1/*
2******************************************************************************
3*
4*   Copyright (C) 2002-2011, International Business Machines
5*   Corporation and others.  All Rights Reserved.
6*
7******************************************************************************
8*   file name:  bocu1tst.c
9*   encoding:   US-ASCII
10*   tab size:   8 (not used)
11*   indentation:4
12*
13*   created on: 2002may27
14*   created by: Markus W. Scherer
15*
16*   This is the reference implementation of BOCU-1,
17*   the MIME-friendly form of the Binary Ordered Compression for Unicode,
18*   taken directly from ### http://source.icu-project.org/repos/icu/icuhtml/trunk/design/conversion/bocu1/
19*   The files bocu1.h and bocu1.c from the design folder are taken
20*   verbatim (minus copyright and #include) and copied together into this file.
21*   The reference code and some of the reference bocu1tst.c
22*   is modified to run as part of the ICU cintltst
23*   test framework (minus main(), log_ln() etc. instead of printf()).
24*
25*   This reference implementation is used here to verify
26*   the ICU BOCU-1 implementation, which is
27*   adapted for ICU conversion APIs and optimized.
28*   ### links in design doc to here and to ucnvbocu.c
29*/
30
31#include "unicode/utypes.h"
32#include "unicode/ustring.h"
33#include "unicode/ucnv.h"
34#include "cmemory.h"
35#include "cintltst.h"
36
37#define LENGTHOF(array) (sizeof(array)/sizeof((array)[0]))
38
39/* icuhtml/design/conversion/bocu1/bocu1.h ---------------------------------- */
40
41/* BOCU-1 constants and macros ---------------------------------------------- */
42
43/*
44 * BOCU-1 encodes the code points of a Unicode string as
45 * a sequence of byte-encoded differences (slope detection),
46 * preserving lexical order.
47 *
48 * Optimize the difference-taking for runs of Unicode text within
49 * small scripts:
50 *
51 * Most small scripts are allocated within aligned 128-blocks of Unicode
52 * code points. Lexical order is preserved if the "previous code point" state
53 * is always moved into the middle of such a block.
54 *
55 * Additionally, "prev" is moved from anywhere in the Unihan and Hangul
56 * areas into the middle of those areas.
57 *
58 * C0 control codes and space are encoded with their US-ASCII bytes.
59 * "prev" is reset for C0 controls but not for space.
60 */
61
62/* initial value for "prev": middle of the ASCII range */
63#define BOCU1_ASCII_PREV        0x40
64
65/* bounding byte values for differences */
66#define BOCU1_MIN               0x21
67#define BOCU1_MIDDLE            0x90
68#define BOCU1_MAX_LEAD          0xfe
69
70/* add the L suffix to make computations with BOCU1_MAX_TRAIL work on 16-bit compilers */
71#define BOCU1_MAX_TRAIL         0xffL
72#define BOCU1_RESET             0xff
73
74/* number of lead bytes */
75#define BOCU1_COUNT             (BOCU1_MAX_LEAD-BOCU1_MIN+1)
76
77/* adjust trail byte counts for the use of some C0 control byte values */
78#define BOCU1_TRAIL_CONTROLS_COUNT  20
79#define BOCU1_TRAIL_BYTE_OFFSET     (BOCU1_MIN-BOCU1_TRAIL_CONTROLS_COUNT)
80
81/* number of trail bytes */
82#define BOCU1_TRAIL_COUNT       ((BOCU1_MAX_TRAIL-BOCU1_MIN+1)+BOCU1_TRAIL_CONTROLS_COUNT)
83
84/*
85 * number of positive and negative single-byte codes
86 * (counting 0==BOCU1_MIDDLE among the positive ones)
87 */
88#define BOCU1_SINGLE            64
89
90/* number of lead bytes for positive and negative 2/3/4-byte sequences */
91#define BOCU1_LEAD_2            43
92#define BOCU1_LEAD_3            3
93#define BOCU1_LEAD_4            1
94
95/* The difference value range for single-byters. */
96#define BOCU1_REACH_POS_1   (BOCU1_SINGLE-1)
97#define BOCU1_REACH_NEG_1   (-BOCU1_SINGLE)
98
99/* The difference value range for double-byters. */
100#define BOCU1_REACH_POS_2   (BOCU1_REACH_POS_1+BOCU1_LEAD_2*BOCU1_TRAIL_COUNT)
101#define BOCU1_REACH_NEG_2   (BOCU1_REACH_NEG_1-BOCU1_LEAD_2*BOCU1_TRAIL_COUNT)
102
103/* The difference value range for 3-byters. */
104#define BOCU1_REACH_POS_3   \
105    (BOCU1_REACH_POS_2+BOCU1_LEAD_3*BOCU1_TRAIL_COUNT*BOCU1_TRAIL_COUNT)
106
107#define BOCU1_REACH_NEG_3   (BOCU1_REACH_NEG_2-BOCU1_LEAD_3*BOCU1_TRAIL_COUNT*BOCU1_TRAIL_COUNT)
108
109/* The lead byte start values. */
110#define BOCU1_START_POS_2   (BOCU1_MIDDLE+BOCU1_REACH_POS_1+1)
111#define BOCU1_START_POS_3   (BOCU1_START_POS_2+BOCU1_LEAD_2)
112#define BOCU1_START_POS_4   (BOCU1_START_POS_3+BOCU1_LEAD_3)
113     /* ==BOCU1_MAX_LEAD */
114
115#define BOCU1_START_NEG_2   (BOCU1_MIDDLE+BOCU1_REACH_NEG_1)
116#define BOCU1_START_NEG_3   (BOCU1_START_NEG_2-BOCU1_LEAD_2)
117#define BOCU1_START_NEG_4   (BOCU1_START_NEG_3-BOCU1_LEAD_3)
118     /* ==BOCU1_MIN+1 */
119
120/* The length of a byte sequence, according to the lead byte (!=BOCU1_RESET). */
121#define BOCU1_LENGTH_FROM_LEAD(lead) \
122    ((BOCU1_START_NEG_2<=(lead) && (lead)<BOCU1_START_POS_2) ? 1 : \
123     (BOCU1_START_NEG_3<=(lead) && (lead)<BOCU1_START_POS_3) ? 2 : \
124     (BOCU1_START_NEG_4<=(lead) && (lead)<BOCU1_START_POS_4) ? 3 : 4)
125
126/* The length of a byte sequence, according to its packed form. */
127#define BOCU1_LENGTH_FROM_PACKED(packed) \
128    ((uint32_t)(packed)<0x04000000 ? (packed)>>24 : 4)
129
130/*
131 * 12 commonly used C0 control codes (and space) are only used to encode
132 * themselves directly,
133 * which makes BOCU-1 MIME-usable and reasonably safe for
134 * ASCII-oriented software.
135 *
136 * These controls are
137 *  0   NUL
138 *
139 *  7   BEL
140 *  8   BS
141 *
142 *  9   TAB
143 *  a   LF
144 *  b   VT
145 *  c   FF
146 *  d   CR
147 *
148 *  e   SO
149 *  f   SI
150 *
151 * 1a   SUB
152 * 1b   ESC
153 *
154 * The other 20 C0 controls are also encoded directly (to preserve order)
155 * but are also used as trail bytes in difference encoding
156 * (for better compression).
157 */
158#define BOCU1_TRAIL_TO_BYTE(t) ((t)>=BOCU1_TRAIL_CONTROLS_COUNT ? (t)+BOCU1_TRAIL_BYTE_OFFSET : bocu1TrailToByte[t])
159
160/*
161 * Byte value map for control codes,
162 * from external byte values 0x00..0x20
163 * to trail byte values 0..19 (0..0x13) as used in the difference calculation.
164 * External byte values that are illegal as trail bytes are mapped to -1.
165 */
166static const int8_t
167bocu1ByteToTrail[BOCU1_MIN]={
168/*  0     1     2     3     4     5     6     7    */
169    -1,   0x00, 0x01, 0x02, 0x03, 0x04, 0x05, -1,
170
171/*  8     9     a     b     c     d     e     f    */
172    -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,
173
174/*  10    11    12    13    14    15    16    17   */
175    0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d,
176
177/*  18    19    1a    1b    1c    1d    1e    1f   */
178    0x0e, 0x0f, -1,   -1,   0x10, 0x11, 0x12, 0x13,
179
180/*  20   */
181    -1
182};
183
184/*
185 * Byte value map for control codes,
186 * from trail byte values 0..19 (0..0x13) as used in the difference calculation
187 * to external byte values 0x00..0x20.
188 */
189static const int8_t
190bocu1TrailToByte[BOCU1_TRAIL_CONTROLS_COUNT]={
191/*  0     1     2     3     4     5     6     7    */
192    0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x10, 0x11,
193
194/*  8     9     a     b     c     d     e     f    */
195    0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19,
196
197/*  10    11    12    13   */
198    0x1c, 0x1d, 0x1e, 0x1f
199};
200
201/**
202 * Integer division and modulo with negative numerators
203 * yields negative modulo results and quotients that are one more than
204 * what we need here.
205 * This macro adjust the results so that the modulo-value m is always >=0.
206 *
207 * For positive n, the if() condition is always FALSE.
208 *
209 * @param n Number to be split into quotient and rest.
210 *          Will be modified to contain the quotient.
211 * @param d Divisor.
212 * @param m Output variable for the rest (modulo result).
213 */
214#define NEGDIVMOD(n, d, m) { \
215    (m)=(n)%(d); \
216    (n)/=(d); \
217    if((m)<0) { \
218        --(n); \
219        (m)+=(d); \
220    } \
221}
222
223/* State for BOCU-1 decoder function. */
224struct Bocu1Rx {
225    int32_t prev, count, diff;
226};
227
228typedef struct Bocu1Rx Bocu1Rx;
229
230/* Function prototypes ------------------------------------------------------ */
231
232/* see bocu1.c */
233U_CFUNC int32_t
234packDiff(int32_t diff);
235
236U_CFUNC int32_t
237encodeBocu1(int32_t *pPrev, int32_t c);
238
239U_CFUNC int32_t
240decodeBocu1(Bocu1Rx *pRx, uint8_t b);
241
242/* icuhtml/design/conversion/bocu1/bocu1.c ---------------------------------- */
243
244/* BOCU-1 implementation functions ------------------------------------------ */
245
246/**
247 * Compute the next "previous" value for differencing
248 * from the current code point.
249 *
250 * @param c current code point, 0..0x10ffff
251 * @return "previous code point" state value
252 */
253static U_INLINE int32_t
254bocu1Prev(int32_t c) {
255    /* compute new prev */
256    if(0x3040<=c && c<=0x309f) {
257        /* Hiragana is not 128-aligned */
258        return 0x3070;
259    } else if(0x4e00<=c && c<=0x9fa5) {
260        /* CJK Unihan */
261        return 0x4e00-BOCU1_REACH_NEG_2;
262    } else if(0xac00<=c && c<=0xd7a3) {
263        /* Korean Hangul (cast to int32_t to avoid wraparound on 16-bit compilers) */
264        return ((int32_t)0xd7a3+(int32_t)0xac00)/2;
265    } else {
266        /* mostly small scripts */
267        return (c&~0x7f)+BOCU1_ASCII_PREV;
268    }
269}
270
271/**
272 * Encode a difference -0x10ffff..0x10ffff in 1..4 bytes
273 * and return a packed integer with them.
274 *
275 * The encoding favors small absolut differences with short encodings
276 * to compress runs of same-script characters.
277 *
278 * @param diff difference value -0x10ffff..0x10ffff
279 * @return
280 *      0x010000zz for 1-byte sequence zz
281 *      0x0200yyzz for 2-byte sequence yy zz
282 *      0x03xxyyzz for 3-byte sequence xx yy zz
283 *      0xwwxxyyzz for 4-byte sequence ww xx yy zz (ww>0x03)
284 */
285U_CFUNC int32_t
286packDiff(int32_t diff) {
287    int32_t result, m, lead, count, shift;
288
289    if(diff>=BOCU1_REACH_NEG_1) {
290        /* mostly positive differences, and single-byte negative ones */
291        if(diff<=BOCU1_REACH_POS_1) {
292            /* single byte */
293            return 0x01000000|(BOCU1_MIDDLE+diff);
294        } else if(diff<=BOCU1_REACH_POS_2) {
295            /* two bytes */
296            diff-=BOCU1_REACH_POS_1+1;
297            lead=BOCU1_START_POS_2;
298            count=1;
299        } else if(diff<=BOCU1_REACH_POS_3) {
300            /* three bytes */
301            diff-=BOCU1_REACH_POS_2+1;
302            lead=BOCU1_START_POS_3;
303            count=2;
304        } else {
305            /* four bytes */
306            diff-=BOCU1_REACH_POS_3+1;
307            lead=BOCU1_START_POS_4;
308            count=3;
309        }
310    } else {
311        /* two- and four-byte negative differences */
312        if(diff>=BOCU1_REACH_NEG_2) {
313            /* two bytes */
314            diff-=BOCU1_REACH_NEG_1;
315            lead=BOCU1_START_NEG_2;
316            count=1;
317        } else if(diff>=BOCU1_REACH_NEG_3) {
318            /* three bytes */
319            diff-=BOCU1_REACH_NEG_2;
320            lead=BOCU1_START_NEG_3;
321            count=2;
322        } else {
323            /* four bytes */
324            diff-=BOCU1_REACH_NEG_3;
325            lead=BOCU1_START_NEG_4;
326            count=3;
327        }
328    }
329
330    /* encode the length of the packed result */
331    if(count<3) {
332        result=(count+1)<<24;
333    } else /* count==3, MSB used for the lead byte */ {
334        result=0;
335    }
336
337    /* calculate trail bytes like digits in itoa() */
338    shift=0;
339    do {
340        NEGDIVMOD(diff, BOCU1_TRAIL_COUNT, m);
341        result|=BOCU1_TRAIL_TO_BYTE(m)<<shift;
342        shift+=8;
343    } while(--count>0);
344
345    /* add lead byte */
346    result|=(lead+diff)<<shift;
347
348    return result;
349}
350
351/**
352 * BOCU-1 encoder function.
353 *
354 * @param pPrev pointer to the integer that holds
355 *        the "previous code point" state;
356 *        the initial value should be 0 which
357 *        encodeBocu1 will set to the actual BOCU-1 initial state value
358 * @param c the code point to encode
359 * @return the packed 1/2/3/4-byte encoding, see packDiff(),
360 *         or 0 if an error occurs
361 *
362 * @see packDiff
363 */
364U_CFUNC int32_t
365encodeBocu1(int32_t *pPrev, int32_t c) {
366    int32_t prev;
367
368    if(pPrev==NULL || c<0 || c>0x10ffff) {
369        /* illegal argument */
370        return 0;
371    }
372
373    prev=*pPrev;
374    if(prev==0) {
375        /* lenient handling of initial value 0 */
376        prev=*pPrev=BOCU1_ASCII_PREV;
377    }
378
379    if(c<=0x20) {
380        /*
381         * ISO C0 control & space:
382         * Encode directly for MIME compatibility,
383         * and reset state except for space, to not disrupt compression.
384         */
385        if(c!=0x20) {
386            *pPrev=BOCU1_ASCII_PREV;
387        }
388        return 0x01000000|c;
389    }
390
391    /*
392     * all other Unicode code points c==U+0021..U+10ffff
393     * are encoded with the difference c-prev
394     *
395     * a new prev is computed from c,
396     * placed in the middle of a 0x80-block (for most small scripts) or
397     * in the middle of the Unihan and Hangul blocks
398     * to statistically minimize the following difference
399     */
400    *pPrev=bocu1Prev(c);
401    return packDiff(c-prev);
402}
403
404/**
405 * Function for BOCU-1 decoder; handles multi-byte lead bytes.
406 *
407 * @param pRx pointer to the decoder state structure
408 * @param b lead byte;
409 *          BOCU1_MIN<=b<BOCU1_START_NEG_2 or BOCU1_START_POS_2<=b<=BOCU1_MAX_LEAD
410 * @return -1 (state change only)
411 *
412 * @see decodeBocu1
413 */
414static int32_t
415decodeBocu1LeadByte(Bocu1Rx *pRx, uint8_t b) {
416    int32_t c, count;
417
418    if(b>=BOCU1_START_NEG_2) {
419        /* positive difference */
420        if(b<BOCU1_START_POS_3) {
421            /* two bytes */
422            c=((int32_t)b-BOCU1_START_POS_2)*BOCU1_TRAIL_COUNT+BOCU1_REACH_POS_1+1;
423            count=1;
424        } else if(b<BOCU1_START_POS_4) {
425            /* three bytes */
426            c=((int32_t)b-BOCU1_START_POS_3)*BOCU1_TRAIL_COUNT*BOCU1_TRAIL_COUNT+BOCU1_REACH_POS_2+1;
427            count=2;
428        } else {
429            /* four bytes */
430            c=BOCU1_REACH_POS_3+1;
431            count=3;
432        }
433    } else {
434        /* negative difference */
435        if(b>=BOCU1_START_NEG_3) {
436            /* two bytes */
437            c=((int32_t)b-BOCU1_START_NEG_2)*BOCU1_TRAIL_COUNT+BOCU1_REACH_NEG_1;
438            count=1;
439        } else if(b>BOCU1_MIN) {
440            /* three bytes */
441            c=((int32_t)b-BOCU1_START_NEG_3)*BOCU1_TRAIL_COUNT*BOCU1_TRAIL_COUNT+BOCU1_REACH_NEG_2;
442            count=2;
443        } else {
444            /* four bytes */
445            c=-BOCU1_TRAIL_COUNT*BOCU1_TRAIL_COUNT*BOCU1_TRAIL_COUNT+BOCU1_REACH_NEG_3;
446            count=3;
447        }
448    }
449
450    /* set the state for decoding the trail byte(s) */
451    pRx->diff=c;
452    pRx->count=count;
453    return -1;
454}
455
456/**
457 * Function for BOCU-1 decoder; handles multi-byte trail bytes.
458 *
459 * @param pRx pointer to the decoder state structure
460 * @param b trail byte
461 * @return result value, same as decodeBocu1
462 *
463 * @see decodeBocu1
464 */
465static int32_t
466decodeBocu1TrailByte(Bocu1Rx *pRx, uint8_t b) {
467    int32_t t, c, count;
468
469    if(b<=0x20) {
470        /* skip some C0 controls and make the trail byte range contiguous */
471        t=bocu1ByteToTrail[b];
472        if(t<0) {
473            /* illegal trail byte value */
474            pRx->prev=BOCU1_ASCII_PREV;
475            pRx->count=0;
476            return -99;
477        }
478#if BOCU1_MAX_TRAIL<0xff
479    } else if(b>BOCU1_MAX_TRAIL) {
480        return -99;
481#endif
482    } else {
483        t=(int32_t)b-BOCU1_TRAIL_BYTE_OFFSET;
484    }
485
486    /* add trail byte into difference and decrement count */
487    c=pRx->diff;
488    count=pRx->count;
489
490    if(count==1) {
491        /* final trail byte, deliver a code point */
492        c=pRx->prev+c+t;
493        if(0<=c && c<=0x10ffff) {
494            /* valid code point result */
495            pRx->prev=bocu1Prev(c);
496            pRx->count=0;
497            return c;
498        } else {
499            /* illegal code point result */
500            pRx->prev=BOCU1_ASCII_PREV;
501            pRx->count=0;
502            return -99;
503        }
504    }
505
506    /* intermediate trail byte */
507    if(count==2) {
508        pRx->diff=c+t*BOCU1_TRAIL_COUNT;
509    } else /* count==3 */ {
510        pRx->diff=c+t*BOCU1_TRAIL_COUNT*BOCU1_TRAIL_COUNT;
511    }
512    pRx->count=count-1;
513    return -1;
514}
515
516/**
517 * BOCU-1 decoder function.
518 *
519 * @param pRx pointer to the decoder state structure;
520 *        the initial values should be 0 which
521 *        decodeBocu1 will set to actual initial state values
522 * @param b an input byte
523 * @return
524 *      0..0x10ffff for a result code point
525 *      -1 if only the state changed without code point output
526 *     <-1 if an error occurs
527 */
528U_CFUNC int32_t
529decodeBocu1(Bocu1Rx *pRx, uint8_t b) {
530    int32_t prev, c, count;
531
532    if(pRx==NULL) {
533        /* illegal argument */
534        return -99;
535    }
536
537    prev=pRx->prev;
538    if(prev==0) {
539        /* lenient handling of initial 0 values */
540        prev=pRx->prev=BOCU1_ASCII_PREV;
541        count=pRx->count=0;
542    } else {
543        count=pRx->count;
544    }
545
546    if(count==0) {
547        /* byte in lead position */
548        if(b<=0x20) {
549            /*
550             * Direct-encoded C0 control code or space.
551             * Reset prev for C0 control codes but not for space.
552             */
553            if(b!=0x20) {
554                pRx->prev=BOCU1_ASCII_PREV;
555            }
556            return b;
557        }
558
559        /*
560         * b is a difference lead byte.
561         *
562         * Return a code point directly from a single-byte difference.
563         *
564         * For multi-byte difference lead bytes, set the decoder state
565         * with the partial difference value from the lead byte and
566         * with the number of trail bytes.
567         *
568         * For four-byte differences, the signedness also affects the
569         * first trail byte, which has special handling farther below.
570         */
571        if(b>=BOCU1_START_NEG_2 && b<BOCU1_START_POS_2) {
572            /* single-byte difference */
573            c=prev+((int32_t)b-BOCU1_MIDDLE);
574            pRx->prev=bocu1Prev(c);
575            return c;
576        } else if(b==BOCU1_RESET) {
577            /* only reset the state, no code point */
578            pRx->prev=BOCU1_ASCII_PREV;
579            return -1;
580        } else {
581            return decodeBocu1LeadByte(pRx, b);
582        }
583    } else {
584        /* trail byte in any position */
585        return decodeBocu1TrailByte(pRx, b);
586    }
587}
588
589/* icuhtml/design/conversion/bocu1/bocu1tst.c ------------------------------- */
590
591/* test code ---------------------------------------------------------------- */
592
593/* test code options */
594
595/* ignore comma when processing name lists in testText() */
596#define TEST_IGNORE_COMMA       1
597
598/**
599 * Write a packed BOCU-1 byte sequence into a byte array,
600 * without overflow check.
601 * Test function.
602 *
603 * @param packed packed BOCU-1 byte sequence, see packDiff()
604 * @param p pointer to byte array
605 * @return number of bytes
606 *
607 * @see packDiff
608 */
609static int32_t
610writePacked(int32_t packed, uint8_t *p) {
611    int32_t count=BOCU1_LENGTH_FROM_PACKED(packed);
612    switch(count) {
613    case 4:
614        *p++=(uint8_t)(packed>>24);
615    case 3:
616        *p++=(uint8_t)(packed>>16);
617    case 2:
618        *p++=(uint8_t)(packed>>8);
619    case 1:
620        *p++=(uint8_t)packed;
621    default:
622        break;
623    }
624
625    return count;
626}
627
628/**
629 * Unpack a packed BOCU-1 non-C0/space byte sequence and get
630 * the difference to initialPrev.
631 * Used only for round-trip testing of the difference encoding and decoding.
632 * Test function.
633 *
634 * @param initialPrev bogus "previous code point" value to make sure that
635 *                    the resulting code point is in the range 0..0x10ffff
636 * @param packed packed BOCU-1 byte sequence
637 * @return the difference to initialPrev
638 *
639 * @see packDiff
640 * @see writeDiff
641 */
642static int32_t
643unpackDiff(int32_t initialPrev, int32_t packed) {
644    Bocu1Rx rx={ 0, 0, 0 };
645    int32_t count;
646
647    rx.prev=initialPrev;
648    count=BOCU1_LENGTH_FROM_PACKED(packed);
649    switch(count) {
650    case 4:
651        decodeBocu1(&rx, (uint8_t)(packed>>24));
652    case 3:
653        decodeBocu1(&rx, (uint8_t)(packed>>16));
654    case 2:
655        decodeBocu1(&rx, (uint8_t)(packed>>8));
656    case 1:
657        /* subtract initial prev */
658        return decodeBocu1(&rx, (uint8_t)packed)-initialPrev;
659    default:
660        return -0x7fffffff;
661    }
662}
663
664/**
665 * Encode one difference value -0x10ffff..+0x10ffff in 1..4 bytes,
666 * preserving lexical order.
667 * Also checks for roundtripping of the difference encoding.
668 * Test function.
669 *
670 * @param diff difference value to test, -0x10ffff..0x10ffff
671 * @param p pointer to output byte array
672 * @return p advanced by number of bytes output
673 *
674 * @see unpackDiff
675 */
676static uint8_t *
677writeDiff(int32_t diff, uint8_t *p) {
678    /* generate the difference as a packed value and serialize it */
679    int32_t packed, initialPrev;
680
681    packed=packDiff(diff);
682
683    /*
684     * bogus initial "prev" to work around
685     * code point range check in decodeBocu1()
686     */
687    if(diff<=0) {
688        initialPrev=0x10ffff;
689    } else {
690        initialPrev=-1;
691    }
692
693    if(diff!=unpackDiff(initialPrev, packed)) {
694        log_err("error: unpackDiff(packDiff(diff=%ld)=0x%08lx)=%ld!=diff\n",
695                diff, packed, unpackDiff(initialPrev, packed));
696    }
697    return p+writePacked(packed, p);
698}
699
700/**
701 * Encode a UTF-16 string in BOCU-1.
702 * Does not check for overflows, but otherwise useful function.
703 *
704 * @param s input UTF-16 string
705 * @param length number of UChar code units in s
706 * @param p pointer to output byte array
707 * @return number of bytes output
708 */
709static int32_t
710writeString(const UChar *s, int32_t length, uint8_t *p) {
711    uint8_t *p0;
712    int32_t c, prev, i;
713
714    prev=0;
715    p0=p;
716    i=0;
717    while(i<length) {
718        UTF_NEXT_CHAR(s, i, length, c);
719        p+=writePacked(encodeBocu1(&prev, c), p);
720    }
721    return (int32_t)(p-p0);
722}
723
724/**
725 * Decode a BOCU-1 byte sequence to a UTF-16 string.
726 * Does not check for overflows, but otherwise useful function.
727 *
728 * @param p pointer to input BOCU-1 bytes
729 * @param length number of input bytes
730 * @param s point to output UTF-16 string array
731 * @return number of UChar code units output
732 */
733static int32_t
734readString(const uint8_t *p, int32_t length, UChar *s) {
735    Bocu1Rx rx={ 0, 0, 0 };
736    int32_t c, i, sLength;
737
738    i=sLength=0;
739    while(i<length) {
740        c=decodeBocu1(&rx, p[i++]);
741        if(c<-1) {
742            log_err("error: readString detects encoding error at string index %ld\n", i);
743            return -1;
744        }
745        if(c>=0) {
746            UTF_APPEND_CHAR_UNSAFE(s, sLength, c);
747        }
748    }
749    return sLength;
750}
751
752static U_INLINE char
753hexDigit(uint8_t digit) {
754    return digit<=9 ? (char)('0'+digit) : (char)('a'-10+digit);
755}
756
757/**
758 * Pretty-print 0-terminated byte values.
759 * Helper function for test output.
760 *
761 * @param bytes 0-terminated byte array to print
762 */
763static void
764printBytes(uint8_t *bytes, char *out) {
765    int i;
766    uint8_t b;
767
768    i=0;
769    while((b=*bytes++)!=0) {
770        *out++=' ';
771        *out++=hexDigit((uint8_t)(b>>4));
772        *out++=hexDigit((uint8_t)(b&0xf));
773        ++i;
774    }
775    i=3*(5-i);
776    while(i>0) {
777        *out++=' ';
778        --i;
779    }
780    *out=0;
781}
782
783/**
784 * Basic BOCU-1 test function, called when there are no command line arguments.
785 * Prints some of the #define values and performs round-trip tests of the
786 * difference encoding and decoding.
787 */
788static void
789TestBOCU1RefDiff(void) {
790    char buf1[80], buf2[80];
791    uint8_t prev[5], level[5];
792    int32_t i, cmp, countErrors;
793
794    log_verbose("reach of single bytes: %ld\n", 1+BOCU1_REACH_POS_1-BOCU1_REACH_NEG_1);
795    log_verbose("reach of 2 bytes     : %ld\n", 1+BOCU1_REACH_POS_2-BOCU1_REACH_NEG_2);
796    log_verbose("reach of 3 bytes     : %ld\n\n", 1+BOCU1_REACH_POS_3-BOCU1_REACH_NEG_3);
797
798    log_verbose("    BOCU1_REACH_NEG_1 %8ld    BOCU1_REACH_POS_1 %8ld\n", BOCU1_REACH_NEG_1, BOCU1_REACH_POS_1);
799    log_verbose("    BOCU1_REACH_NEG_2 %8ld    BOCU1_REACH_POS_2 %8ld\n", BOCU1_REACH_NEG_2, BOCU1_REACH_POS_2);
800    log_verbose("    BOCU1_REACH_NEG_3 %8ld    BOCU1_REACH_POS_3 %8ld\n\n", BOCU1_REACH_NEG_3, BOCU1_REACH_POS_3);
801
802    log_verbose("    BOCU1_MIDDLE      0x%02x\n", BOCU1_MIDDLE);
803    log_verbose("    BOCU1_START_NEG_2 0x%02x    BOCU1_START_POS_2 0x%02x\n", BOCU1_START_NEG_2, BOCU1_START_POS_2);
804    log_verbose("    BOCU1_START_NEG_3 0x%02x    BOCU1_START_POS_3 0x%02x\n\n", BOCU1_START_NEG_3, BOCU1_START_POS_3);
805
806    /* test packDiff() & unpackDiff() with some specific values */
807    writeDiff(0, level);
808    writeDiff(1, level);
809    writeDiff(65, level);
810    writeDiff(130, level);
811    writeDiff(30000, level);
812    writeDiff(1000000, level);
813    writeDiff(-65, level);
814    writeDiff(-130, level);
815    writeDiff(-30000, level);
816    writeDiff(-1000000, level);
817
818    /* test that each value is smaller than any following one */
819    countErrors=0;
820    i=-0x10ffff;
821    *writeDiff(i, prev)=0;
822
823    /* show first number and bytes */
824    printBytes(prev, buf1);
825    log_verbose("              wD(%8ld)                    %s\n", i, buf1);
826
827    for(++i; i<=0x10ffff; ++i) {
828        *writeDiff(i, level)=0;
829        cmp=strcmp((const char *)prev, (const char *)level);
830        if(BOCU1_LENGTH_FROM_LEAD(level[0])!=(int32_t)strlen((const char *)level)) {
831            log_verbose("BOCU1_LENGTH_FROM_LEAD(0x%02x)=%ld!=%ld=strlen(writeDiff(%ld))\n",
832                   level[0], BOCU1_LENGTH_FROM_LEAD(level[0]), strlen((const char *)level), i);
833        }
834        if(cmp<0) {
835            if(i==0 || i==1 || strlen((const char *)prev)!=strlen((const char *)level)) {
836                /*
837                 * if the result is good, then print only if the length changed
838                 * to get little but interesting output
839                 */
840                printBytes(prev, buf1);
841                printBytes(level, buf2);
842                log_verbose("ok:    strcmp(wD(%8ld), wD(%8ld))=%2d  %s%s\n", i-1, i, cmp, buf1, buf2);
843            }
844        } else {
845            ++countErrors;
846            printBytes(prev, buf1);
847            printBytes(level, buf2);
848            log_verbose("wrong: strcmp(wD(%8ld), wD(%8ld))=%2d  %s%s\n", i-1, i, cmp, buf1, buf2);
849        }
850        /* remember the previous bytes */
851        memcpy(prev, level, 4);
852    }
853
854    /* show last number and bytes */
855    printBytes((uint8_t *)"", buf1);
856    printBytes(prev, buf2);
857    log_verbose("                            wD(%8ld)      %s%s\n", i-1, buf1, buf2);
858
859    if(countErrors==0) {
860        log_verbose("writeDiff(-0x10ffff..0x10ffff) works fine\n");
861    } else {
862        log_err("writeDiff(-0x10ffff..0x10ffff) violates lexical ordering in %d cases\n", countErrors);
863    }
864
865    /* output signature byte sequence */
866    i=0;
867    writePacked(encodeBocu1(&i, 0xfeff), level);
868    log_verbose("\nBOCU-1 signature byte sequence: %02x %02x %02x\n",
869            level[0], level[1], level[2]);
870}
871
872/* cintltst code ------------------------------------------------------------ */
873
874static const int32_t DEFAULT_BUFFER_SIZE = 30000;
875
876
877/* test one string with the ICU and the reference BOCU-1 implementations */
878static void
879roundtripBOCU1(UConverter *bocu1, int32_t number, const UChar *text, int32_t length) {
880    UChar *roundtripRef, *roundtripICU;
881    char *bocu1Ref, *bocu1ICU;
882
883    int32_t bocu1RefLength, bocu1ICULength, roundtripRefLength, roundtripICULength;
884    UErrorCode errorCode;
885
886    roundtripRef = malloc(DEFAULT_BUFFER_SIZE * sizeof(UChar));
887    roundtripICU = malloc(DEFAULT_BUFFER_SIZE * sizeof(UChar));
888    bocu1Ref = malloc(DEFAULT_BUFFER_SIZE);
889    bocu1ICU = malloc(DEFAULT_BUFFER_SIZE);
890
891    /* Unicode -> BOCU-1 */
892    bocu1RefLength=writeString(text, length, (uint8_t *)bocu1Ref);
893
894    errorCode=U_ZERO_ERROR;
895    bocu1ICULength=ucnv_fromUChars(bocu1, bocu1ICU, DEFAULT_BUFFER_SIZE, text, length, &errorCode);
896    if(U_FAILURE(errorCode)) {
897        log_err("ucnv_fromUChars(BOCU-1, text(%d)[%d]) failed: %s\n", number, length, u_errorName(errorCode));
898        goto cleanup;
899    }
900
901    if(bocu1RefLength!=bocu1ICULength || 0!=uprv_memcmp(bocu1Ref, bocu1ICU, bocu1RefLength)) {
902        log_err("Unicode(%d)[%d] -> BOCU-1: reference[%d]!=ICU[%d]\n", number, length, bocu1RefLength, bocu1ICULength);
903        goto cleanup;
904    }
905
906    /* BOCU-1 -> Unicode */
907    roundtripRefLength=readString((uint8_t *)bocu1Ref, bocu1RefLength, roundtripRef);
908    if(roundtripRefLength<0) {
909        goto cleanup; /* readString() found an error and reported it */
910    }
911
912    roundtripICULength=ucnv_toUChars(bocu1, roundtripICU, DEFAULT_BUFFER_SIZE, bocu1ICU, bocu1ICULength, &errorCode);
913    if(U_FAILURE(errorCode)) {
914        log_err("ucnv_toUChars(BOCU-1, text(%d)[%d]) failed: %s\n", number, length, u_errorName(errorCode));
915        goto cleanup;
916    }
917
918    if(length!=roundtripRefLength || 0!=u_memcmp(text, roundtripRef, length)) {
919        log_err("BOCU-1 -> Unicode: original(%d)[%d]!=reference[%d]\n", number, length, roundtripRefLength);
920        goto cleanup;
921    }
922    if(roundtripRefLength!=roundtripICULength || 0!=u_memcmp(roundtripRef, roundtripICU, roundtripRefLength)) {
923        log_err("BOCU-1 -> Unicode: reference(%d)[%d]!=ICU[%d]\n", number, roundtripRefLength, roundtripICULength);
924        goto cleanup;
925    }
926cleanup:
927    free(roundtripRef);
928    free(roundtripICU);
929    free(bocu1Ref);
930    free(bocu1ICU);
931}
932
933static const UChar feff[]={ 0xfeff };
934static const UChar ascii[]={ 0x61, 0x62, 0x20, 0x63, 0x61 };
935static const UChar crlf[]={ 0xd, 0xa, 0x20 };
936static const UChar nul[]={ 0 };
937static const UChar latin[]={ 0xdf, 0xe6 };
938static const UChar devanagari[]={ 0x930, 0x20, 0x918, 0x909 };
939static const UChar hiragana[]={ 0x3086, 0x304d, 0x20, 0x3053, 0x4000 };
940static const UChar unihan[]={ 0x4e00, 0x7777, 0x20, 0x9fa5, 0x4e00 };
941static const UChar hangul[]={ 0xac00, 0xbcde, 0x20, 0xd7a3 };
942static const UChar surrogates[]={ 0xdc00, 0xd800 }; /* single surrogates, unmatched! */
943static const UChar plane1[]={ 0xd800, 0xdc00 };
944static const UChar plane2[]={ 0xd845, 0xdddd };
945static const UChar plane15[]={ 0xdbbb, 0xddee, 0x20 };
946static const UChar plane16[]={ 0xdbff, 0xdfff };
947static const UChar c0[]={ 1, 0xe40, 0x20, 9 };
948
949static const struct {
950    const UChar *s;
951    int32_t length;
952} strings[]={
953    { feff,         LENGTHOF(feff) },
954    { ascii,        LENGTHOF(ascii) },
955    { crlf,         LENGTHOF(crlf) },
956    { nul,          LENGTHOF(nul) },
957    { latin,        LENGTHOF(latin) },
958    { devanagari,   LENGTHOF(devanagari) },
959    { hiragana,     LENGTHOF(hiragana) },
960    { unihan,       LENGTHOF(unihan) },
961    { hangul,       LENGTHOF(hangul) },
962    { surrogates,   LENGTHOF(surrogates) },
963    { plane1,       LENGTHOF(plane1) },
964    { plane2,       LENGTHOF(plane2) },
965    { plane15,      LENGTHOF(plane15) },
966    { plane16,      LENGTHOF(plane16) },
967    { c0,           LENGTHOF(c0) }
968};
969
970/*
971 * Verify that the ICU BOCU-1 implementation produces the same results as
972 * the reference implementation from the design folder.
973 * Generate some texts and convert them with both converters, verifying
974 * identical results and roundtripping.
975 */
976static void
977TestBOCU1(void) {
978    UChar *text;
979    int32_t i, length;
980
981    UConverter *bocu1;
982    UErrorCode errorCode;
983
984    errorCode=U_ZERO_ERROR;
985    bocu1=ucnv_open("BOCU-1", &errorCode);
986    if(U_FAILURE(errorCode)) {
987        log_err("error: unable to open BOCU-1 converter: %s\n", u_errorName(errorCode));
988        return;
989    }
990
991    text = malloc(DEFAULT_BUFFER_SIZE * sizeof(UChar));
992
993    /* text 1: each of strings[] once */
994    length=0;
995    for(i=0; i<LENGTHOF(strings); ++i) {
996        u_memcpy(text+length, strings[i].s, strings[i].length);
997        length+=strings[i].length;
998    }
999    roundtripBOCU1(bocu1, 1, text, length);
1000
1001    /* text 2: each of strings[] twice */
1002    length=0;
1003    for(i=0; i<LENGTHOF(strings); ++i) {
1004        u_memcpy(text+length, strings[i].s, strings[i].length);
1005        length+=strings[i].length;
1006        u_memcpy(text+length, strings[i].s, strings[i].length);
1007        length+=strings[i].length;
1008    }
1009    roundtripBOCU1(bocu1, 2, text, length);
1010
1011    /* text 3: each of strings[] many times (set step vs. |strings| so that all strings are used) */
1012    length=0;
1013    for(i=1; length<5000; i+=7) {
1014        if(i>=LENGTHOF(strings)) {
1015            i-=LENGTHOF(strings);
1016        }
1017        u_memcpy(text+length, strings[i].s, strings[i].length);
1018        length+=strings[i].length;
1019    }
1020    roundtripBOCU1(bocu1, 3, text, length);
1021
1022    ucnv_close(bocu1);
1023    free(text);
1024}
1025
1026U_CFUNC void addBOCU1Tests(TestNode** root);
1027
1028U_CFUNC void
1029addBOCU1Tests(TestNode** root) {
1030    addTest(root, TestBOCU1RefDiff, "tsconv/bocu1tst/TestBOCU1RefDiff");
1031    addTest(root, TestBOCU1, "tsconv/bocu1tst/TestBOCU1");
1032}
1033