1// Copyright (c) 2012-2018 Ugorji Nwoke. All rights reserved.
2// Use of this source code is governed by a MIT license found in the LICENSE file.
3
4package codec
5
6import (
7 "math"
8 "reflect"
9 "time"
10)
11
12const (
13 _ uint8 = iota
14 simpleVdNil = 1
15 simpleVdFalse = 2
16 simpleVdTrue = 3
17 simpleVdFloat32 = 4
18 simpleVdFloat64 = 5
19
20 // each lasts for 4 (ie n, n+1, n+2, n+3)
21 simpleVdPosInt = 8
22 simpleVdNegInt = 12
23
24 simpleVdTime = 24
25
26 // containers: each lasts for 4 (ie n, n+1, n+2, ... n+7)
27 simpleVdString = 216
28 simpleVdByteArray = 224
29 simpleVdArray = 232
30 simpleVdMap = 240
31 simpleVdExt = 248
32)
33
34type simpleEncDriver struct {
35 noBuiltInTypes
36 // encNoSeparator
37 e *Encoder
38 h *SimpleHandle
39 w encWriter
40 b [8]byte
41 // c containerState
42 encDriverTrackContainerWriter
43 // encDriverNoopContainerWriter
44 _ [2]uint64 // padding
45}
46
47func (e *simpleEncDriver) EncodeNil() {
48 e.w.writen1(simpleVdNil)
49}
50
51func (e *simpleEncDriver) EncodeBool(b bool) {
52 if e.h.EncZeroValuesAsNil && e.c != containerMapKey && !b {
53 e.EncodeNil()
54 return
55 }
56 if b {
57 e.w.writen1(simpleVdTrue)
58 } else {
59 e.w.writen1(simpleVdFalse)
60 }
61}
62
63func (e *simpleEncDriver) EncodeFloat32(f float32) {
64 if e.h.EncZeroValuesAsNil && e.c != containerMapKey && f == 0.0 {
65 e.EncodeNil()
66 return
67 }
68 e.w.writen1(simpleVdFloat32)
69 bigenHelper{e.b[:4], e.w}.writeUint32(math.Float32bits(f))
70}
71
72func (e *simpleEncDriver) EncodeFloat64(f float64) {
73 if e.h.EncZeroValuesAsNil && e.c != containerMapKey && f == 0.0 {
74 e.EncodeNil()
75 return
76 }
77 e.w.writen1(simpleVdFloat64)
78 bigenHelper{e.b[:8], e.w}.writeUint64(math.Float64bits(f))
79}
80
81func (e *simpleEncDriver) EncodeInt(v int64) {
82 if v < 0 {
83 e.encUint(uint64(-v), simpleVdNegInt)
84 } else {
85 e.encUint(uint64(v), simpleVdPosInt)
86 }
87}
88
89func (e *simpleEncDriver) EncodeUint(v uint64) {
90 e.encUint(v, simpleVdPosInt)
91}
92
93func (e *simpleEncDriver) encUint(v uint64, bd uint8) {
94 if e.h.EncZeroValuesAsNil && e.c != containerMapKey && v == 0 {
95 e.EncodeNil()
96 return
97 }
98 if v <= math.MaxUint8 {
99 e.w.writen2(bd, uint8(v))
100 } else if v <= math.MaxUint16 {
101 e.w.writen1(bd + 1)
102 bigenHelper{e.b[:2], e.w}.writeUint16(uint16(v))
103 } else if v <= math.MaxUint32 {
104 e.w.writen1(bd + 2)
105 bigenHelper{e.b[:4], e.w}.writeUint32(uint32(v))
106 } else { // if v <= math.MaxUint64 {
107 e.w.writen1(bd + 3)
108 bigenHelper{e.b[:8], e.w}.writeUint64(v)
109 }
110}
111
112func (e *simpleEncDriver) encLen(bd byte, length int) {
113 if length == 0 {
114 e.w.writen1(bd)
115 } else if length <= math.MaxUint8 {
116 e.w.writen1(bd + 1)
117 e.w.writen1(uint8(length))
118 } else if length <= math.MaxUint16 {
119 e.w.writen1(bd + 2)
120 bigenHelper{e.b[:2], e.w}.writeUint16(uint16(length))
121 } else if int64(length) <= math.MaxUint32 {
122 e.w.writen1(bd + 3)
123 bigenHelper{e.b[:4], e.w}.writeUint32(uint32(length))
124 } else {
125 e.w.writen1(bd + 4)
126 bigenHelper{e.b[:8], e.w}.writeUint64(uint64(length))
127 }
128}
129
130func (e *simpleEncDriver) EncodeExt(rv interface{}, xtag uint64, ext Ext, _ *Encoder) {
131 bs := ext.WriteExt(rv)
132 if bs == nil {
133 e.EncodeNil()
134 return
135 }
136 e.encodeExtPreamble(uint8(xtag), len(bs))
137 e.w.writeb(bs)
138}
139
140func (e *simpleEncDriver) EncodeRawExt(re *RawExt, _ *Encoder) {
141 e.encodeExtPreamble(uint8(re.Tag), len(re.Data))
142 e.w.writeb(re.Data)
143}
144
145func (e *simpleEncDriver) encodeExtPreamble(xtag byte, length int) {
146 e.encLen(simpleVdExt, length)
147 e.w.writen1(xtag)
148}
149
150func (e *simpleEncDriver) WriteArrayStart(length int) {
151 e.c = containerArrayStart
152 e.encLen(simpleVdArray, length)
153}
154
155func (e *simpleEncDriver) WriteMapStart(length int) {
156 e.c = containerMapStart
157 e.encLen(simpleVdMap, length)
158}
159
160func (e *simpleEncDriver) EncodeString(c charEncoding, v string) {
161 if false && e.h.EncZeroValuesAsNil && e.c != containerMapKey && v == "" {
162 e.EncodeNil()
163 return
164 }
165 e.encLen(simpleVdString, len(v))
166 e.w.writestr(v)
167}
168
169// func (e *simpleEncDriver) EncodeSymbol(v string) {
170// e.EncodeString(cUTF8, v)
171// }
172
173func (e *simpleEncDriver) EncodeStringBytes(c charEncoding, v []byte) {
174 // if e.h.EncZeroValuesAsNil && e.c != containerMapKey && v == nil {
175 if v == nil {
176 e.EncodeNil()
177 return
178 }
179 e.encLen(simpleVdByteArray, len(v))
180 e.w.writeb(v)
181}
182
183func (e *simpleEncDriver) EncodeTime(t time.Time) {
184 // if e.h.EncZeroValuesAsNil && e.c != containerMapKey && t.IsZero() {
185 if t.IsZero() {
186 e.EncodeNil()
187 return
188 }
189 v, err := t.MarshalBinary()
190 if err != nil {
191 e.e.errorv(err)
192 return
193 }
194 // time.Time marshalbinary takes about 14 bytes.
195 e.w.writen2(simpleVdTime, uint8(len(v)))
196 e.w.writeb(v)
197}
198
199//------------------------------------
200
201type simpleDecDriver struct {
202 d *Decoder
203 h *SimpleHandle
204 r decReader
205 bdRead bool
206 bd byte
207 br bool // a bytes reader?
208 c containerState
209 // b [scratchByteArrayLen]byte
210 noBuiltInTypes
211 // noStreamingCodec
212 decDriverNoopContainerReader
213 _ [3]uint64 // padding
214}
215
216func (d *simpleDecDriver) readNextBd() {
217 d.bd = d.r.readn1()
218 d.bdRead = true
219}
220
221func (d *simpleDecDriver) uncacheRead() {
222 if d.bdRead {
223 d.r.unreadn1()
224 d.bdRead = false
225 }
226}
227
228func (d *simpleDecDriver) ContainerType() (vt valueType) {
229 if !d.bdRead {
230 d.readNextBd()
231 }
232 switch d.bd {
233 case simpleVdNil:
234 return valueTypeNil
235 case simpleVdByteArray, simpleVdByteArray + 1,
236 simpleVdByteArray + 2, simpleVdByteArray + 3, simpleVdByteArray + 4:
237 return valueTypeBytes
238 case simpleVdString, simpleVdString + 1,
239 simpleVdString + 2, simpleVdString + 3, simpleVdString + 4:
240 return valueTypeString
241 case simpleVdArray, simpleVdArray + 1,
242 simpleVdArray + 2, simpleVdArray + 3, simpleVdArray + 4:
243 return valueTypeArray
244 case simpleVdMap, simpleVdMap + 1,
245 simpleVdMap + 2, simpleVdMap + 3, simpleVdMap + 4:
246 return valueTypeMap
247 // case simpleVdTime:
248 // return valueTypeTime
249 }
250 // else {
251 // d.d.errorf("isContainerType: unsupported parameter: %v", vt)
252 // }
253 return valueTypeUnset
254}
255
256func (d *simpleDecDriver) TryDecodeAsNil() bool {
257 if !d.bdRead {
258 d.readNextBd()
259 }
260 if d.bd == simpleVdNil {
261 d.bdRead = false
262 return true
263 }
264 return false
265}
266
267func (d *simpleDecDriver) decCheckInteger() (ui uint64, neg bool) {
268 if !d.bdRead {
269 d.readNextBd()
270 }
271 switch d.bd {
272 case simpleVdPosInt:
273 ui = uint64(d.r.readn1())
274 case simpleVdPosInt + 1:
275 ui = uint64(bigen.Uint16(d.r.readx(2)))
276 case simpleVdPosInt + 2:
277 ui = uint64(bigen.Uint32(d.r.readx(4)))
278 case simpleVdPosInt + 3:
279 ui = uint64(bigen.Uint64(d.r.readx(8)))
280 case simpleVdNegInt:
281 ui = uint64(d.r.readn1())
282 neg = true
283 case simpleVdNegInt + 1:
284 ui = uint64(bigen.Uint16(d.r.readx(2)))
285 neg = true
286 case simpleVdNegInt + 2:
287 ui = uint64(bigen.Uint32(d.r.readx(4)))
288 neg = true
289 case simpleVdNegInt + 3:
290 ui = uint64(bigen.Uint64(d.r.readx(8)))
291 neg = true
292 default:
293 d.d.errorf("integer only valid from pos/neg integer1..8. Invalid descriptor: %v", d.bd)
294 return
295 }
296 // don't do this check, because callers may only want the unsigned value.
297 // if ui > math.MaxInt64 {
298 // d.d.errorf("decIntAny: Integer out of range for signed int64: %v", ui)
299 // return
300 // }
301 return
302}
303
304func (d *simpleDecDriver) DecodeInt64() (i int64) {
305 ui, neg := d.decCheckInteger()
306 i = chkOvf.SignedIntV(ui)
307 if neg {
308 i = -i
309 }
310 d.bdRead = false
311 return
312}
313
314func (d *simpleDecDriver) DecodeUint64() (ui uint64) {
315 ui, neg := d.decCheckInteger()
316 if neg {
317 d.d.errorf("assigning negative signed value to unsigned type")
318 return
319 }
320 d.bdRead = false
321 return
322}
323
324func (d *simpleDecDriver) DecodeFloat64() (f float64) {
325 if !d.bdRead {
326 d.readNextBd()
327 }
328 if d.bd == simpleVdFloat32 {
329 f = float64(math.Float32frombits(bigen.Uint32(d.r.readx(4))))
330 } else if d.bd == simpleVdFloat64 {
331 f = math.Float64frombits(bigen.Uint64(d.r.readx(8)))
332 } else {
333 if d.bd >= simpleVdPosInt && d.bd <= simpleVdNegInt+3 {
334 f = float64(d.DecodeInt64())
335 } else {
336 d.d.errorf("float only valid from float32/64: Invalid descriptor: %v", d.bd)
337 return
338 }
339 }
340 d.bdRead = false
341 return
342}
343
344// bool can be decoded from bool only (single byte).
345func (d *simpleDecDriver) DecodeBool() (b bool) {
346 if !d.bdRead {
347 d.readNextBd()
348 }
349 if d.bd == simpleVdTrue {
350 b = true
351 } else if d.bd == simpleVdFalse {
352 } else {
353 d.d.errorf("cannot decode bool - %s: %x", msgBadDesc, d.bd)
354 return
355 }
356 d.bdRead = false
357 return
358}
359
360func (d *simpleDecDriver) ReadMapStart() (length int) {
361 if !d.bdRead {
362 d.readNextBd()
363 }
364 d.bdRead = false
365 d.c = containerMapStart
366 return d.decLen()
367}
368
369func (d *simpleDecDriver) ReadArrayStart() (length int) {
370 if !d.bdRead {
371 d.readNextBd()
372 }
373 d.bdRead = false
374 d.c = containerArrayStart
375 return d.decLen()
376}
377
378func (d *simpleDecDriver) ReadArrayElem() {
379 d.c = containerArrayElem
380}
381
382func (d *simpleDecDriver) ReadArrayEnd() {
383 d.c = containerArrayEnd
384}
385
386func (d *simpleDecDriver) ReadMapElemKey() {
387 d.c = containerMapKey
388}
389
390func (d *simpleDecDriver) ReadMapElemValue() {
391 d.c = containerMapValue
392}
393
394func (d *simpleDecDriver) ReadMapEnd() {
395 d.c = containerMapEnd
396}
397
398func (d *simpleDecDriver) decLen() int {
399 switch d.bd % 8 {
400 case 0:
401 return 0
402 case 1:
403 return int(d.r.readn1())
404 case 2:
405 return int(bigen.Uint16(d.r.readx(2)))
406 case 3:
407 ui := uint64(bigen.Uint32(d.r.readx(4)))
408 if chkOvf.Uint(ui, intBitsize) {
409 d.d.errorf("overflow integer: %v", ui)
410 return 0
411 }
412 return int(ui)
413 case 4:
414 ui := bigen.Uint64(d.r.readx(8))
415 if chkOvf.Uint(ui, intBitsize) {
416 d.d.errorf("overflow integer: %v", ui)
417 return 0
418 }
419 return int(ui)
420 }
421 d.d.errorf("cannot read length: bd%%8 must be in range 0..4. Got: %d", d.bd%8)
422 return -1
423}
424
425func (d *simpleDecDriver) DecodeString() (s string) {
426 return string(d.DecodeBytes(d.d.b[:], true))
427}
428
429func (d *simpleDecDriver) DecodeStringAsBytes() (s []byte) {
430 return d.DecodeBytes(d.d.b[:], true)
431}
432
433func (d *simpleDecDriver) DecodeBytes(bs []byte, zerocopy bool) (bsOut []byte) {
434 if !d.bdRead {
435 d.readNextBd()
436 }
437 if d.bd == simpleVdNil {
438 d.bdRead = false
439 return
440 }
441 // check if an "array" of uint8's (see ContainerType for how to infer if an array)
442 if d.bd >= simpleVdArray && d.bd <= simpleVdMap+4 {
443 if len(bs) == 0 && zerocopy {
444 bs = d.d.b[:]
445 }
446 bsOut, _ = fastpathTV.DecSliceUint8V(bs, true, d.d)
447 return
448 }
449
450 clen := d.decLen()
451 d.bdRead = false
452 if zerocopy {
453 if d.br {
454 return d.r.readx(clen)
455 } else if len(bs) == 0 {
456 bs = d.d.b[:]
457 }
458 }
459 return decByteSlice(d.r, clen, d.d.h.MaxInitLen, bs)
460}
461
462func (d *simpleDecDriver) DecodeTime() (t time.Time) {
463 if !d.bdRead {
464 d.readNextBd()
465 }
466 if d.bd == simpleVdNil {
467 d.bdRead = false
468 return
469 }
470 if d.bd != simpleVdTime {
471 d.d.errorf("invalid descriptor for time.Time - expect 0x%x, received 0x%x", simpleVdTime, d.bd)
472 return
473 }
474 d.bdRead = false
475 clen := int(d.r.readn1())
476 b := d.r.readx(clen)
477 if err := (&t).UnmarshalBinary(b); err != nil {
478 d.d.errorv(err)
479 }
480 return
481}
482
483func (d *simpleDecDriver) DecodeExt(rv interface{}, xtag uint64, ext Ext) (realxtag uint64) {
484 if xtag > 0xff {
485 d.d.errorf("ext: tag must be <= 0xff; got: %v", xtag)
486 return
487 }
488 realxtag1, xbs := d.decodeExtV(ext != nil, uint8(xtag))
489 realxtag = uint64(realxtag1)
490 if ext == nil {
491 re := rv.(*RawExt)
492 re.Tag = realxtag
493 re.Data = detachZeroCopyBytes(d.br, re.Data, xbs)
494 } else {
495 ext.ReadExt(rv, xbs)
496 }
497 return
498}
499
500func (d *simpleDecDriver) decodeExtV(verifyTag bool, tag byte) (xtag byte, xbs []byte) {
501 if !d.bdRead {
502 d.readNextBd()
503 }
504 switch d.bd {
505 case simpleVdExt, simpleVdExt + 1, simpleVdExt + 2, simpleVdExt + 3, simpleVdExt + 4:
506 l := d.decLen()
507 xtag = d.r.readn1()
508 if verifyTag && xtag != tag {
509 d.d.errorf("wrong extension tag. Got %b. Expecting: %v", xtag, tag)
510 return
511 }
512 xbs = d.r.readx(l)
513 case simpleVdByteArray, simpleVdByteArray + 1,
514 simpleVdByteArray + 2, simpleVdByteArray + 3, simpleVdByteArray + 4:
515 xbs = d.DecodeBytes(nil, true)
516 default:
517 d.d.errorf("ext - %s - expecting extensions/bytearray, got: 0x%x", msgBadDesc, d.bd)
518 return
519 }
520 d.bdRead = false
521 return
522}
523
524func (d *simpleDecDriver) DecodeNaked() {
525 if !d.bdRead {
526 d.readNextBd()
527 }
528
529 n := d.d.n
530 var decodeFurther bool
531
532 switch d.bd {
533 case simpleVdNil:
534 n.v = valueTypeNil
535 case simpleVdFalse:
536 n.v = valueTypeBool
537 n.b = false
538 case simpleVdTrue:
539 n.v = valueTypeBool
540 n.b = true
541 case simpleVdPosInt, simpleVdPosInt + 1, simpleVdPosInt + 2, simpleVdPosInt + 3:
542 if d.h.SignedInteger {
543 n.v = valueTypeInt
544 n.i = d.DecodeInt64()
545 } else {
546 n.v = valueTypeUint
547 n.u = d.DecodeUint64()
548 }
549 case simpleVdNegInt, simpleVdNegInt + 1, simpleVdNegInt + 2, simpleVdNegInt + 3:
550 n.v = valueTypeInt
551 n.i = d.DecodeInt64()
552 case simpleVdFloat32:
553 n.v = valueTypeFloat
554 n.f = d.DecodeFloat64()
555 case simpleVdFloat64:
556 n.v = valueTypeFloat
557 n.f = d.DecodeFloat64()
558 case simpleVdTime:
559 n.v = valueTypeTime
560 n.t = d.DecodeTime()
561 case simpleVdString, simpleVdString + 1,
562 simpleVdString + 2, simpleVdString + 3, simpleVdString + 4:
563 n.v = valueTypeString
564 n.s = d.DecodeString()
565 case simpleVdByteArray, simpleVdByteArray + 1,
566 simpleVdByteArray + 2, simpleVdByteArray + 3, simpleVdByteArray + 4:
567 n.v = valueTypeBytes
568 n.l = d.DecodeBytes(nil, false)
569 case simpleVdExt, simpleVdExt + 1, simpleVdExt + 2, simpleVdExt + 3, simpleVdExt + 4:
570 n.v = valueTypeExt
571 l := d.decLen()
572 n.u = uint64(d.r.readn1())
573 n.l = d.r.readx(l)
574 case simpleVdArray, simpleVdArray + 1, simpleVdArray + 2,
575 simpleVdArray + 3, simpleVdArray + 4:
576 n.v = valueTypeArray
577 decodeFurther = true
578 case simpleVdMap, simpleVdMap + 1, simpleVdMap + 2, simpleVdMap + 3, simpleVdMap + 4:
579 n.v = valueTypeMap
580 decodeFurther = true
581 default:
582 d.d.errorf("cannot infer value - %s 0x%x", msgBadDesc, d.bd)
583 }
584
585 if !decodeFurther {
586 d.bdRead = false
587 }
588 return
589}
590
591//------------------------------------
592
593// SimpleHandle is a Handle for a very simple encoding format.
594//
595// simple is a simplistic codec similar to binc, but not as compact.
596// - Encoding of a value is always preceded by the descriptor byte (bd)
597// - True, false, nil are encoded fully in 1 byte (the descriptor)
598// - Integers (intXXX, uintXXX) are encoded in 1, 2, 4 or 8 bytes (plus a descriptor byte).
599// There are positive (uintXXX and intXXX >= 0) and negative (intXXX < 0) integers.
600// - Floats are encoded in 4 or 8 bytes (plus a descriptor byte)
601// - Length of containers (strings, bytes, array, map, extensions)
602// are encoded in 0, 1, 2, 4 or 8 bytes.
603// Zero-length containers have no length encoded.
604// For others, the number of bytes is given by pow(2, bd%3)
605// - maps are encoded as [bd] [length] [[key][value]]...
606// - arrays are encoded as [bd] [length] [value]...
607// - extensions are encoded as [bd] [length] [tag] [byte]...
608// - strings/bytearrays are encoded as [bd] [length] [byte]...
609// - time.Time are encoded as [bd] [length] [byte]...
610//
611// The full spec will be published soon.
612type SimpleHandle struct {
613 BasicHandle
614 binaryEncodingType
615 noElemSeparators
616 // EncZeroValuesAsNil says to encode zero values for numbers, bool, string, etc as nil
617 EncZeroValuesAsNil bool
618
619 // _ [1]uint64 // padding
620}
621
622// Name returns the name of the handle: simple
623func (h *SimpleHandle) Name() string { return "simple" }
624
625// SetBytesExt sets an extension
626func (h *SimpleHandle) SetBytesExt(rt reflect.Type, tag uint64, ext BytesExt) (err error) {
627 return h.SetExt(rt, tag, &extWrapper{ext, interfaceExtFailer{}})
628}
629
630func (h *SimpleHandle) hasElemSeparators() bool { return true } // as it implements Write(Map|Array)XXX
631
632func (h *SimpleHandle) newEncDriver(e *Encoder) encDriver {
633 return &simpleEncDriver{e: e, w: e.w, h: h}
634}
635
636func (h *SimpleHandle) newDecDriver(d *Decoder) decDriver {
637 return &simpleDecDriver{d: d, h: h, r: d.r, br: d.bytes}
638}
639
640func (e *simpleEncDriver) reset() {
641 e.c = 0
642 e.w = e.e.w
643}
644
645func (d *simpleDecDriver) reset() {
646 d.c = 0
647 d.r, d.br = d.d.r, d.d.bytes
648 d.bd, d.bdRead = 0, false
649}
650
651var _ decDriver = (*simpleDecDriver)(nil)
652var _ encDriver = (*simpleEncDriver)(nil)