modules/luci-base/src/template_lmo.c

   1 /*
   2  * lmo - Lua Machine Objects - Base functions
   3  *
   4  *   Copyright (C) 2009-2010 Jo-Philipp Wich <jow@openwrt.org>
   5  *
   6  *  Licensed under the Apache License, Version 2.0 (the "License");
   7  *  you may not use this file except in compliance with the License.
   8  *  You may obtain a copy of the License at
   9  *
  10  *      http://www.apache.org/licenses/LICENSE-2.0
  11  *
  12  *  Unless required by applicable law or agreed to in writing, software
  13  *  distributed under the License is distributed on an "AS IS" BASIS,
  14  *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  15  *  See the License for the specific language governing permissions and
  16  *  limitations under the License.
  17  */
  18
  19 #include "template_lmo.h"
  20
  21 /*
  22  * Hash function from http://www.azillionmonkeys.com/qed/hash.html
  23  * Copyright (C) 2004-2008 by Paul Hsieh
  24  */
  25
  26 uint32_t sfh_hash(const char *data, int len)
  27 {
  28         uint32_t hash = len, tmp;
  29         int rem;
  30
  31         if (len <= 0 || data == NULL) return 0;
  32
  33         rem = len & 3;
  34         len >>= 2;
  35
  36         /* Main loop */
  37         for (;len > 0; len--) {
  38                 hash  += sfh_get16(data);
  39                 tmp    = (sfh_get16(data+2) << 11) ^ hash;
  40                 hash   = (hash << 16) ^ tmp;
  41                 data  += 2*sizeof(uint16_t);
  42                 hash  += hash >> 11;
  43         }
  44
  45         /* Handle end cases */
  46         switch (rem) {
  47                 case 3: hash += sfh_get16(data);
  48                         hash ^= hash << 16;
  49                         hash ^= (signed char)data[sizeof(uint16_t)] << 18;
  50                         hash += hash >> 11;
  51                         break;
  52                 case 2: hash += sfh_get16(data);
  53                         hash ^= hash << 11;
  54                         hash += hash >> 17;
  55                         break;
  56                 case 1: hash += (signed char)*data;
  57                         hash ^= hash << 10;
  58                         hash += hash >> 1;
  59         }
  60
  61         /* Force "avalanching" of final 127 bits */
  62         hash ^= hash << 3;
  63         hash += hash >> 5;
  64         hash ^= hash << 4;
  65         hash += hash >> 17;
  66         hash ^= hash << 25;
  67         hash += hash >> 6;
  68
  69         return hash;
  70 }
  71
  72 uint32_t lmo_canon_hash(const char *str, int len)
  73 {
  74         char res[4096];
  75         char *ptr, prev;
  76         int off;
  77
  78         if (!str || len >= sizeof(res))
  79                 return 0;
  80
  81         for (prev = ' ', ptr = res, off = 0; off < len; prev = *str, off++, str++)
  82         {
  83                 if (isspace(*str))
  84                 {
  85                         if (!isspace(prev))
  86                                 *ptr++ = ' ';
  87                 }
  88                 else
  89                 {
  90                         *ptr++ = *str;
  91                 }
  92         }
  93
  94         if ((ptr > res) && isspace(*(ptr-1)))
  95                 ptr--;
  96
  97         return sfh_hash(res, ptr - res);
  98 }
  99
 100 lmo_archive_t * lmo_open(const char *file)
 101 {
 102         int in = -1;
 103         uint32_t idx_offset = 0;
 104         struct stat s;
 105
 106         lmo_archive_t *ar = NULL;
 107
 108         if (stat(file, &s) == -1)
 109                 goto err;
 110
 111         if ((in = open(file, O_RDONLY)) == -1)
 112                 goto err;
 113
 114         if ((ar = (lmo_archive_t *)malloc(sizeof(*ar))) != NULL)
 115         {
 116                 memset(ar, 0, sizeof(*ar));
 117
 118                 ar->fd     = in;
 119                 ar->size = s.st_size;
 120
 121                 fcntl(ar->fd, F_SETFD, fcntl(ar->fd, F_GETFD) | FD_CLOEXEC);
 122
 123                 if ((ar->mmap = mmap(NULL, ar->size, PROT_READ, MAP_SHARED, ar->fd, 0)) == MAP_FAILED)
 124                         goto err;
 125
 126                 idx_offset = ntohl(*((const uint32_t *)
 127                                      (ar->mmap + ar->size - sizeof(uint32_t))));
 128
 129                 if (idx_offset >= ar->size)
 130                         goto err;
 131
 132                 ar->index  = (lmo_entry_t *)(ar->mmap + idx_offset);
 133                 ar->length = (ar->size - idx_offset - sizeof(uint32_t)) / sizeof(lmo_entry_t);
 134                 ar->end    = ar->mmap + ar->size;
 135
 136                 return ar;
 137         }
 138
 139 err:
 140         if (in > -1)
 141                 close(in);
 142
 143         if (ar != NULL)
 144         {
 145                 if ((ar->mmap != NULL) && (ar->mmap != MAP_FAILED))
 146                         munmap(ar->mmap, ar->size);
 147
 148                 free(ar);
 149         }
 150
 151         return NULL;
 152 }
 153
 154 void lmo_close(lmo_archive_t *ar)
 155 {
 156         if (ar != NULL)
 157         {
 158                 if ((ar->mmap != NULL) && (ar->mmap != MAP_FAILED))
 159                         munmap(ar->mmap, ar->size);
 160
 161                 close(ar->fd);
 162                 free(ar);
 163
 164                 ar = NULL;
 165         }
 166 }
 167
 168
 169 lmo_catalog_t *_lmo_catalogs = NULL;
 170 lmo_catalog_t *_lmo_active_catalog = NULL;
 171
 172 int lmo_load_catalog(const char *lang, const char *dir)
 173 {
 174         DIR *dh = NULL;
 175         char pattern[16];
 176         char path[PATH_MAX];
 177         struct dirent *de = NULL;
 178
 179         lmo_archive_t *ar = NULL;
 180         lmo_catalog_t *cat = NULL;
 181
 182         if (!lmo_change_catalog(lang))
 183                 return 0;
 184
 185         if (!dir || !(dh = opendir(dir)))
 186                 goto err;
 187
 188         if (!(cat = malloc(sizeof(*cat))))
 189                 goto err;
 190
 191         memset(cat, 0, sizeof(*cat));
 192
 193         snprintf(cat->lang, sizeof(cat->lang), "%s", lang);
 194         snprintf(pattern, sizeof(pattern), "*.%s.lmo", lang);
 195
 196         while ((de = readdir(dh)) != NULL)
 197         {
 198                 if (!fnmatch(pattern, de->d_name, 0))
 199                 {
 200                         snprintf(path, sizeof(path), "%s/%s", dir, de->d_name);
 201                         ar = lmo_open(path);
 202
 203                         if (ar)
 204                         {
 205                                 ar->next = cat->archives;
 206                                 cat->archives = ar;
 207                         }
 208                 }
 209         }
 210
 211         closedir(dh);
 212
 213         cat->next = _lmo_catalogs;
 214         _lmo_catalogs = cat;
 215
 216         if (!_lmo_active_catalog)
 217                 _lmo_active_catalog = cat;
 218
 219         return cat->archives ? 0 : -1;
 220
 221 err:
 222         if (dh) closedir(dh);
 223         if (cat) free(cat);
 224
 225         return -1;
 226 }
 227
 228 int lmo_change_catalog(const char *lang)
 229 {
 230         lmo_catalog_t *cat;
 231
 232         for (cat = _lmo_catalogs; cat; cat = cat->next)
 233         {
 234                 if (!strncmp(cat->lang, lang, sizeof(cat->lang)))
 235                 {
 236                         _lmo_active_catalog = cat;
 237                         return 0;
 238                 }
 239         }
 240
 241         return -1;
 242 }
 243
 244 static lmo_entry_t * lmo_find_entry(lmo_archive_t *ar, uint32_t hash)
 245 {
 246         unsigned int m, l, r;
 247         uint32_t k;
 248
 249         l = 0;
 250         r = ar->length - 1;
 251
 252         while (1)
 253         {
 254                 m = l + ((r - l) / 2);
 255
 256                 if (r < l)
 257                         break;
 258
 259                 k = ntohl(ar->index[m].key_id);
 260
 261                 if (k == hash)
 262                         return &ar->index[m];
 263
 264                 if (k > hash)
 265                 {
 266                         if (!m)
 267                                 break;
 268
 269                         r = m - 1;
 270                 }
 271                 else
 272                 {
 273                         l = m + 1;
 274                 }
 275         }
 276
 277         return NULL;
 278 }
 279
 280 int lmo_translate(const char *key, int keylen, char **out, int *outlen)
 281 {
 282         uint32_t hash;
 283         lmo_entry_t *e;
 284         lmo_archive_t *ar;
 285
 286         if (!key || !_lmo_active_catalog)
 287                 return -2;
 288
 289         hash = lmo_canon_hash(key, keylen);
 290
 291         for (ar = _lmo_active_catalog->archives; ar; ar = ar->next)
 292         {
 293                 if ((e = lmo_find_entry(ar, hash)) != NULL)
 294                 {
 295                         *out = ar->mmap + ntohl(e->offset);
 296                         *outlen = ntohl(e->length);
 297                         return 0;
 298                 }
 299         }
 300
 301         return -1;
 302 }
 303
 304 void lmo_iterate(lmo_iterate_cb_t cb, void *priv)
 305 {
 306         unsigned int i;
 307         lmo_entry_t *e;
 308         lmo_archive_t *ar;
 309
 310         if (!_lmo_active_catalog)
 311                 return;
 312
 313         for (ar = _lmo_active_catalog->archives; ar; ar = ar->next)
 314                 for (i = 0, e = &ar->index[0]; i < ar->length; e = &ar->index[++i])
 315                         cb(ntohl(e->key_id), ar->mmap + ntohl(e->offset), ntohl(e->length), priv);
 316 }
 317
 318 void lmo_close_catalog(const char *lang)
 319 {
 320         lmo_archive_t *ar, *next;
 321         lmo_catalog_t *cat, *prev;
 322
 323         for (prev = NULL, cat = _lmo_catalogs; cat; prev = cat, cat = cat->next)
 324         {
 325                 if (!strncmp(cat->lang, lang, sizeof(cat->lang)))
 326                 {
 327                         if (prev)
 328                                 prev->next = cat->next;
 329                         else
 330                                 _lmo_catalogs = cat->next;
 331
 332                         for (ar = cat->archives; ar; ar = next)
 333                         {
 334                                 next = ar->next;
 335                                 lmo_close(ar);
 336                         }
 337
 338                         free(cat);
 339                         break;
 340                 }
 341         }
 342 }