xdiff / xutils.con commit Merge branch 'ee/clean-test-fixes' into maint (fb8880d)
   1/*
   2 *  LibXDiff by Davide Libenzi ( File Differential Library )
   3 *  Copyright (C) 2003  Davide Libenzi
   4 *
   5 *  This library is free software; you can redistribute it and/or
   6 *  modify it under the terms of the GNU Lesser General Public
   7 *  License as published by the Free Software Foundation; either
   8 *  version 2.1 of the License, or (at your option) any later version.
   9 *
  10 *  This library is distributed in the hope that it will be useful,
  11 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13 *  Lesser General Public License for more details.
  14 *
  15 *  You should have received a copy of the GNU Lesser General Public
  16 *  License along with this library; if not, write to the Free Software
  17 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18 *
  19 *  Davide Libenzi <davidel@xmailserver.org>
  20 *
  21 */
  22
  23#include <limits.h>
  24#include <assert.h>
  25#include "xinclude.h"
  26
  27
  28
  29
  30long xdl_bogosqrt(long n) {
  31        long i;
  32
  33        /*
  34         * Classical integer square root approximation using shifts.
  35         */
  36        for (i = 1; n > 0; n >>= 2)
  37                i <<= 1;
  38
  39        return i;
  40}
  41
  42
  43int xdl_emit_diffrec(char const *rec, long size, char const *pre, long psize,
  44                     xdemitcb_t *ecb) {
  45        int i = 2;
  46        mmbuffer_t mb[3];
  47
  48        mb[0].ptr = (char *) pre;
  49        mb[0].size = psize;
  50        mb[1].ptr = (char *) rec;
  51        mb[1].size = size;
  52        if (size > 0 && rec[size - 1] != '\n') {
  53                mb[2].ptr = (char *) "\n\\ No newline at end of file\n";
  54                mb[2].size = strlen(mb[2].ptr);
  55                i++;
  56        }
  57        if (ecb->outf(ecb->priv, mb, i) < 0) {
  58
  59                return -1;
  60        }
  61
  62        return 0;
  63}
  64
  65void *xdl_mmfile_first(mmfile_t *mmf, long *size)
  66{
  67        *size = mmf->size;
  68        return mmf->ptr;
  69}
  70
  71
  72long xdl_mmfile_size(mmfile_t *mmf)
  73{
  74        return mmf->size;
  75}
  76
  77
  78int xdl_cha_init(chastore_t *cha, long isize, long icount) {
  79
  80        cha->head = cha->tail = NULL;
  81        cha->isize = isize;
  82        cha->nsize = icount * isize;
  83        cha->ancur = cha->sncur = NULL;
  84        cha->scurr = 0;
  85
  86        return 0;
  87}
  88
  89
  90void xdl_cha_free(chastore_t *cha) {
  91        chanode_t *cur, *tmp;
  92
  93        for (cur = cha->head; (tmp = cur) != NULL;) {
  94                cur = cur->next;
  95                xdl_free(tmp);
  96        }
  97}
  98
  99
 100void *xdl_cha_alloc(chastore_t *cha) {
 101        chanode_t *ancur;
 102        void *data;
 103
 104        if (!(ancur = cha->ancur) || ancur->icurr == cha->nsize) {
 105                if (!(ancur = (chanode_t *) xdl_malloc(sizeof(chanode_t) + cha->nsize))) {
 106
 107                        return NULL;
 108                }
 109                ancur->icurr = 0;
 110                ancur->next = NULL;
 111                if (cha->tail)
 112                        cha->tail->next = ancur;
 113                if (!cha->head)
 114                        cha->head = ancur;
 115                cha->tail = ancur;
 116                cha->ancur = ancur;
 117        }
 118
 119        data = (char *) ancur + sizeof(chanode_t) + ancur->icurr;
 120        ancur->icurr += cha->isize;
 121
 122        return data;
 123}
 124
 125long xdl_guess_lines(mmfile_t *mf, long sample) {
 126        long nl = 0, size, tsize = 0;
 127        char const *data, *cur, *top;
 128
 129        if ((cur = data = xdl_mmfile_first(mf, &size)) != NULL) {
 130                for (top = data + size; nl < sample && cur < top; ) {
 131                        nl++;
 132                        if (!(cur = memchr(cur, '\n', top - cur)))
 133                                cur = top;
 134                        else
 135                                cur++;
 136                }
 137                tsize += (long) (cur - data);
 138        }
 139
 140        if (nl && tsize)
 141                nl = xdl_mmfile_size(mf) / (tsize / nl);
 142
 143        return nl + 1;
 144}
 145
 146int xdl_blankline(const char *line, long size, long flags)
 147{
 148        long i;
 149
 150        if (!(flags & XDF_WHITESPACE_FLAGS))
 151                return (size <= 1);
 152
 153        for (i = 0; i < size && XDL_ISSPACE(line[i]); i++)
 154                ;
 155
 156        return (i == size);
 157}
 158
 159int xdl_recmatch(const char *l1, long s1, const char *l2, long s2, long flags)
 160{
 161        int i1, i2;
 162
 163        if (s1 == s2 && !memcmp(l1, l2, s1))
 164                return 1;
 165        if (!(flags & XDF_WHITESPACE_FLAGS))
 166                return 0;
 167
 168        i1 = 0;
 169        i2 = 0;
 170
 171        /*
 172         * -w matches everything that matches with -b, and -b in turn
 173         * matches everything that matches with --ignore-space-at-eol.
 174         *
 175         * Each flavor of ignoring needs different logic to skip whitespaces
 176         * while we have both sides to compare.
 177         */
 178        if (flags & XDF_IGNORE_WHITESPACE) {
 179                goto skip_ws;
 180                while (i1 < s1 && i2 < s2) {
 181                        if (l1[i1++] != l2[i2++])
 182                                return 0;
 183                skip_ws:
 184                        while (i1 < s1 && XDL_ISSPACE(l1[i1]))
 185                                i1++;
 186                        while (i2 < s2 && XDL_ISSPACE(l2[i2]))
 187                                i2++;
 188                }
 189        } else if (flags & XDF_IGNORE_WHITESPACE_CHANGE) {
 190                while (i1 < s1 && i2 < s2) {
 191                        if (XDL_ISSPACE(l1[i1]) && XDL_ISSPACE(l2[i2])) {
 192                                /* Skip matching spaces and try again */
 193                                while (i1 < s1 && XDL_ISSPACE(l1[i1]))
 194                                        i1++;
 195                                while (i2 < s2 && XDL_ISSPACE(l2[i2]))
 196                                        i2++;
 197                                continue;
 198                        }
 199                        if (l1[i1++] != l2[i2++])
 200                                return 0;
 201                }
 202        } else if (flags & XDF_IGNORE_WHITESPACE_AT_EOL) {
 203                while (i1 < s1 && i2 < s2 && l1[i1++] == l2[i2++])
 204                        ; /* keep going */
 205        }
 206
 207        /*
 208         * After running out of one side, the remaining side must have
 209         * nothing but whitespace for the lines to match.  Note that
 210         * ignore-whitespace-at-eol case may break out of the loop
 211         * while there still are characters remaining on both lines.
 212         */
 213        if (i1 < s1) {
 214                while (i1 < s1 && XDL_ISSPACE(l1[i1]))
 215                        i1++;
 216                if (s1 != i1)
 217                        return 0;
 218        }
 219        if (i2 < s2) {
 220                while (i2 < s2 && XDL_ISSPACE(l2[i2]))
 221                        i2++;
 222                return (s2 == i2);
 223        }
 224        return 1;
 225}
 226
 227static unsigned long xdl_hash_record_with_whitespace(char const **data,
 228                char const *top, long flags) {
 229        unsigned long ha = 5381;
 230        char const *ptr = *data;
 231
 232        for (; ptr < top && *ptr != '\n'; ptr++) {
 233                if (XDL_ISSPACE(*ptr)) {
 234                        const char *ptr2 = ptr;
 235                        int at_eol;
 236                        while (ptr + 1 < top && XDL_ISSPACE(ptr[1])
 237                                        && ptr[1] != '\n')
 238                                ptr++;
 239                        at_eol = (top <= ptr + 1 || ptr[1] == '\n');
 240                        if (flags & XDF_IGNORE_WHITESPACE)
 241                                ; /* already handled */
 242                        else if (flags & XDF_IGNORE_WHITESPACE_CHANGE
 243                                 && !at_eol) {
 244                                ha += (ha << 5);
 245                                ha ^= (unsigned long) ' ';
 246                        }
 247                        else if (flags & XDF_IGNORE_WHITESPACE_AT_EOL
 248                                 && !at_eol) {
 249                                while (ptr2 != ptr + 1) {
 250                                        ha += (ha << 5);
 251                                        ha ^= (unsigned long) *ptr2;
 252                                        ptr2++;
 253                                }
 254                        }
 255                        continue;
 256                }
 257                ha += (ha << 5);
 258                ha ^= (unsigned long) *ptr;
 259        }
 260        *data = ptr < top ? ptr + 1: ptr;
 261
 262        return ha;
 263}
 264
 265#ifdef XDL_FAST_HASH
 266
 267#define REPEAT_BYTE(x)  ((~0ul / 0xff) * (x))
 268
 269#define ONEBYTES        REPEAT_BYTE(0x01)
 270#define NEWLINEBYTES    REPEAT_BYTE(0x0a)
 271#define HIGHBITS        REPEAT_BYTE(0x80)
 272
 273/* Return the high bit set in the first byte that is a zero */
 274static inline unsigned long has_zero(unsigned long a)
 275{
 276        return ((a - ONEBYTES) & ~a) & HIGHBITS;
 277}
 278
 279static inline long count_masked_bytes(unsigned long mask)
 280{
 281        if (sizeof(long) == 8) {
 282                /*
 283                 * Jan Achrenius on G+: microoptimized version of
 284                 * the simpler "(mask & ONEBYTES) * ONEBYTES >> 56"
 285                 * that works for the bytemasks without having to
 286                 * mask them first.
 287                 */
 288                /*
 289                 * return mask * 0x0001020304050608 >> 56;
 290                 *
 291                 * Doing it like this avoids warnings on 32-bit machines.
 292                 */
 293                long a = (REPEAT_BYTE(0x01) / 0xff + 1);
 294                return mask * a >> (sizeof(long) * 7);
 295        } else {
 296                /* Carl Chatfield / Jan Achrenius G+ version for 32-bit */
 297                /* (000000 0000ff 00ffff ffffff) -> ( 1 1 2 3 ) */
 298                long a = (0x0ff0001 + mask) >> 23;
 299                /* Fix the 1 for 00 case */
 300                return a & mask;
 301        }
 302}
 303
 304unsigned long xdl_hash_record(char const **data, char const *top, long flags)
 305{
 306        unsigned long hash = 5381;
 307        unsigned long a = 0, mask = 0;
 308        char const *ptr = *data;
 309        char const *end = top - sizeof(unsigned long) + 1;
 310
 311        if (flags & XDF_WHITESPACE_FLAGS)
 312                return xdl_hash_record_with_whitespace(data, top, flags);
 313
 314        ptr -= sizeof(unsigned long);
 315        do {
 316                hash += hash << 5;
 317                hash ^= a;
 318                ptr += sizeof(unsigned long);
 319                if (ptr >= end)
 320                        break;
 321                a = *(unsigned long *)ptr;
 322                /* Do we have any '\n' bytes in this word? */
 323                mask = has_zero(a ^ NEWLINEBYTES);
 324        } while (!mask);
 325
 326        if (ptr >= end) {
 327                /*
 328                 * There is only a partial word left at the end of the
 329                 * buffer. Because we may work with a memory mapping,
 330                 * we have to grab the rest byte by byte instead of
 331                 * blindly reading it.
 332                 *
 333                 * To avoid problems with masking in a signed value,
 334                 * we use an unsigned char here.
 335                 */
 336                const char *p;
 337                for (p = top - 1; p >= ptr; p--)
 338                        a = (a << 8) + *((const unsigned char *)p);
 339                mask = has_zero(a ^ NEWLINEBYTES);
 340                if (!mask)
 341                        /*
 342                         * No '\n' found in the partial word.  Make a
 343                         * mask that matches what we read.
 344                         */
 345                        mask = 1UL << (8 * (top - ptr) + 7);
 346        }
 347
 348        /* The mask *below* the first high bit set */
 349        mask = (mask - 1) & ~mask;
 350        mask >>= 7;
 351        hash += hash << 5;
 352        hash ^= a & mask;
 353
 354        /* Advance past the last (possibly partial) word */
 355        ptr += count_masked_bytes(mask);
 356
 357        if (ptr < top) {
 358                assert(*ptr == '\n');
 359                ptr++;
 360        }
 361
 362        *data = ptr;
 363
 364        return hash;
 365}
 366
 367#else /* XDL_FAST_HASH */
 368
 369unsigned long xdl_hash_record(char const **data, char const *top, long flags) {
 370        unsigned long ha = 5381;
 371        char const *ptr = *data;
 372
 373        if (flags & XDF_WHITESPACE_FLAGS)
 374                return xdl_hash_record_with_whitespace(data, top, flags);
 375
 376        for (; ptr < top && *ptr != '\n'; ptr++) {
 377                ha += (ha << 5);
 378                ha ^= (unsigned long) *ptr;
 379        }
 380        *data = ptr < top ? ptr + 1: ptr;
 381
 382        return ha;
 383}
 384
 385#endif /* XDL_FAST_HASH */
 386
 387unsigned int xdl_hashbits(unsigned int size) {
 388        unsigned int val = 1, bits = 0;
 389
 390        for (; val < size && bits < CHAR_BIT * sizeof(unsigned int); val <<= 1, bits++);
 391        return bits ? bits: 1;
 392}
 393
 394
 395int xdl_num_out(char *out, long val) {
 396        char *ptr, *str = out;
 397        char buf[32];
 398
 399        ptr = buf + sizeof(buf) - 1;
 400        *ptr = '\0';
 401        if (val < 0) {
 402                *--ptr = '-';
 403                val = -val;
 404        }
 405        for (; val && ptr > buf; val /= 10)
 406                *--ptr = "0123456789"[val % 10];
 407        if (*ptr)
 408                for (; *ptr; ptr++, str++)
 409                        *str = *ptr;
 410        else
 411                *str++ = '0';
 412        *str = '\0';
 413
 414        return str - out;
 415}
 416
 417int xdl_emit_hunk_hdr(long s1, long c1, long s2, long c2,
 418                      const char *func, long funclen, xdemitcb_t *ecb) {
 419        int nb = 0;
 420        mmbuffer_t mb;
 421        char buf[128];
 422
 423        memcpy(buf, "@@ -", 4);
 424        nb += 4;
 425
 426        nb += xdl_num_out(buf + nb, c1 ? s1: s1 - 1);
 427
 428        if (c1 != 1) {
 429                memcpy(buf + nb, ",", 1);
 430                nb += 1;
 431
 432                nb += xdl_num_out(buf + nb, c1);
 433        }
 434
 435        memcpy(buf + nb, " +", 2);
 436        nb += 2;
 437
 438        nb += xdl_num_out(buf + nb, c2 ? s2: s2 - 1);
 439
 440        if (c2 != 1) {
 441                memcpy(buf + nb, ",", 1);
 442                nb += 1;
 443
 444                nb += xdl_num_out(buf + nb, c2);
 445        }
 446
 447        memcpy(buf + nb, " @@", 3);
 448        nb += 3;
 449        if (func && funclen) {
 450                buf[nb++] = ' ';
 451                if (funclen > sizeof(buf) - nb - 1)
 452                        funclen = sizeof(buf) - nb - 1;
 453                memcpy(buf + nb, func, funclen);
 454                nb += funclen;
 455        }
 456        buf[nb++] = '\n';
 457
 458        mb.ptr = buf;
 459        mb.size = nb;
 460        if (ecb->outf(ecb->priv, &mb, 1) < 0)
 461                return -1;
 462
 463        return 0;
 464}
 465
 466int xdl_fall_back_diff(xdfenv_t *diff_env, xpparam_t const *xpp,
 467                int line1, int count1, int line2, int count2)
 468{
 469        /*
 470         * This probably does not work outside Git, since
 471         * we have a very simple mmfile structure.
 472         *
 473         * Note: ideally, we would reuse the prepared environment, but
 474         * the libxdiff interface does not (yet) allow for diffing only
 475         * ranges of lines instead of the whole files.
 476         */
 477        mmfile_t subfile1, subfile2;
 478        xdfenv_t env;
 479
 480        subfile1.ptr = (char *)diff_env->xdf1.recs[line1 - 1]->ptr;
 481        subfile1.size = diff_env->xdf1.recs[line1 + count1 - 2]->ptr +
 482                diff_env->xdf1.recs[line1 + count1 - 2]->size - subfile1.ptr;
 483        subfile2.ptr = (char *)diff_env->xdf2.recs[line2 - 1]->ptr;
 484        subfile2.size = diff_env->xdf2.recs[line2 + count2 - 2]->ptr +
 485                diff_env->xdf2.recs[line2 + count2 - 2]->size - subfile2.ptr;
 486        if (xdl_do_diff(&subfile1, &subfile2, xpp, &env) < 0)
 487                return -1;
 488
 489        memcpy(diff_env->xdf1.rchg + line1 - 1, env.xdf1.rchg, count1);
 490        memcpy(diff_env->xdf2.rchg + line2 - 1, env.xdf2.rchg, count2);
 491
 492        xdl_free_env(&env);
 493
 494        return 0;
 495}