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
 190 unsigned long xdl_hash_record(char const **data, char const *top) {
 191         unsigned long ha = 5381;
 192         char const *ptr = *data;
 193
 194         for (; ptr < top && *ptr != '\n'; ptr++) {
 195                 ha += (ha << 5);
 196                 ha ^= (unsigned long) *ptr;
 197         }
 198         *data = ptr < top ? ptr + 1: ptr;
 199
 200         return ha;
 201 }
 202
 203
 204 unsigned int xdl_hashbits(unsigned int size) {
 205         unsigned int val = 1, bits = 0;
 206
 207         for (; val < size && bits < CHAR_BIT * sizeof(unsigned int); val <<= 1, bits++);
 208         return bits ? bits: 1;
 209 }
 210
 211
 212 int xdl_num_out(char *out, long val) {
 213         char *ptr, *str = out;
 214         char buf[32];
 215
 216         ptr = buf + sizeof(buf) - 1;
 217         *ptr = '\0';
 218         if (val < 0) {
 219                 *--ptr = '-';
 220                 val = -val;
 221         }
 222         for (; val && ptr > buf; val /= 10)
 223                 *--ptr = "0123456789"[val % 10];
 224         if (*ptr)
 225                 for (; *ptr; ptr++, str++)
 226                         *str = *ptr;
 227         else
 228                 *str++ = '0';
 229         *str = '\0';
 230
 231         return str - out;
 232 }
 233
 234
 235 long xdl_atol(char const *str, char const **next) {
 236         long val, base;
 237         char const *top;
 238
 239         for (top = str; XDL_ISDIGIT(*top); top++);
 240         if (next)
 241                 *next = top;
 242         for (val = 0, base = 1, top--; top >= str; top--, base *= 10)
 243                 val += base * (long)(*top - '0');
 244         return val;
 245 }
 246
 247
 248 int xdl_emit_hunk_hdr(long s1, long c1, long s2, long c2,
 249                       const char *func, long funclen, xdemitcb_t *ecb) {
 250         int nb = 0;
 251         mmbuffer_t mb;
 252         char buf[128];
 253
 254         memcpy(buf, "@@ -", 4);
 255         nb += 4;
 256
 257         nb += xdl_num_out(buf + nb, c1 ? s1: s1 - 1);
 258
 259         if (c1 != 1) {
 260                 memcpy(buf + nb, ",", 1);
 261                 nb += 1;
 262
 263                 nb += xdl_num_out(buf + nb, c1);
 264         }
 265
 266         memcpy(buf + nb, " +", 2);
 267         nb += 2;
 268
 269         nb += xdl_num_out(buf + nb, c2 ? s2: s2 - 1);
 270
 271         if (c2 != 1) {
 272                 memcpy(buf + nb, ",", 1);
 273                 nb += 1;
 274
 275                 nb += xdl_num_out(buf + nb, c2);
 276         }
 277
 278         memcpy(buf + nb, " @@", 3);
 279         nb += 3;
 280         if (func && funclen) {
 281                 buf[nb++] = ' ';
 282                 if (funclen > sizeof(buf) - nb - 1)
 283                         funclen = sizeof(buf) - nb - 1;
 284                 memcpy(buf + nb, func, funclen);
 285                 nb += funclen;
 286         }
 287         buf[nb++] = '\n';
 288
 289         mb.ptr = buf;
 290         mb.size = nb;
 291         if (ecb->outf(ecb->priv, &mb, 1) < 0)
 292                 return -1;
 293
 294         return 0;
 295 }
 296