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 *encWriterSwitch
40	b [8]byte
41	// c containerState
42	encDriverTrackContainerWriter
43	// encDriverNoopContainerWriter
44	_ [3]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
160// func (e *simpleEncDriver) EncodeSymbol(v string) {
161// 	e.EncodeStringEnc(cUTF8, v)
162// }
163
164func (e *simpleEncDriver) EncodeStringEnc(c charEncoding, v string) {
165	if false && e.h.EncZeroValuesAsNil && e.c != containerMapKey && v == "" {
166		e.EncodeNil()
167		return
168	}
169	e.encLen(simpleVdString, len(v))
170	e.w.writestr(v)
171}
172
173func (e *simpleEncDriver) EncodeString(c charEncoding, v string) {
174	e.EncodeStringEnc(c, v)
175}
176
177func (e *simpleEncDriver) EncodeStringBytes(c charEncoding, v []byte) {
178	e.EncodeStringBytesRaw(v)
179}
180
181func (e *simpleEncDriver) EncodeStringBytesRaw(v []byte) {
182	// if e.h.EncZeroValuesAsNil && e.c != containerMapKey && v == nil {
183	if v == nil {
184		e.EncodeNil()
185		return
186	}
187	e.encLen(simpleVdByteArray, len(v))
188	e.w.writeb(v)
189}
190
191func (e *simpleEncDriver) EncodeTime(t time.Time) {
192	// if e.h.EncZeroValuesAsNil && e.c != containerMapKey && t.IsZero() {
193	if t.IsZero() {
194		e.EncodeNil()
195		return
196	}
197	v, err := t.MarshalBinary()
198	if err != nil {
199		e.e.errorv(err)
200		return
201	}
202	// time.Time marshalbinary takes about 14 bytes.
203	e.w.writen2(simpleVdTime, uint8(len(v)))
204	e.w.writeb(v)
205}
206
207//------------------------------------
208
209type simpleDecDriver struct {
210	d      *Decoder
211	h      *SimpleHandle
212	r      *decReaderSwitch
213	bdRead bool
214	bd     byte
215	br     bool // a bytes reader?
216	c      containerState
217	// b      [scratchByteArrayLen]byte
218	noBuiltInTypes
219	// noStreamingCodec
220	decDriverNoopContainerReader
221	// _ [3]uint64 // padding
222}
223
224func (d *simpleDecDriver) readNextBd() {
225	d.bd = d.r.readn1()
226	d.bdRead = true
227}
228
229func (d *simpleDecDriver) uncacheRead() {
230	if d.bdRead {
231		d.r.unreadn1()
232		d.bdRead = false
233	}
234}
235
236func (d *simpleDecDriver) ContainerType() (vt valueType) {
237	if !d.bdRead {
238		d.readNextBd()
239	}
240	switch d.bd {
241	case simpleVdNil:
242		return valueTypeNil
243	case simpleVdByteArray, simpleVdByteArray + 1,
244		simpleVdByteArray + 2, simpleVdByteArray + 3, simpleVdByteArray + 4:
245		return valueTypeBytes
246	case simpleVdString, simpleVdString + 1,
247		simpleVdString + 2, simpleVdString + 3, simpleVdString + 4:
248		return valueTypeString
249	case simpleVdArray, simpleVdArray + 1,
250		simpleVdArray + 2, simpleVdArray + 3, simpleVdArray + 4:
251		return valueTypeArray
252	case simpleVdMap, simpleVdMap + 1,
253		simpleVdMap + 2, simpleVdMap + 3, simpleVdMap + 4:
254		return valueTypeMap
255		// case simpleVdTime:
256		// 	return valueTypeTime
257	}
258	// else {
259	// d.d.errorf("isContainerType: unsupported parameter: %v", vt)
260	// }
261	return valueTypeUnset
262}
263
264func (d *simpleDecDriver) TryDecodeAsNil() bool {
265	if !d.bdRead {
266		d.readNextBd()
267	}
268	if d.bd == simpleVdNil {
269		d.bdRead = false
270		return true
271	}
272	return false
273}
274
275func (d *simpleDecDriver) decCheckInteger() (ui uint64, neg bool) {
276	if !d.bdRead {
277		d.readNextBd()
278	}
279	switch d.bd {
280	case simpleVdPosInt:
281		ui = uint64(d.r.readn1())
282	case simpleVdPosInt + 1:
283		ui = uint64(bigen.Uint16(d.r.readx(2)))
284	case simpleVdPosInt + 2:
285		ui = uint64(bigen.Uint32(d.r.readx(4)))
286	case simpleVdPosInt + 3:
287		ui = uint64(bigen.Uint64(d.r.readx(8)))
288	case simpleVdNegInt:
289		ui = uint64(d.r.readn1())
290		neg = true
291	case simpleVdNegInt + 1:
292		ui = uint64(bigen.Uint16(d.r.readx(2)))
293		neg = true
294	case simpleVdNegInt + 2:
295		ui = uint64(bigen.Uint32(d.r.readx(4)))
296		neg = true
297	case simpleVdNegInt + 3:
298		ui = uint64(bigen.Uint64(d.r.readx(8)))
299		neg = true
300	default:
301		d.d.errorf("integer only valid from pos/neg integer1..8. Invalid descriptor: %v", d.bd)
302		return
303	}
304	// don't do this check, because callers may only want the unsigned value.
305	// if ui > math.MaxInt64 {
306	// 	d.d.errorf("decIntAny: Integer out of range for signed int64: %v", ui)
307	//		return
308	// }
309	return
310}
311
312func (d *simpleDecDriver) DecodeInt64() (i int64) {
313	ui, neg := d.decCheckInteger()
314	i = chkOvf.SignedIntV(ui)
315	if neg {
316		i = -i
317	}
318	d.bdRead = false
319	return
320}
321
322func (d *simpleDecDriver) DecodeUint64() (ui uint64) {
323	ui, neg := d.decCheckInteger()
324	if neg {
325		d.d.errorf("assigning negative signed value to unsigned type")
326		return
327	}
328	d.bdRead = false
329	return
330}
331
332func (d *simpleDecDriver) DecodeFloat64() (f float64) {
333	if !d.bdRead {
334		d.readNextBd()
335	}
336	if d.bd == simpleVdFloat32 {
337		f = float64(math.Float32frombits(bigen.Uint32(d.r.readx(4))))
338	} else if d.bd == simpleVdFloat64 {
339		f = math.Float64frombits(bigen.Uint64(d.r.readx(8)))
340	} else {
341		if d.bd >= simpleVdPosInt && d.bd <= simpleVdNegInt+3 {
342			f = float64(d.DecodeInt64())
343		} else {
344			d.d.errorf("float only valid from float32/64: Invalid descriptor: %v", d.bd)
345			return
346		}
347	}
348	d.bdRead = false
349	return
350}
351
352// bool can be decoded from bool only (single byte).
353func (d *simpleDecDriver) DecodeBool() (b bool) {
354	if !d.bdRead {
355		d.readNextBd()
356	}
357	if d.bd == simpleVdTrue {
358		b = true
359	} else if d.bd == simpleVdFalse {
360	} else {
361		d.d.errorf("cannot decode bool - %s: %x", msgBadDesc, d.bd)
362		return
363	}
364	d.bdRead = false
365	return
366}
367
368func (d *simpleDecDriver) ReadMapStart() (length int) {
369	if !d.bdRead {
370		d.readNextBd()
371	}
372	d.bdRead = false
373	d.c = containerMapStart
374	return d.decLen()
375}
376
377func (d *simpleDecDriver) ReadArrayStart() (length int) {
378	if !d.bdRead {
379		d.readNextBd()
380	}
381	d.bdRead = false
382	d.c = containerArrayStart
383	return d.decLen()
384}
385
386func (d *simpleDecDriver) ReadArrayElem() {
387	d.c = containerArrayElem
388}
389
390func (d *simpleDecDriver) ReadArrayEnd() {
391	d.c = containerArrayEnd
392}
393
394func (d *simpleDecDriver) ReadMapElemKey() {
395	d.c = containerMapKey
396}
397
398func (d *simpleDecDriver) ReadMapElemValue() {
399	d.c = containerMapValue
400}
401
402func (d *simpleDecDriver) ReadMapEnd() {
403	d.c = containerMapEnd
404}
405
406func (d *simpleDecDriver) decLen() int {
407	switch d.bd % 8 {
408	case 0:
409		return 0
410	case 1:
411		return int(d.r.readn1())
412	case 2:
413		return int(bigen.Uint16(d.r.readx(2)))
414	case 3:
415		ui := uint64(bigen.Uint32(d.r.readx(4)))
416		if chkOvf.Uint(ui, intBitsize) {
417			d.d.errorf("overflow integer: %v", ui)
418			return 0
419		}
420		return int(ui)
421	case 4:
422		ui := bigen.Uint64(d.r.readx(8))
423		if chkOvf.Uint(ui, intBitsize) {
424			d.d.errorf("overflow integer: %v", ui)
425			return 0
426		}
427		return int(ui)
428	}
429	d.d.errorf("cannot read length: bd%%8 must be in range 0..4. Got: %d", d.bd%8)
430	return -1
431}
432
433func (d *simpleDecDriver) DecodeString() (s string) {
434	return string(d.DecodeBytes(d.d.b[:], true))
435}
436
437func (d *simpleDecDriver) DecodeStringAsBytes() (s []byte) {
438	return d.DecodeBytes(d.d.b[:], true)
439}
440
441func (d *simpleDecDriver) DecodeBytes(bs []byte, zerocopy bool) (bsOut []byte) {
442	if !d.bdRead {
443		d.readNextBd()
444	}
445	if d.bd == simpleVdNil {
446		d.bdRead = false
447		return
448	}
449	// check if an "array" of uint8's (see ContainerType for how to infer if an array)
450	if d.bd >= simpleVdArray && d.bd <= simpleVdMap+4 {
451		if len(bs) == 0 && zerocopy {
452			bs = d.d.b[:]
453		}
454		bsOut, _ = fastpathTV.DecSliceUint8V(bs, true, d.d)
455		return
456	}
457
458	clen := d.decLen()
459	d.bdRead = false
460	if zerocopy {
461		if d.br {
462			return d.r.readx(uint(clen))
463		} else if len(bs) == 0 {
464			bs = d.d.b[:]
465		}
466	}
467	return decByteSlice(d.r, clen, d.d.h.MaxInitLen, bs)
468}
469
470func (d *simpleDecDriver) DecodeTime() (t time.Time) {
471	if !d.bdRead {
472		d.readNextBd()
473	}
474	if d.bd == simpleVdNil {
475		d.bdRead = false
476		return
477	}
478	if d.bd != simpleVdTime {
479		d.d.errorf("invalid descriptor for time.Time - expect 0x%x, received 0x%x", simpleVdTime, d.bd)
480		return
481	}
482	d.bdRead = false
483	clen := int(d.r.readn1())
484	b := d.r.readx(uint(clen))
485	if err := (&t).UnmarshalBinary(b); err != nil {
486		d.d.errorv(err)
487	}
488	return
489}
490
491func (d *simpleDecDriver) DecodeExt(rv interface{}, xtag uint64, ext Ext) (realxtag uint64) {
492	if xtag > 0xff {
493		d.d.errorf("ext: tag must be <= 0xff; got: %v", xtag)
494		return
495	}
496	realxtag1, xbs := d.decodeExtV(ext != nil, uint8(xtag))
497	realxtag = uint64(realxtag1)
498	if ext == nil {
499		re := rv.(*RawExt)
500		re.Tag = realxtag
501		re.Data = detachZeroCopyBytes(d.br, re.Data, xbs)
502	} else {
503		ext.ReadExt(rv, xbs)
504	}
505	return
506}
507
508func (d *simpleDecDriver) decodeExtV(verifyTag bool, tag byte) (xtag byte, xbs []byte) {
509	if !d.bdRead {
510		d.readNextBd()
511	}
512	switch d.bd {
513	case simpleVdExt, simpleVdExt + 1, simpleVdExt + 2, simpleVdExt + 3, simpleVdExt + 4:
514		l := d.decLen()
515		xtag = d.r.readn1()
516		if verifyTag && xtag != tag {
517			d.d.errorf("wrong extension tag. Got %b. Expecting: %v", xtag, tag)
518			return
519		}
520		if d.br {
521			xbs = d.r.readx(uint(l))
522		} else {
523			xbs = decByteSlice(d.r, l, d.d.h.MaxInitLen, d.d.b[:])
524		}
525	case simpleVdByteArray, simpleVdByteArray + 1,
526		simpleVdByteArray + 2, simpleVdByteArray + 3, simpleVdByteArray + 4:
527		xbs = d.DecodeBytes(nil, true)
528	default:
529		d.d.errorf("ext - %s - expecting extensions/bytearray, got: 0x%x", msgBadDesc, d.bd)
530		return
531	}
532	d.bdRead = false
533	return
534}
535
536func (d *simpleDecDriver) DecodeNaked() {
537	if !d.bdRead {
538		d.readNextBd()
539	}
540
541	n := d.d.naked()
542	var decodeFurther bool
543
544	switch d.bd {
545	case simpleVdNil:
546		n.v = valueTypeNil
547	case simpleVdFalse:
548		n.v = valueTypeBool
549		n.b = false
550	case simpleVdTrue:
551		n.v = valueTypeBool
552		n.b = true
553	case simpleVdPosInt, simpleVdPosInt + 1, simpleVdPosInt + 2, simpleVdPosInt + 3:
554		if d.h.SignedInteger {
555			n.v = valueTypeInt
556			n.i = d.DecodeInt64()
557		} else {
558			n.v = valueTypeUint
559			n.u = d.DecodeUint64()
560		}
561	case simpleVdNegInt, simpleVdNegInt + 1, simpleVdNegInt + 2, simpleVdNegInt + 3:
562		n.v = valueTypeInt
563		n.i = d.DecodeInt64()
564	case simpleVdFloat32:
565		n.v = valueTypeFloat
566		n.f = d.DecodeFloat64()
567	case simpleVdFloat64:
568		n.v = valueTypeFloat
569		n.f = d.DecodeFloat64()
570	case simpleVdTime:
571		n.v = valueTypeTime
572		n.t = d.DecodeTime()
573	case simpleVdString, simpleVdString + 1,
574		simpleVdString + 2, simpleVdString + 3, simpleVdString + 4:
575		n.v = valueTypeString
576		n.s = d.DecodeString()
577	case simpleVdByteArray, simpleVdByteArray + 1,
578		simpleVdByteArray + 2, simpleVdByteArray + 3, simpleVdByteArray + 4:
579		decNakedReadRawBytes(d, d.d, n, d.h.RawToString)
580	case simpleVdExt, simpleVdExt + 1, simpleVdExt + 2, simpleVdExt + 3, simpleVdExt + 4:
581		n.v = valueTypeExt
582		l := d.decLen()
583		n.u = uint64(d.r.readn1())
584		if d.br {
585			n.l = d.r.readx(uint(l))
586		} else {
587			n.l = decByteSlice(d.r, l, d.d.h.MaxInitLen, d.d.b[:])
588		}
589	case simpleVdArray, simpleVdArray + 1, simpleVdArray + 2,
590		simpleVdArray + 3, simpleVdArray + 4:
591		n.v = valueTypeArray
592		decodeFurther = true
593	case simpleVdMap, simpleVdMap + 1, simpleVdMap + 2, simpleVdMap + 3, simpleVdMap + 4:
594		n.v = valueTypeMap
595		decodeFurther = true
596	default:
597		d.d.errorf("cannot infer value - %s 0x%x", msgBadDesc, d.bd)
598	}
599
600	if !decodeFurther {
601		d.bdRead = false
602	}
603}
604
605//------------------------------------
606
607// SimpleHandle is a Handle for a very simple encoding format.
608//
609// simple is a simplistic codec similar to binc, but not as compact.
610//   - Encoding of a value is always preceded by the descriptor byte (bd)
611//   - True, false, nil are encoded fully in 1 byte (the descriptor)
612//   - Integers (intXXX, uintXXX) are encoded in 1, 2, 4 or 8 bytes (plus a descriptor byte).
613//     There are positive (uintXXX and intXXX >= 0) and negative (intXXX < 0) integers.
614//   - Floats are encoded in 4 or 8 bytes (plus a descriptor byte)
615//   - Length of containers (strings, bytes, array, map, extensions)
616//     are encoded in 0, 1, 2, 4 or 8 bytes.
617//     Zero-length containers have no length encoded.
618//     For others, the number of bytes is given by pow(2, bd%3)
619//   - maps are encoded as [bd] [length] [[key][value]]...
620//   - arrays are encoded as [bd] [length] [value]...
621//   - extensions are encoded as [bd] [length] [tag] [byte]...
622//   - strings/bytearrays are encoded as [bd] [length] [byte]...
623//   - time.Time are encoded as [bd] [length] [byte]...
624//
625// The full spec will be published soon.
626type SimpleHandle struct {
627	BasicHandle
628	binaryEncodingType
629	noElemSeparators
630	// EncZeroValuesAsNil says to encode zero values for numbers, bool, string, etc as nil
631	EncZeroValuesAsNil bool
632
633	// _ [1]uint64 // padding
634}
635
636// Name returns the name of the handle: simple
637func (h *SimpleHandle) Name() string { return "simple" }
638
639// SetBytesExt sets an extension
640func (h *SimpleHandle) SetBytesExt(rt reflect.Type, tag uint64, ext BytesExt) (err error) {
641	return h.SetExt(rt, tag, &extWrapper{ext, interfaceExtFailer{}})
642}
643
644func (h *SimpleHandle) hasElemSeparators() bool { return true } // as it implements Write(Map|Array)XXX
645
646func (h *SimpleHandle) newEncDriver(e *Encoder) encDriver {
647	return &simpleEncDriver{e: e, w: e.w, h: h}
648}
649
650func (h *SimpleHandle) newDecDriver(d *Decoder) decDriver {
651	return &simpleDecDriver{d: d, h: h, r: d.r, br: d.bytes}
652}
653
654func (e *simpleEncDriver) reset() {
655	e.c = 0
656	e.w = e.e.w
657}
658
659func (d *simpleDecDriver) reset() {
660	d.c = 0
661	d.r, d.br = d.d.r, d.d.bytes
662	d.bd, d.bdRead = 0, false
663}
664
665var _ decDriver = (*simpleDecDriver)(nil)
666var _ encDriver = (*simpleEncDriver)(nil)
667