source/texk/web2c/luatexdir/luazlib/lgzip.c

   1 /************************************************************************
   2 * Author    : Tiago Dionizio (tngd@mega.ist.utl.pt)                     *
   3 * Library   : lgzip - a gzip file access binding for Lua 5              *
   4 *             based on liolib.c from Lua 5.0 library                    *
   5 *                                                                       *
   6 * Permission is hereby granted, free of charge, to any person obtaining *
   7 * a copy of this software and associated documentation files (the       *
   8 * "Software"), to deal in the Software without restriction, including   *
   9 * without limitation the rights to use, copy, modify, merge, publish,   *
  10 * distribute, sublicense, and/or sell copies of the Software, and to    *
  11 * permit persons to whom the Software is furnished to do so, subject to *
  12 * the following conditions:                                             *
  13 *                                                                       *
  14 * The above copyright notice and this permission notice shall be        *
  15 * included in all copies or substantial portions of the Software.       *
  16 *                                                                       *
  17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       *
  18 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    *
  19 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*
  20 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  *
  21 * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  *
  22 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     *
  23 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                *
  24 ************************************************************************/
  25
  26 /************************************************************************
  27 $Id: lgzip.c,v 1.2 2003/12/28 01:26:16 tngd Exp $
  28 Changes:
  29 ************************************************************************/
  30 #include <errno.h>
  31 #include <stdlib.h>
  32 #include <string.h>
  33
  34 #include "zlib.h"
  35
  36 #include "lua.h"
  37 #include "lauxlib.h"
  38
  39
  40
  41 /*
  42 ** {======================================================
  43 ** FILE Operations
  44 ** =======================================================
  45 */
  46
  47
  48 #define FILEHANDLE              "zlib.gzFile"
  49
  50
  51 static int pushresult (lua_State *L, int i, const char *filename) {
  52   if (i) {
  53     lua_pushboolean(L, 1);
  54     return 1;
  55   }
  56   else {
  57     lua_pushnil(L);
  58     if (filename)
  59       lua_pushfstring(L, "%s: %s", filename, strerror(errno));
  60     else
  61       lua_pushfstring(L, "%s", strerror(errno));
  62     lua_pushnumber(L, errno);
  63     return 3;
  64   }
  65 }
  66
  67
  68 static gzFile *topfile (lua_State *L, int findex) {
  69   gzFile*f = (gzFile*)luaL_checkudata(L, findex, FILEHANDLE);
  70   if (f == NULL) luaL_argerror(L, findex, "bad file");
  71   return f;
  72 }
  73
  74
  75 static gzFile tofile (lua_State *L, int findex) {
  76   gzFile*f = topfile(L, findex);
  77   if (*f == NULL)
  78     luaL_error(L, "attempt to use a closed file");
  79   return *f;
  80 }
  81
  82
  83
  84 /*
  85 ** When creating file handles, always creates a `closed' file handle
  86 ** before opening the actual file; so, if there is a memory error, the
  87 ** file is not left opened.
  88 */
  89 static gzFile *newfile (lua_State *L) {
  90   gzFile *pf = (gzFile*)lua_newuserdata(L, sizeof(gzFile));
  91   *pf = NULL;  /* file handle is currently `closed' */
  92   luaL_getmetatable(L, FILEHANDLE);
  93   lua_setmetatable(L, -2);
  94   return pf;
  95 }
  96
  97
  98 static int aux_close (lua_State *L) {
  99   gzFile f = tofile(L, 1);
 100   int ok = (gzclose(f) == Z_OK);
 101   if (ok)
 102     *(gzFile*)lua_touserdata(L, 1) = NULL;  /* mark file as closed */
 103   return ok;
 104 }
 105
 106
 107 static int io_close (lua_State *L) {
 108   return pushresult(L, aux_close(L), NULL);
 109 }
 110
 111
 112 static int io_gc (lua_State *L) {
 113   gzFile *f = topfile(L, 1);
 114   if (*f != NULL)  /* ignore closed files */
 115     aux_close(L);
 116   return 0;
 117 }
 118
 119
 120 static int io_tostring (lua_State *L) {
 121   char buff[128];
 122   gzFile *f = topfile(L, 1);
 123   if (*f == NULL)
 124     strcpy(buff, "closed");
 125   else
 126     sprintf(buff, "%p", lua_touserdata(L, 1));
 127   lua_pushfstring(L, "gzip file (%s)", buff);
 128   return 1;
 129 }
 130
 131
 132 static int io_open (lua_State *L) {
 133   const char *filename = luaL_checkstring(L, 1);
 134   const char *mode = luaL_optstring(L, 2, "rb");
 135   gzFile *pf = newfile(L);
 136   *pf = gzopen(filename, mode);
 137   return (*pf == NULL) ? pushresult(L, 0, filename) : 1;
 138 }
 139
 140
 141 static int io_readline (lua_State *L);
 142
 143 static void aux_lines (lua_State *L, int idx, int close) {
 144   lua_pushliteral(L, FILEHANDLE);
 145   lua_rawget(L, LUA_REGISTRYINDEX);
 146   lua_pushvalue(L, idx);
 147   lua_pushboolean(L, close);  /* close/not close file when finished */
 148   lua_pushcclosure(L, io_readline, 3);
 149 }
 150
 151
 152 static int f_lines (lua_State *L) {
 153   tofile(L, 1);  /* check that it's a valid file handle */
 154   aux_lines(L, 1, 0);
 155   return 1;
 156 }
 157
 158
 159 static int io_lines (lua_State *L) {
 160   const char *filename = luaL_checkstring(L, 1);
 161   gzFile *pf = newfile(L);
 162   *pf = gzopen(filename, "rb");
 163   luaL_argcheck(L, *pf, 1,  strerror(errno));
 164   aux_lines(L, lua_gettop(L), 1);
 165   return 1;
 166 }
 167
 168
 169 /*
 170 ** {======================================================
 171 ** READ
 172 ** =======================================================
 173 */
 174
 175
 176 static int test_eof (lua_State *L, gzFile f) {
 177   lua_pushlstring(L, NULL, 0);
 178   return (gzeof(f) != 1);
 179 }
 180
 181
 182 static int read_line (lua_State *L, gzFile f) {
 183   luaL_Buffer b;
 184   luaL_buffinit(L, &b);
 185   for (;;) {
 186     size_t l;
 187     char *p = luaL_prepbuffer(&b);
 188     if (gzgets(f, p, LUAL_BUFFERSIZE) == NULL) {  /* eof? */
 189       luaL_pushresult(&b);  /* close buffer */
 190       return (lua_rawlen(L, -1) > 0);  /* check whether read something */
 191     }
 192     l = strlen(p);
 193     if (p[l-1] != '\n')
 194       luaL_addsize(&b, l);
 195     else {
 196       luaL_addsize(&b, l - 1);  /* do not include `eol' */
 197       luaL_pushresult(&b);  /* close buffer */
 198       return 1;  /* read at least an `eol' */
 199     }
 200   }
 201 }
 202
 203
 204 static int read_chars (lua_State *L, gzFile f, size_t n) {
 205   size_t rlen;  /* how much to read */
 206   size_t nr;  /* number of chars actually read */
 207   luaL_Buffer b;
 208   luaL_buffinit(L, &b);
 209   rlen = LUAL_BUFFERSIZE;  /* try to read that much each time */
 210   do {
 211     char *p = luaL_prepbuffer(&b);
 212     if (rlen > n) rlen = n;  /* cannot read more than asked */
 213     nr = gzread(f, p, rlen);
 214     luaL_addsize(&b, nr);
 215     n -= nr;  /* still have to read `n' chars */
 216   } while (n > 0 && nr == rlen);  /* until end of count or eof */
 217   luaL_pushresult(&b);  /* close buffer */
 218   return (n == 0 || lua_rawlen(L, -1) > 0);
 219 }
 220
 221
 222 static int g_read (lua_State *L, gzFile f, int first) {
 223   int nargs = lua_gettop(L) - 1;
 224   int success;
 225   int n;
 226   if (nargs == 0) {  /* no arguments? */
 227     success = read_line(L, f);
 228     n = first+1;  /* to return 1 result */
 229   }
 230   else {  /* ensure stack space for all results and for auxlib's buffer */
 231     luaL_checkstack(L, nargs+LUA_MINSTACK, "too many arguments");
 232     success = 1;
 233     for (n = first; nargs-- && success; n++) {
 234       if (lua_type(L, n) == LUA_TNUMBER) {
 235         size_t l = (size_t)lua_tonumber(L, n);
 236         success = (l == 0) ? test_eof(L, f) : read_chars(L, f, l);
 237       }
 238       else {
 239         const char *p = lua_tostring(L, n);
 240         luaL_argcheck(L, p && p[0] == '*', n, "invalid option");
 241         switch (p[1]) {
 242           case 'l':  /* line */
 243             success = read_line(L, f);
 244             break;
 245           case 'a':  /* file */
 246             read_chars(L, f, ~((size_t)0));  /* read MAX_SIZE_T chars */
 247             success = 1; /* always success */
 248             break;
 249           default:
 250             return luaL_argerror(L, n, "invalid format");
 251         }
 252       }
 253     }
 254   }
 255   if (!success) {
 256     lua_pop(L, 1);  /* remove last result */
 257     lua_pushnil(L);  /* push nil instead */
 258   }
 259   return n - first;
 260 }
 261
 262
 263 static int f_read (lua_State *L) {
 264   return g_read(L, tofile(L, 1), 2);
 265 }
 266
 267
 268 static int io_readline (lua_State *L) {
 269   gzFile f = *(gzFile*)lua_touserdata(L, lua_upvalueindex(2));
 270   if (f == NULL)  /* file is already closed? */
 271     luaL_error(L, "file is already closed");
 272   if (read_line(L, f)) return 1;
 273   else {  /* EOF */
 274     if (lua_toboolean(L, lua_upvalueindex(3))) {  /* generator created file? */
 275       lua_settop(L, 0);
 276       lua_pushvalue(L, lua_upvalueindex(2));
 277       aux_close(L);  /* close it */
 278     }
 279     return 0;
 280   }
 281 }
 282
 283 /* }====================================================== */
 284
 285
 286 static int g_write (lua_State *L, gzFile f, int arg) {
 287   int nargs = lua_gettop(L) - 1;
 288   int status = 1;
 289   for (; nargs--; arg++) {
 290     if (lua_type(L, arg) == LUA_TNUMBER) {
 291       /* optimization: could be done exactly as for strings */
 292       status = status &&
 293           gzprintf(f, LUA_NUMBER_FMT, lua_tonumber(L, arg)) > 0;
 294     }
 295     else {
 296       size_t l;
 297       const char *s = luaL_checklstring(L, arg, &l);
 298       status = status && (gzwrite(f, (char*)s, l) == l);
 299     }
 300   }
 301   return pushresult(L, status, NULL);
 302 }
 303
 304
 305 static int f_write (lua_State *L) {
 306   return g_write(L, tofile(L, 1), 2);
 307 }
 308
 309
 310 static int f_seek (lua_State *L) {
 311   static const int mode[] = {SEEK_SET, SEEK_CUR};
 312   static const char *const modenames[] = {"set", "cur", NULL};
 313   gzFile f = tofile(L, 1);
 314   int op = luaL_checkoption(L, 2, "cur", modenames);
 315   long offset = luaL_optlong(L, 3, 0);
 316   luaL_argcheck(L, op != -1, 2, "invalid mode");
 317   op = gzseek(f, offset, mode[op]);
 318   if (op == -1)
 319     return pushresult(L, 0, NULL);  /* error */
 320   else {
 321     lua_pushnumber(L, op);
 322     return 1;
 323   }
 324 }
 325
 326
 327 static int f_flush (lua_State *L) {
 328   return pushresult(L, gzflush(tofile(L, 1), Z_FINISH) == Z_OK, NULL);
 329 }
 330
 331
 332 static const luaL_Reg iolib[] = {
 333   {"lines", io_lines},
 334   {"close", io_close},
 335   {"open", io_open},
 336   {NULL, NULL}
 337 };
 338
 339
 340 static const luaL_Reg flib[] = {
 341   {"flush", f_flush},
 342   {"read", f_read},
 343   {"lines", f_lines},
 344   {"seek", f_seek},
 345   {"write", f_write},
 346   {"close", io_close},
 347   {"__gc", io_gc},
 348   {"__tostring", io_tostring},
 349   {NULL, NULL}
 350 };
 351
 352
 353 static void createmeta (lua_State *L) {
 354   luaL_newmetatable(L, FILEHANDLE);  /* create new metatable for file handles */
 355   /* file methods */
 356   lua_pushliteral(L, "__index");
 357   lua_pushvalue(L, -2);  /* push metatable */
 358   lua_rawset(L, -3);  /* metatable.__index = metatable */
 359   luaL_openlib(L, NULL, flib, 0);
 360 }
 361
 362
 363 /* }====================================================== */
 364
 365
 366
 367 LUALIB_API int luaopen_gzip (lua_State *L) {
 368   createmeta(L);
 369   lua_pushvalue(L, -1);
 370   luaL_openlib(L, "gzip", iolib, 1);
 371   return 1;
 372 }
 373