xdiff / xutils.con commit Merge branch 'jk/fetch-all-peeled-fix' (0079732)
   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, see
  17 *  <http://www.gnu.org/licenses/>.
  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
 159/*
 160 * Have we eaten everything on the line, except for an optional
 161 * CR at the very end?
 162 */
 163static int ends_with_optional_cr(const char *l, long s, long i)
 164{
 165        int complete = s && l[s-1] == '\n';
 166
 167        if (complete)
 168                s--;
 169        if (s == i)
 170                return 1;
 171        /* do not ignore CR at the end of an incomplete line */
 172        if (complete && s == i + 1 && l[i] == '\r')
 173                return 1;
 174        return 0;
 175}
 176
 177int xdl_recmatch(const char *l1, long s1, const char *l2, long s2, long flags)
 178{
 179        int i1, i2;
 180
 181        if (s1 == s2 && !memcmp(l1, l2, s1))
 182                return 1;
 183        if (!(flags & XDF_WHITESPACE_FLAGS))
 184                return 0;
 185
 186        i1 = 0;
 187        i2 = 0;
 188
 189        /*
 190         * -w matches everything that matches with -b, and -b in turn
 191         * matches everything that matches with --ignore-space-at-eol,
 192         * which in turn matches everything that matches with --ignore-cr-at-eol.
 193         *
 194         * Each flavor of ignoring needs different logic to skip whitespaces
 195         * while we have both sides to compare.
 196         */
 197        if (flags & XDF_IGNORE_WHITESPACE) {
 198                goto skip_ws;
 199                while (i1 < s1 && i2 < s2) {
 200                        if (l1[i1++] != l2[i2++])
 201                                return 0;
 202                skip_ws:
 203                        while (i1 < s1 && XDL_ISSPACE(l1[i1]))
 204                                i1++;
 205                        while (i2 < s2 && XDL_ISSPACE(l2[i2]))
 206                                i2++;
 207                }
 208        } else if (flags & XDF_IGNORE_WHITESPACE_CHANGE) {
 209                while (i1 < s1 && i2 < s2) {
 210                        if (XDL_ISSPACE(l1[i1]) && XDL_ISSPACE(l2[i2])) {
 211                                /* Skip matching spaces and try again */
 212                                while (i1 < s1 && XDL_ISSPACE(l1[i1]))
 213                                        i1++;
 214                                while (i2 < s2 && XDL_ISSPACE(l2[i2]))
 215                                        i2++;
 216                                continue;
 217                        }
 218                        if (l1[i1++] != l2[i2++])
 219                                return 0;
 220                }
 221        } else if (flags & XDF_IGNORE_WHITESPACE_AT_EOL) {
 222                while (i1 < s1 && i2 < s2 && l1[i1] == l2[i2]) {
 223                        i1++;
 224                        i2++;
 225                }
 226        } else if (flags & XDF_IGNORE_CR_AT_EOL) {
 227                /* Find the first difference and see how the line ends */
 228                while (i1 < s1 && i2 < s2 && l1[i1] == l2[i2]) {
 229                        i1++;
 230                        i2++;
 231                }
 232                return (ends_with_optional_cr(l1, s1, i1) &&
 233                        ends_with_optional_cr(l2, s2, i2));
 234        }
 235
 236        /*
 237         * After running out of one side, the remaining side must have
 238         * nothing but whitespace for the lines to match.  Note that
 239         * ignore-whitespace-at-eol case may break out of the loop
 240         * while there still are characters remaining on both lines.
 241         */
 242        if (i1 < s1) {
 243                while (i1 < s1 && XDL_ISSPACE(l1[i1]))
 244                        i1++;
 245                if (s1 != i1)
 246                        return 0;
 247        }
 248        if (i2 < s2) {
 249                while (i2 < s2 && XDL_ISSPACE(l2[i2]))
 250                        i2++;
 251                return (s2 == i2);
 252        }
 253        return 1;
 254}
 255
 256static unsigned long xdl_hash_record_with_whitespace(char const **data,
 257                char const *top, long flags) {
 258        unsigned long ha = 5381;
 259        char const *ptr = *data;
 260        int cr_at_eol_only = (flags & XDF_WHITESPACE_FLAGS) == XDF_IGNORE_CR_AT_EOL;
 261
 262        for (; ptr < top && *ptr != '\n'; ptr++) {
 263                if (cr_at_eol_only) {
 264                        /* do not ignore CR at the end of an incomplete line */
 265                        if (*ptr == '\r' &&
 266                            (ptr + 1 < top && ptr[1] == '\n'))
 267                                continue;
 268                }
 269                else if (XDL_ISSPACE(*ptr)) {
 270                        const char *ptr2 = ptr;
 271                        int at_eol;
 272                        while (ptr + 1 < top && XDL_ISSPACE(ptr[1])
 273                                        && ptr[1] != '\n')
 274                                ptr++;
 275                        at_eol = (top <= ptr + 1 || ptr[1] == '\n');
 276                        if (flags & XDF_IGNORE_WHITESPACE)
 277                                ; /* already handled */
 278                        else if (flags & XDF_IGNORE_WHITESPACE_CHANGE
 279                                 && !at_eol) {
 280                                ha += (ha << 5);
 281                                ha ^= (unsigned long) ' ';
 282                        }
 283                        else if (flags & XDF_IGNORE_WHITESPACE_AT_EOL
 284                                 && !at_eol) {
 285                                while (ptr2 != ptr + 1) {
 286                                        ha += (ha << 5);
 287                                        ha ^= (unsigned long) *ptr2;
 288                                        ptr2++;
 289                                }
 290                        }
 291                        continue;
 292                }
 293                ha += (ha << 5);
 294                ha ^= (unsigned long) *ptr;
 295        }
 296        *data = ptr < top ? ptr + 1: ptr;
 297
 298        return ha;
 299}
 300
 301unsigned long xdl_hash_record(char const **data, char const *top, long flags) {
 302        unsigned long ha = 5381;
 303        char const *ptr = *data;
 304
 305        if (flags & XDF_WHITESPACE_FLAGS)
 306                return xdl_hash_record_with_whitespace(data, top, flags);
 307
 308        for (; ptr < top && *ptr != '\n'; ptr++) {
 309                ha += (ha << 5);
 310                ha ^= (unsigned long) *ptr;
 311        }
 312        *data = ptr < top ? ptr + 1: ptr;
 313
 314        return ha;
 315}
 316
 317unsigned int xdl_hashbits(unsigned int size) {
 318        unsigned int val = 1, bits = 0;
 319
 320        for (; val < size && bits < CHAR_BIT * sizeof(unsigned int); val <<= 1, bits++);
 321        return bits ? bits: 1;
 322}
 323
 324
 325int xdl_num_out(char *out, long val) {
 326        char *ptr, *str = out;
 327        char buf[32];
 328
 329        ptr = buf + sizeof(buf) - 1;
 330        *ptr = '\0';
 331        if (val < 0) {
 332                *--ptr = '-';
 333                val = -val;
 334        }
 335        for (; val && ptr > buf; val /= 10)
 336                *--ptr = "0123456789"[val % 10];
 337        if (*ptr)
 338                for (; *ptr; ptr++, str++)
 339                        *str = *ptr;
 340        else
 341                *str++ = '0';
 342        *str = '\0';
 343
 344        return str - out;
 345}
 346
 347int xdl_emit_hunk_hdr(long s1, long c1, long s2, long c2,
 348                      const char *func, long funclen, xdemitcb_t *ecb) {
 349        int nb = 0;
 350        mmbuffer_t mb;
 351        char buf[128];
 352
 353        memcpy(buf, "@@ -", 4);
 354        nb += 4;
 355
 356        nb += xdl_num_out(buf + nb, c1 ? s1: s1 - 1);
 357
 358        if (c1 != 1) {
 359                memcpy(buf + nb, ",", 1);
 360                nb += 1;
 361
 362                nb += xdl_num_out(buf + nb, c1);
 363        }
 364
 365        memcpy(buf + nb, " +", 2);
 366        nb += 2;
 367
 368        nb += xdl_num_out(buf + nb, c2 ? s2: s2 - 1);
 369
 370        if (c2 != 1) {
 371                memcpy(buf + nb, ",", 1);
 372                nb += 1;
 373
 374                nb += xdl_num_out(buf + nb, c2);
 375        }
 376
 377        memcpy(buf + nb, " @@", 3);
 378        nb += 3;
 379        if (func && funclen) {
 380                buf[nb++] = ' ';
 381                if (funclen > sizeof(buf) - nb - 1)
 382                        funclen = sizeof(buf) - nb - 1;
 383                memcpy(buf + nb, func, funclen);
 384                nb += funclen;
 385        }
 386        buf[nb++] = '\n';
 387
 388        mb.ptr = buf;
 389        mb.size = nb;
 390        if (ecb->outf(ecb->priv, &mb, 1) < 0)
 391                return -1;
 392
 393        return 0;
 394}
 395
 396int xdl_fall_back_diff(xdfenv_t *diff_env, xpparam_t const *xpp,
 397                int line1, int count1, int line2, int count2)
 398{
 399        /*
 400         * This probably does not work outside Git, since
 401         * we have a very simple mmfile structure.
 402         *
 403         * Note: ideally, we would reuse the prepared environment, but
 404         * the libxdiff interface does not (yet) allow for diffing only
 405         * ranges of lines instead of the whole files.
 406         */
 407        mmfile_t subfile1, subfile2;
 408        xdfenv_t env;
 409
 410        subfile1.ptr = (char *)diff_env->xdf1.recs[line1 - 1]->ptr;
 411        subfile1.size = diff_env->xdf1.recs[line1 + count1 - 2]->ptr +
 412                diff_env->xdf1.recs[line1 + count1 - 2]->size - subfile1.ptr;
 413        subfile2.ptr = (char *)diff_env->xdf2.recs[line2 - 1]->ptr;
 414        subfile2.size = diff_env->xdf2.recs[line2 + count2 - 2]->ptr +
 415                diff_env->xdf2.recs[line2 + count2 - 2]->size - subfile2.ptr;
 416        if (xdl_do_diff(&subfile1, &subfile2, xpp, &env) < 0)
 417                return -1;
 418
 419        memcpy(diff_env->xdf1.rchg + line1 - 1, env.xdf1.rchg, count1);
 420        memcpy(diff_env->xdf2.rchg + line2 - 1, env.xdf2.rchg, count2);
 421
 422        xdl_free_env(&env);
 423
 424        return 0;
 425}