icuSources/tools/makeconv/gencnvex.c

   1 /*
   2 *******************************************************************************
   3 *
   4 *   Copyright (C) 2003-2014, 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 static void
  31 CnvExtClose(NewConverter *cnvData);
  32
  33 static UBool
  34 CnvExtIsValid(NewConverter *cnvData,
  35               const uint8_t *bytes, int32_t length);
  36
  37 static UBool
  38 CnvExtAddTable(NewConverter *cnvData, UCMTable *table, UConverterStaticData *staticData);
  39
  40 static uint32_t
  41 CnvExtWrite(NewConverter *cnvData, const UConverterStaticData *staticData,
  42             UNewDataMemory *pData, int32_t tableType);
  43
  44 typedef struct CnvExtData {
  45     NewConverter newConverter;
  46
  47     UCMFile *ucm;
  48
  49     /* toUnicode (state table in ucm->states) */
  50     UToolMemory *toUTable, *toUUChars;
  51
  52     /* fromUnicode */
  53     UToolMemory *fromUTableUChars, *fromUTableValues, *fromUBytes;
  54
  55     uint16_t stage1[MBCS_STAGE_1_SIZE];
  56     uint16_t stage2[MBCS_STAGE_2_SIZE];
  57     uint16_t stage3[0x10000<<UCNV_EXT_STAGE_2_LEFT_SHIFT]; /* 0x10000 because of 16-bit stage 2/3 indexes */
  58     uint32_t stage3b[0x10000];
  59
  60     int32_t stage1Top, stage2Top, stage3Top, stage3bTop;
  61
  62     /* for stage3 compaction of <subchar1> |2 mappings */
  63     uint16_t stage3Sub1Block;
  64
  65     /* statistics */
  66     int32_t
  67         maxInBytes, maxOutBytes, maxBytesPerUChar,
  68         maxInUChars, maxOutUChars, maxUCharsPerByte;
  69 } CnvExtData;
  70
  71 NewConverter *
  72 CnvExtOpen(UCMFile *ucm) {
  73     CnvExtData *extData;
  74
  75     extData=(CnvExtData *)uprv_malloc(sizeof(CnvExtData));
  76     if(extData==NULL) {
  77         printf("out of memory\n");
  78         exit(U_MEMORY_ALLOCATION_ERROR);
  79     }
  80     uprv_memset(extData, 0, sizeof(CnvExtData));
  81
  82     extData->ucm=ucm; /* aliased, not owned */
  83
  84     extData->newConverter.close=CnvExtClose;
  85     extData->newConverter.isValid=CnvExtIsValid;
  86     extData->newConverter.addTable=CnvExtAddTable;
  87     extData->newConverter.write=CnvExtWrite;
  88     return &extData->newConverter;
  89 }
  90
  91 static void
  92 CnvExtClose(NewConverter *cnvData) {
  93     CnvExtData *extData=(CnvExtData *)cnvData;
  94     if(extData!=NULL) {
  95         utm_close(extData->toUTable);
  96         utm_close(extData->toUUChars);
  97         utm_close(extData->fromUTableUChars);
  98         utm_close(extData->fromUTableValues);
  99         utm_close(extData->fromUBytes);
 100         uprv_free(extData);
 101     }
 102 }
 103
 104 /* we do not expect this to be called */
 105 static UBool
 106 CnvExtIsValid(NewConverter *cnvData,
 107         const uint8_t *bytes, int32_t length) {
 108     return FALSE;
 109 }
 110
 111 static uint32_t
 112 CnvExtWrite(NewConverter *cnvData, const UConverterStaticData *staticData,
 113             UNewDataMemory *pData, int32_t tableType) {
 114     CnvExtData *extData=(CnvExtData *)cnvData;
 115     int32_t length, top, headerSize;
 116
 117     int32_t indexes[UCNV_EXT_INDEXES_MIN_LENGTH]={ 0 };
 118
 119     if(tableType&TABLE_BASE) {
 120         headerSize=0;
 121     } else {
 122         _MBCSHeader header={ { 0, 0, 0, 0 }, 0, 0, 0, 0, 0, 0, 0 };
 123
 124         /* write the header and base table name for an extension-only table */
 125         length=(int32_t)uprv_strlen(extData->ucm->baseName)+1;
 126         while(length&3) {
 127             /* add padding */
 128             extData->ucm->baseName[length++]=0;
 129         }
 130
 131         headerSize=MBCS_HEADER_V4_LENGTH*4+length;
 132
 133         /* fill the header */
 134         header.version[0]=4;
 135         header.version[1]=2;
 136         header.flags=(uint32_t)((headerSize<<8)|MBCS_OUTPUT_EXT_ONLY);
 137
 138         /* write the header and the base table name */
 139         udata_writeBlock(pData, &header, MBCS_HEADER_V4_LENGTH*4);
 140         udata_writeBlock(pData, extData->ucm->baseName, length);
 141     }
 142
 143     /* fill indexes[] - offsets/indexes are in units of the target array */
 144     top=0;
 145
 146     indexes[UCNV_EXT_INDEXES_LENGTH]=length=UCNV_EXT_INDEXES_MIN_LENGTH;
 147     top+=length*4;
 148
 149     indexes[UCNV_EXT_TO_U_INDEX]=top;
 150     indexes[UCNV_EXT_TO_U_LENGTH]=length=utm_countItems(extData->toUTable);
 151     top+=length*4;
 152
 153     indexes[UCNV_EXT_TO_U_UCHARS_INDEX]=top;
 154     indexes[UCNV_EXT_TO_U_UCHARS_LENGTH]=length=utm_countItems(extData->toUUChars);
 155     top+=length*2;
 156
 157     indexes[UCNV_EXT_FROM_U_UCHARS_INDEX]=top;
 158     length=utm_countItems(extData->fromUTableUChars);
 159     top+=length*2;
 160
 161     if(top&3) {
 162         /* add padding */
 163         *((UChar *)utm_alloc(extData->fromUTableUChars))=0;
 164         *((uint32_t *)utm_alloc(extData->fromUTableValues))=0;
 165         ++length;
 166         top+=2;
 167     }
 168     indexes[UCNV_EXT_FROM_U_LENGTH]=length;
 169
 170     indexes[UCNV_EXT_FROM_U_VALUES_INDEX]=top;
 171     top+=length*4;
 172
 173     indexes[UCNV_EXT_FROM_U_BYTES_INDEX]=top;
 174     length=utm_countItems(extData->fromUBytes);
 175     top+=length;
 176
 177     if(top&1) {
 178         /* add padding */
 179         *((uint8_t *)utm_alloc(extData->fromUBytes))=0;
 180         ++length;
 181         ++top;
 182     }
 183     indexes[UCNV_EXT_FROM_U_BYTES_LENGTH]=length;
 184
 185     indexes[UCNV_EXT_FROM_U_STAGE_12_INDEX]=top;
 186     indexes[UCNV_EXT_FROM_U_STAGE_1_LENGTH]=length=extData->stage1Top;
 187     indexes[UCNV_EXT_FROM_U_STAGE_12_LENGTH]=length+=extData->stage2Top;
 188     top+=length*2;
 189
 190     indexes[UCNV_EXT_FROM_U_STAGE_3_INDEX]=top;
 191     length=extData->stage3Top;
 192     top+=length*2;
 193
 194     if(top&3) {
 195         /* add padding */
 196         extData->stage3[extData->stage3Top++]=0;
 197         ++length;
 198         top+=2;
 199     }
 200     indexes[UCNV_EXT_FROM_U_STAGE_3_LENGTH]=length;
 201
 202     indexes[UCNV_EXT_FROM_U_STAGE_3B_INDEX]=top;
 203     indexes[UCNV_EXT_FROM_U_STAGE_3B_LENGTH]=length=extData->stage3bTop;
 204     top+=length*4;
 205
 206     indexes[UCNV_EXT_SIZE]=top;
 207
 208     /* statistics */
 209     indexes[UCNV_EXT_COUNT_BYTES]=
 210         (extData->maxInBytes<<16)|
 211         (extData->maxOutBytes<<8)|
 212         extData->maxBytesPerUChar;
 213     indexes[UCNV_EXT_COUNT_UCHARS]=
 214         (extData->maxInUChars<<16)|
 215         (extData->maxOutUChars<<8)|
 216         extData->maxUCharsPerByte;
 217
 218     indexes[UCNV_EXT_FLAGS]=extData->ucm->ext->unicodeMask;
 219
 220     /* write the extension data */
 221     udata_writeBlock(pData, indexes, sizeof(indexes));
 222     udata_writeBlock(pData, utm_getStart(extData->toUTable), indexes[UCNV_EXT_TO_U_LENGTH]*4);
 223     udata_writeBlock(pData, utm_getStart(extData->toUUChars), indexes[UCNV_EXT_TO_U_UCHARS_LENGTH]*2);
 224
 225     udata_writeBlock(pData, utm_getStart(extData->fromUTableUChars), indexes[UCNV_EXT_FROM_U_LENGTH]*2);
 226     udata_writeBlock(pData, utm_getStart(extData->fromUTableValues), indexes[UCNV_EXT_FROM_U_LENGTH]*4);
 227     udata_writeBlock(pData, utm_getStart(extData->fromUBytes), indexes[UCNV_EXT_FROM_U_BYTES_LENGTH]);
 228
 229     udata_writeBlock(pData, extData->stage1, extData->stage1Top*2);
 230     udata_writeBlock(pData, extData->stage2, extData->stage2Top*2);
 231     udata_writeBlock(pData, extData->stage3, extData->stage3Top*2);
 232     udata_writeBlock(pData, extData->stage3b, extData->stage3bTop*4);
 233
 234 #if 0
 235     {
 236         int32_t i, j;
 237
 238         length=extData->stage1Top;
 239         printf("\nstage1[%x]:\n", length);
 240
 241         for(i=0; i<length; ++i) {
 242             if(extData->stage1[i]!=length) {
 243                 printf("stage1[%04x]=%04x\n", i, extData->stage1[i]);
 244             }
 245         }
 246
 247         j=length;
 248         length=extData->stage2Top;
 249         printf("\nstage2[%x]:\n", length);
 250
 251         for(i=0; i<length; ++j, ++i) {
 252             if(extData->stage2[i]!=0) {
 253                 printf("stage12[%04x]=%04x\n", j, extData->stage2[i]);
 254             }
 255         }
 256
 257         length=extData->stage3Top;
 258         printf("\nstage3[%x]:\n", length);
 259
 260         for(i=0; i<length; ++i) {
 261             if(extData->stage3[i]!=0) {
 262                 printf("stage3[%04x]=%04x\n", i, extData->stage3[i]);
 263             }
 264         }
 265
 266         length=extData->stage3bTop;
 267         printf("\nstage3b[%x]:\n", length);
 268
 269         for(i=0; i<length; ++i) {
 270             if(extData->stage3b[i]!=0) {
 271                 printf("stage3b[%04x]=%08x\n", i, extData->stage3b[i]);
 272             }
 273         }
 274     }
 275 #endif
 276
 277     if(VERBOSE) {
 278         printf("size of extension data: %ld\n", (long)top);
 279     }
 280
 281     /* return the number of bytes that should have been written */
 282     return (uint32_t)(headerSize+top);
 283 }
 284
 285 /* to Unicode --------------------------------------------------------------- */
 286
 287 /*
 288  * Remove fromUnicode fallbacks and SUB mappings which are irrelevant for
 289  * the toUnicode table.
 290  * This includes mappings with MBCS_FROM_U_EXT_FLAG which were suitable
 291  * for the base toUnicode table but not for the base fromUnicode table.
 292  * The table must be sorted.
 293  * Modifies previous data in the reverseMap.
 294  */
 295 static int32_t
 296 reduceToUMappings(UCMTable *table) {
 297     UCMapping *mappings;
 298     int32_t *map;
 299     int32_t i, j, count;
 300     int8_t flag;
 301
 302     mappings=table->mappings;
 303     map=table->reverseMap;
 304     count=table->mappingsLength;
 305
 306     /* leave the map alone for the initial mappings with desired flags */
 307     for(i=j=0; i<count; ++i) {
 308         flag=mappings[map[i]].f;
 309         if(flag!=0 && flag!=3) {
 310             break;
 311         }
 312     }
 313
 314     /* reduce from here to the rest */
 315     for(j=i; i<count; ++i) {
 316         flag=mappings[map[i]].f;
 317         if(flag==0 || flag==3) {
 318             map[j++]=map[i];
 319         }
 320     }
 321
 322     return j;
 323 }
 324
 325 static uint32_t
 326 getToUnicodeValue(CnvExtData *extData, UCMTable *table, UCMapping *m) {
 327     UChar32 *u32;
 328     UChar *u;
 329     uint32_t value;
 330     int32_t u16Length, ratio;
 331     UErrorCode errorCode;
 332
 333     /* write the Unicode result code point or string index */
 334     if(m->uLen==1) {
 335         u16Length=U16_LENGTH(m->u);
 336         value=(uint32_t)(UCNV_EXT_TO_U_MIN_CODE_POINT+m->u);
 337     } else {
 338         /* the parser enforces m->uLen<=UCNV_EXT_MAX_UCHARS */
 339
 340         /* get the result code point string and its 16-bit string length */
 341         u32=UCM_GET_CODE_POINTS(table, m);
 342         errorCode=U_ZERO_ERROR;
 343         u_strFromUTF32(NULL, 0, &u16Length, u32, m->uLen, &errorCode);
 344         if(U_FAILURE(errorCode) && errorCode!=U_BUFFER_OVERFLOW_ERROR) {
 345             exit(errorCode);
 346         }
 347
 348         /* allocate it and put its length and index into the value */
 349         value=
 350             (((uint32_t)u16Length+UCNV_EXT_TO_U_LENGTH_OFFSET)<<UCNV_EXT_TO_U_LENGTH_SHIFT)|
 351             ((uint32_t)utm_countItems(extData->toUUChars));
 352         u=utm_allocN(extData->toUUChars, u16Length);
 353
 354         /* write the result 16-bit string */
 355         errorCode=U_ZERO_ERROR;
 356         u_strFromUTF32(u, u16Length, NULL, u32, m->uLen, &errorCode);
 357         if(U_FAILURE(errorCode) && errorCode!=U_BUFFER_OVERFLOW_ERROR) {
 358             exit(errorCode);
 359         }
 360     }
 361     if(m->f==0) {
 362         value|=UCNV_EXT_TO_U_ROUNDTRIP_FLAG;
 363     }
 364
 365     /* update statistics */
 366     if(m->bLen>extData->maxInBytes) {
 367         extData->maxInBytes=m->bLen;
 368     }
 369     if(u16Length>extData->maxOutUChars) {
 370         extData->maxOutUChars=u16Length;
 371     }
 372
 373     ratio=(u16Length+(m->bLen-1))/m->bLen;
 374     if(ratio>extData->maxUCharsPerByte) {
 375         extData->maxUCharsPerByte=ratio;
 376     }
 377
 378     return value;
 379 }
 380
 381 /*
 382  * Recursive toUTable generator core function.
 383  * Preconditions:
 384  * - start<limit (There is at least one mapping.)
 385  * - The mappings are sorted lexically. (Access is through the reverseMap.)
 386  * - All mappings between start and limit have input sequences that share
 387  *   the same prefix of unitIndex length, and therefore all of these sequences
 388  *   are at least unitIndex+1 long.
 389  * - There are only relevant mappings available through the reverseMap,
 390  *   see reduceToUMappings().
 391  *
 392  * One function invocation generates one section table.
 393  *
 394  * Steps:
 395  * 1. Count the number of unique unit values and get the low/high unit values
 396  *    that occur at unitIndex.
 397  * 2. Allocate the section table with possible optimization for linear access.
 398  * 3. Write temporary version of the section table with start indexes of
 399  *    subsections, each corresponding to one unit value at unitIndex.
 400  * 4. Iterate through the table once more, and depending on the subsection length:
 401  *    0: write 0 as a result value (unused byte in linear-access section table)
 402  *   >0: if there is one mapping with an input unit sequence of unitIndex+1
 403  *       then defaultValue=compute the mapping result for this whole sequence
 404  *       else defaultValue=0
 405  *
 406  *       recurse into the subsection
 407  */
 408 static UBool
 409 generateToUTable(CnvExtData *extData, UCMTable *table,
 410                  int32_t start, int32_t limit, int32_t unitIndex,
 411                  uint32_t defaultValue) {
 412     UCMapping *mappings, *m;
 413     int32_t *map;
 414     int32_t i, j, uniqueCount, count, subStart, subLimit;
 415
 416     uint8_t *bytes;
 417     int32_t low, high, prev;
 418
 419     uint32_t *section;
 420
 421     mappings=table->mappings;
 422     map=table->reverseMap;
 423
 424     /* step 1: examine the input units; set low, high, uniqueCount */
 425     m=mappings+map[start];
 426     bytes=UCM_GET_BYTES(table, m);
 427     low=bytes[unitIndex];
 428     uniqueCount=1;
 429
 430     prev=high=low;
 431     for(i=start+1; i<limit; ++i) {
 432         m=mappings+map[i];
 433         bytes=UCM_GET_BYTES(table, m);
 434         high=bytes[unitIndex];
 435
 436         if(high!=prev) {
 437             prev=high;
 438             ++uniqueCount;
 439         }
 440     }
 441
 442     /* step 2: allocate the section; set count, section */
 443     count=(high-low)+1;
 444     if(count<0x100 && (unitIndex==0 || uniqueCount>=(3*count)/4)) {
 445         /*
 446          * for the root table and for fairly full tables:
 447          * allocate for direct, linear array access
 448          * by keeping count, to write an entry for each unit value
 449          * from low to high
 450          * exception: use a compact table if count==0x100 because
 451          * that cannot be encoded in the length byte
 452          */
 453     } else {
 454         count=uniqueCount;
 455     }
 456
 457     if(count>=0x100) {
 458         fprintf(stderr, "error: toUnicode extension table section overflow: %ld section entries\n", (long)count);
 459         return FALSE;
 460     }
 461
 462     /* allocate the section: 1 entry for the header + count for the items */
 463     section=(uint32_t *)utm_allocN(extData->toUTable, 1+count);
 464
 465     /* write the section header */
 466     *section++=((uint32_t)count<<UCNV_EXT_TO_U_BYTE_SHIFT)|defaultValue;
 467
 468     /* step 3: write temporary section table with subsection starts */
 469     prev=low-1; /* just before low to prevent empty subsections before low */
 470     j=0; /* section table index */
 471     for(i=start; i<limit; ++i) {
 472         m=mappings+map[i];
 473         bytes=UCM_GET_BYTES(table, m);
 474         high=bytes[unitIndex];
 475
 476         if(high!=prev) {
 477             /* start of a new subsection for unit high */
 478             if(count>uniqueCount) {
 479                 /* write empty subsections for unused units in a linear table */
 480                 while(++prev<high) {
 481                     section[j++]=((uint32_t)prev<<UCNV_EXT_TO_U_BYTE_SHIFT)|(uint32_t)i;
 482                 }
 483             } else {
 484                 prev=high;
 485             }
 486
 487             /* write the entry with the subsection start */
 488             section[j++]=((uint32_t)high<<UCNV_EXT_TO_U_BYTE_SHIFT)|(uint32_t)i;
 489         }
 490     }
 491     /* assert(j==count) */
 492
 493     /* step 4: recurse and write results */
 494     subLimit=UCNV_EXT_TO_U_GET_VALUE(section[0]);
 495     for(j=0; j<count; ++j) {
 496         subStart=subLimit;
 497         subLimit= (j+1)<count ? UCNV_EXT_TO_U_GET_VALUE(section[j+1]) : limit;
 498
 499         /* remove the subStart temporary value */
 500         section[j]&=~UCNV_EXT_TO_U_VALUE_MASK;
 501
 502         if(subStart==subLimit) {
 503             /* leave the value zero: empty subsection for unused unit in a linear table */
 504             continue;
 505         }
 506
 507         /* see if there is exactly one input unit sequence of length unitIndex+1 */
 508         defaultValue=0;
 509         m=mappings+map[subStart];
 510         if(m->bLen==unitIndex+1) {
 511             /* do not include this in generateToUTable() */
 512             ++subStart;
 513
 514             if(subStart<subLimit && mappings[map[subStart]].bLen==unitIndex+1) {
 515                 /* print error for multiple same-input-sequence mappings */
 516                 fprintf(stderr, "error: multiple mappings from same bytes\n");
 517                 ucm_printMapping(table, m, stderr);
 518                 ucm_printMapping(table, mappings+map[subStart], stderr);
 519                 return FALSE;
 520             }
 521
 522             defaultValue=getToUnicodeValue(extData, table, m);
 523         }
 524
 525         if(subStart==subLimit) {
 526             /* write the result for the input sequence ending here */
 527             section[j]|=defaultValue;
 528         } else {
 529             /* write the index to the subsection table */
 530             section[j]|=(uint32_t)utm_countItems(extData->toUTable);
 531
 532             /* recurse */
 533             if(!generateToUTable(extData, table, subStart, subLimit, unitIndex+1, defaultValue)) {
 534                 return FALSE;
 535             }
 536         }
 537     }
 538     return TRUE;
 539 }
 540
 541 /*
 542  * Generate the toUTable and toUUChars from the input table.
 543  * The input table must be sorted, and all precision flags must be 0..3.
 544  * This function will modify the table's reverseMap.
 545  */
 546 static UBool
 547 makeToUTable(CnvExtData *extData, UCMTable *table) {
 548     int32_t toUCount;
 549
 550     toUCount=reduceToUMappings(table);
 551
 552     extData->toUTable=utm_open("cnv extension toUTable", 0x10000, UCNV_EXT_TO_U_MIN_CODE_POINT, 4);
 553     extData->toUUChars=utm_open("cnv extension toUUChars", 0x10000, UCNV_EXT_TO_U_INDEX_MASK+1, 2);
 554
 555     return generateToUTable(extData, table, 0, toUCount, 0, 0);
 556 }
 557
 558 /* from Unicode ------------------------------------------------------------- */
 559
 560 /*
 561  * preprocessing:
 562  * rebuild reverseMap with mapping indexes for mappings relevant for from Unicode
 563  * change each Unicode string to encode all but the first code point in 16-bit form
 564  *
 565  * generation:
 566  * for each unique code point
 567  *   write an entry in the 3-stage trie
 568  *   check that there is only one single-code point sequence
 569  *   start recursion for following 16-bit input units
 570  */
 571
 572 /*
 573  * Remove toUnicode fallbacks and non-<subchar1> SUB mappings
 574  * which are irrelevant for the fromUnicode extension table.
 575  * Remove MBCS_FROM_U_EXT_FLAG bits.
 576  * Overwrite the reverseMap with an index array to the relevant mappings.
 577  * Modify the code point sequences to a generator-friendly format where
 578  * the first code points remains unchanged but the following are recoded
 579  * into 16-bit Unicode string form.
 580  * The table must be sorted.
 581  * Destroys previous data in the reverseMap.
 582  */
 583 static int32_t
 584 prepareFromUMappings(UCMTable *table) {
 585     UCMapping *mappings, *m;
 586     int32_t *map;
 587     int32_t i, j, count;
 588     int8_t flag;
 589
 590     mappings=table->mappings;
 591     map=table->reverseMap;
 592     count=table->mappingsLength;
 593
 594     /*
 595      * we do not go through the map on input because the mappings are
 596      * sorted lexically
 597      */
 598     m=mappings;
 599
 600     for(i=j=0; i<count; ++m, ++i) {
 601         flag=m->f;
 602         if(flag>=0) {
 603             flag&=MBCS_FROM_U_EXT_MASK;
 604             m->f=flag;
 605         }
 606         if(flag==0 || flag==1 || (flag==2 && m->bLen==1) || flag==4) {
 607             map[j++]=i;
 608
 609             if(m->uLen>1) {
 610                 /* recode all but the first code point to 16-bit Unicode */
 611                 UChar32 *u32;
 612                 UChar *u;
 613                 UChar32 c;
 614                 int32_t q, r;
 615
 616                 u32=UCM_GET_CODE_POINTS(table, m);
 617                 u=(UChar *)u32; /* destructive in-place recoding */
 618                 for(r=2, q=1; q<m->uLen; ++q) {
 619                     c=u32[q];
 620                     U16_APPEND_UNSAFE(u, r, c);
 621                 }
 622
 623                 /* counts the first code point always at 2 - the first 16-bit unit is at 16-bit index 2 */
 624                 m->uLen=(int8_t)r;
 625             }
 626         }
 627     }
 628
 629     return j;
 630 }
 631
 632 static uint32_t
 633 getFromUBytesValue(CnvExtData *extData, UCMTable *table, UCMapping *m) {
 634     uint8_t *bytes, *resultBytes;
 635     uint32_t value;
 636     int32_t u16Length, ratio;
 637
 638     if(m->f==2) {
 639         /*
 640          * no mapping, <subchar1> preferred
 641          *
 642          * no need to count in statistics because the subchars are already
 643          * counted for maxOutBytes and maxBytesPerUChar in UConverterStaticData,
 644          * and this non-mapping does not count for maxInUChars which are always
 645          * trivially at least two if counting unmappable supplementary code points
 646          */
 647         return UCNV_EXT_FROM_U_SUBCHAR1;
 648     }
 649
 650     bytes=UCM_GET_BYTES(table, m);
 651     value=0;
 652     switch(m->bLen) {
 653         /* 1..3: store the bytes in the value word */
 654     case 3:
 655         value=((uint32_t)*bytes++)<<16;
 656     case 2:
 657         value|=((uint32_t)*bytes++)<<8;
 658     case 1:
 659         value|=*bytes;
 660         break;
 661     default:
 662         /* the parser enforces m->bLen<=UCNV_EXT_MAX_BYTES */
 663         /* store the bytes in fromUBytes[] and the index in the value word */
 664         value=(uint32_t)utm_countItems(extData->fromUBytes);
 665         resultBytes=utm_allocN(extData->fromUBytes, m->bLen);
 666         uprv_memcpy(resultBytes, bytes, m->bLen);
 667         break;
 668     }
 669     value|=(uint32_t)m->bLen<<UCNV_EXT_FROM_U_LENGTH_SHIFT;
 670     if(m->f==0) {
 671         value|=UCNV_EXT_FROM_U_ROUNDTRIP_FLAG;
 672     } else if(m->f==4) {
 673         value|=UCNV_EXT_FROM_U_GOOD_ONE_WAY_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>UPRV_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>UPRV_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++)>=UPRV_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 }