xdiff/xutils.c

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