summaryrefslogtreecommitdiffstats
path: root/cmd/binapi-generator/generate.go
blob: e386f8d4a23c08b1829f157daa876fb49f5ee2fe (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
// Copyright (c) 2017 Cisco and/or its affiliates.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at:
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package main

import (
	"bytes"
	"fmt"
	"io"
	"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

	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
type context struct {
	inputFile  string // input file with VPP API in JSON
	outputFile string // output file with generated Go package

	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
}

// 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)
	}

	ctx := &context{
		inputFile: inputFile,
	}

	// package name
	inputFileName := filepath.Base(inputFile)
	ctx.moduleName = inputFileName[:strings.Index(inputFileName, ".")]

	// alter package names for modules that are reserved keywords in Go
	switch ctx.moduleName {
	case "interface":
		ctx.packageName = "interfaces"
	case "map":
		ctx.packageName = "maps"
	default:
		ctx.packageName = ctx.moduleName
	}

	// output file
	packageDir := filepath.Join(outputDir, ctx.packageName)
	outputFileName := ctx.packageName + outputFileExt
	ctx.outputFile = filepath.Join(packageDir, outputFileName)

	return ctx, nil
}

func generatePackage(ctx *context, w io.Writer) error {
	logf("generating package %q", ctx.packageName)

	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)

	// 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)

	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)
	}
	fmt.Fprintln(w, ")")
	fmt.Fprintln(w)

	// generate enums
	if len(ctx.packageData.Enums) > 0 {
		for _, enum := range ctx.packageData.Enums {
			generateEnum(ctx, w, &enum)
		}
	}

	// generate aliases
	if len(ctx.packageData.Aliases) > 0 {
		for _, alias := range ctx.packageData.Aliases {
			generateAlias(ctx, w, &alias)
		}
	}

	// generate types
	if len(ctx.packageData.Types) > 0 {
		for _, typ := range ctx.packageData.Types {
			generateType(ctx, w, &typ)
		}
	}

	// generate unions
	if len(ctx.packageData.Unions) > 0 {
		for _, union := range ctx.packageData.Unions {
			generateUnion(ctx, w, &union)
		}
	}

	// generate messages
	if len(ctx.packageData.Messages) > 0 {
		for _, msg := range ctx.packageData.Messages {
			generateMessage(ctx, w, &msg)
		}

		// 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, "}")
	}

	if ctx.includeServices {
		// generate services
		if len(ctx.packageData.Services) > 0 {
			generateServices(ctx, w, ctx.packageData.Services)
		}
	}

	generateFooter(ctx, w)

	return nil
}

func generateHeader(ctx *context, w io.Writer) {
	fmt.Fprintln(w, "/*")
	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 consists of:")
	printObjNum := func(obj string, num int) {
		if num > 0 {
			if num > 1 {
				if strings.HasSuffix(obj, "s") {

					obj += "es"
				} else {
					obj += "s"
				}
			}
			fmt.Fprintf(w, "\t%3d %s\n", num, obj)
		}
	}
	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.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")
	fmt.Fprintln(w, ")")
	fmt.Fprintln(w)
}

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 _ = bytes.NewBuffer\n")
	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")
}

func generateComment(ctx *context, w io.Writer, goName string, vppName string, objKind string) {
	if objKind == "service" {
		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)
	}

	if !ctx.includeComments {
		return
	}

	var isNotSpace = func(r rune) bool {
		return !unicode.IsSpace(r)
	}

	// print out the source of the generated object
	mapType := false
	objFound := false
	objTitle := fmt.Sprintf(`"%s",`, vppName)
	switch objKind {
	case "alias", "service":
		objTitle = fmt.Sprintf(`"%s": {`, vppName)
		mapType = true
	}

	inputBuff := bytes.NewBuffer(ctx.inputData)
	inputLine := 0

	var trimIndent string
	var indent int
	for {
		line, err := inputBuff.ReadString('\n')
		if err != nil {
			break
		}
		inputLine++

		noSpaceAt := strings.IndexFunc(line, isNotSpace)
		if !objFound {
			indent = strings.Index(line, objTitle)
			if indent == -1 {
				continue
			}
			trimIndent = line[:indent]
			// If no other non-whitespace character then we are at the message header.
			if trimmed := strings.TrimSpace(line); trimmed == objTitle {
				objFound = true
				fmt.Fprintln(w, "//")
			}
		} else if noSpaceAt < indent {
			break // end of the definition in JSON for array types
		} else if objFound && mapType && noSpaceAt <= indent {
			fmt.Fprintf(w, "//\t%s", strings.TrimPrefix(line, trimIndent))
			break // end of the definition in JSON for map types (aliases, services)
		}
		fmt.Fprintf(w, "//\t%s", strings.TrimPrefix(line, trimIndent))
	}

	fmt.Fprintln(w, "//")
}

func generateEnum(ctx *context, w io.Writer, enum *Enum) {
	name := camelCaseName(enum.Name)
	typ := binapiTypes[enum.Type]

	logf(" writing enum %q (%s) with %d entries", enum.Name, name, len(enum.Entries))

	// generate enum comment
	generateComment(ctx, w, name, enum.Name, "enum")

	// generate enum definition
	fmt.Fprintf(w, "type %s %s\n", name, typ)
	fmt.Fprintln(w)

	// 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 generateAlias(ctx *context, w io.Writer, alias *Alias) {
	name := camelCaseName(alias.Name)

	logf(" writing type %q (%s), length: %d", alias.Name, name, alias.Length)

	// generate struct comment
	generateComment(ctx, w, name, alias.Name, "alias")

	// generate struct definition
	fmt.Fprintf(w, "type %s ", name)

	if alias.Length > 0 {
		fmt.Fprintf(w, "[%d]", alias.Length)
	}

	dataType := convertToGoType(ctx, alias.Type)
	fmt.Fprintf(w, "%s\n", dataType)

	fmt.Fprintln(w)
}

func generateUnion(ctx *context, w io.Writer, union *Union) {
	name := camelCaseName(union.Name)

	logf(" writing union %q (%s) with %d fields", union.Name, name, len(union.Fields))

	// generate struct comment
	generateComment(ctx, w, name, union.Name, "union")

	// generate struct definition
	fmt.Fprintln(w, "type", name, "struct {")

	// maximum size for union
	maxSize := getUnionSize(ctx, union)

	// generate data field
	fmt.Fprintf(w, "\t%s [%d]byte\n", unionDataField, maxSize)

	// generate end of the struct
	fmt.Fprintln(w, "}")

	// generate name getter
	generateTypeNameGetter(w, name, union.Name)

	// generate CRC getter
	if union.CRC != "" {
		generateCrcGetter(w, name, union.CRC)
	}

	// generate getters for fields
	for _, field := range union.Fields {
		fieldName := camelCaseName(field.Name)
		fieldType := convertToGoType(ctx, field.Type)
		generateUnionGetterSetter(w, name, fieldName, fieldType)
	}

	// generate union methods
	//generateUnionMethods(w, name)

	fmt.Fprintln(w)
}

// generateUnionMethods generates methods that implement struc.Custom
// 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) {
	// generate struc.Custom implementation for union
	fmt.Fprintf(w, `
func (u *%[1]s) Pack(p []byte, opt *struc.Options) (int, error) {
	var b = new(bytes.Buffer)
	if err := struc.PackWithOptions(b, u.union_data, opt); err != nil {
		return 0, err
	}
	copy(p, b.Bytes())
	return b.Len(), nil
}
func (u *%[1]s) Unpack(r io.Reader, length int, opt *struc.Options) error {
	return struc.UnpackWithOptions(r, u.union_data[:], opt)
}
func (u *%[1]s) Size(opt *struc.Options) int {
	return len(u.union_data)
}
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.%[4]s[:], b.Bytes())
}
func (u *%[1]s) Get%[2]s() (a %[3]s) {
	var b = bytes.NewReader(u.%[4]s[:])
	struc.Unpack(b, &a)
	return
}
`, 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)
}

func generateMessage(ctx *context, w io.Writer, msg *Message) {
	name := camelCaseName(msg.Name)

	logf(" writing message %q (%s) with %d fields", msg.Name, name, len(msg.Fields))

	// generate struct comment
	generateComment(ctx, w, name, msg.Name, "message")

	// generate struct definition
	fmt.Fprintf(w, "type %s struct {", name)

	msgType := otherMessage
	wasClientIndex := false

	// generate struct fields
	n := 0
	for i, field := range msg.Fields {
		if i == 1 {
			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 == contextField {
				// reply needs "context" as the second member
				msgType = replyMessage
			}
		} else if i == 2 {
			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 crcField, msgIdField:
			continue
		case clientIndexField, contextField:
			if n == 0 {
				continue
			}
		}
		n++
		if n == 1 {
			fmt.Fprintln(w)
		}

		generateField(ctx, w, msg.Fields, i)
	}

	// generate end of the struct
	fmt.Fprintln(w, "}")

	// generate name getter
	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)
}

func generateField(ctx *context, w io.Writer, fields []Field, i int) {
	field := fields[i]

	fieldName := strings.TrimPrefix(field.Name, "_")
	fieldName = camelCaseName(fieldName)

	// generate length field for strings
	if field.Type == "string" {
		fmt.Fprintf(w, "\tXXX_%sLen uint32 `struc:\"sizeof=%s\"`\n", fieldName, fieldName)
	}

	dataType := convertToGoType(ctx, field.Type)
	fieldType := dataType

	// check if it is array
	if field.Length > 0 || field.SizeFrom != "" {
		if dataType == "uint8" {
			dataType = "byte"
		}
		fieldType = "[]" + dataType
	}
	fmt.Fprintf(w, "\t%s %s", fieldName, fieldType)

	fieldTags := map[string]string{}

	if field.Length > 0 {
		// fixed size array
		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)
				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)
}

func generateMessageNameGetter(w io.Writer, structName, msgName string) {
	fmt.Fprintf(w, `func (*%s) GetMessageName() string {
	return %q
}
`, structName, msgName)
}

func generateTypeNameGetter(w io.Writer, structName, msgName string) {
	fmt.Fprintf(w, `func (*%s) GetTypeName() string {
	return %q
}
`, structName, msgName)
}

func generateCrcGetter(w io.Writer, structName, crc string) {
	crc = strings.TrimPrefix(crc, "0x")
	fmt.Fprintf(w, `func (*%s) GetCrcString() string {
	return %q
}
`, structName, crc)
}

func generateMessageTypeGetter(w io.Writer, structName string, msgType MessageType) {
	fmt.Fprintln(w, "func (*"+structName+") GetMessageType() api.MessageType {")
	if msgType == requestMessage {
		fmt.Fprintln(w, "\treturn api.RequestMessage")
	} else if msgType == replyMessage {
		fmt.Fprintln(w, "\treturn api.ReplyMessage")
	} else if msgType == eventMessage {
		fmt.Fprintln(w, "\treturn api.EventMessage")
	} else {
		fmt.Fprintln(w, "\treturn api.OtherMessage")
	}
	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)
}