slowly getting rid of global index

commands.go

@@ -211,15 +211,11 @@ func BroadcastCommand(sys *System) Command {
 
 func NearbyCommand(sys *System) Command {
 	handler := func(c *Connection, args ...string) {
-		neighbors, err := sys.Nearby(25)
-		if err != nil {
-			log_error("unable to get neighbors: %v", err)
-			return
-		}
+		neighbors := c.game.galaxy.Neighborhood(sys)
 		c.Printf("--------------------------------------------------------------------------------\n")
 		c.Printf("%-4s %-20s %-12s %s\n", "id", "name", "distance", "trip time")
 		c.Printf("--------------------------------------------------------------------------------\n")
-		for _, neighbor := range neighbors {
+		for _, neighbor := range neighbors[:25] {
 			other := index[neighbor.id]
 			dur := NewTravel(c, sys, other).(*TravelState).tripTime()
 			c.Printf("%-4d %-20s %-12.6v %v\n", other.id, other.name, neighbor.distance, dur)

connection.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"io"
 	"net"
+	"runtime"
 	"sort"
 	"strings"
 	"time"
@@ -52,9 +53,22 @@ func (c *Connection) Tick(frame int64) {
 func (c *Connection) RunCommand(name string, args ...string) {
 	defer func() {
 		if r := recover(); r != nil {
-			c.Printf("something is broken.  Log this as a ticket!\n")
-			c.Printf("recovered: %v\n", r)
+			c.Printf("(something is broken)")
+			c.Printf("ERROR: %v\n", r)
+			callers := make([]uintptr, 40)
+			n := runtime.Callers(5, callers)
+			callers = callers[:n]
+			frames := runtime.CallersFrames(callers)
 			log_error("recovered: %v", r)
+			for {
+				frame, more := frames.Next()
+
+				if !more {
+					break
+				}
+
+				log_error("  %s +%d (%s)\n", frame.File, frame.Line, frame.Function)
+			}
 		}
 	}()
 	switch name {

galaxy.go

@@ -0,0 +1,77 @@
+package main
+
+import (
+	"math/rand"
+	"sort"
+	"strconv"
+)
+
+// Galaxy is a collection of systems
+type Galaxy struct {
+	systems map[int]*System
+	names   map[string]int
+}
+
+func NewGalaxy() *Galaxy {
+	g := &Galaxy{
+		systems: make(map[int]*System),
+		names:   make(map[string]int),
+	}
+	g.indexSystems()
+	return g
+}
+
+func (g *Galaxy) indexSystems() {
+	rows, err := db.Query(`select * from planets`)
+	if err != nil {
+		log_error("unable to select all planets: %v", err)
+		return
+	}
+	defer rows.Close()
+
+	for rows.Next() {
+		s := System{}
+		if err := rows.Scan(&s.id, &s.name, &s.x, &s.y, &s.z, &s.planets); err != nil {
+			log_info("unable to scan planet row: %v", err)
+			continue
+		}
+		g.systems[s.id] = &s
+		g.names[s.name] = s.id
+		s.money = int64(rand.NormFloat64()*options.moneySigma + options.moneyMean)
+	}
+}
+
+// GetSystem gets a system by either ID or name. If the provided string
+// contains an integer, we assume the lookup is intended to be by ID.
+func (g *Galaxy) GetSystem(s string) *System {
+	id, err := strconv.Atoi(s)
+	if err == nil {
+		return g.GetSystemByID(id)
+	}
+
+	return g.GetSystemByName(s)
+}
+
+func (g *Galaxy) GetSystemByID(id int) *System {
+	return g.systems[id]
+}
+
+func (g *Galaxy) GetSystemByName(name string) *System {
+	id := g.SystemID(name)
+	if id == 0 {
+		return nil
+	}
+	return g.GetSystemByID(id)
+}
+
+func (g *Galaxy) SystemID(name string) int { return g.names[name] }
+
+// Neighborhood generates the neighborhood for a given system.
+func (g *Galaxy) Neighborhood(sys *System) Neighborhood {
+	neighbors := make(Neighborhood, 0, len(g.systems))
+	for id, sys2 := range g.systems {
+		neighbors = append(neighbors, Neighbor{id: id, distance: sys.DistanceTo(sys2)})
+	}
+	sort.Sort(neighbors)
+	return neighbors
+}

game.go

@@ -16,6 +16,7 @@ type Game struct {
 	connections map[*Connection]bool
 	frame       int64
 	elems       map[GameElement]bool
+	galaxy      *Galaxy
 }
 
 func gamesTable() {
@@ -49,6 +50,7 @@ func NewGame() *Game {
 		done:        make(chan interface{}),
 		connections: make(map[*Connection]bool, 32),
 		elems:       make(map[GameElement]bool, 32),
+		galaxy:      NewGalaxy(),
 	}
 	if err := game.Create(); err != nil {
 		log_error("unable to create game: %v", err)

idle.go

@@ -65,9 +65,9 @@ func (i *IdleState) Tick(c *Connection, frame int64) ConnectionState {
 }
 
 func (i *IdleState) travelTo(c *Connection, args ...string) {
-	dest, err := GetSystem(args[0])
-	if err != nil {
-		c.Printf("%v\n", err)
+	dest := c.game.galaxy.GetSystem(args[0])
+	if dest == nil {
+		c.Printf("no such system: %s", args[0])
 		return
 	}
 	c.SetState(NewTravel(c, i.System, dest))
@@ -83,9 +83,9 @@ func (i *IdleState) bomb(c *Connection, args ...string) {
 		return
 	}
 
-	target, err := GetSystem(args[0])
-	if err != nil {
-		c.Printf("Cannot send bomb: %v\n", err)
+	target := c.game.galaxy.GetSystem(args[0])
+	if target == nil {
+		c.Printf("Cannot send bomb: no such system: %v\n", args[0])
 		return
 	}
 

system.go

@@ -5,7 +5,6 @@ import (
 	"fmt"
 	"math"
 	"math/rand"
-	"strconv"
 	"time"
 )
 
@@ -26,22 +25,6 @@ type System struct {
 	money       int64
 }
 
-func GetSystem(id string) (*System, error) {
-	idNum, err := strconv.Atoi(id)
-	if err == nil {
-		sys, ok := index[idNum]
-		if !ok {
-			return nil, fmt.Errorf("No such system: %v", idNum)
-		}
-		return sys, nil
-	}
-	sys, ok := nameIndex[id]
-	if !ok {
-		return nil, fmt.Errorf("No such system: %v", id)
-	}
-	return sys, nil
-}
-
 func (s *System) Tick(frame int64) {
 	if s.colonizedBy != nil && s.money > 0 {
 		s.colonizedBy.Deposit(1)
@@ -215,36 +198,17 @@ func (s System) String() string {
 	return fmt.Sprintf("%s (id: %v)", s.name, s.id)
 }
 
+type Neighborhood []Neighbor
+
+func (n Neighborhood) Len() int           { return len(n) }
+func (n Neighborhood) Less(i, j int) bool { return n[i].distance < n[j].distance }
+func (n Neighborhood) Swap(i, j int)      { n[i], n[j] = n[j], n[i] }
+
 type Neighbor struct {
 	id       int
 	distance float64
 }
 
-func (e *System) Nearby(n int) ([]Neighbor, error) {
-	rows, err := db.Query(`
-        select planets.id, edges.distance
-        from edges
-        join planets on edges.id_2 = planets.id
-        where edges.id_1 = ?
-        order by distance
-        limit ?
-    ;`, e.id, n)
-	if err != nil {
-		log_error("unable to get nearby systems for %s: %v", e.name, err)
-		return nil, err
-	}
-	neighbors := make([]Neighbor, 0, n)
-	for rows.Next() {
-		var neighbor Neighbor
-		if err := rows.Scan(&neighbor.id, &neighbor.distance); err != nil {
-			log_error("error unpacking row from nearby neighbors query: %v", err)
-			continue
-		}
-		neighbors = append(neighbors, neighbor)
-	}
-	return neighbors, nil
-}
-
 func countSystems() (int, error) {
 	row := db.QueryRow(`select count(*) from planets`)