Update v0.12.6

README.md

@@ -1,8 +1,10 @@
 # Netkit
 
-**Netkit** is a Go graph algorithm library focused on clarity, extensibility, and practical performance.
+**Netkit** is a Go toolkit for graph algorithms, network analysis, and P2P network simulation.
 
-It provides reusable graph data structures and common network analysis algorithms, with selected results validated against [NetworkX](https://networkx.org/).
+It provides reusable graph data structures, common network analysis algorithms, and a programmable P2P layer for testing message propagation over graph-based network topologies.
+
+Selected graph algorithm results are validated against [NetworkX](https://networkx.org/).
 
 - Go 1.25+
 - Module: `github.com/elecbug/netkit`
@@ -12,7 +14,7 @@ It provides reusable graph data structures and common network analysis algorithm
 
 ## Features
 
-Netkit provides graph utilities and network analysis algorithms for both directed and undirected graphs.
+Netkit provides graph utilities, network analysis algorithms, and P2P simulation tools for both directed and undirected graphs.
 
 Current focus areas include:
 
@@ -23,6 +25,8 @@ Current focus areas include:
 - Graph diameter
 - PageRank
 - Modularity analysis
+- P2P overlay construction
+- Message propagation simulation
 - NetworkX-compatible validation for selected algorithms
 
 Implemented or planned algorithms include:
@@ -38,13 +42,22 @@ Implemented or planned algorithms include:
 - Diameter / weighted diameter
 - Modularity
 
+The P2P simulation layer supports:
+
+- Creating peer networks from graph topologies
+- Defining message propagation behavior
+- Configuring processing latency
+- Configuring network latency
+- Testing broadcast and relay strategies
+- Evaluating propagation behavior over generated or custom graphs
+
 ---
 
 ## Installation
 
 ```bash
 go get github.com/elecbug/netkit@latest
-````
+```
 
 ---
 
@@ -53,6 +66,8 @@ go get github.com/elecbug/netkit@latest
 > [!NOTE]
 > Netkit is under active development. Public APIs may change before the first stable release.
 
+The same graph can be used both for graph analysis and as a P2P overlay topology.
+
 ```go
 package main
 
@@ -61,6 +76,7 @@ import (
 
 	"github.com/elecbug/netkit/v2/analyzer"
 	"github.com/elecbug/netkit/v2/graph"
+	"github.com/elecbug/netkit/v2/p2p"
 )
 
 func main() {
@@ -73,21 +89,108 @@ func main() {
 	g.AddEdge("0", "1")
 	g.AddEdge("1", "2")
 
-	a := analyzer.NewAnalyzer(g, nil)
+	a := analyzer.NewAnalyzer(g, 4, analyzer.DefaultConfig())
 
 	degree, err := a.DegreeCentrality()
 	if err != nil {
 		panic(err)
 	}
 
-	fmt.Println(degree)
+	fmt.Println("degree centrality:", degree)
+
+	cfg := &p2p.Config{
+		ProcessingLatencyFunc: func(src p2p.PeerID) float64 {
+			return 100
+		},
+		NetworkLatencyFunc: func(src, dst p2p.PeerID) float64 {
+			return 1
+		},
+	}
+
+	network, err := p2p.New(g, cfg)
+	if err != nil {
+		panic(err)
+	}
+
+	_ = network
+
+	// The graph is now also available as a P2P overlay.
+	// Users can define propagation behavior and run message dissemination tests
+	// over the same topology used for graph analysis.
+}
+```
+
+A propagation function can decide which peers should receive a message next.
+
+```go
+package main
+
+import "github.com/elecbug/netkit/v2/p2p"
+
+func ForwardToUnseenPeers(
+	id p2p.PeerID,
+	msg p2p.Message,
+	known []p2p.PeerID,
+	sent []p2p.PeerID,
+	received []p2p.PeerID,
+	params map[string]any,
+) *[]p2p.PeerID {
+	result := make([]p2p.PeerID, 0)
+
+	for _, peerID := range known {
+		alreadySent := false
+		for _, s := range sent {
+			if peerID == s {
+				alreadySent = true
+				break
+			}
+		}
+		if alreadySent {
+			continue
+		}
+
+		alreadyReceived := false
+		for _, r := range received {
+			if peerID == r {
+				alreadyReceived = true
+				break
+			}
+		}
+		if alreadyReceived {
+			continue
+		}
+
+		result = append(result, peerID)
+	}
+
+	return &result
 }
 ```
 
 > API details may vary by version. See package documentation and examples for the latest usage.
 
 ---
 
+## P2P Simulation
+
+Netkit can form a P2P network directly from a graph.
+
+This allows users to generate or load a topology, analyze its structural properties, and then run message propagation experiments on the same network.
+
+Typical use cases include:
+
+* Broadcast protocol testing
+* Gossip-style dissemination experiments
+* Overlay topology evaluation
+* Reachability analysis
+* Duplicate message analysis
+* Latency-sensitive propagation experiments
+* Comparing propagation behavior across graph models
+
+This makes Netkit useful not only as a graph algorithm library, but also as a lightweight experimental framework for P2P network behavior.
+
+---
+
 ## Validation
 
 Netkit reimplements common graph and network algorithms in Go.
@@ -143,12 +246,15 @@ Netkit is designed with the following goals:
    Algorithms should be readable and easy to inspect.
 
 2. **Extensibility**
-   Graph structures and analysis components should be easy to extend.
+   Graph structures, analysis components, and P2P protocol logic should be easy to extend.
 
 3. **Practical performance**
-   Implementations should be efficient enough for medium-to-large network analysis workloads.
+   Implementations should be efficient enough for medium-to-large network analysis and simulation workloads.
+
+4. **P2P experimentation**
+   Users should be able to construct graph-based overlays and test message propagation behavior on them.
 
-4. **Validation**
+5. **Validation**
    Results should be checked against established libraries such as NetworkX when possible.
 
 ---
@@ -163,4 +269,4 @@ MIT © 2025 elecbug. See [`LICENSE`](./LICENSE).
 
 This project reimplements common graph and network algorithms in Go with selected results validated against NetworkX.
 
-NetworkX is © the NetworkX Developers and distributed under the BSD 3-Clause License.
+NetworkX is © the NetworkX Developers and distributed under the BSD 3-Clause License.

v2/graph/analyzer/analyzer.go

@@ -1,6 +1,7 @@
 package analyzer
 
 import (
+	"runtime"
 	"sync"
 
 	"github.com/elecbug/netkit/v2/graph"
@@ -16,8 +17,8 @@ type Analyzer struct {
 	cfg               *Config                                        // cfg holds configuration options for the analyzer, such as worker counts and normalization settings.
 }
 
-// NewAnalyzer creates a new Analyzer instance based on the provided graph.
-func NewAnalyzer(g *graph.Graph, parallelCoreCount int, cfg *Config) *Analyzer {
+// New creates a new Analyzer instance based on the provided graph.
+func New(g *graph.Graph, parallelCoreCount int, cfg *Config) *Analyzer {
 	return &Analyzer{
 		baseGraph:         g,
 		graphHash:         "",
@@ -27,6 +28,20 @@ func NewAnalyzer(g *graph.Graph, parallelCoreCount int, cfg *Config) *Analyzer {
 	}
 }
 
+// ClearCache clears the cached shortest paths and resets the graph hash. This should be called when the underlying graph
+// changes to ensure that subsequent shortest path computations are accurate and not based on stale data.
+func (a *Analyzer) ClearCache() string {
+	a.mu.Lock()
+	defer a.mu.Unlock()
+
+	a.allShortestPaths = make(map[graph.NodeID]map[graph.NodeID][]graph.Path)
+	a.graphHash = ""
+
+	runtime.GC() // Trigger garbage collection to free memory used by the old cache
+
+	return a.graphHash
+}
+
 // Graph returns the base graph associated with the analyzer.
 func (a *Analyzer) Graph() *graph.Graph {
 	return a.baseGraph

v2/graph/analyzer/analyzer_test.go

@@ -36,7 +36,7 @@ func testComputeShortestPath(t *testing.T) {
 	g.AddEdge("A", "C", graph.NewWeight(2))
 	g.AddEdge("C", "D", graph.NewWeight(1))
 
-	a := analyzer.NewAnalyzer(g, 1, analyzer.DefaultConfig())
+	a := analyzer.New(g, 1, analyzer.DefaultConfig())
 
 	paths, err := a.ShortestPaths("A", "D")
 	if err != nil {
@@ -106,7 +106,7 @@ func TestPerformance(t *testing.T) {
 		t.Fatalf("failed to create graph: %v", err)
 	}
 
-	a := analyzer.NewAnalyzer(g, 1, analyzer.DefaultConfig())
+	a := analyzer.New(g, 1, analyzer.DefaultConfig())
 
 	startTime := time.Now()
 	paths, err := a.ShortestPaths("0", "999")
@@ -121,7 +121,7 @@ func TestPerformance(t *testing.T) {
 	duration := time.Since(startTime)
 	fmt.Printf("  - Time taken to compute shortest paths: %v\n", duration)
 
-	a = analyzer.NewAnalyzer(g, 4, analyzer.DefaultConfig())
+	a = analyzer.New(g, 4, analyzer.DefaultConfig())
 
 	startTime = time.Now()
 	pathsCompared, err := a.ShortestPaths("0", "999")
@@ -135,7 +135,7 @@ func TestPerformance(t *testing.T) {
 		t.Errorf("expected total distance %v, got %v", paths[0].TotalDistance(), pathsCompared[0].TotalDistance())
 	}
 
-	a = analyzer.NewAnalyzer(g, 16, analyzer.DefaultConfig())
+	a = analyzer.New(g, 16, analyzer.DefaultConfig())
 
 	startTime = time.Now()
 	pathsCompared, err = a.ShortestPaths("0", "999")
@@ -149,7 +149,7 @@ func TestPerformance(t *testing.T) {
 		t.Errorf("expected total distance %v, got %v", paths[0].TotalDistance(), pathsCompared[0].TotalDistance())
 	}
 
-	a = analyzer.NewAnalyzer(g, 32, analyzer.DefaultConfig())
+	a = analyzer.New(g, 32, analyzer.DefaultConfig())
 
 	startTime = time.Now()
 	pathsCompared, err = a.ShortestPaths("0", "999")
@@ -204,7 +204,7 @@ func TestAnaylzer(t *testing.T) {
 	}
 
 	cfg := analyzer.DefaultConfig()
-	a := analyzer.NewAnalyzer(g, 16, cfg)
+	a := analyzer.New(g, 16, cfg)
 
 	t.Run("ShortestPaths", func(t *testing.T) {
 		results["shortest_paths"] = make(map[string]any)

v2/graph/graph.go

@@ -34,6 +34,13 @@ func New(directed bool, weighted bool) *Graph {
 	}
 }
 
+// Free clears all nodes and edges from the graph, effectively resetting it to an empty state.
+func (g *Graph) Free() {
+	for id := range g.nodes {
+		delete(g.nodes, id)
+	}
+}
+
 /* Node */
 
 // AddNode adds a node to the graph.

v2/p2p/p2p.go

@@ -68,6 +68,14 @@ func New(source *graph.Graph, cfg *Config) (*P2P, error) {
 	return &P2P{peers: nodes, cfg: cfg}, nil
 }
 
+// Free clears all peers from the P2P network, effectively resetting it to an empty state.
+func (p *P2P) Free() {
+	for id := range p.peers {
+		p.peers[id].eachStop()
+		delete(p.peers, id)
+	}
+}
+
 /* Basic Actions */
 
 // Run starts the message handling routines for all peers in the network.
@@ -250,6 +258,7 @@ func (p *P2P) MessageInfo(peerID PeerID, content string) (map[string]any, error)
 	}
 
 	info["seen"] = peer.seenAt[content].String()
+	info["first_from"] = peer.firstFrom[content]
 
 	return info, nil
 }

v2/p2p/peer.go

@@ -146,3 +146,12 @@ func (p *peer) eachPublish(network *P2P, msg Message) {
 		}(edgeCopy)
 	}
 }
+
+// eachStop marks the peer as inactive and closes its message queue.
+func (p *peer) eachStop() {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+
+	p.alive = false
+	close(p.msgQueue)
+}