icuSources/tools/makeconv/gencnvex.c

   1 /*
   2 *******************************************************************************
   3 *
   4 *   Copyright (C) 2003-2007, International Business Machines
   5 *   Corporation and others.  All Rights Reserved.
   6 *
   7 *******************************************************************************
   8 *   file name:  gencnvex.c
   9 *   encoding:   US-ASCII
  10 *   tab size:   8 (not used)
  11 *   indentation:4
  12 *
  13 *   created on: 2003oct12
  14 *   created by: Markus W. Scherer
  15 */
  16
  17 #include <stdio.h>
  18 #include "unicode/utypes.h"
  19 #include "unicode/ustring.h"
  20 #include "cstring.h"
  21 #include "cmemory.h"
  22 #include "ucnv_cnv.h"
  23 #include "ucnvmbcs.h"
  24 #include "toolutil.h"
  25 #include "unewdata.h"
  26 #include "ucm.h"
  27 #include "makeconv.h"
  28 #include "genmbcs.h"
  29
  30 #define LENGTHOF(array) (int32_t)(sizeof(array)/sizeof((array)[0]))
  31
  32
  33 static void
  34 CnvExtClose(NewConverter *cnvData);
  35
  36 static UBool
  37 CnvExtIsValid(NewConverter *cnvData,
  38               const uint8_t *bytes, int32_t length);
  39
  40 static UBool
  41 CnvExtAddTable(NewConverter *cnvData, UCMTable *table, UConverterStaticData *staticData);
  42
  43 static uint32_t
  44 CnvExtWrite(NewConverter *cnvData, const UConverterStaticData *staticData,
  45             UNewDataMemory *pData, int32_t tableType);
  46
  47 typedef struct CnvExtData {
  48     NewConverter newConverter;
  49
  50     UCMFile *ucm;
  51
  52     /* toUnicode (state table in ucm->states) */
  53     UToolMemory *toUTable, *toUUChars;
  54
  55     /* fromUnicode */
  56     UToolMemory *fromUTableUChars, *fromUTableValues, *fromUBytes;
  57
  58     uint16_t stage1[MBCS_STAGE_1_SIZE];
  59     uint16_t stage2[MBCS_STAGE_2_SIZE];
  60     uint16_t stage3[0x10000<<UCNV_EXT_STAGE_2_LEFT_SHIFT]; /* 0x10000 because of 16-bit stage 2/3 indexes */
  61     uint32_t stage3b[0x10000];
  62
  63     int32_t stage1Top, stage2Top, stage3Top, stage3bTop;
  64
  65     /* for stage3 compaction of <subchar1> |2 mappings */
  66     uint16_t stage3Sub1Block;
  67
  68     /* statistics */
  69     int32_t
  70         maxInBytes, maxOutBytes, maxBytesPerUChar,
  71         maxInUChars, maxOutUChars, maxUCharsPerByte;
  72 } CnvExtData;
  73
  74 NewConverter *
  75 CnvExtOpen(UCMFile *ucm) {
  76     CnvExtData *extData;
  77
  78     extData=(CnvExtData *)uprv_malloc(sizeof(CnvExtData));
  79     if(extData==NULL) {
  80         printf("out of memory\n");
  81         exit(U_MEMORY_ALLOCATION_ERROR);
  82     }
  83     uprv_memset(extData, 0, sizeof(CnvExtData));
  84
  85     extData->ucm=ucm; /* aliased, not owned */
  86
  87     extData->newConverter.close=CnvExtClose;
  88     extData->newConverter.isValid=CnvExtIsValid;
  89     extData->newConverter.addTable=CnvExtAddTable;
  90     extData->newConverter.write=CnvExtWrite;
  91     return &extData->newConverter;
  92 }
  93
  94 static void
  95 CnvExtClose(NewConverter *cnvData) {
  96     CnvExtData *extData=(CnvExtData *)cnvData;
  97     if(extData!=NULL) {
  98         utm_close(extData->toUTable);
  99         utm_close(extData->toUUChars);
 100         utm_close(extData->fromUTableUChars);
 101         utm_close(extData->fromUTableValues);
 102         utm_close(extData->fromUBytes);
 103     }
 104 }
 105
 106 /* we do not expect this to be called */
 107 static UBool
 108 CnvExtIsValid(NewConverter *cnvData,
 109         const uint8_t *bytes, int32_t length) {
 110     return FALSE;
 111 }
 112
 113 static uint32_t
 114 CnvExtWrite(NewConverter *cnvData, const UConverterStaticData *staticData,
 115             UNewDataMemory *pData, int32_t tableType) {
 116     CnvExtData *extData=(CnvExtData *)cnvData;
 117     int32_t length, top, headerSize;
 118
 119     int32_t indexes[UCNV_EXT_INDEXES_MIN_LENGTH]={ 0 };
 120
 121     if(tableType&TABLE_BASE) {
 122         headerSize=0;
 123     } else {
 124         _MBCSHeader header={ { 0, 0, 0, 0 }, 0, 0, 0, 0, 0, 0, 0 };
 125
 126         /* write the header and base table name for an extension-only table */
 127         length=(int32_t)uprv_strlen(extData->ucm->baseName)+1;
 128         while(length&3) {
 129             /* add padding */
 130             extData->ucm->baseName[length++]=0;
 131         }
 132
 133         headerSize=MBCS_HEADER_V4_LENGTH*4+length;
 134
 135         /* fill the header */
 136         header.version[0]=4;
 137         header.version[1]=2;
 138         header.flags=(uint32_t)((headerSize<<8)|MBCS_OUTPUT_EXT_ONLY);
 139
 140         /* write the header and the base table name */
 141         udata_writeBlock(pData, &header, MBCS_HEADER_V4_LENGTH*4);
 142         udata_writeBlock(pData, extData->ucm->baseName, length);
 143     }
 144
 145     /* fill indexes[] - offsets/indexes are in units of the target array */
 146     top=0;
 147
 148     indexes[UCNV_EXT_INDEXES_LENGTH]=length=UCNV_EXT_INDEXES_MIN_LENGTH;
 149     top+=length*4;
 150
 151     indexes[UCNV_EXT_TO_U_INDEX]=top;
 152     indexes[UCNV_EXT_TO_U_LENGTH]=length=utm_countItems(extData->toUTable);
 153     top+=length*4;
 154
 155     indexes[UCNV_EXT_TO_U_UCHARS_INDEX]=top;
 156     indexes[UCNV_EXT_TO_U_UCHARS_LENGTH]=length=utm_countItems(extData->toUUChars);
 157     top+=length*2;
 158
 159     indexes[UCNV_EXT_FROM_U_UCHARS_INDEX]=top;
 160     length=utm_countItems(extData->fromUTableUChars);
 161     top+=length*2;
 162
 163     if(top&3) {
 164         /* add padding */
 165         *((UChar *)utm_alloc(extData->fromUTableUChars))=0;
 166         *((uint32_t *)utm_alloc(extData->fromUTableValues))=0;
 167         ++length;
 168         top+=2;
 169     }
 170     indexes[UCNV_EXT_FROM_U_LENGTH]=length;
 171
 172     indexes[UCNV_EXT_FROM_U_VALUES_INDEX]=top;
 173     top+=length*4;
 174
 175     indexes[UCNV_EXT_FROM_U_BYTES_INDEX]=top;
 176     length=utm_countItems(extData->fromUBytes);
 177     top+=length;
 178
 179     if(top&1) {
 180         /* add padding */
 181         *((uint8_t *)utm_alloc(extData->fromUBytes))=0;
 182         ++length;
 183         ++top;
 184     }
 185     indexes[UCNV_EXT_FROM_U_BYTES_LENGTH]=length;
 186
 187     indexes[UCNV_EXT_FROM_U_STAGE_12_INDEX]=top;
 188     indexes[UCNV_EXT_FROM_U_STAGE_1_LENGTH]=length=extData->stage1Top;
 189     indexes[UCNV_EXT_FROM_U_STAGE_12_LENGTH]=length+=extData->stage2Top;
 190     top+=length*2;
 191
 192     indexes[UCNV_EXT_FROM_U_STAGE_3_INDEX]=top;
 193     length=extData->stage3Top;
 194     top+=length*2;
 195
 196     if(top&3) {
 197         /* add padding */
 198         extData->stage3[extData->stage3Top++]=0;
 199         ++length;
 200         top+=2;
 201     }
 202     indexes[UCNV_EXT_FROM_U_STAGE_3_LENGTH]=length;
 203
 204     indexes[UCNV_EXT_FROM_U_STAGE_3B_INDEX]=top;
 205     indexes[UCNV_EXT_FROM_U_STAGE_3B_LENGTH]=length=extData->stage3bTop;
 206     top+=length*4;
 207
 208     indexes[UCNV_EXT_SIZE]=top;
 209
 210     /* statistics */
 211     indexes[UCNV_EXT_COUNT_BYTES]=
 212         (extData->maxInBytes<<16)|
 213         (extData->maxOutBytes<<8)|
 214         extData->maxBytesPerUChar;
 215     indexes[UCNV_EXT_COUNT_UCHARS]=
 216         (extData->maxInUChars<<16)|
 217         (extData->maxOutUChars<<8)|
 218         extData->maxUCharsPerByte;
 219
 220     indexes[UCNV_EXT_FLAGS]=extData->ucm->ext->unicodeMask;
 221
 222     /* write the extension data */
 223     udata_writeBlock(pData, indexes, sizeof(indexes));
 224     udata_writeBlock(pData, utm_getStart(extData->toUTable), indexes[UCNV_EXT_TO_U_LENGTH]*4);
 225     udata_writeBlock(pData, utm_getStart(extData->toUUChars), indexes[UCNV_EXT_TO_U_UCHARS_LENGTH]*2);
 226
 227     udata_writeBlock(pData, utm_getStart(extData->fromUTableUChars), indexes[UCNV_EXT_FROM_U_LENGTH]*2);
 228     udata_writeBlock(pData, utm_getStart(extData->fromUTableValues), indexes[UCNV_EXT_FROM_U_LENGTH]*4);
 229     udata_writeBlock(pData, utm_getStart(extData->fromUBytes), indexes[UCNV_EXT_FROM_U_BYTES_LENGTH]);
 230
 231     udata_writeBlock(pData, extData->stage1, extData->stage1Top*2);
 232     udata_writeBlock(pData, extData->stage2, extData->stage2Top*2);
 233     udata_writeBlock(pData, extData->stage3, extData->stage3Top*2);
 234     udata_writeBlock(pData, extData->stage3b, extData->stage3bTop*4);
 235
 236 #if 0
 237     {
 238         int32_t i, j;
 239
 240         length=extData->stage1Top;
 241         printf("\nstage1[%x]:\n", length);
 242
 243         for(i=0; i<length; ++i) {
 244             if(extData->stage1[i]!=length) {
 245                 printf("stage1[%04x]=%04x\n", i, extData->stage1[i]);
 246             }
 247         }
 248
 249         j=length;
 250         length=extData->stage2Top;
 251         printf("\nstage2[%x]:\n", length);
 252
 253         for(i=0; i<length; ++j, ++i) {
 254             if(extData->stage2[i]!=0) {
 255                 printf("stage12[%04x]=%04x\n", j, extData->stage2[i]);
 256             }
 257         }
 258
 259         length=extData->stage3Top;
 260         printf("\nstage3[%x]:\n", length);
 261
 262         for(i=0; i<length; ++i) {
 263             if(extData->stage3[i]!=0) {
 264                 printf("stage3[%04x]=%04x\n", i, extData->stage3[i]);
 265             }
 266         }
 267
 268         length=extData->stage3bTop;
 269         printf("\nstage3b[%x]:\n", length);
 270
 271         for(i=0; i<length; ++i) {
 272             if(extData->stage3b[i]!=0) {
 273                 printf("stage3b[%04x]=%08x\n", i, extData->stage3b[i]);
 274             }
 275         }
 276     }
 277 #endif
 278
 279     if(VERBOSE) {
 280         printf("size of extension data: %ld\n", (long)top);
 281     }
 282
 283     /* return the number of bytes that should have been written */
 284     return (uint32_t)(headerSize+top);
 285 }
 286
 287 /* to Unicode --------------------------------------------------------------- */
 288
 289 /*
 290  * Remove fromUnicode fallbacks and SUB mappings which are irrelevant for
 291  * the toUnicode table.
 292  * This includes mappings with MBCS_FROM_U_EXT_FLAG which were suitable
 293  * for the base toUnicode table but not for the base fromUnicode table.
 294  * The table must be sorted.
 295  * Modifies previous data in the reverseMap.
 296  */
 297 static int32_t
 298 reduceToUMappings(UCMTable *table) {
 299     UCMapping *mappings;
 300     int32_t *map;
 301     int32_t i, j, count;
 302     int8_t flag;
 303
 304     mappings=table->mappings;
 305     map=table->reverseMap;
 306     count=table->mappingsLength;
 307
 308     /* leave the map alone for the initial mappings with desired flags */
 309     for(i=j=0; i<count; ++i) {
 310         flag=mappings[map[i]].f;
 311         if(flag!=0 && flag!=3) {
 312             break;
 313         }
 314     }
 315
 316     /* reduce from here to the rest */
 317     for(j=i; i<count; ++i) {
 318         flag=mappings[map[i]].f;
 319         if(flag==0 || flag==3) {
 320             map[j++]=map[i];
 321         }
 322     }
 323
 324     return j;
 325 }
 326
 327 static uint32_t
 328 getToUnicodeValue(CnvExtData *extData, UCMTable *table, UCMapping *m) {
 329     UChar32 *u32;
 330     UChar *u;
 331     uint32_t value;
 332     int32_t u16Length, ratio;
 333     UErrorCode errorCode;
 334
 335     /* write the Unicode result code point or string index */
 336     if(m->uLen==1) {
 337         u16Length=U16_LENGTH(m->u);
 338         value=(uint32_t)(UCNV_EXT_TO_U_MIN_CODE_POINT+m->u);
 339     } else {
 340         /* the parser enforces m->uLen<=UCNV_EXT_MAX_UCHARS */
 341
 342         /* get the result code point string and its 16-bit string length */
 343         u32=UCM_GET_CODE_POINTS(table, m);
 344         errorCode=U_ZERO_ERROR;
 345         u_strFromUTF32(NULL, 0, &u16Length, u32, m->uLen, &errorCode);
 346         if(U_FAILURE(errorCode) && errorCode!=U_BUFFER_OVERFLOW_ERROR) {
 347             exit(errorCode);
 348         }
 349
 350         /* allocate it and put its length and index into the value */
 351         value=
 352             (((uint32_t)m->uLen+UCNV_EXT_TO_U_LENGTH_OFFSET)<<UCNV_EXT_TO_U_LENGTH_SHIFT)|
 353             ((uint32_t)utm_countItems(extData->toUUChars));
 354         u=utm_allocN(extData->toUUChars, u16Length);
 355
 356         /* write the result 16-bit string */
 357         errorCode=U_ZERO_ERROR;
 358         u_strFromUTF32(u, u16Length, NULL, u32, m->uLen, &errorCode);
 359         if(U_FAILURE(errorCode) && errorCode!=U_BUFFER_OVERFLOW_ERROR) {
 360             exit(errorCode);
 361         }
 362     }
 363     if(m->f==0) {
 364         value|=UCNV_EXT_TO_U_ROUNDTRIP_FLAG;
 365     }
 366
 367     /* update statistics */
 368     if(m->bLen>extData->maxInBytes) {
 369         extData->maxInBytes=m->bLen;
 370     }
 371     if(u16Length>extData->maxOutUChars) {
 372         extData->maxOutUChars=u16Length;
 373     }
 374
 375     ratio=(u16Length+(m->bLen-1))/m->bLen;
 376     if(ratio>extData->maxUCharsPerByte) {
 377         extData->maxUCharsPerByte=ratio;
 378     }
 379
 380     return value;
 381 }
 382
 383 /*
 384  * Recursive toUTable generator core function.
 385  * Preconditions:
 386  * - start<limit (There is at least one mapping.)
 387  * - The mappings are sorted lexically. (Access is through the reverseMap.)
 388  * - All mappings between start and limit have input sequences that share
 389  *   the same prefix of unitIndex length, and therefore all of these sequences
 390  *   are at least unitIndex+1 long.
 391  * - There are only relevant mappings available through the reverseMap,
 392  *   see reduceToUMappings().
 393  *
 394  * One function invocation generates one section table.
 395  *
 396  * Steps:
 397  * 1. Count the number of unique unit values and get the low/high unit values
 398  *    that occur at unitIndex.
 399  * 2. Allocate the section table with possible optimization for linear access.
 400  * 3. Write temporary version of the section table with start indexes of
 401  *    subsections, each corresponding to one unit value at unitIndex.
 402  * 4. Iterate through the table once more, and depending on the subsection length:
 403  *    0: write 0 as a result value (unused byte in linear-access section table)
 404  *   >0: if there is one mapping with an input unit sequence of unitIndex+1
 405  *       then defaultValue=compute the mapping result for this whole sequence
 406  *       else defaultValue=0
 407  *
 408  *       recurse into the subsection
 409  */
 410 static UBool
 411 generateToUTable(CnvExtData *extData, UCMTable *table,
 412                  int32_t start, int32_t limit, int32_t unitIndex,
 413                  uint32_t defaultValue) {
 414     UCMapping *mappings, *m;
 415     int32_t *map;
 416     int32_t i, j, uniqueCount, count, subStart, subLimit;
 417
 418     uint8_t *bytes;
 419     int32_t low, high, prev;
 420
 421     uint32_t *section;
 422
 423     mappings=table->mappings;
 424     map=table->reverseMap;
 425
 426     /* step 1: examine the input units; set low, high, uniqueCount */
 427     m=mappings+map[start];
 428     bytes=UCM_GET_BYTES(table, m);
 429     low=bytes[unitIndex];
 430     uniqueCount=1;
 431
 432     prev=high=low;
 433     for(i=start+1; i<limit; ++i) {
 434         m=mappings+map[i];
 435         bytes=UCM_GET_BYTES(table, m);
 436         high=bytes[unitIndex];
 437
 438         if(high!=prev) {
 439             prev=high;
 440             ++uniqueCount;
 441         }
 442     }
 443
 444     /* step 2: allocate the section; set count, section */
 445     count=(high-low)+1;
 446     if(count<0x100 && (unitIndex==0 || uniqueCount>=(3*count)/4)) {
 447         /*
 448          * for the root table and for fairly full tables:
 449          * allocate for direct, linear array access
 450          * by keeping count, to write an entry for each unit value
 451          * from low to high
 452          * exception: use a compact table if count==0x100 because
 453          * that cannot be encoded in the length byte
 454          */
 455     } else {
 456         count=uniqueCount;
 457     }
 458
 459     if(count>=0x100) {
 460         fprintf(stderr, "error: toUnicode extension table section overflow: %ld section entries\n", (long)count);
 461         return FALSE;
 462     }
 463
 464     /* allocate the section: 1 entry for the header + count for the items */
 465     section=(uint32_t *)utm_allocN(extData->toUTable, 1+count);
 466
 467     /* write the section header */
 468     *section++=((uint32_t)count<<UCNV_EXT_TO_U_BYTE_SHIFT)|defaultValue;
 469
 470     /* step 3: write temporary section table with subsection starts */
 471     prev=low-1; /* just before low to prevent empty subsections before low */
 472     j=0; /* section table index */
 473     for(i=start; i<limit; ++i) {
 474         m=mappings+map[i];
 475         bytes=UCM_GET_BYTES(table, m);
 476         high=bytes[unitIndex];
 477
 478         if(high!=prev) {
 479             /* start of a new subsection for unit high */
 480             if(count>uniqueCount) {
 481                 /* write empty subsections for unused units in a linear table */
 482                 while(++prev<high) {
 483                     section[j++]=((uint32_t)prev<<UCNV_EXT_TO_U_BYTE_SHIFT)|(uint32_t)i;
 484                 }
 485             } else {
 486                 prev=high;
 487             }
 488
 489             /* write the entry with the subsection start */
 490             section[j++]=((uint32_t)high<<UCNV_EXT_TO_U_BYTE_SHIFT)|(uint32_t)i;
 491         }
 492     }
 493     /* assert(j==count) */
 494
 495     /* step 4: recurse and write results */
 496     subLimit=UCNV_EXT_TO_U_GET_VALUE(section[0]);
 497     for(j=0; j<count; ++j) {
 498         subStart=subLimit;
 499         subLimit= (j+1)<count ? UCNV_EXT_TO_U_GET_VALUE(section[j+1]) : limit;
 500
 501         /* remove the subStart temporary value */
 502         section[j]&=~UCNV_EXT_TO_U_VALUE_MASK;
 503
 504         if(subStart==subLimit) {
 505             /* leave the value zero: empty subsection for unused unit in a linear table */
 506             continue;
 507         }
 508
 509         /* see if there is exactly one input unit sequence of length unitIndex+1 */
 510         defaultValue=0;
 511         m=mappings+map[subStart];
 512         if(m->bLen==unitIndex+1) {
 513             /* do not include this in generateToUTable() */
 514             ++subStart;
 515
 516             if(subStart<subLimit && mappings[map[subStart]].bLen==unitIndex+1) {
 517                 /* print error for multiple same-input-sequence mappings */
 518                 fprintf(stderr, "error: multiple mappings from same bytes\n");
 519                 ucm_printMapping(table, m, stderr);
 520                 ucm_printMapping(table, mappings+map[subStart], stderr);
 521                 return FALSE;
 522             }
 523
 524             defaultValue=getToUnicodeValue(extData, table, m);
 525         }
 526
 527         if(subStart==subLimit) {
 528             /* write the result for the input sequence ending here */
 529             section[j]|=defaultValue;
 530         } else {
 531             /* write the index to the subsection table */
 532             section[j]|=(uint32_t)utm_countItems(extData->toUTable);
 533
 534             /* recurse */
 535             if(!generateToUTable(extData, table, subStart, subLimit, unitIndex+1, defaultValue)) {
 536                 return FALSE;
 537             }
 538         }
 539     }
 540     return TRUE;
 541 }
 542
 543 /*
 544  * Generate the toUTable and toUUChars from the input table.
 545  * The input table must be sorted, and all precision flags must be 0..3.
 546  * This function will modify the table's reverseMap.
 547  */
 548 static UBool
 549 makeToUTable(CnvExtData *extData, UCMTable *table) {
 550     int32_t toUCount;
 551
 552     toUCount=reduceToUMappings(table);
 553
 554     extData->toUTable=utm_open("cnv extension toUTable", 0x10000, UCNV_EXT_TO_U_MIN_CODE_POINT, 4);
 555     extData->toUUChars=utm_open("cnv extension toUUChars", 0x10000, UCNV_EXT_TO_U_INDEX_MASK+1, 2);
 556
 557     return generateToUTable(extData, table, 0, toUCount, 0, 0);
 558 }
 559
 560 /* from Unicode ------------------------------------------------------------- */
 561
 562 /*
 563  * preprocessing:
 564  * rebuild reverseMap with mapping indexes for mappings relevant for from Unicode
 565  * change each Unicode string to encode all but the first code point in 16-bit form
 566  *
 567  * generation:
 568  * for each unique code point
 569  *   write an entry in the 3-stage trie
 570  *   check that there is only one single-code point sequence
 571  *   start recursion for following 16-bit input units
 572  */
 573
 574 /*
 575  * Remove toUnicode fallbacks and non-<subchar1> SUB mappings
 576  * which are irrelevant for the fromUnicode extension table.
 577  * Remove MBCS_FROM_U_EXT_FLAG bits.
 578  * Overwrite the reverseMap with an index array to the relevant mappings.
 579  * Modify the code point sequences to a generator-friendly format where
 580  * the first code points remains unchanged but the following are recoded
 581  * into 16-bit Unicode string form.
 582  * The table must be sorted.
 583  * Destroys previous data in the reverseMap.
 584  */
 585 static int32_t
 586 prepareFromUMappings(UCMTable *table) {
 587     UCMapping *mappings, *m;
 588     int32_t *map;
 589     int32_t i, j, count;
 590     int8_t flag;
 591
 592     mappings=table->mappings;
 593     map=table->reverseMap;
 594     count=table->mappingsLength;
 595
 596     /*
 597      * we do not go through the map on input because the mappings are
 598      * sorted lexically
 599      */
 600     m=mappings;
 601
 602     for(i=j=0; i<count; ++m, ++i) {
 603         flag=m->f;
 604         if(flag>=0) {
 605             flag&=MBCS_FROM_U_EXT_MASK;
 606             m->f=flag;
 607         }
 608         if(flag==0 || flag==1 || (flag==2 && m->bLen==1)) {
 609             map[j++]=i;
 610
 611             if(m->uLen>1) {
 612                 /* recode all but the first code point to 16-bit Unicode */
 613                 UChar32 *u32;
 614                 UChar *u;
 615                 UChar32 c;
 616                 int32_t q, r;
 617
 618                 u32=UCM_GET_CODE_POINTS(table, m);
 619                 u=(UChar *)u32; /* destructive in-place recoding */
 620                 for(r=2, q=1; q<m->uLen; ++q) {
 621                     c=u32[q];
 622                     U16_APPEND_UNSAFE(u, r, c);
 623                 }
 624
 625                 /* counts the first code point always at 2 - the first 16-bit unit is at 16-bit index 2 */
 626                 m->uLen=(int8_t)r;
 627             }
 628         }
 629     }
 630
 631     return j;
 632 }
 633
 634 static uint32_t
 635 getFromUBytesValue(CnvExtData *extData, UCMTable *table, UCMapping *m) {
 636     uint8_t *bytes, *resultBytes;
 637     uint32_t value;
 638     int32_t u16Length, ratio;
 639
 640     if(m->f==2) {
 641         /*
 642          * no mapping, <subchar1> preferred
 643          *
 644          * no need to count in statistics because the subchars are already
 645          * counted for maxOutBytes and maxBytesPerUChar in UConverterStaticData,
 646          * and this non-mapping does not count for maxInUChars which are always
 647          * trivially at least two if counting unmappable supplementary code points
 648          */
 649         return UCNV_EXT_FROM_U_SUBCHAR1;
 650     }
 651
 652     bytes=UCM_GET_BYTES(table, m);
 653     value=0;
 654     switch(m->bLen) {
 655         /* 1..3: store the bytes in the value word */
 656     case 3:
 657         value=((uint32_t)*bytes++)<<16;
 658     case 2:
 659         value|=((uint32_t)*bytes++)<<8;
 660     case 1:
 661         value|=*bytes;
 662         break;
 663     default:
 664         /* the parser enforces m->bLen<=UCNV_EXT_MAX_BYTES */
 665         /* store the bytes in fromUBytes[] and the index in the value word */
 666         value=(uint32_t)utm_countItems(extData->fromUBytes);
 667         resultBytes=utm_allocN(extData->fromUBytes, m->bLen);
 668         uprv_memcpy(resultBytes, bytes, m->bLen);
 669         break;
 670     }
 671     value|=(uint32_t)m->bLen<<UCNV_EXT_FROM_U_LENGTH_SHIFT;
 672     if(m->f==0) {
 673         value|=UCNV_EXT_FROM_U_ROUNDTRIP_FLAG;
 674     }
 675
 676     /* calculate the real UTF-16 length (see recoding in prepareFromUMappings()) */
 677     if(m->uLen==1) {
 678         u16Length=U16_LENGTH(m->u);
 679     } else {
 680         u16Length=U16_LENGTH(UCM_GET_CODE_POINTS(table, m)[0])+(m->uLen-2);
 681     }
 682
 683     /* update statistics */
 684     if(u16Length>extData->maxInUChars) {
 685         extData->maxInUChars=u16Length;
 686     }
 687     if(m->bLen>extData->maxOutBytes) {
 688         extData->maxOutBytes=m->bLen;
 689     }
 690
 691     ratio=(m->bLen+(u16Length-1))/u16Length;
 692     if(ratio>extData->maxBytesPerUChar) {
 693         extData->maxBytesPerUChar=ratio;
 694     }
 695
 696     return value;
 697 }
 698
 699 /*
 700  * works like generateToUTable(), except that the
 701  * output section consists of two arrays, one for input UChars and one
 702  * for result values
 703  *
 704  * also, fromUTable sections are always stored in a compact form for
 705  * access via binary search
 706  */
 707 static UBool
 708 generateFromUTable(CnvExtData *extData, UCMTable *table,
 709                    int32_t start, int32_t limit, int32_t unitIndex,
 710                    uint32_t defaultValue) {
 711     UCMapping *mappings, *m;
 712     int32_t *map;
 713     int32_t i, j, uniqueCount, count, subStart, subLimit;
 714
 715     UChar *uchars;
 716     UChar32 low, high, prev;
 717
 718     UChar *sectionUChars;
 719     uint32_t *sectionValues;
 720
 721     mappings=table->mappings;
 722     map=table->reverseMap;
 723
 724     /* step 1: examine the input units; set low, high, uniqueCount */
 725     m=mappings+map[start];
 726     uchars=(UChar *)UCM_GET_CODE_POINTS(table, m);
 727     low=uchars[unitIndex];
 728     uniqueCount=1;
 729
 730     prev=high=low;
 731     for(i=start+1; i<limit; ++i) {
 732         m=mappings+map[i];
 733         uchars=(UChar *)UCM_GET_CODE_POINTS(table, m);
 734         high=uchars[unitIndex];
 735
 736         if(high!=prev) {
 737             prev=high;
 738             ++uniqueCount;
 739         }
 740     }
 741
 742     /* step 2: allocate the section; set count, section */
 743     /* the fromUTable always stores for access via binary search */
 744     count=uniqueCount;
 745
 746     /* allocate the section: 1 entry for the header + count for the items */
 747     sectionUChars=(UChar *)utm_allocN(extData->fromUTableUChars, 1+count);
 748     sectionValues=(uint32_t *)utm_allocN(extData->fromUTableValues, 1+count);
 749
 750     /* write the section header */
 751     *sectionUChars++=(UChar)count;
 752     *sectionValues++=defaultValue;
 753
 754     /* step 3: write temporary section table with subsection starts */
 755     prev=low-1; /* just before low to prevent empty subsections before low */
 756     j=0; /* section table index */
 757     for(i=start; i<limit; ++i) {
 758         m=mappings+map[i];
 759         uchars=(UChar *)UCM_GET_CODE_POINTS(table, m);
 760         high=uchars[unitIndex];
 761
 762         if(high!=prev) {
 763             /* start of a new subsection for unit high */
 764             prev=high;
 765
 766             /* write the entry with the subsection start */
 767             sectionUChars[j]=(UChar)high;
 768             sectionValues[j]=(uint32_t)i;
 769             ++j;
 770         }
 771     }
 772     /* assert(j==count) */
 773
 774     /* step 4: recurse and write results */
 775     subLimit=(int32_t)(sectionValues[0]);
 776     for(j=0; j<count; ++j) {
 777         subStart=subLimit;
 778         subLimit= (j+1)<count ? (int32_t)(sectionValues[j+1]) : limit;
 779
 780         /* see if there is exactly one input unit sequence of length unitIndex+1 */
 781         defaultValue=0;
 782         m=mappings+map[subStart];
 783         if(m->uLen==unitIndex+1) {
 784             /* do not include this in generateToUTable() */
 785             ++subStart;
 786
 787             if(subStart<subLimit && mappings[map[subStart]].uLen==unitIndex+1) {
 788                 /* print error for multiple same-input-sequence mappings */
 789                 fprintf(stderr, "error: multiple mappings from same Unicode code points\n");
 790                 ucm_printMapping(table, m, stderr);
 791                 ucm_printMapping(table, mappings+map[subStart], stderr);
 792                 return FALSE;
 793             }
 794
 795             defaultValue=getFromUBytesValue(extData, table, m);
 796         }
 797
 798         if(subStart==subLimit) {
 799             /* write the result for the input sequence ending here */
 800             sectionValues[j]=defaultValue;
 801         } else {
 802             /* write the index to the subsection table */
 803             sectionValues[j]=(uint32_t)utm_countItems(extData->fromUTableValues);
 804
 805             /* recurse */
 806             if(!generateFromUTable(extData, table, subStart, subLimit, unitIndex+1, defaultValue)) {
 807                 return FALSE;
 808             }
 809         }
 810     }
 811     return TRUE;
 812 }
 813
 814 /*
 815  * add entries to the fromUnicode trie,
 816  * assume to be called with code points in ascending order
 817  * and use that to build the trie in precompacted form
 818  */
 819 static void
 820 addFromUTrieEntry(CnvExtData *extData, UChar32 c, uint32_t value) {
 821     int32_t i1, i2, i3, i3b, nextOffset, min, newBlock;
 822
 823     if(value==0) {
 824         return;
 825     }
 826
 827     /*
 828      * compute the index for each stage,
 829      * allocate a stage block if necessary,
 830      * and write the stage value
 831      */
 832     i1=c>>10;
 833     if(i1>=extData->stage1Top) {
 834         extData->stage1Top=i1+1;
 835     }
 836
 837     nextOffset=(c>>4)&0x3f;
 838
 839     if(extData->stage1[i1]==0) {
 840         /* allocate another block in stage 2; overlap with the previous block */
 841         newBlock=extData->stage2Top;
 842         min=newBlock-nextOffset; /* minimum block start with overlap */
 843         while(min<newBlock && extData->stage2[newBlock-1]==0) {
 844             --newBlock;
 845         }
 846
 847         extData->stage1[i1]=(uint16_t)newBlock;
 848         extData->stage2Top=newBlock+MBCS_STAGE_2_BLOCK_SIZE;
 849         if(extData->stage2Top>LENGTHOF(extData->stage2)) {
 850             fprintf(stderr, "error: too many stage 2 entries at U+%04x\n", (int)c);
 851             exit(U_MEMORY_ALLOCATION_ERROR);
 852         }
 853     }
 854
 855     i2=extData->stage1[i1]+nextOffset;
 856     nextOffset=c&0xf;
 857
 858     if(extData->stage2[i2]==0) {
 859         /* allocate another block in stage 3; overlap with the previous block */
 860         newBlock=extData->stage3Top;
 861         min=newBlock-nextOffset; /* minimum block start with overlap */
 862         while(min<newBlock && extData->stage3[newBlock-1]==0) {
 863             --newBlock;
 864         }
 865
 866         /* round up to a multiple of stage 3 granularity >1 (similar to utrie.c) */
 867         newBlock=(newBlock+(UCNV_EXT_STAGE_3_GRANULARITY-1))&~(UCNV_EXT_STAGE_3_GRANULARITY-1);
 868         extData->stage2[i2]=(uint16_t)(newBlock>>UCNV_EXT_STAGE_2_LEFT_SHIFT);
 869
 870         extData->stage3Top=newBlock+MBCS_STAGE_3_BLOCK_SIZE;
 871         if(extData->stage3Top>LENGTHOF(extData->stage3)) {
 872             fprintf(stderr, "error: too many stage 3 entries at U+%04x\n", (int)c);
 873             exit(U_MEMORY_ALLOCATION_ERROR);
 874         }
 875     }
 876
 877     i3=((int32_t)extData->stage2[i2]<<UCNV_EXT_STAGE_2_LEFT_SHIFT)+nextOffset;
 878     /*
 879      * assume extData->stage3[i3]==0 because we get
 880      * code points in strictly ascending order
 881      */
 882
 883     if(value==UCNV_EXT_FROM_U_SUBCHAR1) {
 884         /* <subchar1> SUB mapping, see getFromUBytesValue() and prepareFromUMappings() */
 885         extData->stage3[i3]=1;
 886
 887         /*
 888          * precompaction is not optimal for <subchar1> |2 mappings because
 889          * stage3 values for them are all the same, unlike for other mappings
 890          * which all have unique values;
 891          * use a simple compaction of reusing a whole block filled with these
 892          * mappings
 893          */
 894
 895         /* is the entire block filled with <subchar1> |2 mappings? */
 896         if(nextOffset==MBCS_STAGE_3_BLOCK_SIZE-1) {
 897             for(min=i3-nextOffset;
 898                 min<i3 && extData->stage3[min]==1;
 899                 ++min) {}
 900
 901             if(min==i3) {
 902                 /* the entire block is filled with these mappings */
 903                 if(extData->stage3Sub1Block!=0) {
 904                     /* point to the previous such block and remove this block from stage3 */
 905                     extData->stage2[i2]=extData->stage3Sub1Block;
 906                     extData->stage3Top-=MBCS_STAGE_3_BLOCK_SIZE;
 907                     uprv_memset(extData->stage3+extData->stage3Top, 0, MBCS_STAGE_3_BLOCK_SIZE*2);
 908                 } else {
 909                     /* remember this block's stage2 entry */
 910                     extData->stage3Sub1Block=extData->stage2[i2];
 911                 }
 912             }
 913         }
 914     } else {
 915         if((i3b=extData->stage3bTop++)>=LENGTHOF(extData->stage3b)) {
 916             fprintf(stderr, "error: too many stage 3b entries at U+%04x\n", (int)c);
 917             exit(U_MEMORY_ALLOCATION_ERROR);
 918         }
 919
 920         /* roundtrip or fallback mapping */
 921         extData->stage3[i3]=(uint16_t)i3b;
 922         extData->stage3b[i3b]=value;
 923     }
 924 }
 925
 926 static UBool
 927 generateFromUTrie(CnvExtData *extData, UCMTable *table, int32_t mapLength) {
 928     UCMapping *mappings, *m;
 929     int32_t *map;
 930     uint32_t value;
 931     int32_t subStart, subLimit;
 932
 933     UChar32 *codePoints;
 934     UChar32 c, next;
 935
 936     if(mapLength==0) {
 937         return TRUE;
 938     }
 939
 940     mappings=table->mappings;
 941     map=table->reverseMap;
 942
 943     /*
 944      * iterate over same-initial-code point mappings,
 945      * enter the initial code point into the trie,
 946      * and start a recursion on the corresponding mappings section
 947      * with generateFromUTable()
 948      */
 949     m=mappings+map[0];
 950     codePoints=UCM_GET_CODE_POINTS(table, m);
 951     next=codePoints[0];
 952     subLimit=0;
 953     while(subLimit<mapLength) {
 954         /* get a new subsection of mappings starting with the same code point */
 955         subStart=subLimit;
 956         c=next;
 957         while(next==c && ++subLimit<mapLength) {
 958             m=mappings+map[subLimit];
 959             codePoints=UCM_GET_CODE_POINTS(table, m);
 960             next=codePoints[0];
 961         }
 962
 963         /*
 964          * compute the value for this code point;
 965          * if there is a mapping for this code point alone, it is at subStart
 966          * because the table is sorted lexically
 967          */
 968         value=0;
 969         m=mappings+map[subStart];
 970         codePoints=UCM_GET_CODE_POINTS(table, m);
 971         if(m->uLen==1) {
 972             /* do not include this in generateFromUTable() */
 973             ++subStart;
 974
 975             if(subStart<subLimit && mappings[map[subStart]].uLen==1) {
 976                 /* print error for multiple same-input-sequence mappings */
 977                 fprintf(stderr, "error: multiple mappings from same Unicode code points\n");
 978                 ucm_printMapping(table, m, stderr);
 979                 ucm_printMapping(table, mappings+map[subStart], stderr);
 980                 return FALSE;
 981             }
 982
 983             value=getFromUBytesValue(extData, table, m);
 984         }
 985
 986         if(subStart==subLimit) {
 987             /* write the result for this one code point */
 988             addFromUTrieEntry(extData, c, value);
 989         } else {
 990             /* write the index to the subsection table */
 991             addFromUTrieEntry(extData, c, (uint32_t)utm_countItems(extData->fromUTableValues));
 992
 993             /* recurse, starting from 16-bit-unit index 2, the first 16-bit unit after c */
 994             if(!generateFromUTable(extData, table, subStart, subLimit, 2, value)) {
 995                 return FALSE;
 996             }
 997         }
 998     }
 999     return TRUE;
1000 }
1001
1002 /*
1003  * Generate the fromU data structures from the input table.
1004  * The input table must be sorted, and all precision flags must be 0..3.
1005  * This function will modify the table's reverseMap.
1006  */
1007 static UBool
1008 makeFromUTable(CnvExtData *extData, UCMTable *table) {
1009     uint16_t *stage1;
1010     int32_t i, stage1Top, fromUCount;
1011
1012     fromUCount=prepareFromUMappings(table);
1013
1014     extData->fromUTableUChars=utm_open("cnv extension fromUTableUChars", 0x10000, UCNV_EXT_FROM_U_DATA_MASK+1, 2);
1015     extData->fromUTableValues=utm_open("cnv extension fromUTableValues", 0x10000, UCNV_EXT_FROM_U_DATA_MASK+1, 4);
1016     extData->fromUBytes=utm_open("cnv extension fromUBytes", 0x10000, UCNV_EXT_FROM_U_DATA_MASK+1, 1);
1017
1018     /* allocate all-unassigned stage blocks */
1019     extData->stage2Top=MBCS_STAGE_2_FIRST_ASSIGNED;
1020     extData->stage3Top=MBCS_STAGE_3_FIRST_ASSIGNED;
1021
1022     /*
1023      * stage 3b stores only unique values, and in
1024      * index 0: 0 for "no mapping"
1025      * index 1: "no mapping" with preference for <subchar1> rather than <subchar>
1026      */
1027     extData->stage3b[1]=UCNV_EXT_FROM_U_SUBCHAR1;
1028     extData->stage3bTop=2;
1029
1030     /* allocate the first entry in the fromUTable because index 0 means "no result" */
1031     utm_alloc(extData->fromUTableUChars);
1032     utm_alloc(extData->fromUTableValues);
1033
1034     if(!generateFromUTrie(extData, table, fromUCount)) {
1035         return FALSE;
1036     }
1037
1038     /*
1039      * offset the stage 1 trie entries by stage1Top because they will
1040      * be stored in a single array
1041      */
1042     stage1=extData->stage1;
1043     stage1Top=extData->stage1Top;
1044     for(i=0; i<stage1Top; ++i) {
1045         stage1[i]=(uint16_t)(stage1[i]+stage1Top);
1046     }
1047
1048     return TRUE;
1049 }
1050
1051 /* -------------------------------------------------------------------------- */
1052
1053 static UBool
1054 CnvExtAddTable(NewConverter *cnvData, UCMTable *table, UConverterStaticData *staticData) {
1055     CnvExtData *extData;
1056
1057     if(table->unicodeMask&UCNV_HAS_SURROGATES) {
1058         fprintf(stderr, "error: contains mappings for surrogate code points\n");
1059         return FALSE;
1060     }
1061
1062     staticData->conversionType=UCNV_MBCS;
1063
1064     extData=(CnvExtData *)cnvData;
1065
1066     /*
1067      * assume that the table is sorted
1068      *
1069      * call the functions in this order because
1070      * makeToUTable() modifies the original reverseMap,
1071      * makeFromUTable() writes a whole new mapping into reverseMap
1072      */
1073     return
1074         makeToUTable(extData, table) &&
1075         makeFromUTable(extData, table);
1076 }