core, trie: replace state caches with trie journal

1 files changed, 0 insertions, 206 deletions

diff --git a/trie/arc.go b/trie/arc.go
deleted file mode 100644
index fc7a3259f..000000000
--- a/trie/arc.go
+++ /dev/null
@@ -1,206 +0,0 @@
-// Copyright (c) 2015 Hans Alexander Gugel <alexander.gugel@gmail.com>
-//
-// 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.
-
-// This file contains a modified version of package arc from
-// https://github.com/alexanderGugel/arc
-//
-// It implements the ARC (Adaptive Replacement Cache) algorithm as detailed in
-// https://www.usenix.org/legacy/event/fast03/tech/full_papers/megiddo/megiddo.pdf
-
-package trie
-
-import (
-	"container/list"
-	"sync"
-)
-
-type arc struct {
-	p     int
-	c     int
-	t1    *list.List
-	b1    *list.List
-	t2    *list.List
-	b2    *list.List
-	cache map[string]*entry
-	mutex sync.Mutex
-}
-
-type entry struct {
-	key   hashNode
-	value node
-	ll    *list.List
-	el    *list.Element
-}
-
-// newARC returns a new Adaptive Replacement Cache with the
-// given capacity.
-func newARC(c int) *arc {
-	return &arc{
-		c:     c,
-		t1:    list.New(),
-		b1:    list.New(),
-		t2:    list.New(),
-		b2:    list.New(),
-		cache: make(map[string]*entry, c),
-	}
-}
-
-// Clear clears the cache
-func (a *arc) Clear() {
-	a.mutex.Lock()
-	defer a.mutex.Unlock()
-	a.p = 0
-	a.t1 = list.New()
-	a.b1 = list.New()
-	a.t2 = list.New()
-	a.b2 = list.New()
-	a.cache = make(map[string]*entry, a.c)
-}
-
-// Put inserts a new key-value pair into the cache.
-// This optimizes future access to this entry (side effect).
-func (a *arc) Put(key hashNode, value node) bool {
-	a.mutex.Lock()
-	defer a.mutex.Unlock()
-	ent, ok := a.cache[string(key)]
-	if ok != true {
-		ent = &entry{key: key, value: value}
-		a.req(ent)
-		a.cache[string(key)] = ent
-	} else {
-		ent.value = value
-		a.req(ent)
-	}
-	return ok
-}
-
-// Get retrieves a previously via Set inserted entry.
-// This optimizes future access to this entry (side effect).
-func (a *arc) Get(key hashNode) (value node, ok bool) {
-	a.mutex.Lock()
-	defer a.mutex.Unlock()
-	ent, ok := a.cache[string(key)]
-	if ok {
-		a.req(ent)
-		return ent.value, ent.value != nil
-	}
-	return nil, false
-}
-
-func (a *arc) req(ent *entry) {
-	if ent.ll == a.t1 || ent.ll == a.t2 {
-		// Case I
-		ent.setMRU(a.t2)
-	} else if ent.ll == a.b1 {
-		// Case II
-		// Cache Miss in t1 and t2
-
-		// Adaptation
-		var d int
-		if a.b1.Len() >= a.b2.Len() {
-			d = 1
-		} else {
-			d = a.b2.Len() / a.b1.Len()
-		}
-		a.p = a.p + d
-		if a.p > a.c {
-			a.p = a.c
-		}
-
-		a.replace(ent)
-		ent.setMRU(a.t2)
-	} else if ent.ll == a.b2 {
-		// Case III
-		// Cache Miss in t1 and t2
-
-		// Adaptation
-		var d int
-		if a.b2.Len() >= a.b1.Len() {
-			d = 1
-		} else {
-			d = a.b1.Len() / a.b2.Len()
-		}
-		a.p = a.p - d
-		if a.p < 0 {
-			a.p = 0
-		}
-
-		a.replace(ent)
-		ent.setMRU(a.t2)
-	} else if ent.ll == nil {
-		// Case IV
-
-		if a.t1.Len()+a.b1.Len() == a.c {
-			// Case A
-			if a.t1.Len() < a.c {
-				a.delLRU(a.b1)
-				a.replace(ent)
-			} else {
-				a.delLRU(a.t1)
-			}
-		} else if a.t1.Len()+a.b1.Len() < a.c {
-			// Case B
-			if a.t1.Len()+a.t2.Len()+a.b1.Len()+a.b2.Len() >= a.c {
-				if a.t1.Len()+a.t2.Len()+a.b1.Len()+a.b2.Len() == 2*a.c {
-					a.delLRU(a.b2)
-				}
-				a.replace(ent)
-			}
-		}
-
-		ent.setMRU(a.t1)
-	}
-}
-
-func (a *arc) delLRU(list *list.List) {
-	lru := list.Back()
-	list.Remove(lru)
-	delete(a.cache, string(lru.Value.(*entry).key))
-}
-
-func (a *arc) replace(ent *entry) {
-	if a.t1.Len() > 0 && ((a.t1.Len() > a.p) || (ent.ll == a.b2 && a.t1.Len() == a.p)) {
-		lru := a.t1.Back().Value.(*entry)
-		lru.value = nil
-		lru.setMRU(a.b1)
-	} else {
-		lru := a.t2.Back().Value.(*entry)
-		lru.value = nil
-		lru.setMRU(a.b2)
-	}
-}
-
-func (e *entry) setLRU(list *list.List) {
-	e.detach()
-	e.ll = list
-	e.el = e.ll.PushBack(e)
-}
-
-func (e *entry) setMRU(list *list.List) {
-	e.detach()
-	e.ll = list
-	e.el = e.ll.PushFront(e)
-}
-
-func (e *entry) detach() {
-	if e.ll != nil {
-		e.ll.Remove(e.el)
-	}
-}