Use unsafe to reduce the number of string to slice copies in templates.

Use sliced arrays to reduce the amount of null padding in template fragments.
Revert a failed optimisation in templates.
Remove a few more redundant branches in variant templates.

Added the unsafe function StringToBytes.
Added BenchmarkTopicGuestRouteParallelWithRouterAlt.

common/files.go

@@ -154,6 +154,24 @@ func (list SFileList) JSTmplInit() error {
 				data[braceAt] = ' ' // Blank it
 			}
 		})
+		each("w.Write(StringToBytes(", func(index int) {
+			braceAt, hasEndBrace := skipUntilIfExists(data, index, ')')
+			// TODO: Make sure we don't go onto the next line in case someone misplaced a brace
+			if hasEndBrace {
+				data[braceAt] = ' ' // Blank it
+			}
+			braceAt, hasEndBrace = skipUntilIfExists(data, braceAt, ')')
+			if hasEndBrace {
+				data[braceAt] = ' ' // Blank this one too
+			}
+		})
+		each(" = StringToBytes(", func(index int) {
+			braceAt, hasEndBrace := skipUntilIfExists(data, index, ')')
+			// TODO: Make sure we don't go onto the next line in case someone misplaced a brace
+			if hasEndBrace {
+				data[braceAt] = ' ' // Blank it
+			}
+		})
 		each("w.Write(", func(index int) {
 			braceAt, hasEndBrace := skipUntilIfExists(data, index, ')')
 			// TODO: Make sure we don't go onto the next line in case someone misplaced a brace
@@ -183,6 +201,7 @@ func (list SFileList) JSTmplInit() error {
 		})
 		data = replace(data, "for _, item := range ", "for(item of ")
 		data = replace(data, "w.Write([]byte(", "out += ")
+		data = replace(data, "w.Write(StringToBytes(", "out += ")
 		data = replace(data, "w.Write(", "out += ")
 		data = replace(data, "strconv.Itoa(", "")
 		data = replace(data, "strconv.FormatInt(", "")
@@ -194,6 +213,7 @@ func (list SFileList) JSTmplInit() error {
 		//data = replace(data, "var phrases = GetTmplPhrasesBytes("+shortName+"_tmpl_phrase_id)", "let phrases = tmplPhrases[\""+tmplName+"\"];\nconsole.log('tmplName:','"+tmplName+"')\nconsole.log('phrases:', phrases);")
 		data = replace(data, "var cached_var_", "let cached_var_")
 		data = replace(data, " = []byte(", " = ")
+		data = replace(data, " = StringToBytes(", " = ")
 		data = replace(data, "if ", "if(")
 		data = replace(data, "return nil", "return out")
 		data = replace(data, " )", ")")

common/template_init.go

@@ -509,18 +509,29 @@ func writeTemplateList(c *tmpl.CTemplateSet, wg *sync.WaitGroup, prefix string)
 		}
 		getterstr += "}\nreturn nil\n}\n"
 		out += "\n// nolint\nfunc init() {\n"
-		var bodyMap = make(map[string]string) //map[body]fragmentPrefix
+		//var bodyMap = make(map[string]string) //map[body]fragmentPrefix
+		var tmpCount = 0
 		for _, frag := range c.FragOut {
-			var fragmentPrefix string
 			front := frag.TmplName + "_frags[" + strconv.Itoa(frag.Index) + "]"
-			fp, ok := bodyMap[frag.Body]
+			/*fp, ok := bodyMap[frag.Body]
 			if !ok {
-				fragmentPrefix = front + " = []byte(`" + frag.Body + "`)\n"
-				bodyMap[frag.Body] = front
+				bodyMap[frag.Body] = front*/
+			var bits string
+			for _, char := range []byte(frag.Body) {
+				if char == '\'' {
+					bits += "'\\" + string(char) + "',"
 				} else {
-				fragmentPrefix = front + " = " + fp + "\n"
+					bits += "'" + string(char) + "',"
 				}
-			out += fragmentPrefix
+			}
+			tmpStr := strconv.Itoa(tmpCount)
+			out += "arr_" + tmpStr + " := [...]byte{" + bits + "}\n"
+			out += front + " = arr_" + tmpStr + "[:]\n"
+			tmpCount++
+			//out += front + " = []byte(`" + frag.Body + "`)\n"
+			/*} else {
+				out += front + " = " + fp + "\n"
+			}*/
 		}
 		out += "\n" + getterstr + "}\n"
 		err := writeFile(prefix+"template_list.go", out)

common/templates/templates.go

@@ -425,6 +425,15 @@ func (c *CTemplateSet) rootIterate(tree *parse.Tree, con CContext) {
 	c.retCall("rootIterate")
 }
 
+var inSlice = func(haystack []string, expr string) bool {
+	for _, needle := range haystack {
+		if needle == expr {
+			return true
+		}
+	}
+	return false
+}
+
 func (c *CTemplateSet) compileSwitch(con CContext, node parse.Node) {
 	c.dumpCall("compileSwitch", con, node)
 	defer c.retCall("compileSwitch")
@@ -451,14 +460,6 @@ func (c *CTemplateSet) compileSwitch(con CContext, node parse.Node) {
 		c.detail("Expression:", expr)
 		// Simple member / guest optimisation for now
 		// TODO: Expand upon this
-		var inSlice = func(haystack []string, expr string) bool {
-			for _, needle := range haystack {
-				if needle == expr {
-					return true
-				}
-			}
-			return false
-		}
 		var userExprs = []string{
 			con.RootHolder + ".CurrentUser.Loggedin",
 			con.RootHolder + ".CurrentUser.IsSuperMod",
@@ -861,7 +862,7 @@ func (c *CTemplateSet) compileIdentSwitch(con CContext, node *parse.CommandNode)
 	c.dumpCall("compileIdentSwitch", con, node)
 	var litString = func(inner string, bytes bool) {
 		if !bytes {
-			inner = "[]byte(" + inner + ")"
+			inner = "StringToBytes(" + inner + ")"
 		}
 		out = "w.Write(" + inner + ")\n"
 		literal = true
@@ -1219,7 +1220,7 @@ func (c *CTemplateSet) compileVarSub(con CContext, varname string, val reflect.V
 
 	// Is this a literal string?
 	if len(varname) != 0 && varname[0] == '"' {
-		con.Push("lvarsub", onEnd(assLines+"w.Write([]byte("+varname+"))\n"))
+		con.Push("lvarsub", onEnd(assLines+"w.Write(StringToBytes("+varname+"))\n"))
 		return
 	}
 	for _, varItem := range c.varList {
@@ -1250,9 +1251,44 @@ func (c *CTemplateSet) compileVarSub(con CContext, varname string, val reflect.V
 	switch val.Kind() {
 	case reflect.Int:
 		c.importMap["strconv"] = "strconv"
-		base = "[]byte(strconv.Itoa(" + varname + "))"
+		base = "StringToBytes(strconv.Itoa(" + varname + "))"
 	case reflect.Bool:
-		// TODO: Take c.guestOnly / c.memberOnly into account
+		// TODO: Take c.memberOnly into account
+		// TODO: Make this a template fragment so more optimisations can be applied to this
+		// TODO: De-duplicate this logic
+		var userExprs = []string{
+			con.RootHolder + ".CurrentUser.Loggedin",
+			con.RootHolder + ".CurrentUser.IsSuperMod",
+			con.RootHolder + ".CurrentUser.IsAdmin",
+		}
+		var negUserExprs = []string{
+			"!" + con.RootHolder + ".CurrentUser.Loggedin",
+			"!" + con.RootHolder + ".CurrentUser.IsSuperMod",
+			"!" + con.RootHolder + ".CurrentUser.IsAdmin",
+		}
+		if c.guestOnly {
+			c.detail("optimising away member branch")
+			if inSlice(userExprs, varname) {
+				c.detail("positive conditional:", varname)
+				con.Push("varsub", "[]byte(\"false\")")
+				return
+			} else if inSlice(negUserExprs, varname) {
+				c.detail("negative conditional:", varname)
+				con.Push("varsub", "[]byte(\"true\")")
+				return
+			}
+		} else if c.memberOnly {
+			c.detail("optimising away guest branch")
+			if (con.RootHolder + ".CurrentUser.Loggedin") == varname {
+				c.detail("positive conditional:", varname)
+				con.Push("varsub", "[]byte(\"true\")")
+				return
+			} else if ("!" + con.RootHolder + ".CurrentUser.Loggedin") == varname {
+				c.detail("negative conditional:", varname)
+				con.Push("varsub", "[]byte(\"false\")")
+				return
+			}
+		}
 		con.Push("startif", "if "+varname+" {\n")
 		con.Push("varsub", "[]byte(\"true\")")
 		con.Push("endif", "} ")
@@ -1264,19 +1300,19 @@ func (c *CTemplateSet) compileVarSub(con CContext, varname string, val reflect.V
 		if val.Type().Name() != "string" && !strings.HasPrefix(varname, "string(") {
 			varname = "string(" + varname + ")"
 		}
-		base = "[]byte(" + varname + ")"
+		base = "StringToBytes(" + varname + ")"
 		// We don't to waste time on this conversion / w.Write call when guests don't have sessions
 		// TODO: Implement this properly
-		if c.guestOnly && base == "[]byte("+con.RootHolder+".CurrentUser.Session))" {
+		if c.guestOnly && base == "StringToBytes("+con.RootHolder+".CurrentUser.Session))" {
 			return
 		}
 	case reflect.Int64:
 		c.importMap["strconv"] = "strconv"
-		base = "[]byte(strconv.FormatInt(" + varname + ", 10))"
+		base = "StringToBytes(strconv.FormatInt(" + varname + ", 10))"
 	case reflect.Struct:
 		// TODO: Avoid clashing with other packages which have structs named Time
 		if val.Type().Name() == "Time" {
-			base = "[]byte(" + varname + ".String())"
+			base = "StringToBytes(" + varname + ".String())"
 		} else {
 			if !val.IsValid() {
 				panic(assLines + varname + "^\n" + "Invalid value. Maybe, it doesn't exist?")

general_test.go

@@ -288,10 +288,16 @@ func BenchmarkTopicGuestRouteParallelWithRouter(b *testing.B) {
 	obRoute(b, "/topic/hm."+benchTid)
 }
 
+func BenchmarkTopicGuestRouteParallelWithRouterAlt(b *testing.B) {
+	obRoute(b, "/topic/hm."+benchTid)
+}
+
 func BenchmarkBadRouteGuestRouteParallelWithRouter(b *testing.B) {
 	obRoute(b, "/garble/haa")
 }
 
+// TODO: Alternate between member and guest to bust some CPU caches?
+
 func binit(b *testing.B) {
 	b.ReportAllocs()
 	err := gloinit()

tmpl_client/stub.go

@@ -1,5 +1,25 @@
 package tmpl
 
+import (
+	"reflect"
+	"runtime"
+	"unsafe"
+)
+
 var GetFrag = func(name string) [][]byte {
 	return nil
 }
+
+type WriteString interface {
+	WriteString(s string) (n int, err error)
+}
+
+func StringToBytes(s string) (bytes []byte) {
+	str := (*reflect.StringHeader)(unsafe.Pointer(&s))
+	slice := (*reflect.SliceHeader)(unsafe.Pointer(&bytes))
+	slice.Data = str.Data
+	slice.Len = str.Len
+	slice.Cap = str.Len
+	runtime.KeepAlive(&s)
+	return bytes
+}

tmpl_stub.go

@@ -1,5 +1,25 @@
 package main
 
+import (
+	"reflect"
+	"runtime"
+	"unsafe"
+)
+
 var GetFrag = func(name string) [][]byte {
 	return nil
 }
+
+type WriteString interface {
+	WriteString(s string) (n int, err error)
+}
+
+func StringToBytes(s string) (bytes []byte) {
+	str := (*reflect.StringHeader)(unsafe.Pointer(&s))
+	slice := (*reflect.SliceHeader)(unsafe.Pointer(&bytes))
+	slice.Data = str.Data
+	slice.Len = str.Len
+	slice.Cap = str.Len
+	runtime.KeepAlive(&s)
+	return bytes
+}