode() + n.cow = c + return +} + +type freeType int + +const ( + ftFreelistFull freeType = iota // node was freed (available for GC, not stored in freelist) + ftStored // node was stored in the freelist for later use + ftNotOwned // node was ignored by COW, since it's owned by another one +) + +// freeNode frees a node within a given COW context, if it's owned by that +// context. It returns what happened to the node (see freeType const +// documentation). +func (c *copyOnWriteContext) freeNode(n *node) freeType { + if n.cow == c { + // clear to allow GC + n.items.truncate(0) + n.children.truncate(0) + n.cow = nil + if c.freelist.freeNode(n) { + return ftStored + } else { + return ftFreelistFull + } + } else { + return ftNotOwned + } +} + +// 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.cow.newNode() + t.root.items = append(t.root.items, item) + t.length++ + return nil + } else { + t.root = t.root.mutableFor(t.cow) + if len(t.root.items) >= t.maxItems() { + item2, second := t.root.split(t.maxItems() / 2) + oldroot := t.root + t.root = t.cow.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 + } + t.root = t.root.mutableFor(t.cow) + 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.cow.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(ascend, greaterOrEqual, lessThan, true, false, 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(ascend, nil, pivot, false, false, 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(ascend, pivot, nil, true, false, 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(ascend, nil, nil, false, false, iterator) +} + +// DescendRange calls the iterator for every value in the tree within the range +// [lessOrEqual, greaterThan), until iterator returns false. +func (t *BTree) DescendRange(lessOrEqual, greaterThan Item, iterator ItemIterator) { + if t.root == nil { + return + } + t.root.iterate(descend, lessOrEqual, greaterThan, true, false, iterator) +} + +// DescendLessOrEqual calls the iterator for every value in the tree within the range +// [pivot, first], until iterator returns false. +func (t *BTree) DescendLessOrEqual(pivot Item, iterator ItemIterator) { + if t.root == nil { + return + } + t.root.iterate(descend, pivot, nil, true, false, iterator) +} + +// DescendGreaterThan calls the iterator for every value in the tree within +// the range (pivot, last], until iterator returns false. +func (t *BTree) DescendGreaterThan(pivot Item, iterator ItemIterator) { + if t.root == nil { + return + } + t.root.iterate(descend, nil, pivot, false, false, iterator) +} + +// Descend calls the iterator for every value in the tree within the range +// [last, first], until iterator returns false. +func (t *BTree) Descend(iterator ItemIterator) { + if t.root == nil { + return + } + t.root.iterate(descend, nil, nil, false, false, 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) +} + +// Min returns the smallest item in the tree, or nil if the tree is empty. +func (t *BTree) Min() Item { + return min(t.root) +} + +// Max returns the largest item in the tree, or nil if the tree is empty. +func (t *BTree) Max() Item { + return max(t.root) +} + +// 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 +} + +// Clear removes all items from the btree. If addNodesToFreelist is true, +// t's nodes are added to its freelist as part of this call, until the freelist +// is full. Otherwise, the root node is simply dereferenced and the subtree +// left to Go's normal GC processes. +// +// This can be much faster +// than calling Delete on all elements, because that requires finding/removing +// each element in the tree and updating the tree accordingly. It also is +// somewhat faster than creating a new tree to replace the old one, because +// nodes from the old tree are reclaimed into the freelist for use by the new +// one, instead of being lost to the garbage collector. +// +// This call takes: +// O(1): when addNodesToFreelist is false, this is a single operation. +// O(1): when the freelist is already full, it breaks out immediately +// O(freelist size): when the freelist is empty and the nodes are all owned +// by this tree, nodes are added to the freelist until full. +// O(tree size): when all nodes are owned by another tree, all nodes are +// iterated over looking for nodes to add to the freelist, and due to +// ownership, none are. +func (t *BTree) Clear(addNodesToFreelist bool) { + if t.root != nil && addNodesToFreelist { + t.root.reset(t.cow) + } + t.root, t.length = nil, 0 +} + +// reset returns a subtree to the freelist. It breaks out immediately if the +// freelist is full, since the only benefit of iterating is to fill that +// freelist up. Returns true if parent reset call should continue. +func (n *node) reset(c *copyOnWriteContext) bool { + for _, child := range n.children { + if !child.reset(c) { + return false + } + } + return c.freeNode(n) != ftFreelistFull +} + +// 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) +} diff --git a/vendor/github.com/peterbourgon/diskv/LICENSE b/vendor/github.com/peterbourgon/diskv/LICENSE new file mode 100644 index 00000000..41ce7f16 --- /dev/null +++ b/vendor/github.com/peterbourgon/diskv/LICENSE @@ -0,0 +1,19 @@ +Copyright (c) 2011-2012 Peter Bourgon + +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. diff --git a/vendor/github.com/peterbourgon/diskv/README.md b/vendor/github.com/peterbourgon/diskv/README.md new file mode 100644 index 00000000..3474739e --- /dev/null +++ b/vendor/github.com/peterbourgon/diskv/README.md @@ -0,0 +1,141 @@ +# What is diskv? + +Diskv (disk-vee) is a simple, persistent key-value store written in the Go +language. It starts with an incredibly simple API for storing arbitrary data on +a filesystem by key, and builds several layers of performance-enhancing +abstraction on top. The end result is a conceptually simple, but highly +performant, disk-backed storage system. + +[![Build Status][1]][2] + +[1]: https://drone.io/github.com/peterbourgon/diskv/status.png +[2]: https://drone.io/github.com/peterbourgon/diskv/latest + + +# Installing + +Install [Go 1][3], either [from source][4] or [with a prepackaged binary][5]. +Then, + +```bash +$ go get github.com/peterbourgon/diskv +``` + +[3]: http://golang.org +[4]: http://golang.org/doc/install/source +[5]: http://golang.org/doc/install + + +# Usage + +```go +package main + +import ( + "fmt" + "github.com/peterbourgon/diskv" +) + +func main() { + // Simplest transform function: put all the data files into the base dir. + flatTransform := func(s string) []string { return []string{} } + + // Initialize a new diskv store, rooted at "my-data-dir", with a 1MB cache. + d := diskv.New(diskv.Options{ + BasePath: "my-data-dir", + Transform: flatTransform, + CacheSizeMax: 1024 * 1024, + }) + + // Write three bytes to the key "alpha". + key := "alpha" + d.Write(key, []byte{'1', '2', '3'}) + + // Read the value back out of the store. + value, _ := d.Read(key) + fmt.Printf("%v\n", value) + + // Erase the key+value from the store (and the disk). + d.Erase(key) +} +``` + +More complex examples can be found in the "examples" subdirectory. + + +# Theory + +## Basic idea + +At its core, diskv is a map of a key (`string`) to arbitrary data (`[]byte`). +The data is written to a single file on disk, with the same name as the key. +The key determines where that file will be stored, via a user-provided +`TransformFunc`, which takes a key and returns a slice (`[]string`) +corresponding to a path list where the key file will be stored. The simplest +TransformFunc, + +```go +func SimpleTransform (key string) []string { + return []string{} +} +``` + +will place all keys in the same, base directory. The design is inspired by +[Redis diskstore][6]; a TransformFunc which emulates the default diskstore +behavior is available in the content-addressable-storage example. + +[6]: http://groups.google.com/group/redis-db/browse_thread/thread/d444bc786689bde9?pli=1 + +**Note** that your TransformFunc should ensure that one valid key doesn't +transform to a subset of another valid key. That is, it shouldn't be possible +to construct valid keys that resolve to directory names. As a concrete example, +if your TransformFunc splits on every 3 characters, then + +```go +d.Write("abcabc", val) // OK: written to /abc/abc/abcabc +d.Write("abc", val) // Error: attempted write to /abc/abc, but it's a directory +``` + +This will be addressed in an upcoming version of diskv. + +Probably the most important design principle behind diskv is that your data is +always flatly available on the disk. diskv will never do anything that would +prevent you from accessing, copying, backing up, or otherwise interacting with +your data via common UNIX commandline tools. + +## Adding a cache + +An in-memory caching layer is provided by combining the BasicStore +functionality with a simple map structure, and keeping it up-to-date as +appropriate. Since the map structure in Go is not threadsafe, it's combined +with a RWMutex to provide safe concurrent access. + +## Adding order + +diskv is a key-value store and therefore inherently unordered. An ordering +system can be injected into the store by passing something which satisfies the +diskv.Index interface. (A default implementation, using Google's +[btree][7] package, is provided.) Basically, diskv keeps an ordered (by a +user-provided Less function) index of the keys, which can be queried. + +[7]: https://github.com/google/btree + +## Adding compression + +Something which implements the diskv.Compression interface may be passed +during store creation, so that all Writes and Reads are filtered through +a compression/decompression pipeline. Several default implementations, +using stdlib compression algorithms, are provided. Note that data is cached +compressed; the cost of decompression is borne with each Read. + +## Streaming + +diskv also now provides ReadStream and WriteStream methods, to allow very large +data to be handled efficiently. + + +# Future plans + + * Needs plenty of robust testing: huge datasets, etc... + * More thorough benchmarking + * Your suggestions for use-cases I haven't thought of diff --git a/vendor/github.com/peterbourgon/diskv/compression.go b/vendor/github.com/peterbourgon/diskv/compression.go new file mode 100644 index 00000000..5192b027 --- /dev/null +++ b/vendor/github.com/peterbourgon/diskv/compression.go @@ -0,0 +1,64 @@ +package diskv + +import ( + "compress/flate" + "compress/gzip" + "compress/zlib" + "io" +) + +// Compression is an interface that Diskv uses to implement compression of +// data. Writer takes a destination io.Writer and returns a WriteCloser that +// compresses all data written through it. Reader takes a source io.Reader and +// returns a ReadCloser that decompresses all data read through it. You may +// define these methods on your own type, or use one of the NewCompression +// helpers. +type Compression interface { + Writer(dst io.Writer) (io.WriteCloser, error) + Reader(src io.Reader) (io.ReadCloser, error) +} + +// NewGzipCompression returns a Gzip-based Compression. +func NewGzipCompression() Compression { + return NewGzipCompressionLevel(flate.DefaultCompression) +} + +// NewGzipCompressionLevel returns a Gzip-based Compression with the given level. +func NewGzipCompressionLevel(level int) Compression { + return &genericCompression{ + wf: func(w io.Writer) (io.WriteCloser, error) { return gzip.NewWriterLevel(w, level) }, + rf: func(r io.Reader) (io.ReadCloser, error) { return gzip.NewReader(r) }, + } +} + +// NewZlibCompression returns a Zlib-based Compression. +func NewZlibCompression() Compression { + return NewZlibCompressionLevel(flate.DefaultCompression) +} + +// NewZlibCompressionLevel returns a Zlib-based Compression with the given level. +func NewZlibCompressionLevel(level int) Compression { + return NewZlibCompressionLevelDict(level, nil) +} + +// NewZlibCompressionLevelDict returns a Zlib-based Compression with the given +// level, based on the given dictionary. +func NewZlibCompressionLevelDict(level int, dict []byte) Compression { + return &genericCompression{ + func(w io.Writer) (io.WriteCloser, error) { return zlib.NewWriterLevelDict(w, level, dict) }, + func(r io.Reader) (io.ReadCloser, error) { return zlib.NewReaderDict(r, dict) }, + } +} + +type genericCompression struct { + wf func(w io.Writer) (io.WriteCloser, error) + rf func(r io.Reader) (io.ReadCloser, error) +} + +func (g *genericCompression) Writer(dst io.Writer) (io.WriteCloser, error) { + return g.wf(dst) +} + +func (g *genericCompression) Reader(src io.Reader) (io.ReadCloser, error) { + return g.rf(src) +} diff --git a/vendor/github.com/peterbourgon/diskv/diskv.go b/vendor/github.com/peterbourgon/diskv/diskv.go new file mode 100644 index 00000000..524dc0a6 --- /dev/null +++ b/vendor/github.com/peterbourgon/diskv/diskv.go @@ -0,0 +1,624 @@ +// Diskv (disk-vee) is a simple, persistent, key-value store. +// It stores all data flatly on the filesystem. + +package diskv + +import ( + "bytes" + "errors" + "fmt" + "io" + "io/ioutil" + "os" + "path/filepath" + "strings" + "sync" + "syscall" +) + +const ( + defaultBasePath = "diskv" + defaultFilePerm os.FileMode = 0666 + defaultPathPerm os.FileMode = 0777 +) + +var ( + defaultTransform = func(s string) []string { return []string{} } + errCanceled = errors.New("canceled") + errEmptyKey = errors.New("empty key") + errBadKey = errors.New("bad key") + errImportDirectory = errors.New("can't import a directory") +) + +// TransformFunction transforms a key into a slice of strings, with each +// element in the slice representing a directory in the file path where the +// key's entry will eventually be stored. +// +// For example, if TransformFunc transforms "abcdef" to ["ab", "cde", "f"], +// the final location of the data file will be /ab/cde/f/abcdef +type TransformFunction func(s string) []string + +// Options define a set of properties that dictate Diskv behavior. +// All values are optional. +type Options struct { + BasePath string + Transform TransformFunction + CacheSizeMax uint64 // bytes + PathPerm os.FileMode + FilePerm os.FileMode + // If TempDir is set, it will enable filesystem atomic writes by + // writing temporary files to that location before being moved + // to BasePath. + // Note that TempDir MUST be on the same device/partition as + // BasePath. + TempDir string + + Index Index + IndexLess LessFunction + + Compression Compression +} + +// Diskv implements the Diskv interface. You shouldn't construct Diskv +// structures directly; instead, use the New constructor. +type Diskv struct { + Options + mu sync.RWMutex + cache map[string][]byte + cacheSize uint64 +} + +// New returns an initialized Diskv structure, ready to use. +// If the path identified by baseDir already contains data, +// it will be accessible, but not yet cached. +func New(o Options) *Diskv { + if o.BasePath == "" { + o.BasePath = defaultBasePath + } + if o.Transform == nil { + o.Transform = defaultTransform + } + if o.PathPerm == 0 { + o.PathPerm = defaultPathPerm + } + if o.FilePerm == 0 { + o.FilePerm = defaultFilePerm + } + + d := &Diskv{ + Options: o, + cache: map[string][]byte{}, + cacheSize: 0, + } + + if d.Index != nil && d.IndexLess != nil { + d.Index.Initialize(d.IndexLess, d.Keys(nil)) + } + + return d +} + +// Write synchronously writes the key-value pair to disk, making it immediately +// available for reads. Write relies on the filesystem to perform an eventual +// sync to physical media. If you need stronger guarantees, see WriteStream. +func (d *Diskv) Write(key string, val []byte) error { + return d.WriteStream(key, bytes.NewBuffer(val), false) +} + +// WriteStream writes the data represented by the io.Reader to the disk, under +// the provided key. If sync is true, WriteStream performs an explicit sync on +// the file as soon as it's written. +// +// bytes.Buffer provides io.Reader semantics for basic data types. +func (d *Diskv) WriteStream(key string, r io.Reader, sync bool) error { + if len(key) <= 0 { + return errEmptyKey + } + + d.mu.Lock() + defer d.mu.Unlock() + + return d.writeStreamWithLock(key, r, sync) +} + +// createKeyFileWithLock either creates the key file directly, or +// creates a temporary file in TempDir if it is set. +func (d *Diskv) createKeyFileWithLock(key string) (*os.File, error) { + if d.TempDir != "" { + if err := os.MkdirAll(d.TempDir, d.PathPerm); err != nil { + return nil, fmt.Errorf("temp mkdir: %s", err) + } + f, err := ioutil.TempFile(d.TempDir, "") + if err != nil { + return nil, fmt.Errorf("temp file: %s", err) + } + + if err := f.Chmod(d.FilePerm); err != nil { + f.Close() // error deliberately ignored + os.Remove(f.Name()) // error deliberately ignored + return nil, fmt.Errorf("chmod: %s", err) + } + return f, nil + } + + mode := os.O_WRONLY | os.O_CREATE | os.O_TRUNC // overwrite if exists + f, err := os.OpenFile(d.completeFilename(key), mode, d.FilePerm) + if err != nil { + return nil, fmt.Errorf("open file: %s", err) + } + return f, nil +} + +// writeStream does no input validation checking. +func (d *Diskv) writeStreamWithLock(key string, r io.Reader, sync bool) error { + if err := d.ensurePathWithLock(key); err != nil { + return fmt.Errorf("ensure path: %s", err) + } + + f, err := d.createKeyFileWithLock(key) + if err != nil { + return fmt.Errorf("create key file: %s", err) + } + + wc := io.WriteCloser(&nopWriteCloser{f}) + if d.Compression != nil { + wc, err = d.Compression.Writer(f) + if err != nil { + f.Close() // error deliberately ignored + os.Remove(f.Name()) // error deliberately ignored + return fmt.Errorf("compression writer: %s", err) + } + } + + if _, err := io.Copy(wc, r); err != nil { + f.Close() // error deliberately ignored + os.Remove(f.Name()) // error deliberately ignored + return fmt.Errorf("i/o copy: %s", err) + } + + if err := wc.Close(); err != nil { + f.Close() // error deliberately ignored + os.Remove(f.Name()) // error deliberately ignored + return fmt.Errorf("compression close: %s", err) + } + + if sync { + if err := f.Sync(); err != nil { + f.Close() // error deliberately ignored + os.Remove(f.Name()) // error deliberately ignored + return fmt.Errorf("file sync: %s", err) + } + } + + if err := f.Close(); err != nil { + return fmt.Errorf("file close: %s", err) + } + + if f.Name() != d.completeFilename(key) { + if err := os.Rename(f.Name(), d.completeFilename(key)); err != nil { + os.Remove(f.Name()) // error deliberately ignored + return fmt.Errorf("rename: %s", err) + } + } + + if d.Index != nil { + d.Index.Insert(key) + } + + d.bustCacheWithLock(key) // cache only on read + + return nil +} + +// Import imports the source file into diskv under the destination key. If the +// destination key already exists, it's overwritten. If move is true, the +// source file is removed after a successful import. +func (d *Diskv) Import(srcFilename, dstKey string, move bool) (err error) { + if dstKey == "" { + return errEmptyKey + } + + if fi, err := os.Stat(srcFilename); err != nil { + return err + } else if fi.IsDir() { + return errImportDirectory + } + + d.mu.Lock() + defer d.mu.Unlock() + + if err := d.ensurePathWithLock(dstKey); err != nil { + return fmt.Errorf("ensure path: %s", err) + } + + if move { + if err := syscall.Rename(srcFilename, d.completeFilename(dstKey)); err == nil { + d.bustCacheWithLock(dstKey) + return nil + } else if err != syscall.EXDEV { + // If it failed due to being on a different device, fall back to copying + return err + } + } + + f, err := os.Open(srcFilename) + if err != nil { + return err + } + defer f.Close() + err = d.writeStreamWithLock(dstKey, f, false) + if err == nil && move { + err = os.Remove(srcFilename) + } + return err +} + +// Read reads the key and returns the value. +// If the key is available in the cache, Read won't touch the disk. +// If the key is not in the cache, Read will have the side-effect of +// lazily caching the value. +func (d *Diskv) Read(key string) ([]byte, error) { + rc, err := d.ReadStream(key, false) + if err != nil { + return []byte{}, err + } + defer rc.Close() + return ioutil.ReadAll(rc) +} + +// ReadStream reads the key and returns the value (data) as an io.ReadCloser. +// If the value is cached from a previous read, and direct is false, +// ReadStream will use the cached value. Otherwise, it will return a handle to +// the file on disk, and cache the data on read. +// +// If direct is true, ReadStream will lazily delete any cached value for the +// key, and return a direct handle to the file on disk. +// +// If compression is enabled, ReadStream taps into the io.Reader stream prior +// to decompression, and caches the compressed data. +func (d *Diskv) ReadStream(key string, direct bool) (io.ReadCloser, error) { + d.mu.RLock() + defer d.mu.RUnlock() + + if val, ok := d.cache[key]; ok { + if !direct { + buf := bytes.NewBuffer(val) + if d.Compression != nil { + return d.Compression.Reader(buf) + } + return ioutil.NopCloser(buf), nil + } + + go func() { + d.mu.Lock() + defer d.mu.Unlock() + d.uncacheWithLock(key, uint64(len(val))) + }() + } + + return d.readWithRLock(key) +} + +// read ignores the cache, and returns an io.ReadCloser representing the +// decompressed data for the given key, streamed from the disk. Clients should +// acquire a read lock on the Diskv and check the cache themselves before +// calling read. +func (d *Diskv) readWithRLock(key string) (io.ReadCloser, error) { + filename := d.completeFilename(key) + + fi, err := os.Stat(filename) + if err != nil { + return nil, err + } + if fi.IsDir() { + return nil, os.ErrNotExist + } + + f, err := os.Open(filename) + if err != nil { + return nil, err + } + + var r io.Reader + if d.CacheSizeMax > 0 { + r = newSiphon(f, d, key) + } else { + r = &closingReader{f} + } + + var rc = io.ReadCloser(ioutil.NopCloser(r)) + if d.Compression != nil { + rc, err = d.Compression.Reader(r) + if err != nil { + return nil, err + } + } + + return rc, nil +} + +// closingReader provides a Reader that automatically closes the +// embedded ReadCloser when it reaches EOF +type closingReader struct { + rc io.ReadCloser +} + +func (cr closingReader) Read(p []byte) (int, error) { + n, err := cr.rc.Read(p) + if err == io.EOF { + if closeErr := cr.rc.Close(); closeErr != nil { + return n, closeErr // close must succeed for Read to succeed + } + } + return n, err +} + +// siphon is like a TeeReader: it copies all data read through it to an +// internal buffer, and moves that buffer to the cache at EOF. +type siphon struct { + f *os.File + d *Diskv + key string + buf *bytes.Buffer +} + +// newSiphon constructs a siphoning reader that represents the passed file. +// When a successful series of reads ends in an EOF, the siphon will write +// the buffered data to Diskv's cache under the given key. +func newSiphon(f *os.File, d *Diskv, key string) io.Reader { + return &siphon{ + f: f, + d: d, + key: key, + buf: &bytes.Buffer{}, + } +} + +// Read implements the io.Reader interface for siphon. +func (s *siphon) Read(p []byte) (int, error) { + n, err := s.f.Read(p) + + if err == nil { + return s.buf.Write(p[0:n]) // Write must succeed for Read to succeed + } + + if err == io.EOF { + s.d.cacheWithoutLock(s.key, s.buf.Bytes()) // cache may fail + if closeErr := s.f.Close(); closeErr != nil { + return n, closeErr // close must succeed for Read to succeed + } + return n, err + } + + return n, err +} + +// Erase synchronously erases the given key from the disk and the cache. +func (d *Diskv) Erase(key string) error { + d.mu.Lock() + defer d.mu.Unlock() + + d.bustCacheWithLock(key) + + // erase from index + if d.Index != nil { + d.Index.Delete(key) + } + + // erase from disk + filename := d.completeFilename(key) + if s, err := os.Stat(filename); err == nil { + if s.IsDir() { + return errBadKey + } + if err = os.Remove(filename); err != nil { + return err + } + } else { + // Return err as-is so caller can do os.IsNotExist(err). + return err + } + + // clean up and return + d.pruneDirsWithLock(key) + return nil +} + +// EraseAll will delete all of the data from the store, both in the cache and on +// the disk. Note that EraseAll doesn't distinguish diskv-related data from non- +// diskv-related data. Care should be taken to always specify a diskv base +// directory that is exclusively for diskv data. +func (d *Diskv) EraseAll() error { + d.mu.Lock() + defer d.mu.Unlock() + d.cache = make(map[string][]byte) + d.cacheSize = 0 + if d.TempDir != "" { + os.RemoveAll(d.TempDir) // errors ignored + } + return os.RemoveAll(d.BasePath) +} + +// Has returns true if the given key exists. +func (d *Diskv) Has(key string) bool { + d.mu.Lock() + defer d.mu.Unlock() + + if _, ok := d.cache[key]; ok { + return true + } + + filename := d.completeFilename(key) + s, err := os.Stat(filename) + if err != nil { + return false + } + if s.IsDir() { + return false + } + + return true +} + +// Keys returns a channel that will yield every key accessible by the store, +// in undefined order. If a cancel channel is provided, closing it will +// terminate and close the keys channel. +func (d *Diskv) Keys(cancel <-chan struct{}) <-chan string { + return d.KeysPrefix("", cancel) +} + +// KeysPrefix returns a channel that will yield every key accessible by the +// store with the given prefix, in undefined order. If a cancel channel is +// provided, closing it will terminate and close the keys channel. If the +// provided prefix is the empty string, all keys will be yielded. +func (d *Diskv) KeysPrefix(prefix string, cancel <-chan struct{}) <-chan string { + var prepath string + if prefix == "" { + prepath = d.BasePath + } else { + prepath = d.pathFor(prefix) + } + c := make(chan string) + go func() { + filepath.Walk(prepath, walker(c, prefix, cancel)) + close(c) + }() + return c +} + +// walker returns a function which satisfies the filepath.WalkFunc interface. +// It sends every non-directory file entry down the channel c. +func walker(c chan<- string, prefix string, cancel <-chan struct{}) filepath.WalkFunc { + return func(path string, info os.FileInfo, err error) error { + if err != nil { + return err + } + + if info.IsDir() || !strings.HasPrefix(info.Name(), prefix) { + return nil // "pass" + } + + select { + case c <- info.Name(): + case <-cancel: + return errCanceled + } + + return nil + } +} + +// pathFor returns the absolute path for location on the filesystem where the +// data for the given key will be stored. +func (d *Diskv) pathFor(key string) string { + return filepath.Join(d.BasePath, filepath.Join(d.Transform(key)...)) +} + +// ensurePathWithLock is a helper function that generates all necessary +// directories on the filesystem for the given key. +func (d *Diskv) ensurePathWithLock(key string) error { + return os.MkdirAll(d.pathFor(key), d.PathPerm) +} + +// completeFilename returns the absolute path to the file for the given key. +func (d *Diskv) completeFilename(key string) string { + return filepath.Join(d.pathFor(key), key) +} + +// cacheWithLock attempts to cache the given key-value pair in the store's +// cache. It can fail if the value is larger than the cache's maximum size. +func (d *Diskv) cacheWithLock(key string, val []byte) error { + valueSize := uint64(len(val)) + if err := d.ensureCacheSpaceWithLock(valueSize); err != nil { + return fmt.Errorf("%s; not caching", err) + } + + // be very strict about memory guarantees + if (d.cacheSize + valueSize) > d.CacheSizeMax { + panic(fmt.Sprintf("failed to make room for value (%d/%d)", valueSize, d.CacheSizeMax)) + } + + d.cache[key] = val + d.cacheSize += valueSize + return nil +} + +// cacheWithoutLock acquires the store's (write) mutex and calls cacheWithLock. +func (d *Diskv) cacheWithoutLock(key string, val []byte) error { + d.mu.Lock() + defer d.mu.Unlock() + return d.cacheWithLock(key, val) +} + +func (d *Diskv) bustCacheWithLock(key string) { + if val, ok := d.cache[key]; ok { + d.uncacheWithLock(key, uint64(len(val))) + } +} + +func (d *Diskv) uncacheWithLock(key string, sz uint64) { + d.cacheSize -= sz + delete(d.cache, key) +} + +// pruneDirsWithLock deletes empty directories in the path walk leading to the +// key k. Typically this function is called after an Erase is made. +func (d *Diskv) pruneDirsWithLock(key string) error { + pathlist := d.Transform(key) + for i := range pathlist { + dir := filepath.Join(d.BasePath, filepath.Join(pathlist[:len(pathlist)-i]...)) + + // thanks to Steven Blenkinsop for this snippet + switch fi, err := os.Stat(dir); true { + case err != nil: + return err + case !fi.IsDir(): + panic(fmt.Sprintf("corrupt dirstate at %s", dir)) + } + + nlinks, err := filepath.Glob(filepath.Join(dir, "*")) + if err != nil { + return err + } else if len(nlinks) > 0 { + return nil // has subdirs -- do not prune + } + if err = os.Remove(dir); err != nil { + return err + } + } + + return nil +} + +// ensureCacheSpaceWithLock deletes entries from the cache in arbitrary order +// until the cache has at least valueSize bytes available. +func (d *Diskv) ensureCacheSpaceWithLock(valueSize uint64) error { + if valueSize > d.CacheSizeMax { + return fmt.Errorf("value size (%d bytes) too large for cache (%d bytes)", valueSize, d.CacheSizeMax) + } + + safe := func() bool { return (d.cacheSize + valueSize) <= d.CacheSizeMax } + + for key, val := range d.cache { + if safe() { + break + } + + d.uncacheWithLock(key, uint64(len(val))) + } + + if !safe() { + panic(fmt.Sprintf("%d bytes still won't fit in the cache! (max %d bytes)", valueSize, d.CacheSizeMax)) + } + + return nil +} + +// nopWriteCloser wraps an io.Writer and provides a no-op Close method to +// satisfy the io.WriteCloser interface. +type nopWriteCloser struct { + io.Writer +} + +func (wc *nopWriteCloser) Write(p []byte) (int, error) { return wc.Writer.Write(p) } +func (wc *nopWriteCloser) Close() error { return nil } diff --git a/vendor/github.com/peterbourgon/diskv/index.go b/vendor/github.com/peterbourgon/diskv/index.go new file mode 100644 index 00000000..96fee515 --- /dev/null +++ b/vendor/github.com/peterbourgon/diskv/index.go @@ -0,0 +1,115 @@ +package diskv + +import ( + "sync" + + "github.com/google/btree" +) + +// Index is a generic interface for things that can +// provide an ordered list of keys. +type Index interface { + Initialize(less LessFunction, keys <-chan string) + Insert(key string) + Delete(key string) + Keys(from string, n int) []string +} + +// LessFunction is used to initialize an Index of keys in a specific order. +type LessFunction func(string, string) bool + +// btreeString is a custom data type that satisfies the BTree Less interface, +// making the strings it wraps sortable by the BTree package. +type btreeString struct { + s string + l LessFunction +} + +// Less satisfies the BTree.Less interface using the btreeString's LessFunction. +func (s btreeString) Less(i btree.Item) bool { + return s.l(s.s, i.(btreeString).s) +} + +// BTreeIndex is an implementation of the Index interface using google/btree. +type BTreeIndex struct { + sync.RWMutex + LessFunction + *btree.BTree +} + +// Initialize populates the BTree tree with data from the keys channel, +// according to the passed less function. It's destructive to the BTreeIndex. +func (i *BTreeIndex) Initialize(less LessFunction, keys <-chan string) { + i.Lock() + defer i.Unlock() + i.LessFunction = less + i.BTree = rebuild(less, keys) +} + +// Insert inserts the given key (only) into the BTree tree. +func (i *BTreeIndex) Insert(key string) { + i.Lock() + defer i.Unlock() + if i.BTree == nil || i.LessFunction == nil { + panic("uninitialized index") + } + i.BTree.ReplaceOrInsert(btreeString{s: key, l: i.LessFunction}) +} + +// Delete removes the given key (only) from the BTree tree. +func (i *BTreeIndex) Delete(key string) { + i.Lock() + defer i.Unlock() + if i.BTree == nil || i.LessFunction == nil { + panic("uninitialized index") + } + i.BTree.Delete(btreeString{s: key, l: i.LessFunction}) +} + +// Keys yields a maximum of n keys in order. If the passed 'from' key is empty, +// Keys will return the first n keys. If the passed 'from' key is non-empty, the +// first key in the returned slice will be the key that immediately follows the +// passed key, in key order. +func (i *BTreeIndex) Keys(from string, n int) []string { + i.RLock() + defer i.RUnlock() + + if i.BTree == nil || i.LessFunction == nil { + panic("uninitialized index") + } + + if i.BTree.Len() <= 0 { + return []string{} + } + + btreeFrom := btreeString{s: from, l: i.LessFunction} + skipFirst := true + if len(from) <= 0 || !i.BTree.Has(btreeFrom) { + // no such key, so fabricate an always-smallest item + btreeFrom = btreeString{s: "", l: func(string, string) bool { return true }} + skipFirst = false + } + + keys := []string{} + iterator := func(i btree.Item) bool { + keys = append(keys, i.(btreeString).s) + return len(keys) < n + } + i.BTree.AscendGreaterOrEqual(btreeFrom, iterator) + + if skipFirst && len(keys) > 0 { + keys = keys[1:] + } + + return keys +} + +// rebuildIndex does the work of regenerating the index +// with the given keys. +func rebuild(less LessFunction, keys <-chan string) *btree.BTree { + tree := btree.New(2) + for key := range keys { + tree.ReplaceOrInsert(btreeString{s: key, l: less}) + } + return tree +} diff --git a/vendor/modules.txt b/vendor/modules.txt index 457c4f32..0f08d54c 100644 --- a/vendor/modules.txt +++ b/vendor/modules.txt @@ -203,6 +203,8 @@ github.com/golang/protobuf/ptypes/duration github.com/golang/protobuf/ptypes/timestamp # github.com/golang/snappy v0.0.3 github.com/golang/snappy +# github.com/google/btree v1.0.0 +github.com/google/btree # github.com/google/go-containerregistry v0.6.0 ## explicit github.com/google/go-containerregistry/internal/and @@ -399,6 +401,9 @@ github.com/otiai10/copy # github.com/pelletier/go-toml v1.9.4 ## explicit github.com/pelletier/go-toml +# github.com/peterbourgon/diskv v2.0.1+incompatible +## explicit +github.com/peterbourgon/diskv # github.com/philopon/go-toposort v0.0.0-20170620085441-9be86dbd762f ## explicit github.com/philopon/go-toposort