Add server

cmd/propagation_simulator/handler.go

@@ -0,0 +1,37 @@
+package main
+
+import (
+	"log"
+	"net/http"
+
+	"github.com/divan/graphx/formats"
+)
+
+// simulationHandler serves request to start simulation. It expectes network graph
+// in the request body, syncronously runs a new simulation on this network and
+// sends back simulation log in JSON format.
+//
+// TODO(divan): in the future, simulation will probably take longer, so it'll have to upgrade
+// connection to Websocket and talk to frontend this way.
+func simulationHandler(w http.ResponseWriter, r *http.Request) {
+	if r.Method != "POST" {
+		w.WriteHeader(http.StatusBadRequest)
+		return
+	}
+
+	data, err := formats.FromD3JSONReader(r.Body)
+	if err != nil {
+		log.Println("[ERROR] Bad payload:", err)
+		w.WriteHeader(http.StatusBadRequest)
+		return
+	}
+	defer r.Body.Close()
+
+	log.Printf("Loaded graph with %d nodes", len(data.Nodes()))
+	sim := NewSimulation(data)
+	sim.Start()
+	defer sim.Stop()
+
+	log.Println("Sending propagation log")
+	sim.WriteOutput(w)
+}

cmd/propagation_simulator/handler_test.go

@@ -0,0 +1,35 @@
+package main
+
+import (
+	"bytes"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+)
+
+func TestHandler(t *testing.T) {
+	payload := bytes.NewBuffer(testdataJSON)
+	req, err := http.NewRequest("POST", "/", payload)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	rr := httptest.NewRecorder()
+	handler := http.HandlerFunc(simulationHandler)
+
+	handler.ServeHTTP(rr, req)
+
+	if status := rr.Code; status != http.StatusOK {
+		t.Errorf("handler returned wrong status code: got %v want %v",
+			status, http.StatusOK)
+	}
+
+	// Check the response body size (it should be reasonably big)
+	// We can't compare output as it's non-deterministic (each simulation
+	// produce different results).
+	// TODO(divan): decode response and compare data sizes fields, at least.
+	if len(rr.Body.String()) < 100 {
+		t.Errorf("handler returned unexpected body: got %v",
+			rr.Body.String())
+	}
+}

cmd/propagation_simulator/main.go

@@ -1,70 +1,59 @@
 package main
 
 import (
-	"encoding/json"
 	"flag"
 	"log"
+	"net/http"
 	"os"
-	"time"
 
 	"github.com/divan/graphx/formats"
 	gethlog "github.com/ethereum/go-ethereum/log"
-	"github.com/status-im/simulation/propagation"
-	"github.com/status-im/simulation/propagation/naivep2p"
-	"github.com/status-im/simulation/propagation/whisperv6"
 	"github.com/status-im/simulation/stats"
 )
 
 func main() {
 	var (
-		simType       = flag.String("type", "whisperv6", "Type of simulators (naivep2p, whisperv6)")
-		ttl           = flag.Int("ttl", 10, "Message TTL for simulation")
-		naiveP2PN     = flag.Int("naivep2p.N", 3, "Number of peers to propagate (0..N of peers)")
-		naiveP2PDelay = flag.Duration("naivep2p.delay", 10*time.Millisecond, "Delay for each step")
-		input         = flag.String("i", "network.json", "Input filename for pregenerated data to be used with simulation")
-		output        = flag.String("o", "propagation.json", "Output filename for p2p sending data")
-		gethlogLevel  = flag.String("loglevel", "crit", "Geth log level for whisper simulator (crti, error, warn, info, debug, trace)")
+		input        = flag.String("i", "network.json", "Input filename for pregenerated data to be used with simulation")
+		output       = flag.String("o", "propagation.json", "Output filename for p2p sending data")
+		gethlogLevel = flag.String("loglevel", "crit", "Geth log level for whisper simulator (crti, error, warn, info, debug, trace)")
+		server       = flag.Bool("server", false, "Start as server to be used with whisperviz")
+		serverAddr   = flag.String("h", "localhost:8084", "Address to bind to in server mode")
 	)
 	flag.Parse()
 
+	setGethLogLevel(*gethlogLevel)
+
+	if *server {
+		log.Println("Starting simulator server on", *serverAddr)
+		http.HandleFunc("/", simulationHandler)
+		log.Fatal(http.ListenAndServe(*serverAddr, nil))
+		return
+	}
+
 	data, err := formats.FromD3JSON(*input)
 	if err != nil {
 		log.Fatal("Opening input file failed: ", err)
 	}
 
-	fd, err := os.Create(*output)
-	if err != nil {
-		log.Fatal("Opening output file failed: ", err)
-	}
-	defer fd.Close()
+	sim := NewSimulation(data)
+	log.Printf("Starting message sending simulation for graph with %d nodes...", len(data.Nodes()))
+	sim.Start()
+	defer sim.Stop()
+	sim.WriteOutputToFile(*output)
 
-	var sim propagation.Simulator
-	switch *simType {
-	case "naivep2p":
-		sim = naivep2p.NewSimulator(data, *naiveP2PN, *naiveP2PDelay)
-	case "whisperv6":
-		lvl, err := gethlog.LvlFromString(*gethlogLevel)
-		if err != nil {
-			lvl = gethlog.LvlCrit
-		}
-		gethlog.Root().SetHandler(gethlog.LvlFilterHandler(lvl, gethlog.StreamHandler(os.Stderr, gethlog.TerminalFormat(true))))
-		sim = whisperv6.NewSimulator(data)
-	default:
-		log.Fatal("Unknown simulation type: ", *simType)
-	}
 	defer sim.Stop()
 
-	// Start simulation by sending single message
-	log.Printf("Starting message sending %s simulation for graph with %d nodes...", *simType, len(data.Nodes()))
-	plog := sim.SendMessage(0, *ttl)
-
 	// stats
-	ss := stats.Analyze(data, plog)
+	ss := stats.Analyze(data, sim.plog)
 	ss.PrintVerbose()
 
-	err = json.NewEncoder(fd).Encode(plog)
-	if err != nil {
-		log.Fatal(err)
-	}
-	log.Printf("Written %s propagation data into %s", *simType, *output)
+	log.Printf("Written propagation data into %s", *output)
+}
+
+func setGethLogLevel(level string) {
+	lvl, err := gethlog.LvlFromString(level)
+	if err != nil {
+		lvl = gethlog.LvlCrit
+	}
+	gethlog.Root().SetHandler(gethlog.LvlFilterHandler(lvl, gethlog.StreamHandler(os.Stderr, gethlog.TerminalFormat(true))))
 }

cmd/propagation_simulator/simulation.go

@@ -0,0 +1,55 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"os"
+
+	"github.com/divan/graphx/graph"
+	"github.com/status-im/simulation/propagation"
+	"github.com/status-im/simulation/propagation/whisperv6"
+)
+
+// Simulation represents single simulation.
+type Simulation struct {
+	network *graph.Graph
+	sim     propagation.Simulator
+	plog    *propagation.Log
+}
+
+// NewSimulation creates Simulation for the given network.
+func NewSimulation(network *graph.Graph) *Simulation {
+	sim := whisperv6.NewSimulator(network)
+
+	return &Simulation{
+		network: network,
+		sim:     sim,
+	}
+}
+
+// Start starts simulation, creating network and preparing it for message sending.
+func (s *Simulation) Start() {
+	s.plog = s.sim.SendMessage(0, 10)
+}
+
+// Stop stops simulation and shuts down network.
+func (s *Simulation) Stop() error {
+	return s.sim.Stop()
+}
+
+// WriteOutput writes propagation log to the given io.Writer.
+func (s *Simulation) WriteOutput(w io.Writer) error {
+	return json.NewEncoder(w).Encode(s.plog)
+}
+
+// WriteOutputToFile writes propagation log to the given io.Writer.
+func (s *Simulation) WriteOutputToFile(path string) error {
+	fd, err := os.Create(path)
+	if err != nil {
+		return fmt.Errorf("create output file: %v", err)
+	}
+	defer fd.Close()
+
+	return s.WriteOutput(fd)
+}