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