let's export less stuff

ent/class.go

@@ -1,6 +1,7 @@
 package ent
 
 import (
+	"fmt"
 	"github.com/jordanorelli/hyperstone/dota"
 )
 
@@ -15,6 +16,10 @@ func (c *Class) New() *Entity {
 	return &Entity{Class: c}
 }
 
+func (c Class) String() string {
+	return fmt.Sprintf("{%s %d}", c.Name, c.Version)
+}
+
 type classId struct {
 	name    Symbol
 	version int

ent/dict.go

@@ -2,44 +2,114 @@ package ent
 
 import (
 	"fmt"
+
+	"github.com/golang/protobuf/proto"
+
 	"github.com/jordanorelli/hyperstone/bit"
+	"github.com/jordanorelli/hyperstone/dota"
 )
 
-type Context struct {
+// Dict corresponds to the edict_t in Valve's documentation for the Source
+// engine. See here: https://developer.valvesoftware.com/wiki/Edict_t
+//
+// From the Valve docs:
+//   edict_t ("entity dictionary") is an interface struct that allows entities
+//   to cross the client/server divide: with one attached, an entity has the
+//   same index at both ends. The edict also manages the state of the entity's
+//   DataTable and provides a common representation across all DLLs. It cannot
+//   be used on the client.
+type Dict struct {
 	*Namespace
 	entities map[int]Entity
+	br       *bit.BufReader
 }
 
-func NewContext() *Context {
-	return &Context{Namespace: new(Namespace), entities: make(map[int]Entity)}
+func NewDict() *Dict {
+	return &Dict{
+		Namespace: new(Namespace),
+		entities:  make(map[int]Entity),
+		br:        new(bit.BufReader),
+	}
 }
 
-func (c *Context) CreateEntity(id int, r bit.Reader) error {
-	classId := int(c.readClassId(r))
-	if len(c.Namespace.classes) == 0 {
+// creates an entity with the provided id. the entity's contents data are read
+// off of the Dict's internal bit stream br
+func (d *Dict) createEntity(id int) error {
+	classId := int(d.readClassId(d.br))
+	if len(d.Namespace.classes) == 0 {
 		return fmt.Errorf("unable to create entity %d: namespace has no classes", id)
 	}
-	r.ReadBits(17) // ???
-	classV := int(bit.ReadVarInt(r))
-	className := c.classIds[classId]
-	class := c.Class(className, classV)
+	d.br.ReadBits(17) // ???
+	classV := int(bit.ReadVarInt(d.br))
+	className := d.classIds[classId]
+	class := d.Class(className, classV)
 	if class == nil {
 		return fmt.Errorf("unable to create entity %d: no class found for class name %s, version %d", className, classV)
 	}
 	Debug.Printf("create entity id: %d classId: %d className: %v class: %v\n", id, classId, className, class)
 	e := class.New()
-	e.Read(r)
+	e.Read(d.br)
 	return nil
 }
 
-func (c *Context) UpdateEntity(id int, r bit.Reader) {
+func (d *Dict) updateEntity(id int) error {
 	Debug.Printf("update entity id: %d\n", id)
+	return nil
 }
 
-func (c *Context) DeleteEntity(id int) {
+func (d *Dict) deleteEntity(id int) error {
 	Debug.Printf("delete entity id: %d\n", id)
+	return nil
 }
 
-func (c *Context) LeaveEntity(id int) {
+func (d *Dict) leaveEntity(id int) error {
 	Debug.Printf("leave entity id: %d\n", id)
+	return nil
+}
+
+func (d *Dict) Handle(m proto.Message) {
+	switch v := m.(type) {
+	case *dota.CDemoSendTables:
+		d.mergeSendTables(v)
+
+	case *dota.CDemoClassInfo:
+		d.mergeClassInfo(v)
+
+	case *dota.CSVCMsg_PacketEntities:
+		d.mergeEntities(v)
+	}
+}
+
+func (d *Dict) mergeEntities(m *dota.CSVCMsg_PacketEntities) error {
+	data := m.GetEntityData()
+
+	Debug.Printf("packet header MaxEntries: %d UpdatedEntries: %v IsDelta: %t UpdateBaseline: %t Baseline: %d DeltaFrom: %d PendingFullFrame: %t ActiveSpawngroupHandle: %d", m.GetMaxEntries(), m.GetUpdatedEntries(), m.GetIsDelta(), m.GetUpdateBaseline(), m.GetBaseline(), m.GetDeltaFrom(), m.GetPendingFullFrame(), m.GetActiveSpawngroupHandle())
+
+	d.br.SetSource(data)
+	id := -1
+	// for i := 0; i < int(m.GetUpdatedEntries()); i++ {
+	for i := 0; i < 1; i++ {
+		id++
+		// there may be a jump indicator, indicating how many id positions
+		// to skip.
+		id += int(bit.ReadUBitVar(d.br))
+
+		// next two bits encode one of four entity mutate operations
+		var fn func(int) error
+		switch d.br.ReadBits(2) {
+		case 0:
+			fn = d.updateEntity
+		case 1:
+			fn = d.leaveEntity
+		case 2:
+			fn = d.createEntity
+		case 3:
+			fn = d.deleteEntity
+		}
+
+		if err := fn(id); err != nil {
+			return fmt.Errorf("entity merge error: %v", err)
+		}
+	}
+	return nil
 }

ent/namespace.go

@@ -27,7 +27,7 @@ type Namespace struct {
 }
 
 // Merges in the ClassInfo data found in the replay protobufs
-func (n *Namespace) MergeClassInfo(ci *dota.CDemoClassInfo) {
+func (n *Namespace) mergeClassInfo(ci *dota.CDemoClassInfo) {
 	if n.classIds == nil {
 		n.classIds = make(map[int]string, len(ci.GetClasses()))
 	}
@@ -37,7 +37,9 @@ func (n *Namespace) MergeClassInfo(ci *dota.CDemoClassInfo) {
 	n.idBits = int(math.Floor(math.Log2(float64(len(n.classIds))))) + 1
 }
 
-func (n *Namespace) MergeSendTables(st *dota.CDemoSendTables) {
+// merges the send table data found in the replay protobufs. The send table
+// data contains a specification for an entity type system.
+func (n *Namespace) mergeSendTables(st *dota.CDemoSendTables) {
 	// sendtables only has one field, a binary data field.
 	data := st.GetData()
 	br := bit.NewBytesReader(data)

entities.go

@@ -1,67 +0,0 @@
-package main
-
-import (
-	"fmt"
-	"github.com/golang/protobuf/proto"
-	"github.com/jordanorelli/hyperstone/bit"
-	"github.com/jordanorelli/hyperstone/dota"
-	"github.com/jordanorelli/hyperstone/ent"
-)
-
-// type CSVCMsg_PacketEntities struct {
-// 	MaxEntries                    *int32
-// 	UpdatedEntries                *int32
-// 	IsDelta                       *bool
-// 	UpdateBaseline                *bool
-// 	Baseline                      *int32
-// 	DeltaFrom                     *int32
-// 	EntityData                    []byte
-// 	PendingFullFrame              *bool
-// 	ActiveSpawngroupHandle        *uint32
-// 	MaxSpawngroupCreationsequence *uint32
-// }
-
-var ctx = ent.NewContext()
-
-func dumpEntities(m proto.Message) {
-	switch v := m.(type) {
-	case *dota.CDemoSendTables:
-		ctx.MergeSendTables(v)
-
-	case *dota.CDemoClassInfo:
-		ctx.MergeClassInfo(v)
-
-	case *dota.CSVCMsg_PacketEntities:
-		data := v.GetEntityData()
-		var datap []byte
-		if len(data) > 32 {
-			datap = data[:32]
-		} else {
-			datap = data
-		}
-
-		fmt.Printf("{MaxEntries: %d UpdatedEntries: %v IsDelta: %t UpdateBaseline: %t Baseline: %d DeltaFrom: %d EntityData: %x PendingFullFrame: %t ActiveSpawngroupHandle: %d}\n", v.GetMaxEntries(), v.GetUpdatedEntries(), v.GetIsDelta(), v.GetUpdateBaseline(), v.GetBaseline(), v.GetDeltaFrom(), datap, v.GetPendingFullFrame(), v.GetActiveSpawngroupHandle())
-
-		br := bit.NewBytesReader(data)
-		id := -1
-		// for i := 0; i < int(v.GetUpdatedEntries()); i++ {
-		for i := 0; i < 1; i++ {
-			id++
-			// there may be a jump indicator, indicating how many id positions
-			// to skip.
-			id += int(bit.ReadUBitVar(br))
-
-			// next two bits encode one of four entity mutate operations
-			switch br.ReadBits(2) {
-			case 0:
-				ctx.UpdateEntity(id, br)
-			case 1:
-				ctx.LeaveEntity(id)
-			case 2:
-				ctx.CreateEntity(id, br)
-			case 3:
-				ctx.DeleteEntity(id)
-			}
-		}
-	}
-}

main.go

@@ -141,7 +141,9 @@ func main() {
 	case "class-info":
 		handle = dumpClasses
 	case "entities":
-		handle = dumpEntities
+		ent.Debug = log.New(os.Stdout, "", 0)
+		d := ent.NewDict()
+		handle = d.Handle
 	default:
 		bail(1, "no such action: %s", flag.Arg(0))
 	}