a45e89bbed5ba582f31aff62b13fd6ddb27b1a85
   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 "xinclude.h"
  24
  25
  26
  27
  28long xdl_bogosqrt(long n) {
  29        long i;
  30
  31        /*
  32         * Classical integer square root approximation using shifts.
  33         */
  34        for (i = 1; n > 0; n >>= 2)
  35                i <<= 1;
  36
  37        return i;
  38}
  39
  40
  41int xdl_emit_diffrec(char const *rec, long size, char const *pre, long psize,
  42                     xdemitcb_t *ecb) {
  43        int i = 2;
  44        mmbuffer_t mb[3];
  45
  46        mb[0].ptr = (char *) pre;
  47        mb[0].size = psize;
  48        mb[1].ptr = (char *) rec;
  49        mb[1].size = size;
  50        if (size > 0 && rec[size - 1] != '\n') {
  51                mb[2].ptr = (char *) "\n\\ No newline at end of file\n";
  52                mb[2].size = strlen(mb[2].ptr);
  53                i++;
  54        }
  55        if (ecb->outf(ecb->priv, mb, i) < 0) {
  56
  57                return -1;
  58        }
  59
  60        return 0;
  61}
  62
  63void *xdl_mmfile_first(mmfile_t *mmf, long *size)
  64{
  65        *size = mmf->size;
  66        return mmf->ptr;
  67}
  68
  69
  70void *xdl_mmfile_next(mmfile_t *mmf, long *size)
  71{
  72        return NULL;
  73}
  74
  75
  76long xdl_mmfile_size(mmfile_t *mmf)
  77{
  78        return mmf->size;
  79}
  80
  81
  82int xdl_cha_init(chastore_t *cha, long isize, long icount) {
  83
  84        cha->head = cha->tail = NULL;
  85        cha->isize = isize;
  86        cha->nsize = icount * isize;
  87        cha->ancur = cha->sncur = NULL;
  88        cha->scurr = 0;
  89
  90        return 0;
  91}
  92
  93
  94void xdl_cha_free(chastore_t *cha) {
  95        chanode_t *cur, *tmp;
  96
  97        for (cur = cha->head; (tmp = cur) != NULL;) {
  98                cur = cur->next;
  99                xdl_free(tmp);
 100        }
 101}
 102
 103
 104void *xdl_cha_alloc(chastore_t *cha) {
 105        chanode_t *ancur;
 106        void *data;
 107
 108        if (!(ancur = cha->ancur) || ancur->icurr == cha->nsize) {
 109                if (!(ancur = (chanode_t *) xdl_malloc(sizeof(chanode_t) + cha->nsize))) {
 110
 111                        return NULL;
 112                }
 113                ancur->icurr = 0;
 114                ancur->next = NULL;
 115                if (cha->tail)
 116                        cha->tail->next = ancur;
 117                if (!cha->head)
 118                        cha->head = ancur;
 119                cha->tail = ancur;
 120                cha->ancur = ancur;
 121        }
 122
 123        data = (char *) ancur + sizeof(chanode_t) + ancur->icurr;
 124        ancur->icurr += cha->isize;
 125
 126        return data;
 127}
 128
 129
 130void *xdl_cha_first(chastore_t *cha) {
 131        chanode_t *sncur;
 132
 133        if (!(cha->sncur = sncur = cha->head))
 134                return NULL;
 135
 136        cha->scurr = 0;
 137
 138        return (char *) sncur + sizeof(chanode_t) + cha->scurr;
 139}
 140
 141
 142void *xdl_cha_next(chastore_t *cha) {
 143        chanode_t *sncur;
 144
 145        if (!(sncur = cha->sncur))
 146                return NULL;
 147        cha->scurr += cha->isize;
 148        if (cha->scurr == sncur->icurr) {
 149                if (!(sncur = cha->sncur = sncur->next))
 150                        return NULL;
 151                cha->scurr = 0;
 152        }
 153
 154        return (char *) sncur + sizeof(chanode_t) + cha->scurr;
 155}
 156
 157
 158long xdl_guess_lines(mmfile_t *mf, long sample) {
 159        long nl = 0, size, tsize = 0;
 160        char const *data, *cur, *top;
 161
 162        if ((cur = data = xdl_mmfile_first(mf, &size)) != NULL) {
 163                for (top = data + size; nl < sample;) {
 164                        if (cur >= top) {
 165                                tsize += (long) (cur - data);
 166                                if (!(cur = data = xdl_mmfile_next(mf, &size)))
 167                                        break;
 168                                top = data + size;
 169                        }
 170                        nl++;
 171                        if (!(cur = memchr(cur, '\n', top - cur)))
 172                                cur = top;
 173                        else
 174                                cur++;
 175                }
 176                tsize += (long) (cur - data);
 177        }
 178
 179        if (nl && tsize)
 180                nl = xdl_mmfile_size(mf) / (tsize / nl);
 181
 182        return nl + 1;
 183}
 184
 185int xdl_recmatch(const char *l1, long s1, const char *l2, long s2, long flags)
 186{
 187        int i1, i2;
 188
 189        if (s1 == s2 && !memcmp(l1, l2, s1))
 190                return 1;
 191        if (!(flags & XDF_WHITESPACE_FLAGS))
 192                return 0;
 193
 194        i1 = 0;
 195        i2 = 0;
 196
 197        /*
 198         * -w matches everything that matches with -b, and -b in turn
 199         * matches everything that matches with --ignore-space-at-eol.
 200         *
 201         * Each flavor of ignoring needs different logic to skip whitespaces
 202         * while we have both sides to compare.
 203         */
 204        if (flags & XDF_IGNORE_WHITESPACE) {
 205                goto skip_ws;
 206                while (i1 < s1 && i2 < s2) {
 207                        if (l1[i1++] != l2[i2++])
 208                                return 0;
 209                skip_ws:
 210                        while (i1 < s1 && XDL_ISSPACE(l1[i1]))
 211                                i1++;
 212                        while (i2 < s2 && XDL_ISSPACE(l2[i2]))
 213                                i2++;
 214                }
 215        } else if (flags & XDF_IGNORE_WHITESPACE_CHANGE) {
 216                while (i1 < s1 && i2 < s2) {
 217                        if (XDL_ISSPACE(l1[i1]) && XDL_ISSPACE(l2[i2])) {
 218                                /* Skip matching spaces and try again */
 219                                while (i1 < s1 && XDL_ISSPACE(l1[i1]))
 220                                        i1++;
 221                                while (i2 < s2 && XDL_ISSPACE(l2[i2]))
 222                                        i2++;
 223                                continue;
 224                        }
 225                        if (l1[i1++] != l2[i2++])
 226                                return 0;
 227                }
 228        } else if (flags & XDF_IGNORE_WHITESPACE_AT_EOL) {
 229                while (i1 < s1 && i2 < s2 && l1[i1++] == l2[i2++])
 230                        ; /* keep going */
 231        }
 232
 233        /*
 234         * After running out of one side, the remaining side must have
 235         * nothing but whitespace for the lines to match.  Note that
 236         * ignore-whitespace-at-eol case may break out of the loop
 237         * while there still are characters remaining on both lines.
 238         */
 239        if (i1 < s1) {
 240                while (i1 < s1 && XDL_ISSPACE(l1[i1]))
 241                        i1++;
 242                if (s1 != i1)
 243                        return 0;
 244        }
 245        if (i2 < s2) {
 246                while (i2 < s2 && XDL_ISSPACE(l2[i2]))
 247                        i2++;
 248                return (s2 == i2);
 249        }
 250        return 1;
 251}
 252
 253static unsigned long xdl_hash_record_with_whitespace(char const **data,
 254                char const *top, long flags) {
 255        unsigned long ha = 5381;
 256        char const *ptr = *data;
 257
 258        for (; ptr < top && *ptr != '\n'; ptr++) {
 259                if (XDL_ISSPACE(*ptr)) {
 260                        const char *ptr2 = ptr;
 261                        int at_eol;
 262                        while (ptr + 1 < top && XDL_ISSPACE(ptr[1])
 263                                        && ptr[1] != '\n')
 264                                ptr++;
 265                        at_eol = (top <= ptr + 1 || ptr[1] == '\n');
 266                        if (flags & XDF_IGNORE_WHITESPACE)
 267                                ; /* already handled */
 268                        else if (flags & XDF_IGNORE_WHITESPACE_CHANGE
 269                                 && !at_eol) {
 270                                ha += (ha << 5);
 271                                ha ^= (unsigned long) ' ';
 272                        }
 273                        else if (flags & XDF_IGNORE_WHITESPACE_AT_EOL
 274                                 && !at_eol) {
 275                                while (ptr2 != ptr + 1) {
 276                                        ha += (ha << 5);
 277                                        ha ^= (unsigned long) *ptr2;
 278                                        ptr2++;
 279                                }
 280                        }
 281                        continue;
 282                }
 283                ha += (ha << 5);
 284                ha ^= (unsigned long) *ptr;
 285        }
 286        *data = ptr < top ? ptr + 1: ptr;
 287
 288        return ha;
 289}
 290
 291
 292unsigned long xdl_hash_record(char const **data, char const *top, long flags) {
 293        unsigned long ha = 5381;
 294        char const *ptr = *data;
 295
 296        if (flags & XDF_WHITESPACE_FLAGS)
 297                return xdl_hash_record_with_whitespace(data, top, flags);
 298
 299        for (; ptr < top && *ptr != '\n'; ptr++) {
 300                ha += (ha << 5);
 301                ha ^= (unsigned long) *ptr;
 302        }
 303        *data = ptr < top ? ptr + 1: ptr;
 304
 305        return ha;
 306}
 307
 308
 309unsigned int xdl_hashbits(unsigned int size) {
 310        unsigned int val = 1, bits = 0;
 311
 312        for (; val < size && bits < CHAR_BIT * sizeof(unsigned int); val <<= 1, bits++);
 313        return bits ? bits: 1;
 314}
 315
 316
 317int xdl_num_out(char *out, long val) {
 318        char *ptr, *str = out;
 319        char buf[32];
 320
 321        ptr = buf + sizeof(buf) - 1;
 322        *ptr = '\0';
 323        if (val < 0) {
 324                *--ptr = '-';
 325                val = -val;
 326        }
 327        for (; val && ptr > buf; val /= 10)
 328                *--ptr = "0123456789"[val % 10];
 329        if (*ptr)
 330                for (; *ptr; ptr++, str++)
 331                        *str = *ptr;
 332        else
 333                *str++ = '0';
 334        *str = '\0';
 335
 336        return str - out;
 337}
 338
 339
 340long xdl_atol(char const *str, char const **next) {
 341        long val, base;
 342        char const *top;
 343
 344        for (top = str; XDL_ISDIGIT(*top); top++);
 345        if (next)
 346                *next = top;
 347        for (val = 0, base = 1, top--; top >= str; top--, base *= 10)
 348                val += base * (long)(*top - '0');
 349        return val;
 350}
 351
 352
 353int xdl_emit_hunk_hdr(long s1, long c1, long s2, long c2,
 354                      const char *func, long funclen, xdemitcb_t *ecb) {
 355        int nb = 0;
 356        mmbuffer_t mb;
 357        char buf[128];
 358
 359        memcpy(buf, "@@ -", 4);
 360        nb += 4;
 361
 362        nb += xdl_num_out(buf + nb, c1 ? s1: s1 - 1);
 363
 364        if (c1 != 1) {
 365                memcpy(buf + nb, ",", 1);
 366                nb += 1;
 367
 368                nb += xdl_num_out(buf + nb, c1);
 369        }
 370
 371        memcpy(buf + nb, " +", 2);
 372        nb += 2;
 373
 374        nb += xdl_num_out(buf + nb, c2 ? s2: s2 - 1);
 375
 376        if (c2 != 1) {
 377                memcpy(buf + nb, ",", 1);
 378                nb += 1;
 379
 380                nb += xdl_num_out(buf + nb, c2);
 381        }
 382
 383        memcpy(buf + nb, " @@", 3);
 384        nb += 3;
 385        if (func && funclen) {
 386                buf[nb++] = ' ';
 387                if (funclen > sizeof(buf) - nb - 1)
 388                        funclen = sizeof(buf) - nb - 1;
 389                memcpy(buf + nb, func, funclen);
 390                nb += funclen;
 391        }
 392        buf[nb++] = '\n';
 393
 394        mb.ptr = buf;
 395        mb.size = nb;
 396        if (ecb->outf(ecb->priv, &mb, 1) < 0)
 397                return -1;
 398
 399        return 0;
 400}
 401
 402int xdl_fall_back_diff(xdfenv_t *diff_env, xpparam_t const *xpp,
 403                int line1, int count1, int line2, int count2)
 404{
 405        /*
 406         * This probably does not work outside Git, since
 407         * we have a very simple mmfile structure.
 408         *
 409         * Note: ideally, we would reuse the prepared environment, but
 410         * the libxdiff interface does not (yet) allow for diffing only
 411         * ranges of lines instead of the whole files.
 412         */
 413        mmfile_t subfile1, subfile2;
 414        xdfenv_t env;
 415
 416        subfile1.ptr = (char *)diff_env->xdf1.recs[line1 - 1]->ptr;
 417        subfile1.size = diff_env->xdf1.recs[line1 + count1 - 2]->ptr +
 418                diff_env->xdf1.recs[line1 + count1 - 2]->size - subfile1.ptr;
 419        subfile2.ptr = (char *)diff_env->xdf2.recs[line2 - 1]->ptr;
 420        subfile2.size = diff_env->xdf2.recs[line2 + count2 - 2]->ptr +
 421                diff_env->xdf2.recs[line2 + count2 - 2]->size - subfile2.ptr;
 422        if (xdl_do_diff(&subfile1, &subfile2, xpp, &env) < 0)
 423                return -1;
 424
 425        memcpy(diff_env->xdf1.rchg + line1 - 1, env.xdf1.rchg, count1);
 426        memcpy(diff_env->xdf2.rchg + line2 - 1, env.xdf2.rchg, count2);
 427
 428        xdl_free_env(&env);
 429
 430        return 0;
 431}