Andrew's git - gitweb.git/blob

   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
  32long 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
  45int 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
  67void *xdl_mmfile_first(mmfile_t *mmf, long *size)
  68{
  69        *size = mmf->size;
  70        return mmf->ptr;
  71}
  72
  73
  74void *xdl_mmfile_next(mmfile_t *mmf, long *size)
  75{
  76        return NULL;
  77}
  78
  79
  80long xdl_mmfile_size(mmfile_t *mmf)
  81{
  82        return mmf->size;
  83}
  84
  85
  86int 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
  98void 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
 108void *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
 134void *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
 146void *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
 162long 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
 189int xdl_recmatch(const char *l1, long s1, const char *l2, long s2, long flags)
 190{
 191        int i1, i2;
 192
 193        if (s1 == s2 && !memcmp(l1, l2, s1))
 194                return 1;
 195        if (!(flags & XDF_WHITESPACE_FLAGS))
 196                return 0;
 197
 198        i1 = 0;
 199        i2 = 0;
 200
 201        /*
 202         * -w matches everything that matches with -b, and -b in turn
 203         * matches everything that matches with --ignore-space-at-eol.
 204         *
 205         * Each flavor of ignoring needs different logic to skip whitespaces
 206         * while we have both sides to compare.
 207         */
 208        if (flags & XDF_IGNORE_WHITESPACE) {
 209                goto skip_ws;
 210                while (i1 < s1 && i2 < s2) {
 211                        if (l1[i1++] != l2[i2++])
 212                                return 0;
 213                skip_ws:
 214                        while (i1 < s1 && XDL_ISSPACE(l1[i1]))
 215                                i1++;
 216                        while (i2 < s2 && XDL_ISSPACE(l2[i2]))
 217                                i2++;
 218                }
 219        } else if (flags & XDF_IGNORE_WHITESPACE_CHANGE) {
 220                while (i1 < s1 && i2 < s2) {
 221                        if (XDL_ISSPACE(l1[i1]) && XDL_ISSPACE(l2[i2])) {
 222                                /* Skip matching spaces and try again */
 223                                while (i1 < s1 && XDL_ISSPACE(l1[i1]))
 224                                        i1++;
 225                                while (i2 < s2 && XDL_ISSPACE(l2[i2]))
 226                                        i2++;
 227                                continue;
 228                        }
 229                        if (l1[i1++] != l2[i2++])
 230                                return 0;
 231                }
 232        } else if (flags & XDF_IGNORE_WHITESPACE_AT_EOL) {
 233                while (i1 < s1 && i2 < s2 && l1[i1++] == l2[i2++])
 234                        ; /* keep going */
 235        }
 236
 237        /*
 238         * After running out of one side, the remaining side must have
 239         * nothing but whitespace for the lines to match.  Note that
 240         * ignore-whitespace-at-eol case may break out of the loop
 241         * while there still are characters remaining on both lines.
 242         */
 243        if (i1 < s1) {
 244                while (i1 < s1 && XDL_ISSPACE(l1[i1]))
 245                        i1++;
 246                if (s1 != i1)
 247                        return 0;
 248        }
 249        if (i2 < s2) {
 250                while (i2 < s2 && XDL_ISSPACE(l2[i2]))
 251                        i2++;
 252                return (s2 == i2);
 253        }
 254        return 1;
 255}
 256
 257static unsigned long xdl_hash_record_with_whitespace(char const **data,
 258                char const *top, long flags) {
 259        unsigned long ha = 5381;
 260        char const *ptr = *data;
 261
 262        for (; ptr < top && *ptr != '\n'; ptr++) {
 263                if (XDL_ISSPACE(*ptr)) {
 264                        const char *ptr2 = ptr;
 265                        int at_eol;
 266                        while (ptr + 1 < top && XDL_ISSPACE(ptr[1])
 267                                        && ptr[1] != '\n')
 268                                ptr++;
 269                        at_eol = (top <= ptr + 1 || ptr[1] == '\n');
 270                        if (flags & XDF_IGNORE_WHITESPACE)
 271                                ; /* already handled */
 272                        else if (flags & XDF_IGNORE_WHITESPACE_CHANGE
 273                                 && !at_eol) {
 274                                ha += (ha << 5);
 275                                ha ^= (unsigned long) ' ';
 276                        }
 277                        else if (flags & XDF_IGNORE_WHITESPACE_AT_EOL
 278                                 && !at_eol) {
 279                                while (ptr2 != ptr + 1) {
 280                                        ha += (ha << 5);
 281                                        ha ^= (unsigned long) *ptr2;
 282                                        ptr2++;
 283                                }
 284                        }
 285                        continue;
 286                }
 287                ha += (ha << 5);
 288                ha ^= (unsigned long) *ptr;
 289        }
 290        *data = ptr < top ? ptr + 1: ptr;
 291
 292        return ha;
 293}
 294
 295
 296unsigned long xdl_hash_record(char const **data, char const *top, long flags) {
 297        unsigned long ha = 5381;
 298        char const *ptr = *data;
 299
 300        if (flags & XDF_WHITESPACE_FLAGS)
 301                return xdl_hash_record_with_whitespace(data, top, flags);
 302
 303        for (; ptr < top && *ptr != '\n'; ptr++) {
 304                ha += (ha << 5);
 305                ha ^= (unsigned long) *ptr;
 306        }
 307        *data = ptr < top ? ptr + 1: ptr;
 308
 309        return ha;
 310}
 311
 312
 313unsigned int xdl_hashbits(unsigned int size) {
 314        unsigned int val = 1, bits = 0;
 315
 316        for (; val < size && bits < CHAR_BIT * sizeof(unsigned int); val <<= 1, bits++);
 317        return bits ? bits: 1;
 318}
 319
 320
 321int xdl_num_out(char *out, long val) {
 322        char *ptr, *str = out;
 323        char buf[32];
 324
 325        ptr = buf + sizeof(buf) - 1;
 326        *ptr = '\0';
 327        if (val < 0) {
 328                *--ptr = '-';
 329                val = -val;
 330        }
 331        for (; val && ptr > buf; val /= 10)
 332                *--ptr = "0123456789"[val % 10];
 333        if (*ptr)
 334                for (; *ptr; ptr++, str++)
 335                        *str = *ptr;
 336        else
 337                *str++ = '0';
 338        *str = '\0';
 339
 340        return str - out;
 341}
 342
 343
 344long xdl_atol(char const *str, char const **next) {
 345        long val, base;
 346        char const *top;
 347
 348        for (top = str; XDL_ISDIGIT(*top); top++);
 349        if (next)
 350                *next = top;
 351        for (val = 0, base = 1, top--; top >= str; top--, base *= 10)
 352                val += base * (long)(*top - '0');
 353        return val;
 354}
 355
 356
 357int xdl_emit_hunk_hdr(long s1, long c1, long s2, long c2,
 358                      const char *func, long funclen, xdemitcb_t *ecb) {
 359        int nb = 0;
 360        mmbuffer_t mb;
 361        char buf[128];
 362
 363        memcpy(buf, "@@ -", 4);
 364        nb += 4;
 365
 366        nb += xdl_num_out(buf + nb, c1 ? s1: s1 - 1);
 367
 368        if (c1 != 1) {
 369                memcpy(buf + nb, ",", 1);
 370                nb += 1;
 371
 372                nb += xdl_num_out(buf + nb, c1);
 373        }
 374
 375        memcpy(buf + nb, " +", 2);
 376        nb += 2;
 377
 378        nb += xdl_num_out(buf + nb, c2 ? s2: s2 - 1);
 379
 380        if (c2 != 1) {
 381                memcpy(buf + nb, ",", 1);
 382                nb += 1;
 383
 384                nb += xdl_num_out(buf + nb, c2);
 385        }
 386
 387        memcpy(buf + nb, " @@", 3);
 388        nb += 3;
 389        if (func && funclen) {
 390                buf[nb++] = ' ';
 391                if (funclen > sizeof(buf) - nb - 1)
 392                        funclen = sizeof(buf) - nb - 1;
 393                memcpy(buf + nb, func, funclen);
 394                nb += funclen;
 395        }
 396        buf[nb++] = '\n';
 397
 398        mb.ptr = buf;
 399        mb.size = nb;
 400        if (ecb->outf(ecb->priv, &mb, 1) < 0)
 401                return -1;
 402
 403        return 0;
 404}