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         mmbuffer_t mb[3];
  48         int i;
  49
  50         mb[0].ptr = (char *) pre;
  51         mb[0].size = psize;
  52         mb[1].ptr = (char *) rec;
  53         mb[1].size = size;
  54         i = 2;
  55
  56         if (!size || rec[size-1] != '\n') {
  57                 mb[2].ptr = "\n\\ No newline at end of file\n";
  58                 mb[2].size = strlen(mb[2].ptr);
  59                 i = 3;
  60         }
  61
  62         if (ecb->outf(ecb->priv, mb, i) < 0) {
  63
  64                 return -1;
  65         }
  66
  67         return 0;
  68 }
  69
  70 void *xdl_mmfile_first(mmfile_t *mmf, long *size)
  71 {
  72         *size = mmf->size;
  73         return mmf->ptr;
  74 }
  75
  76
  77 void *xdl_mmfile_next(mmfile_t *mmf, long *size)
  78 {
  79         return NULL;
  80 }
  81
  82
  83 long xdl_mmfile_size(mmfile_t *mmf)
  84 {
  85         return mmf->size;
  86 }
  87
  88
  89 int xdl_cha_init(chastore_t *cha, long isize, long icount) {
  90
  91         cha->head = cha->tail = NULL;
  92         cha->isize = isize;
  93         cha->nsize = icount * isize;
  94         cha->ancur = cha->sncur = NULL;
  95         cha->scurr = 0;
  96
  97         return 0;
  98 }
  99
 100
 101 void xdl_cha_free(chastore_t *cha) {
 102         chanode_t *cur, *tmp;
 103
 104         for (cur = cha->head; (tmp = cur) != NULL;) {
 105                 cur = cur->next;
 106                 xdl_free(tmp);
 107         }
 108 }
 109
 110
 111 void *xdl_cha_alloc(chastore_t *cha) {
 112         chanode_t *ancur;
 113         void *data;
 114
 115         if (!(ancur = cha->ancur) || ancur->icurr == cha->nsize) {
 116                 if (!(ancur = (chanode_t *) xdl_malloc(sizeof(chanode_t) + cha->nsize))) {
 117
 118                         return NULL;
 119                 }
 120                 ancur->icurr = 0;
 121                 ancur->next = NULL;
 122                 if (cha->tail)
 123                         cha->tail->next = ancur;
 124                 if (!cha->head)
 125                         cha->head = ancur;
 126                 cha->tail = ancur;
 127                 cha->ancur = ancur;
 128         }
 129
 130         data = (char *) ancur + sizeof(chanode_t) + ancur->icurr;
 131         ancur->icurr += cha->isize;
 132
 133         return data;
 134 }
 135
 136
 137 void *xdl_cha_first(chastore_t *cha) {
 138         chanode_t *sncur;
 139
 140         if (!(cha->sncur = sncur = cha->head))
 141                 return NULL;
 142
 143         cha->scurr = 0;
 144
 145         return (char *) sncur + sizeof(chanode_t) + cha->scurr;
 146 }
 147
 148
 149 void *xdl_cha_next(chastore_t *cha) {
 150         chanode_t *sncur;
 151
 152         if (!(sncur = cha->sncur))
 153                 return NULL;
 154         cha->scurr += cha->isize;
 155         if (cha->scurr == sncur->icurr) {
 156                 if (!(sncur = cha->sncur = sncur->next))
 157                         return NULL;
 158                 cha->scurr = 0;
 159         }
 160
 161         return (char *) sncur + sizeof(chanode_t) + cha->scurr;
 162 }
 163
 164
 165 long xdl_guess_lines(mmfile_t *mf) {
 166         long nl = 0, size, tsize = 0;
 167         char const *data, *cur, *top;
 168
 169         if ((cur = data = xdl_mmfile_first(mf, &size)) != NULL) {
 170                 for (top = data + size; nl < XDL_GUESS_NLINES;) {
 171                         if (cur >= top) {
 172                                 tsize += (long) (cur - data);
 173                                 if (!(cur = data = xdl_mmfile_next(mf, &size)))
 174                                         break;
 175                                 top = data + size;
 176                         }
 177                         nl++;
 178                         if (!(cur = memchr(cur, '\n', top - cur)))
 179                                 cur = top;
 180                         else
 181                                 cur++;
 182                 }
 183                 tsize += (long) (cur - data);
 184         }
 185
 186         if (nl && tsize)
 187                 nl = xdl_mmfile_size(mf) / (tsize / nl);
 188
 189         return nl + 1;
 190 }
 191
 192
 193 unsigned long xdl_hash_record(char const **data, char const *top) {
 194         unsigned long ha = 5381;
 195         char const *ptr = *data;
 196
 197         for (; ptr < top && *ptr != '\n'; ptr++) {
 198                 ha += (ha << 5);
 199                 ha ^= (unsigned long) *ptr;
 200         }
 201         *data = ptr < top ? ptr + 1: ptr;
 202
 203         return ha;
 204 }
 205
 206
 207 unsigned int xdl_hashbits(unsigned int size) {
 208         unsigned int val = 1, bits = 0;
 209
 210         for (; val < size && bits < CHAR_BIT * sizeof(unsigned int); val <<= 1, bits++);
 211         return bits ? bits: 1;
 212 }
 213
 214
 215 int xdl_num_out(char *out, long val) {
 216         char *ptr, *str = out;
 217         char buf[32];
 218
 219         ptr = buf + sizeof(buf) - 1;
 220         *ptr = '\0';
 221         if (val < 0) {
 222                 *--ptr = '-';
 223                 val = -val;
 224         }
 225         for (; val && ptr > buf; val /= 10)
 226                 *--ptr = "0123456789"[val % 10];
 227         if (*ptr)
 228                 for (; *ptr; ptr++, str++)
 229                         *str = *ptr;
 230         else
 231                 *str++ = '0';
 232         *str = '\0';
 233
 234         return str - out;
 235 }
 236
 237
 238 long xdl_atol(char const *str, char const **next) {
 239         long val, base;
 240         char const *top;
 241
 242         for (top = str; XDL_ISDIGIT(*top); top++);
 243         if (next)
 244                 *next = top;
 245         for (val = 0, base = 1, top--; top >= str; top--, base *= 10)
 246                 val += base * (long)(*top - '0');
 247         return val;
 248 }
 249
 250
 251 int xdl_emit_hunk_hdr(long s1, long c1, long s2, long c2,
 252                       const char *func, long funclen, xdemitcb_t *ecb) {
 253         int nb = 0;
 254         mmbuffer_t mb;
 255         char buf[128];
 256
 257         memcpy(buf, "@@ -", 4);
 258         nb += 4;
 259
 260         nb += xdl_num_out(buf + nb, c1 ? s1: s1 - 1);
 261
 262         if (c1 != 1) {
 263                 memcpy(buf + nb, ",", 1);
 264                 nb += 1;
 265
 266                 nb += xdl_num_out(buf + nb, c1);
 267         }
 268
 269         memcpy(buf + nb, " +", 2);
 270         nb += 2;
 271
 272         nb += xdl_num_out(buf + nb, c2 ? s2: s2 - 1);
 273
 274         if (c2 != 1) {
 275                 memcpy(buf + nb, ",", 1);
 276                 nb += 1;
 277
 278                 nb += xdl_num_out(buf + nb, c2);
 279         }
 280
 281         memcpy(buf + nb, " @@", 3);
 282         nb += 3;
 283         if (func && funclen) {
 284                 buf[nb++] = ' ';
 285                 if (funclen > sizeof(buf) - nb - 1)
 286                         funclen = sizeof(buf) - nb - 1;
 287                 memcpy(buf + nb, func, funclen);
 288                 nb += funclen;
 289         }
 290         buf[nb++] = '\n';
 291
 292         mb.ptr = buf;
 293         mb.size = nb;
 294         if (ecb->outf(ecb->priv, &mb, 1) < 0)
 295                 return -1;
 296
 297         return 0;
 298 }
 299