X-Git-Url: https://gerrit.fd.io/r/gitweb?a=blobdiff_plain;f=cmd%2Fbinapi-generator%2Fgenerate.go;h=fb6cee5c903d26b14c85e839cf35938414f41515;hb=2df59463fcbb1a5aec2173712b32fb9740157a9d;hp=22b4af65279762c15fed88c6151819822818291f;hpb=5f1917fd11e8562ef4094b7ce3a89af66ace5792;p=govpp.git

diff --git a/cmd/binapi-generator/generate.go b/cmd/binapi-generator/generate.go
index 22b4af6..fb6cee5 100644
--- a/cmd/binapi-generator/generate.go
+++ b/cmd/binapi-generator/generate.go
@@ -15,19 +15,37 @@
 package main
 
 import (
-	"bufio"
 	"bytes"
 	"fmt"
 	"io"
+	"os/exec"
 	"path/filepath"
+	"sort"
 	"strings"
 	"unicode"
 )
 
+// generatedCodeVersion indicates a version of the generated code.
+// It is incremented whenever an incompatibility between the generated code and
+// GoVPP api package is introduced; the generated code references
+// a constant, api.GoVppAPIPackageIsVersionN (where N is generatedCodeVersion).
+const generatedCodeVersion = 1
+
 const (
+	inputFileExt  = ".api.json" // file extension of the VPP API files
+	outputFileExt = ".ba.go"    // file extension of the Go generated files
+
 	govppApiImportPath = "git.fd.io/govpp.git/api" // import path of the govpp API package
-	inputFileExt       = ".api.json"               // file extension of the VPP binary API files
-	outputFileExt      = ".ba.go"                  // file extension of the Go generated files
+
+	constModuleName = "ModuleName" // module name constant
+	constAPIVersion = "APIVersion" // API version constant
+	constVersionCrc = "VersionCrc" // version CRC constant
+
+	unionDataField = "XXX_UnionData" // name for the union data field
+
+	serviceApiName    = "RPCService"    // name for the RPC service interface
+	serviceImplName   = "serviceClient" // name for the RPC service implementation
+	serviceClientName = "ServiceClient" // name for the RPC service client
 )
 
 // context is a structure storing data for code generation
@@ -37,14 +55,19 @@ type context struct {
 
 	inputData []byte // contents of the input file
 
+	includeAPIVersion  bool // include constant with API version string
+	includeComments    bool // include parts of original source in comments
+	includeBinapiNames bool // include binary API names as struct tag
+	includeServices    bool // include service interface with client implementation
+
 	moduleName  string // name of the source VPP module
 	packageName string // name of the Go package being generated
 
 	packageData *Package // parsed package data
 }
 
-// getContext returns context details of the code generation task
-func getContext(inputFile, outputDir string) (*context, error) {
+// newContext returns context details of the code generation task
+func newContext(inputFile, outputDir string) (*context, error) {
 	if !strings.HasSuffix(inputFile, inputFileExt) {
 		return nil, fmt.Errorf("invalid input file name: %q", inputFile)
 	}
@@ -75,104 +98,124 @@ func getContext(inputFile, outputDir string) (*context, error) {
 	return ctx, nil
 }
 
-// generatePackage generates code for the parsed package data and writes it into w
-func generatePackage(ctx *context, w *bufio.Writer) error {
+func generatePackage(ctx *context, w io.Writer) error {
 	logf("generating package %q", ctx.packageName)
 
-	// generate file header
+	fmt.Fprintln(w, "// Code generated by GoVPP's binapi-generator. DO NOT EDIT.")
+	fmt.Fprintf(w, "// source: %s\n", ctx.inputFile)
+	fmt.Fprintln(w)
+
 	generateHeader(ctx, w)
-	generateImports(ctx, w)
 
-	if *includeAPIVer {
-		const APIVerConstName = "VlAPIVersion"
-		fmt.Fprintf(w, "// %s represents version of the binary API module.\n", APIVerConstName)
-		fmt.Fprintf(w, "const %s = %v\n", APIVerConstName, ctx.packageData.APIVersion)
-		fmt.Fprintln(w)
-	}
+	// generate module desc
+	fmt.Fprintln(w, "const (")
+	fmt.Fprintf(w, "\t// %s is the name of this module.\n", constModuleName)
+	fmt.Fprintf(w, "\t%s = \"%s\"\n", constModuleName, ctx.moduleName)
 
-	// generate services
-	if len(ctx.packageData.Services) > 0 {
-		generateServices(ctx, w, ctx.packageData.Services)
+	if ctx.includeAPIVersion {
+		if ctx.packageData.Version != "" {
+			fmt.Fprintf(w, "\t// %s is the API version of this module.\n", constAPIVersion)
+			fmt.Fprintf(w, "\t%s = \"%s\"\n", constAPIVersion, ctx.packageData.Version)
+		}
+		fmt.Fprintf(w, "\t// %s is the CRC of this module.\n", constVersionCrc)
+		fmt.Fprintf(w, "\t%s = %v\n", constVersionCrc, ctx.packageData.CRC)
 	}
-
-	// TODO: generate implementation for Services interface
+	fmt.Fprintln(w, ")")
+	fmt.Fprintln(w)
 
 	// generate enums
 	if len(ctx.packageData.Enums) > 0 {
-		fmt.Fprintf(w, "/* Enums */\n\n")
-
 		for _, enum := range ctx.packageData.Enums {
+			if imp, ok := ctx.packageData.Imports[enum.Name]; ok {
+				generateImportedAlias(ctx, w, enum.Name, &imp)
+				continue
+			}
 			generateEnum(ctx, w, &enum)
 		}
 	}
 
 	// generate aliases
 	if len(ctx.packageData.Aliases) > 0 {
-		fmt.Fprintf(w, "/* Aliases */\n\n")
-
 		for _, alias := range ctx.packageData.Aliases {
+			if imp, ok := ctx.packageData.Imports[alias.Name]; ok {
+				generateImportedAlias(ctx, w, alias.Name, &imp)
+				continue
+			}
 			generateAlias(ctx, w, &alias)
 		}
 	}
 
 	// generate types
 	if len(ctx.packageData.Types) > 0 {
-		fmt.Fprintf(w, "/* Types */\n\n")
-
 		for _, typ := range ctx.packageData.Types {
+			if imp, ok := ctx.packageData.Imports[typ.Name]; ok {
+				generateImportedAlias(ctx, w, typ.Name, &imp)
+				continue
+			}
 			generateType(ctx, w, &typ)
 		}
 	}
 
 	// generate unions
 	if len(ctx.packageData.Unions) > 0 {
-		fmt.Fprintf(w, "/* Unions */\n\n")
-
 		for _, union := range ctx.packageData.Unions {
+			if imp, ok := ctx.packageData.Imports[union.Name]; ok {
+				generateImportedAlias(ctx, w, union.Name, &imp)
+				continue
+			}
 			generateUnion(ctx, w, &union)
 		}
 	}
 
 	// generate messages
 	if len(ctx.packageData.Messages) > 0 {
-		fmt.Fprintf(w, "/* Messages */\n\n")
-
 		for _, msg := range ctx.packageData.Messages {
 			generateMessage(ctx, w, &msg)
 		}
-	}
 
-	// generate message registrations
-	fmt.Fprintln(w)
-	fmt.Fprintln(w, "func init() {")
-	for _, msg := range ctx.packageData.Messages {
-		name := camelCaseName(msg.Name)
-		fmt.Fprintf(w, "\tapi.RegisterMessage((*%s)(nil), \"%s\")\n", name, ctx.moduleName+"."+name)
+		// generate message registrations
+		fmt.Fprintln(w, "func init() {")
+		for _, msg := range ctx.packageData.Messages {
+			name := camelCaseName(msg.Name)
+			fmt.Fprintf(w, "\tapi.RegisterMessage((*%s)(nil), \"%s\")\n", name, ctx.moduleName+"."+name)
+		}
+		fmt.Fprintln(w, "}")
+		fmt.Fprintln(w)
+
+		// generate list of messages
+		fmt.Fprintf(w, "// Messages returns list of all messages in this module.\n")
+		fmt.Fprintln(w, "func AllMessages() []api.Message {")
+		fmt.Fprintln(w, "\treturn []api.Message{")
+		for _, msg := range ctx.packageData.Messages {
+			name := camelCaseName(msg.Name)
+			fmt.Fprintf(w, "\t(*%s)(nil),\n", name)
+		}
+		fmt.Fprintln(w, "}")
+		fmt.Fprintln(w, "}")
 	}
-	fmt.Fprintln(w, "}")
 
-	// flush the data:
-	if err := w.Flush(); err != nil {
-		return fmt.Errorf("flushing data to %s failed: %v", ctx.outputFile, err)
+	if ctx.includeServices {
+		// generate services
+		if len(ctx.packageData.Services) > 0 {
+			generateServices(ctx, w, ctx.packageData.Services)
+		}
 	}
 
+	generateFooter(ctx, w)
+
 	return nil
 }
 
-// generateHeader writes generated package header into w
 func generateHeader(ctx *context, w io.Writer) {
-	fmt.Fprintln(w, "// Code generated by GoVPP binapi-generator. DO NOT EDIT.")
-	fmt.Fprintf(w, "//  source: %s\n", ctx.inputFile)
-	fmt.Fprintln(w)
-
 	fmt.Fprintln(w, "/*")
-	fmt.Fprintf(w, " Package %s is a generated from VPP binary API module '%s'.\n", ctx.packageName, ctx.moduleName)
+	fmt.Fprintf(w, "Package %s is a generated VPP binary API for '%s' module.\n", ctx.packageName, ctx.moduleName)
 	fmt.Fprintln(w)
-	fmt.Fprintln(w, " It contains following objects:")
-	var printObjNum = func(obj string, num int) {
+	fmt.Fprintln(w, "It consists of:")
+	printObjNum := func(obj string, num int) {
 		if num > 0 {
 			if num > 1 {
 				if strings.HasSuffix(obj, "s") {
+
 					obj += "es"
 				} else {
 					obj += "s"
@@ -181,38 +224,85 @@ func generateHeader(ctx *context, w io.Writer) {
 			fmt.Fprintf(w, "\t%3d %s\n", num, obj)
 		}
 	}
-	printObjNum("message", len(ctx.packageData.Messages))
-	printObjNum("type", len(ctx.packageData.Types))
-	printObjNum("alias", len(ctx.packageData.Aliases))
 	printObjNum("enum", len(ctx.packageData.Enums))
+	printObjNum("alias", len(ctx.packageData.Aliases))
+	printObjNum("type", len(ctx.packageData.Types))
 	printObjNum("union", len(ctx.packageData.Unions))
+	printObjNum("message", len(ctx.packageData.Messages))
 	printObjNum("service", len(ctx.packageData.Services))
-	fmt.Fprintln(w)
 	fmt.Fprintln(w, "*/")
 	fmt.Fprintf(w, "package %s\n", ctx.packageName)
 	fmt.Fprintln(w)
+
+	fmt.Fprintln(w, "import (")
+	fmt.Fprintf(w, "\tapi \"%s\"\n", govppApiImportPath)
+	fmt.Fprintf(w, "\tbytes \"%s\"\n", "bytes")
+	fmt.Fprintf(w, "\tcontext \"%s\"\n", "context")
+	fmt.Fprintf(w, "\tio \"%s\"\n", "io")
+	fmt.Fprintf(w, "\tstrconv \"%s\"\n", "strconv")
+	fmt.Fprintf(w, "\tstruc \"%s\"\n", "github.com/lunixbochs/struc")
+	if len(ctx.packageData.Imports) > 0 {
+		fmt.Fprintln(w)
+		for _, imp := range getImports(ctx) {
+			impPkg := getImportPkg(filepath.Dir(ctx.outputFile), imp)
+			fmt.Fprintf(w, "\t%s \"%s\"\n", imp, strings.TrimSpace(impPkg))
+		}
+	}
+	fmt.Fprintln(w, ")")
+	fmt.Fprintln(w)
+}
+
+func getImportPkg(outputDir string, pkg string) string {
+	absPath, _ := filepath.Abs(filepath.Join(outputDir, "..", pkg))
+	cmd := exec.Command("go", "list", absPath)
+	var errbuf, outbuf bytes.Buffer
+	cmd.Stdout = &outbuf
+	cmd.Stderr = &errbuf
+	if err := cmd.Run(); err != nil {
+		fmt.Printf("ERR: %v\n", errbuf.String())
+		panic(err)
+	}
+	return outbuf.String()
+}
+
+func getImports(ctx *context) (imports []string) {
+	impmap := map[string]struct{}{}
+	for _, imp := range ctx.packageData.Imports {
+		if _, ok := impmap[imp.Package]; !ok {
+			imports = append(imports, imp.Package)
+			impmap[imp.Package] = struct{}{}
+		}
+	}
+	sort.Strings(imports)
+	return imports
 }
 
-// generateImports writes generated package imports into w
-func generateImports(ctx *context, w io.Writer) {
-	fmt.Fprintf(w, "import \"%s\"\n", govppApiImportPath)
-	fmt.Fprintf(w, "import \"%s\"\n", "github.com/lunixbochs/struc")
-	fmt.Fprintf(w, "import \"%s\"\n", "bytes")
+func generateFooter(ctx *context, w io.Writer) {
+	fmt.Fprintln(w, "// This is a compile-time assertion to ensure that this generated file")
+	fmt.Fprintln(w, "// is compatible with the GoVPP api package it is being compiled against.")
+	fmt.Fprintln(w, "// A compilation error at this line likely means your copy of the")
+	fmt.Fprintln(w, "// GoVPP api package needs to be updated.")
+	fmt.Fprintf(w, "const _ = api.GoVppAPIPackageIsVersion%d // please upgrade the GoVPP api package\n", generatedCodeVersion)
 	fmt.Fprintln(w)
 
 	fmt.Fprintf(w, "// Reference imports to suppress errors if they are not otherwise used.\n")
 	fmt.Fprintf(w, "var _ = api.RegisterMessage\n")
-	fmt.Fprintf(w, "var _ = struc.Pack\n")
 	fmt.Fprintf(w, "var _ = bytes.NewBuffer\n")
-	fmt.Fprintln(w)
+	fmt.Fprintf(w, "var _ = context.Background\n")
+	fmt.Fprintf(w, "var _ = io.Copy\n")
+	fmt.Fprintf(w, "var _ = strconv.Itoa\n")
+	fmt.Fprintf(w, "var _ = struc.Pack\n")
 }
 
-// generateComment writes generated comment for the object into w
 func generateComment(ctx *context, w io.Writer, goName string, vppName string, objKind string) {
 	if objKind == "service" {
-		fmt.Fprintf(w, "// %s represents VPP binary API services:\n", goName)
+		fmt.Fprintf(w, "// %s represents RPC service API for %s module.\n", goName, ctx.moduleName)
 	} else {
-		fmt.Fprintf(w, "// %s represents VPP binary API %s '%s':\n", goName, objKind, vppName)
+		fmt.Fprintf(w, "// %s represents VPP binary API %s '%s'.\n", goName, objKind, vppName)
+	}
+
+	if !ctx.includeComments {
+		return
 	}
 
 	var isNotSpace = func(r rune) bool {
@@ -265,41 +355,6 @@ func generateComment(ctx *context, w io.Writer, goName string, vppName string, o
 	fmt.Fprintln(w, "//")
 }
 
-// generateServices writes generated code for the Services interface into w
-func generateServices(ctx *context, w *bufio.Writer, services []Service) {
-	// generate services comment
-	generateComment(ctx, w, "Services", "services", "service")
-
-	// generate interface
-	fmt.Fprintf(w, "type %s interface {\n", "Services")
-	for _, svc := range ctx.packageData.Services {
-		generateService(ctx, w, &svc)
-	}
-	fmt.Fprintln(w, "}")
-
-	fmt.Fprintln(w)
-}
-
-// generateService writes generated code for the service into w
-func generateService(ctx *context, w io.Writer, svc *Service) {
-	reqTyp := camelCaseName(svc.RequestType)
-
-	// method name is same as parameter type name by default
-	method := svc.MethodName()
-	params := fmt.Sprintf("*%s", reqTyp)
-	returns := "error"
-	if replyType := camelCaseName(svc.ReplyType); replyType != "" {
-		repTyp := fmt.Sprintf("*%s", replyType)
-		if svc.Stream {
-			repTyp = fmt.Sprintf("[]%s", repTyp)
-		}
-		returns = fmt.Sprintf("(%s, error)", repTyp)
-	}
-
-	fmt.Fprintf(w, "\t%s(%s) %s\n", method, params, returns)
-}
-
-// generateEnum writes generated code for the enum into w
 func generateEnum(ctx *context, w io.Writer, enum *Enum) {
 	name := camelCaseName(enum.Name)
 	typ := binapiTypes[enum.Type]
@@ -313,19 +368,45 @@ func generateEnum(ctx *context, w io.Writer, enum *Enum) {
 	fmt.Fprintf(w, "type %s %s\n", name, typ)
 	fmt.Fprintln(w)
 
-	fmt.Fprintln(w, "const (")
-
 	// generate enum entries
+	fmt.Fprintln(w, "const (")
 	for _, entry := range enum.Entries {
 		fmt.Fprintf(w, "\t%s %s = %v\n", entry.Name, name, entry.Value)
 	}
-
 	fmt.Fprintln(w, ")")
+	fmt.Fprintln(w)
+
+	// generate enum conversion maps
+	fmt.Fprintf(w, "var %s_name = map[%s]string{\n", name, typ)
+	for _, entry := range enum.Entries {
+		fmt.Fprintf(w, "\t%v: \"%s\",\n", entry.Value, entry.Name)
+	}
+	fmt.Fprintln(w, "}")
+	fmt.Fprintln(w)
+
+	fmt.Fprintf(w, "var %s_value = map[string]%s{\n", name, typ)
+	for _, entry := range enum.Entries {
+		fmt.Fprintf(w, "\t\"%s\": %v,\n", entry.Name, entry.Value)
+	}
+	fmt.Fprintln(w, "}")
+	fmt.Fprintln(w)
+
+	fmt.Fprintf(w, "func (x %s) String() string {\n", name)
+	fmt.Fprintf(w, "\ts, ok := %s_name[%s(x)]\n", name, typ)
+	fmt.Fprintf(w, "\tif ok { return s }\n")
+	fmt.Fprintf(w, "\treturn strconv.Itoa(int(x))\n")
+	fmt.Fprintln(w, "}")
+	fmt.Fprintln(w)
+}
+
+func generateImportedAlias(ctx *context, w io.Writer, tName string, imp *Import) {
+	name := camelCaseName(tName)
+
+	fmt.Fprintf(w, "type %s = %s.%s\n", name, imp.Package, name)
 
 	fmt.Fprintln(w)
 }
 
-// generateAlias writes generated code for the alias into w
 func generateAlias(ctx *context, w io.Writer, alias *Alias) {
 	name := camelCaseName(alias.Name)
 
@@ -347,42 +428,6 @@ func generateAlias(ctx *context, w io.Writer, alias *Alias) {
 	fmt.Fprintln(w)
 }
 
-// generateType writes generated code for the type into w
-func generateType(ctx *context, w io.Writer, typ *Type) {
-	name := camelCaseName(typ.Name)
-
-	logf(" writing type %q (%s) with %d fields", typ.Name, name, len(typ.Fields))
-
-	// generate struct comment
-	generateComment(ctx, w, name, typ.Name, "type")
-
-	// generate struct definition
-	fmt.Fprintf(w, "type %s struct {\n", name)
-
-	// generate struct fields
-	for i, field := range typ.Fields {
-		// skip internal fields
-		switch strings.ToLower(field.Name) {
-		case "crc", "_vl_msg_id":
-			continue
-		}
-
-		generateField(ctx, w, typ.Fields, i)
-	}
-
-	// generate end of the struct
-	fmt.Fprintln(w, "}")
-
-	// generate name getter
-	generateTypeNameGetter(w, name, typ.Name)
-
-	// generate CRC getter
-	generateCrcGetter(w, name, typ.CRC)
-
-	fmt.Fprintln(w)
-}
-
-// generateUnion writes generated code for the union into w
 func generateUnion(ctx *context, w io.Writer, union *Union) {
 	name := camelCaseName(union.Name)
 
@@ -398,8 +443,7 @@ func generateUnion(ctx *context, w io.Writer, union *Union) {
 	maxSize := getUnionSize(ctx, union)
 
 	// generate data field
-	fieldName := "Union_data"
-	fmt.Fprintf(w, "\t%s [%d]byte\n", fieldName, maxSize)
+	fmt.Fprintf(w, "\t%s [%d]byte\n", unionDataField, maxSize)
 
 	// generate end of the struct
 	fmt.Fprintln(w, "}")
@@ -408,7 +452,9 @@ func generateUnion(ctx *context, w io.Writer, union *Union) {
 	generateTypeNameGetter(w, name, union.Name)
 
 	// generate CRC getter
-	generateCrcGetter(w, name, union.CRC)
+	if union.CRC != "" {
+		generateCrcGetter(w, name, union.CRC)
+	}
 
 	// generate getters for fields
 	for _, field := range union.Fields {
@@ -424,9 +470,9 @@ func generateUnion(ctx *context, w io.Writer, union *Union) {
 }
 
 // generateUnionMethods generates methods that implement struc.Custom
-// interface to allow having Union_data field unexported
+// interface to allow having XXX_uniondata field unexported
 // TODO: do more testing when unions are actually used in some messages
-func generateUnionMethods(w io.Writer, structName string) {
+/*func generateUnionMethods(w io.Writer, structName string) {
 	// generate struc.Custom implementation for union
 	fmt.Fprintf(w, `
 func (u *%[1]s) Pack(p []byte, opt *struc.Options) (int, error) {
@@ -447,26 +493,65 @@ func (u *%[1]s) String() string {
 	return string(u.union_data[:])
 }
 `, structName)
-}
+}*/
 
 func generateUnionGetterSetter(w io.Writer, structName string, getterField, getterStruct string) {
 	fmt.Fprintf(w, `
+func %[1]s%[2]s(a %[3]s) (u %[1]s) {
+	u.Set%[2]s(a)
+	return
+}
 func (u *%[1]s) Set%[2]s(a %[3]s) {
 	var b = new(bytes.Buffer)
 	if err := struc.Pack(b, &a); err != nil {
 		return
 	}
-	copy(u.Union_data[:], b.Bytes())
+	copy(u.%[4]s[:], b.Bytes())
 }
 func (u *%[1]s) Get%[2]s() (a %[3]s) {
-	var b = bytes.NewReader(u.Union_data[:])
+	var b = bytes.NewReader(u.%[4]s[:])
 	struc.Unpack(b, &a)
 	return
 }
-`, structName, getterField, getterStruct)
+`, structName, getterField, getterStruct, unionDataField)
+}
+
+func generateType(ctx *context, w io.Writer, typ *Type) {
+	name := camelCaseName(typ.Name)
+
+	logf(" writing type %q (%s) with %d fields", typ.Name, name, len(typ.Fields))
+
+	// generate struct comment
+	generateComment(ctx, w, name, typ.Name, "type")
+
+	// generate struct definition
+	fmt.Fprintf(w, "type %s struct {\n", name)
+
+	// generate struct fields
+	for i, field := range typ.Fields {
+		// skip internal fields
+		switch strings.ToLower(field.Name) {
+		case crcField, msgIdField:
+			continue
+		}
+
+		generateField(ctx, w, typ.Fields, i)
+	}
+
+	// generate end of the struct
+	fmt.Fprintln(w, "}")
+
+	// generate name getter
+	generateTypeNameGetter(w, name, typ.Name)
+
+	// generate CRC getter
+	if typ.CRC != "" {
+		generateCrcGetter(w, name, typ.CRC)
+	}
+
+	fmt.Fprintln(w)
 }
 
-// generateMessage writes generated code for the message into w
 func generateMessage(ctx *context, w io.Writer, msg *Message) {
 	name := camelCaseName(msg.Name)
 
@@ -485,26 +570,28 @@ func generateMessage(ctx *context, w io.Writer, msg *Message) {
 	n := 0
 	for i, field := range msg.Fields {
 		if i == 1 {
-			if field.Name == "client_index" {
-				// "client_index" as the second member, this might be an event message or a request
+			if field.Name == clientIndexField {
+				// "client_index" as the second member,
+				// this might be an event message or a request
 				msgType = eventMessage
 				wasClientIndex = true
-			} else if field.Name == "context" {
+			} else if field.Name == contextField {
 				// reply needs "context" as the second member
 				msgType = replyMessage
 			}
 		} else if i == 2 {
-			if wasClientIndex && field.Name == "context" {
-				// request needs "client_index" as the second member and "context" as the third member
+			if wasClientIndex && field.Name == contextField {
+				// request needs "client_index" as the second member
+				// and "context" as the third member
 				msgType = requestMessage
 			}
 		}
 
 		// skip internal fields
 		switch strings.ToLower(field.Name) {
-		case "crc", "_vl_msg_id":
+		case crcField, msgIdField:
 			continue
-		case "client_index", "context":
+		case clientIndexField, contextField:
 			if n == 0 {
 				continue
 			}
@@ -520,17 +607,15 @@ func generateMessage(ctx *context, w io.Writer, msg *Message) {
 	// generate end of the struct
 	fmt.Fprintln(w, "}")
 
-	// generate name getter
+	// generate message methods
+	generateMessageResetMethod(w, name)
 	generateMessageNameGetter(w, name, msg.Name)
-
-	// generate CRC getter
 	generateCrcGetter(w, name, msg.CRC)
-
-	// generate message type getter method
 	generateMessageTypeGetter(w, name, msgType)
+
+	fmt.Fprintln(w)
 }
 
-// generateField writes generated code for the field into w
 func generateField(ctx *context, w io.Writer, fields []Field, i int) {
 	field := fields[i]
 
@@ -538,68 +623,215 @@ func generateField(ctx *context, w io.Writer, fields []Field, i int) {
 	fieldName = camelCaseName(fieldName)
 
 	dataType := convertToGoType(ctx, field.Type)
-
 	fieldType := dataType
-	if field.IsArray() {
+
+	// generate length field for strings
+	if field.Type == "string" && field.Length == 0 {
+		fmt.Fprintf(w, "\tXXX_%sLen uint32 `struc:\"sizeof=%s\"`\n", fieldName, fieldName)
+	}
+
+	// check if it is array
+	if field.Length > 0 || field.SizeFrom != "" {
 		if dataType == "uint8" {
 			dataType = "byte"
 		}
-		fieldType = "[]" + dataType
+		if dataType == "string" && field.SpecifiedLen {
+			fieldType = "string"
+			dataType = "byte"
+		} else {
+			fieldType = "[]" + dataType
+		}
 	}
 	fmt.Fprintf(w, "\t%s %s", fieldName, fieldType)
 
-	if field.Length > 0 {
+	fieldTags := map[string]string{}
+
+	if field.Length > 0 && field.SpecifiedLen {
 		// fixed size array
-		fmt.Fprintf(w, "\t`struc:\"[%d]%s\"`", field.Length, dataType)
+		fieldTags["struc"] = fmt.Sprintf("[%d]%s", field.Length, dataType)
 	} else {
 		for _, f := range fields {
 			if f.SizeFrom == field.Name {
 				// variable sized array
 				sizeOfName := camelCaseName(f.Name)
-				fmt.Fprintf(w, "\t`struc:\"sizeof=%s\"`", sizeOfName)
+				fieldTags["struc"] = fmt.Sprintf("sizeof=%s", sizeOfName)
 			}
 		}
 	}
 
+	if ctx.includeBinapiNames {
+		fieldTags["binapi"] = field.Name
+	}
+	if field.Meta.Limit > 0 {
+		fieldTags["binapi"] = fmt.Sprintf("%s,limit=%d", fieldTags["binapi"], field.Meta.Limit)
+	}
+
+	if len(fieldTags) > 0 {
+		fmt.Fprintf(w, "\t`")
+		var keys []string
+		for k := range fieldTags {
+			keys = append(keys, k)
+		}
+		sort.Strings(keys)
+		var n int
+		for _, tt := range keys {
+			t, ok := fieldTags[tt]
+			if !ok {
+				continue
+			}
+			if n > 0 {
+				fmt.Fprintf(w, " ")
+			}
+			n++
+			fmt.Fprintf(w, `%s:"%s"`, tt, t)
+		}
+		fmt.Fprintf(w, "`")
+	}
+
 	fmt.Fprintln(w)
 }
 
-// generateMessageNameGetter generates getter for original VPP message name into the provider writer
-func generateMessageNameGetter(w io.Writer, structName, msgName string) {
-	fmt.Fprintf(w, `func (*%s) GetMessageName() string {
-	return %q
+func generateMessageResetMethod(w io.Writer, structName string) {
+	fmt.Fprintf(w, "func (m *%[1]s) Reset() { *m = %[1]s{} }\n", structName)
 }
-`, structName, msgName)
+
+func generateMessageNameGetter(w io.Writer, structName, msgName string) {
+	fmt.Fprintf(w, "func (*%s) GetMessageName() string {	return %q }\n", structName, msgName)
 }
 
-// generateTypeNameGetter generates getter for original VPP type name into the provider writer
 func generateTypeNameGetter(w io.Writer, structName, msgName string) {
-	fmt.Fprintf(w, `func (*%s) GetTypeName() string {
-	return %q
-}
-`, structName, msgName)
+	fmt.Fprintf(w, "func (*%s) GetTypeName() string { return %q }\n", structName, msgName)
 }
 
-// generateCrcGetter generates getter for CRC checksum of the message definition into the provider writer
 func generateCrcGetter(w io.Writer, structName, crc string) {
 	crc = strings.TrimPrefix(crc, "0x")
-	fmt.Fprintf(w, `func (*%s) GetCrcString() string {
-	return %q
-}
-`, structName, crc)
+	fmt.Fprintf(w, "func (*%s) GetCrcString() string { return %q }\n", structName, crc)
 }
 
-// generateMessageTypeGetter generates message factory for the generated message into the provider writer
 func generateMessageTypeGetter(w io.Writer, structName string, msgType MessageType) {
-	fmt.Fprintln(w, "func (*"+structName+") GetMessageType() api.MessageType {")
+	fmt.Fprintf(w, "func (*"+structName+") GetMessageType() api.MessageType {")
 	if msgType == requestMessage {
-		fmt.Fprintln(w, "\treturn api.RequestMessage")
+		fmt.Fprintf(w, "\treturn api.RequestMessage")
 	} else if msgType == replyMessage {
-		fmt.Fprintln(w, "\treturn api.ReplyMessage")
+		fmt.Fprintf(w, "\treturn api.ReplyMessage")
 	} else if msgType == eventMessage {
-		fmt.Fprintln(w, "\treturn api.EventMessage")
+		fmt.Fprintf(w, "\treturn api.EventMessage")
 	} else {
-		fmt.Fprintln(w, "\treturn api.OtherMessage")
+		fmt.Fprintf(w, "\treturn api.OtherMessage")
+	}
+	fmt.Fprintln(w, "}")
+	fmt.Fprintln(w)
+}
+
+func generateServices(ctx *context, w io.Writer, services []Service) {
+
+	// generate services comment
+	generateComment(ctx, w, serviceApiName, "services", "service")
+
+	// generate service api
+	fmt.Fprintf(w, "type %s interface {\n", serviceApiName)
+	for _, svc := range services {
+		generateServiceMethod(ctx, w, &svc)
+		fmt.Fprintln(w)
 	}
 	fmt.Fprintln(w, "}")
+	fmt.Fprintln(w)
+
+	// generate client implementation
+	fmt.Fprintf(w, "type %s struct {\n", serviceImplName)
+	fmt.Fprintf(w, "\tch api.Channel\n")
+	fmt.Fprintln(w, "}")
+	fmt.Fprintln(w)
+
+	// generate client constructor
+	fmt.Fprintf(w, "func New%s(ch api.Channel) %s {\n", serviceClientName, serviceApiName)
+	fmt.Fprintf(w, "\treturn &%s{ch}\n", serviceImplName)
+	fmt.Fprintln(w, "}")
+	fmt.Fprintln(w)
+
+	for _, svc := range services {
+		method := camelCaseName(svc.RequestType)
+		if m := strings.TrimSuffix(method, "Dump"); method != m {
+			method = "Dump" + m
+		}
+
+		fmt.Fprintf(w, "func (c *%s) ", serviceImplName)
+		generateServiceMethod(ctx, w, &svc)
+		fmt.Fprintln(w, " {")
+		if svc.Stream {
+			streamImpl := fmt.Sprintf("%s_%sClient", serviceImplName, method)
+			fmt.Fprintf(w, "\tstream := c.ch.SendMultiRequest(in)\n")
+			fmt.Fprintf(w, "\tx := &%s{stream}\n", streamImpl)
+			fmt.Fprintf(w, "\treturn x, nil\n")
+		} else if replyTyp := camelCaseName(svc.ReplyType); replyTyp != "" {
+			fmt.Fprintf(w, "\tout := new(%s)\n", replyTyp)
+			fmt.Fprintf(w, "\terr:= c.ch.SendRequest(in).ReceiveReply(out)\n")
+			fmt.Fprintf(w, "\tif err != nil { return nil, err }\n")
+			fmt.Fprintf(w, "\treturn out, nil\n")
+		} else {
+			fmt.Fprintf(w, "\tc.ch.SendRequest(in)\n")
+			fmt.Fprintf(w, "\treturn nil\n")
+		}
+		fmt.Fprintln(w, "}")
+		fmt.Fprintln(w)
+
+		if svc.Stream {
+			replyTyp := camelCaseName(svc.ReplyType)
+			method := camelCaseName(svc.RequestType)
+			if m := strings.TrimSuffix(method, "Dump"); method != m {
+				method = "Dump" + m
+			}
+			streamApi := fmt.Sprintf("%s_%sClient", serviceApiName, method)
+
+			fmt.Fprintf(w, "type %s interface {\n", streamApi)
+			fmt.Fprintf(w, "\tRecv() (*%s, error)\n", replyTyp)
+			fmt.Fprintln(w, "}")
+			fmt.Fprintln(w)
+
+			streamImpl := fmt.Sprintf("%s_%sClient", serviceImplName, method)
+			fmt.Fprintf(w, "type %s struct {\n", streamImpl)
+			fmt.Fprintf(w, "\tapi.MultiRequestCtx\n")
+			fmt.Fprintln(w, "}")
+			fmt.Fprintln(w)
+
+			fmt.Fprintf(w, "func (c *%s) Recv() (*%s, error) {\n", streamImpl, replyTyp)
+			fmt.Fprintf(w, "\tm := new(%s)\n", replyTyp)
+			fmt.Fprintf(w, "\tstop, err := c.MultiRequestCtx.ReceiveReply(m)\n")
+			fmt.Fprintf(w, "\tif err != nil { return nil, err }\n")
+			fmt.Fprintf(w, "\tif stop { return nil, io.EOF }\n")
+			fmt.Fprintf(w, "\treturn m, nil\n")
+			fmt.Fprintln(w, "}")
+			fmt.Fprintln(w)
+		}
+	}
+
+	fmt.Fprintln(w)
+}
+
+func generateServiceMethod(ctx *context, w io.Writer, svc *Service) {
+	reqTyp := camelCaseName(svc.RequestType)
+
+	// method name is same as parameter type name by default
+	method := reqTyp
+	if svc.Stream {
+		// use Dump as prefix instead of suffix for stream services
+		if m := strings.TrimSuffix(method, "Dump"); method != m {
+			method = "Dump" + m
+		}
+	}
+
+	params := fmt.Sprintf("in *%s", reqTyp)
+	returns := "error"
+
+	if replyType := camelCaseName(svc.ReplyType); replyType != "" {
+		var replyTyp string
+		if svc.Stream {
+			replyTyp = fmt.Sprintf("%s_%sClient", serviceApiName, method)
+		} else {
+			replyTyp = fmt.Sprintf("*%s", replyType)
+		}
+		returns = fmt.Sprintf("(%s, error)", replyTyp)
+	}
+
+	fmt.Fprintf(w, "\t%s(ctx context.Context, %s) %s", method, params, returns)
 }