Improved the memory overhead of GetComponent

LICENSE

@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) 2021 Cem Okulmus
+Copyright (c) 2022 Cem Okulmus
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

algorithms/balsepGlobal.go

@@ -5,6 +5,7 @@ import (
 	"runtime"
 
 	"github.com/cem-okulmus/BalancedGo/lib"
+	"github.com/cem-okulmus/disjoint"
 )
 
 // BalSepGlobal implements the global Balanced Separator algorithm.
@@ -124,6 +125,7 @@ func (b BalSepGlobal) findDecomp(H lib.Graph) lib.Decomp {
 	generators := lib.SplitCombin(edges.Len(), b.K, runtime.GOMAXPROCS(-1), false)
 	parallelSearch := b.Generator.GetSearch(&H, &edges, b.BalFactor, generators)
 	pred := lib.BalancedCheck{}
+	var Vertices = make(map[int]*disjoint.Element)
 	parallelSearch.FindNext(pred) // initial Search
 
 OUTER:
@@ -132,7 +134,7 @@ OUTER:
 
 		// log.Printf("Balanced Sep chosen: %+v\n", Graph{Edges: balsep})
 
-		comps, _, _ := H.GetComponents(balsep)
+		comps, _, _ := H.GetComponents(balsep, Vertices)
 
 		// log.Printf("Comps of Sep: %+v\n", comps)
 

algorithms/balsepHybrid.go

@@ -9,6 +9,7 @@ import (
 	"strconv"
 
 	"github.com/cem-okulmus/BalancedGo/lib"
+	"github.com/cem-okulmus/disjoint"
 )
 
 // BalSepHybrid implements a hybridised algorithm, using BalSep Local and DetKDecomp in tandem
@@ -79,6 +80,7 @@ func (b BalSepHybrid) findDecomp(currentDepth int, H lib.Graph) lib.Decomp {
 	generators := lib.SplitCombin(edges.Len(), b.K, runtime.GOMAXPROCS(-1), true)
 	parallelSearch := b.Generator.GetSearch(&H, &edges, b.BalFactor, generators)
 	pred := lib.BalancedCheck{}
+	var Vertices = make(map[int]*disjoint.Element)
 	parallelSearch.FindNext(pred) // initial Search
 
 	var cache map[uint32]struct{}
@@ -96,7 +98,7 @@ func (b BalSepHybrid) findDecomp(currentDepth int, H lib.Graph) lib.Decomp {
 
 	INNER:
 		for !exhaustedSubedges {
-			comps, _, _ := H.GetComponents(balsep)
+			comps, _, _ := H.GetComponents(balsep, Vertices)
 
 			// log.Printf("Comps of Sep: %+v\n", comps)
 
@@ -175,7 +177,7 @@ func (b BalSepHybrid) findDecomp(currentDepth int, H lib.Graph) lib.Decomp {
 								continue thisLoop
 							}
 
-							if pred.Check(&H, &balsep, b.BalFactor) {
+							if pred.Check(&H, &balsep, b.BalFactor, Vertices) {
 								cache[lib.IntHash(balsep.Vertices())] = lib.Empty
 								nextBalsepFound = true
 							}

algorithms/balsepHybridSeq.go

@@ -5,6 +5,7 @@ import (
 	"strconv"
 
 	"github.com/cem-okulmus/BalancedGo/lib"
+	"github.com/cem-okulmus/disjoint"
 )
 
 // BalSepHybridSeq is a purely sequential version of BalSepHybrid
@@ -67,6 +68,7 @@ func (s BalSepHybridSeq) findDecomp(currentDepth int, H lib.Graph) lib.Decomp {
 	generators := lib.SplitCombin(edges.Len(), s.K, 1, true) // create just one goroutine, making this sequential
 	parallelSearch := s.Generator.GetSearch(&H, &edges, s.BalFactor, generators)
 	pred := lib.BalancedCheck{}
+	var Vertices = make(map[int]*disjoint.Element)
 	parallelSearch.FindNext(pred) // initial Search
 
 	var cache map[uint32]struct{}
@@ -85,7 +87,7 @@ func (s BalSepHybridSeq) findDecomp(currentDepth int, H lib.Graph) lib.Decomp {
 
 	INNER:
 		for !exhaustedSubedges {
-			comps, _, _ := H.GetComponents(balsep)
+			comps, _, _ := H.GetComponents(balsep, Vertices)
 
 			// log.Printf("Comps of Sep: %+v\n", comps)
 
@@ -165,7 +167,7 @@ func (s BalSepHybridSeq) findDecomp(currentDepth int, H lib.Graph) lib.Decomp {
 								continue thisLoop
 							}
 
-							if pred.Check(&H, &balsep, s.BalFactor) {
+							if pred.Check(&H, &balsep, s.BalFactor, Vertices) {
 								cache[lib.IntHash(balsep.Vertices())] = lib.Empty
 								nextBalsepFound = true
 							}

algorithms/balsepLocal.go

@@ -5,6 +5,7 @@ import (
 	"runtime"
 
 	"github.com/cem-okulmus/BalancedGo/lib"
+	"github.com/cem-okulmus/disjoint"
 )
 
 // BalSepLocal implements the local Balanced Separator algorithm for computing GHDs.
@@ -56,13 +57,14 @@ func searchSubEdge(g *BalSepLocal, H *lib.Graph, balsepOrig lib.Edges, sepSub *l
 	}
 	nextBalsepFound := false
 	pred := lib.BalancedCheck{}
+	var Vertices = make(map[int]*disjoint.Element)
 
 	for !nextBalsepFound {
 		if sepSub.HasNext() {
 			balsep = sepSub.GetCurrent()
 			// log.Printf("Testing SSSep: %v of %v , Special Edges %v \n", Graph{Edges: balsep},
 			//        Graph{Edges: balsepOrig}, Sp)
-			if pred.Check(H, &balsep, g.BalFactor) {
+			if pred.Check(H, &balsep, g.BalFactor, Vertices) {
 				nextBalsepFound = true
 			}
 		} else {
@@ -91,6 +93,7 @@ func (b BalSepLocal) findDecomp(H lib.Graph) lib.Decomp {
 	generators := lib.SplitCombin(edges.Len(), b.K, runtime.GOMAXPROCS(-1), true)
 	parallelSearch := b.Generator.GetSearch(&H, &edges, b.BalFactor, generators)
 	pred := lib.BalancedCheck{}
+	var Vertices = make(map[int]*disjoint.Element)
 	parallelSearch.FindNext(pred) // initial Search
 
 	var cache map[uint32]struct{}
@@ -108,7 +111,7 @@ func (b BalSepLocal) findDecomp(H lib.Graph) lib.Decomp {
 
 	INNER:
 		for !exhaustedSubedges {
-			comps, _, _ := H.GetComponents(balsep)
+			comps, _, _ := H.GetComponents(balsep, Vertices)
 
 			// log.Printf("Comps of Sep: %v for H %v \n", comps, H)
 
@@ -143,7 +146,7 @@ func (b BalSepLocal) findDecomp(H lib.Graph) lib.Decomp {
 							if ok { //skip since already seen
 								continue thisLoop
 							}
-							if pred.Check(&H, &balsep, b.BalFactor) {
+							if pred.Check(&H, &balsep, b.BalFactor, Vertices) {
 								cache[lib.IntHash(balsep.Vertices())] = lib.Empty
 								nextBalsepFound = true
 							}

algorithms/detKDecomp.go

@@ -5,6 +5,7 @@ import (
 	"reflect"
 
 	"github.com/cem-okulmus/BalancedGo/lib"
+	"github.com/cem-okulmus/disjoint"
 )
 
 // DetKDecomp computes for a graph and some width K a HD of width K if it exists
@@ -106,6 +107,8 @@ func (d *DetKDecomp) findDecomp(H lib.Graph, oldSep []int, recDepth int) lib.Dec
 
 	gen := lib.NewCover(d.K, conn, bound, H.Edges.Vertices())
 
+	var Vertices = make(map[int]*disjoint.Element)
+
 OUTER:
 	for gen.HasNext {
 		out := gen.NextSubset()
@@ -167,7 +170,7 @@ OUTER:
 				for true {
 
 					// log.Println("Sep chosen ", sepActual, " out ", out)
-					comps, _, _ := H.GetComponents(sepActual)
+					comps, _, _ := H.GetComponents(sepActual, Vertices)
 
 					//check cache for previous encounters
 					if d.cache.CheckNegative(sepActual, comps) {

algorithms/jCostBalsepLocal.go

@@ -6,6 +6,7 @@ import (
 	"runtime"
 
 	"github.com/cem-okulmus/BalancedGo/lib"
+	"github.com/cem-okulmus/disjoint"
 )
 
 // BalSepLocal implements the local Balanced Separator algorithm for computing GHDs.
@@ -176,6 +177,7 @@ func (b JCostBalSepLocal) findDecomp(H lib.Graph) lib.Decomp {
 	generators := lib.SplitCombin(edges.Len(), b.K, runtime.GOMAXPROCS(-1), false)
 	parallelSearch := b.Generator.GetSearch(&H, &edges, b.BalFactor, generators)
 	pred := lib.BalancedCheck{}
+	var Vertices = make(map[int]*disjoint.Element)
 	// parallelSearch.FindNext(pred) // initial Search
 
 	var cache map[uint32]struct{}
@@ -196,7 +198,7 @@ func (b JCostBalSepLocal) findDecomp(H lib.Graph) lib.Decomp {
 
 	INNER:
 		for !exhaustedSubedges {
-			comps, _, _ := H.GetComponents(balsep)
+			comps, _, _ := H.GetComponents(balsep, Vertices)
 
 			// log.Printf("Comps of Sep: %v for H %v \n", comps, H)
 
@@ -231,7 +233,7 @@ func (b JCostBalSepLocal) findDecomp(H lib.Graph) lib.Decomp {
 							if ok { //skip since already seen
 								continue thisLoop
 							}
-							if pred.Check(&H, &balsep, b.BalFactor) {
+							if pred.Check(&H, &balsep, b.BalFactor, Vertices) {
 								cache[lib.IntHash(balsep.Vertices())] = lib.Empty
 								nextBalsepFound = true
 							}

go.mod

@@ -4,7 +4,7 @@ go 1.12
 
 require (
 	github.com/alecthomas/participle v0.3.0
+	github.com/cem-okulmus/disjoint v1.1.2
 	github.com/google/go-cmp v0.3.1
-	github.com/json-iterator/go v1.1.12 // indirect
-	github.com/spakin/disjoint v0.0.0-20170506060253-925e67a26b59
+	github.com/json-iterator/go v1.1.12
 )

go.sum

@@ -1,5 +1,7 @@
 github.com/alecthomas/participle v0.3.0 h1:e8vhrYR1nDjzDxyDwpLO27TWOYWilaT+glkwbPadj50=
 github.com/alecthomas/participle v0.3.0/go.mod h1:SW6HZGeZgSIpcUWX3fXpfZhuaWHnmoD5KCVaqSaNTkk=
+github.com/cem-okulmus/disjoint v1.1.2 h1:1sqm6+PUZ32ZDOSlKf0ouQPfpLFvLKEoQqjVmknI/NQ=
+github.com/cem-okulmus/disjoint v1.1.2/go.mod h1:EvfCBnA21Jt7LcF3pPDUXgKH6VbZx3MTclls/UzuCQU=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
@@ -14,10 +16,7 @@ github.com/modern-go/reflect2 v1.0.2 h1:xBagoLtFs94CBntxluKeaWgTMpvLxC4ur3nMaC9G
 github.com/modern-go/reflect2 v1.0.2/go.mod h1:yWuevngMOJpCy52FWWMvUC8ws7m/LJsjYzDa0/r8luk=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
-github.com/spakin/disjoint v0.0.0-20170506060253-925e67a26b59 h1:WXIGODNpYrroHXcn28J3u4XA0Fa3vwxw27uJZVwCrAI=
-github.com/spakin/disjoint v0.0.0-20170506060253-925e67a26b59/go.mod h1:847lZUtrAEz7RTzAsdAiOC8gq4kqb3lbmtQjWo6naTA=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
-github.com/stretchr/testify v1.2.2 h1:bSDNvY7ZPG5RlJ8otE/7V6gMiyenm9RtJ7IUVIAoJ1w=
 github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
 github.com/stretchr/testify v1.3.0 h1:TivCn/peBQ7UY8ooIcPgZFpTNSz0Q2U6UrFlUfqbe0Q=
 github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=

lib/graph.go

@@ -3,9 +3,9 @@ package lib
 import (
 	"bytes"
 
+	"github.com/cem-okulmus/disjoint"
 	"github.com/google/go-cmp/cmp"
 	"github.com/google/go-cmp/cmp/cmpopts"
-	"github.com/spakin/disjoint"
 )
 
 // A Graph is a collection of (special) edges
@@ -100,10 +100,10 @@ func (g Graph) GetSubset(s []int) Edges {
 }
 
 // GetComponents uses Disjoint Set data structure to compute connected components
-func (g Graph) GetComponents(sep Edges) ([]Graph, map[int]int, []Edge) {
+func (g Graph) GetComponents(sep Edges, vertices map[int]*disjoint.Element) ([]Graph, map[int]int, []Edge) {
 	var outputG []Graph
 
-	var vertices = make(map[int]*disjoint.Element, len(g.Vertices()))
+	// var vertices = make(map[int]*disjoint.Element, len(g.Vertices()))
 	var comps = make(map[*disjoint.Element][]Edge)
 	var compsSp = make(map[*disjoint.Element][]Edges)
 
@@ -115,7 +115,11 @@ func (g Graph) GetComponents(sep Edges) ([]Graph, map[int]int, []Edge) {
 
 	//  Set up the disjoint sets for each node
 	for _, i := range g.Vertices() {
-		vertices[i] = disjoint.NewElement()
+		if e, ok := vertices[i]; ok {
+			e.Reset()
+		} else {
+			vertices[i] = disjoint.NewElement()
+		}
 	}
 
 	// Merge together the connected components

lib/hinge.go

@@ -7,6 +7,8 @@ import (
 	"bytes"
 	"log"
 	"reflect"
+
+	"github.com/cem-okulmus/disjoint"
 )
 
 type hingeEdge struct {
@@ -109,8 +111,9 @@ func (h Hingetree) expandHingeTree(isUsed map[int]bool, parentE int) Hingetree {
 			continue
 		}
 
+		var Vertices = make(map[int]*disjoint.Element)
 		sepEdge := NewEdges([]Edge{*e})
-		hinges, gamma, _ := h.hinge.GetComponents(sepEdge)
+		hinges, gamma, _ := h.hinge.GetComponents(sepEdge, Vertices)
 
 		// Skip reordering step if only single component
 		if len(hinges) <= 1 {

lib/search.go

@@ -5,6 +5,8 @@ package lib
 import (
 	"runtime"
 	"sync"
+
+	"github.com/cem-okulmus/disjoint"
 )
 
 // A Search implements a parallel search for separators fulfilling some given predicate
@@ -62,7 +64,7 @@ func (s *ParallelSearch) GetResult() []int {
 
 // A Predicate checks if for some subgraph and a separator, some condition holds
 type Predicate interface {
-	Check(H *Graph, sep *Edges, balancedFactor int) bool
+	Check(H *Graph, sep *Edges, balancedFactor int, Vertices map[int]*disjoint.Element) bool
 }
 
 // FindNext starts the search and stops if some separator which satisfies the predicate
@@ -117,6 +119,7 @@ func (s ParallelSearch) worker(workernum int, found chan []int, wg *sync.WaitGro
 		}
 	}()
 	defer wg.Done()
+	var Vertices = make(map[int]*disjoint.Element)
 
 	gen := s.Generators[workernum]
 
@@ -130,7 +133,7 @@ func (s ParallelSearch) worker(workernum int, found chan []int, wg *sync.WaitGro
 		j := gen.GetNext()
 
 		sep := GetSubset(*s.Edges, j)
-		if pred.Check(s.H, &sep, s.BalFactor) {
+		if pred.Check(s.H, &sep, s.BalFactor, Vertices) {
 			gen.Found() // cache result
 			found <- j
 			// log.Println("Worker", workernum, "won, found: ", j)
@@ -146,10 +149,10 @@ func (s ParallelSearch) worker(workernum int, found chan []int, wg *sync.WaitGro
 type BalancedCheck struct{}
 
 // Check performs the needed computation to ensure whether sep is a Balanced Separator
-func (b BalancedCheck) Check(H *Graph, sep *Edges, balFactor int) bool {
+func (b BalancedCheck) Check(H *Graph, sep *Edges, balFactor int, Vertices map[int]*disjoint.Element) bool {
 
 	//balancedness condition
-	comps, _, _ := H.GetComponents(*sep)
+	comps, _, _ := H.GetComponents(*sep, Vertices)
 
 	balancednessLimit := (((H.Len()) * (balFactor - 1)) / balFactor)
 
@@ -170,10 +173,10 @@ func (b BalancedCheck) Check(H *Graph, sep *Edges, balFactor int) bool {
 }
 
 // CheckOut does the same as Check, except it also passes on the components found, if output is true
-func (b BalancedCheck) CheckOut(H *Graph, sep *Edges, balFactor int) (bool, []Graph, []Edge) {
+func (b BalancedCheck) CheckOut(H *Graph, sep *Edges, balFactor int, Vertices map[int]*disjoint.Element) (bool, []Graph, []Edge) {
 
 	//balancedness condition
-	comps, _, isolated := H.GetComponents(*sep)
+	comps, _, isolated := H.GetComponents(*sep, Vertices)
 
 	balancednessLimit := (((H.Len()) * (balFactor - 1)) / balFactor)
 
@@ -201,10 +204,10 @@ type ParentCheck struct {
 }
 
 // Check performs the needed computation to ensure whether sep is a good parent
-func (p ParentCheck) Check(H *Graph, sep *Edges, balFactor int) bool {
+func (p ParentCheck) Check(H *Graph, sep *Edges, balFactor int, Vertices map[int]*disjoint.Element) bool {
 
 	//balancedness condition
-	comps, _, _ := H.GetComponents(*sep)
+	comps, _, _ := H.GetComponents(*sep, Vertices)
 
 	foundCompLow := false
 	var compLow Graph

test/cache_test.go

@@ -8,6 +8,7 @@ import (
 	"time"
 
 	"github.com/cem-okulmus/BalancedGo/lib"
+	"github.com/cem-okulmus/disjoint"
 )
 
 var EDGE int
@@ -86,9 +87,10 @@ func TestCache(t *testing.T) {
 	var cache lib.Cache
 	var cacheCopy lib.Cache
 
+	var Vertices = make(map[int]*disjoint.Element)
 	cache.CopyRef(&cacheCopy)
 
-	comps, _, _ := randomGraph.GetComponents(randomSep)
+	comps, _, _ := randomGraph.GetComponents(randomSep, Vertices)
 
 	if len(comps) == 0 { // randomSep covers the entire hypergraph. Nothing you can do
 		return