xref: /redis-3.2.3/deps/lua/src/lua_cmsgpack.c (revision d4a9836f)
1 #include <math.h>
2 #include <stdlib.h>
3 #include <stdint.h>
4 #include <string.h>
5 #include <assert.h>
6 
7 #include "lua.h"
8 #include "lauxlib.h"
9 
10 #define LUACMSGPACK_NAME        "cmsgpack"
11 #define LUACMSGPACK_SAFE_NAME   "cmsgpack_safe"
12 #define LUACMSGPACK_VERSION     "lua-cmsgpack 0.4.0"
13 #define LUACMSGPACK_COPYRIGHT   "Copyright (C) 2012, Salvatore Sanfilippo"
14 #define LUACMSGPACK_DESCRIPTION "MessagePack C implementation for Lua"
15 
16 /* Allows a preprocessor directive to override MAX_NESTING */
17 #ifndef LUACMSGPACK_MAX_NESTING
18     #define LUACMSGPACK_MAX_NESTING  16 /* Max tables nesting. */
19 #endif
20 
21 /* Check if float or double can be an integer without loss of precision */
22 #define IS_INT_TYPE_EQUIVALENT(x, T) (!isinf(x) && (T)(x) == (x))
23 
24 #define IS_INT64_EQUIVALENT(x) IS_INT_TYPE_EQUIVALENT(x, int64_t)
25 #define IS_INT_EQUIVALENT(x) IS_INT_TYPE_EQUIVALENT(x, int)
26 
27 /* If size of pointer is equal to a 4 byte integer, we're on 32 bits. */
28 #if UINTPTR_MAX == UINT_MAX
29     #define BITS_32 1
30 #else
31     #define BITS_32 0
32 #endif
33 
34 #if LUA_VERSION_NUM < 503
35     #if BITS_32
36         #define lua_pushunsigned(L, n) lua_pushnumber(L, n)
37     #else
38         #define lua_pushunsigned(L, n) lua_pushinteger(L, n)
39     #endif
40 #endif
41 
42 /* =============================================================================
43  * MessagePack implementation and bindings for Lua 5.1/5.2.
44  * Copyright(C) 2012 Salvatore Sanfilippo <[email protected]>
45  *
46  * http://github.com/antirez/lua-cmsgpack
47  *
48  * For MessagePack specification check the following web site:
49  * http://wiki.msgpack.org/display/MSGPACK/Format+specification
50  *
51  * See Copyright Notice at the end of this file.
52  *
53  * CHANGELOG:
54  * 19-Feb-2012 (ver 0.1.0): Initial release.
55  * 20-Feb-2012 (ver 0.2.0): Tables encoding improved.
56  * 20-Feb-2012 (ver 0.2.1): Minor bug fixing.
57  * 20-Feb-2012 (ver 0.3.0): Module renamed lua-cmsgpack (was lua-msgpack).
58  * 04-Apr-2014 (ver 0.3.1): Lua 5.2 support and minor bug fix.
59  * 07-Apr-2014 (ver 0.4.0): Multiple pack/unpack, lua allocator, efficiency.
60  * ========================================================================== */
61 
62 /* -------------------------- Endian conversion --------------------------------
63  * We use it only for floats and doubles, all the other conversions performed
64  * in an endian independent fashion. So the only thing we need is a function
65  * that swaps a binary string if arch is little endian (and left it untouched
66  * otherwise). */
67 
68 /* Reverse memory bytes if arch is little endian. Given the conceptual
69  * simplicity of the Lua build system we prefer check for endianess at runtime.
70  * The performance difference should be acceptable. */
71 static void memrevifle(void *ptr, size_t len) {
72     unsigned char   *p = (unsigned char *)ptr,
73                     *e = (unsigned char *)p+len-1,
74                     aux;
75     int test = 1;
76     unsigned char *testp = (unsigned char*) &test;
77 
78     if (testp[0] == 0) return; /* Big endian, nothing to do. */
79     len /= 2;
80     while(len--) {
81         aux = *p;
82         *p = *e;
83         *e = aux;
84         p++;
85         e--;
86     }
87 }
88 
89 /* ---------------------------- String buffer ----------------------------------
90  * This is a simple implementation of string buffers. The only operation
91  * supported is creating empty buffers and appending bytes to it.
92  * The string buffer uses 2x preallocation on every realloc for O(N) append
93  * behavior.  */
94 
95 typedef struct mp_buf {
96     lua_State *L;
97     unsigned char *b;
98     size_t len, free;
99 } mp_buf;
100 
101 static void *mp_realloc(lua_State *L, void *target, size_t osize,size_t nsize) {
102     void *(*local_realloc) (void *, void *, size_t osize, size_t nsize) = NULL;
103     void *ud;
104 
105     local_realloc = lua_getallocf(L, &ud);
106 
107     return local_realloc(ud, target, osize, nsize);
108 }
109 
110 static mp_buf *mp_buf_new(lua_State *L) {
111     mp_buf *buf = NULL;
112 
113     /* Old size = 0; new size = sizeof(*buf) */
114     buf = (mp_buf*)mp_realloc(L, NULL, 0, sizeof(*buf));
115 
116     buf->L = L;
117     buf->b = NULL;
118     buf->len = buf->free = 0;
119     return buf;
120 }
121 
122 static void mp_buf_append(mp_buf *buf, const unsigned char *s, size_t len) {
123     if (buf->free < len) {
124         size_t newlen = buf->len+len;
125 
126         buf->b = (unsigned char*)mp_realloc(buf->L, buf->b, buf->len, newlen*2);
127         buf->free = newlen;
128     }
129     memcpy(buf->b+buf->len,s,len);
130     buf->len += len;
131     buf->free -= len;
132 }
133 
134 void mp_buf_free(mp_buf *buf) {
135     mp_realloc(buf->L, buf->b, buf->len, 0); /* realloc to 0 = free */
136     mp_realloc(buf->L, buf, sizeof(*buf), 0);
137 }
138 
139 /* ---------------------------- String cursor ----------------------------------
140  * This simple data structure is used for parsing. Basically you create a cursor
141  * using a string pointer and a length, then it is possible to access the
142  * current string position with cursor->p, check the remaining length
143  * in cursor->left, and finally consume more string using
144  * mp_cur_consume(cursor,len), to advance 'p' and subtract 'left'.
145  * An additional field cursor->error is set to zero on initialization and can
146  * be used to report errors. */
147 
148 #define MP_CUR_ERROR_NONE   0
149 #define MP_CUR_ERROR_EOF    1   /* Not enough data to complete operation. */
150 #define MP_CUR_ERROR_BADFMT 2   /* Bad data format */
151 
152 typedef struct mp_cur {
153     const unsigned char *p;
154     size_t left;
155     int err;
156 } mp_cur;
157 
158 static void mp_cur_init(mp_cur *cursor, const unsigned char *s, size_t len) {
159     cursor->p = s;
160     cursor->left = len;
161     cursor->err = MP_CUR_ERROR_NONE;
162 }
163 
164 #define mp_cur_consume(_c,_len) do { _c->p += _len; _c->left -= _len; } while(0)
165 
166 /* When there is not enough room we set an error in the cursor and return. This
167  * is very common across the code so we have a macro to make the code look
168  * a bit simpler. */
169 #define mp_cur_need(_c,_len) do { \
170     if (_c->left < _len) { \
171         _c->err = MP_CUR_ERROR_EOF; \
172         return; \
173     } \
174 } while(0)
175 
176 /* ------------------------- Low level MP encoding -------------------------- */
177 
178 static void mp_encode_bytes(mp_buf *buf, const unsigned char *s, size_t len) {
179     unsigned char hdr[5];
180     int hdrlen;
181 
182     if (len < 32) {
183         hdr[0] = 0xa0 | (len&0xff); /* fix raw */
184         hdrlen = 1;
185     } else if (len <= 0xffff) {
186         hdr[0] = 0xda;
187         hdr[1] = (len&0xff00)>>8;
188         hdr[2] = len&0xff;
189         hdrlen = 3;
190     } else {
191         hdr[0] = 0xdb;
192         hdr[1] = (len&0xff000000)>>24;
193         hdr[2] = (len&0xff0000)>>16;
194         hdr[3] = (len&0xff00)>>8;
195         hdr[4] = len&0xff;
196         hdrlen = 5;
197     }
198     mp_buf_append(buf,hdr,hdrlen);
199     mp_buf_append(buf,s,len);
200 }
201 
202 /* we assume IEEE 754 internal format for single and double precision floats. */
203 static void mp_encode_double(mp_buf *buf, double d) {
204     unsigned char b[9];
205     float f = d;
206 
207     assert(sizeof(f) == 4 && sizeof(d) == 8);
208     if (d == (double)f) {
209         b[0] = 0xca;    /* float IEEE 754 */
210         memcpy(b+1,&f,4);
211         memrevifle(b+1,4);
212         mp_buf_append(buf,b,5);
213     } else if (sizeof(d) == 8) {
214         b[0] = 0xcb;    /* double IEEE 754 */
215         memcpy(b+1,&d,8);
216         memrevifle(b+1,8);
217         mp_buf_append(buf,b,9);
218     }
219 }
220 
221 static void mp_encode_int(mp_buf *buf, int64_t n) {
222     unsigned char b[9];
223     int enclen;
224 
225     if (n >= 0) {
226         if (n <= 127) {
227             b[0] = n & 0x7f;    /* positive fixnum */
228             enclen = 1;
229         } else if (n <= 0xff) {
230             b[0] = 0xcc;        /* uint 8 */
231             b[1] = n & 0xff;
232             enclen = 2;
233         } else if (n <= 0xffff) {
234             b[0] = 0xcd;        /* uint 16 */
235             b[1] = (n & 0xff00) >> 8;
236             b[2] = n & 0xff;
237             enclen = 3;
238         } else if (n <= 0xffffffffLL) {
239             b[0] = 0xce;        /* uint 32 */
240             b[1] = (n & 0xff000000) >> 24;
241             b[2] = (n & 0xff0000) >> 16;
242             b[3] = (n & 0xff00) >> 8;
243             b[4] = n & 0xff;
244             enclen = 5;
245         } else {
246             b[0] = 0xcf;        /* uint 64 */
247             b[1] = (n & 0xff00000000000000LL) >> 56;
248             b[2] = (n & 0xff000000000000LL) >> 48;
249             b[3] = (n & 0xff0000000000LL) >> 40;
250             b[4] = (n & 0xff00000000LL) >> 32;
251             b[5] = (n & 0xff000000) >> 24;
252             b[6] = (n & 0xff0000) >> 16;
253             b[7] = (n & 0xff00) >> 8;
254             b[8] = n & 0xff;
255             enclen = 9;
256         }
257     } else {
258         if (n >= -32) {
259             b[0] = ((char)n);   /* negative fixnum */
260             enclen = 1;
261         } else if (n >= -128) {
262             b[0] = 0xd0;        /* int 8 */
263             b[1] = n & 0xff;
264             enclen = 2;
265         } else if (n >= -32768) {
266             b[0] = 0xd1;        /* int 16 */
267             b[1] = (n & 0xff00) >> 8;
268             b[2] = n & 0xff;
269             enclen = 3;
270         } else if (n >= -2147483648LL) {
271             b[0] = 0xd2;        /* int 32 */
272             b[1] = (n & 0xff000000) >> 24;
273             b[2] = (n & 0xff0000) >> 16;
274             b[3] = (n & 0xff00) >> 8;
275             b[4] = n & 0xff;
276             enclen = 5;
277         } else {
278             b[0] = 0xd3;        /* int 64 */
279             b[1] = (n & 0xff00000000000000LL) >> 56;
280             b[2] = (n & 0xff000000000000LL) >> 48;
281             b[3] = (n & 0xff0000000000LL) >> 40;
282             b[4] = (n & 0xff00000000LL) >> 32;
283             b[5] = (n & 0xff000000) >> 24;
284             b[6] = (n & 0xff0000) >> 16;
285             b[7] = (n & 0xff00) >> 8;
286             b[8] = n & 0xff;
287             enclen = 9;
288         }
289     }
290     mp_buf_append(buf,b,enclen);
291 }
292 
293 static void mp_encode_array(mp_buf *buf, int64_t n) {
294     unsigned char b[5];
295     int enclen;
296 
297     if (n <= 15) {
298         b[0] = 0x90 | (n & 0xf);    /* fix array */
299         enclen = 1;
300     } else if (n <= 65535) {
301         b[0] = 0xdc;                /* array 16 */
302         b[1] = (n & 0xff00) >> 8;
303         b[2] = n & 0xff;
304         enclen = 3;
305     } else {
306         b[0] = 0xdd;                /* array 32 */
307         b[1] = (n & 0xff000000) >> 24;
308         b[2] = (n & 0xff0000) >> 16;
309         b[3] = (n & 0xff00) >> 8;
310         b[4] = n & 0xff;
311         enclen = 5;
312     }
313     mp_buf_append(buf,b,enclen);
314 }
315 
316 static void mp_encode_map(mp_buf *buf, int64_t n) {
317     unsigned char b[5];
318     int enclen;
319 
320     if (n <= 15) {
321         b[0] = 0x80 | (n & 0xf);    /* fix map */
322         enclen = 1;
323     } else if (n <= 65535) {
324         b[0] = 0xde;                /* map 16 */
325         b[1] = (n & 0xff00) >> 8;
326         b[2] = n & 0xff;
327         enclen = 3;
328     } else {
329         b[0] = 0xdf;                /* map 32 */
330         b[1] = (n & 0xff000000) >> 24;
331         b[2] = (n & 0xff0000) >> 16;
332         b[3] = (n & 0xff00) >> 8;
333         b[4] = n & 0xff;
334         enclen = 5;
335     }
336     mp_buf_append(buf,b,enclen);
337 }
338 
339 /* --------------------------- Lua types encoding --------------------------- */
340 
341 static void mp_encode_lua_string(lua_State *L, mp_buf *buf) {
342     size_t len;
343     const char *s;
344 
345     s = lua_tolstring(L,-1,&len);
346     mp_encode_bytes(buf,(const unsigned char*)s,len);
347 }
348 
349 static void mp_encode_lua_bool(lua_State *L, mp_buf *buf) {
350     unsigned char b = lua_toboolean(L,-1) ? 0xc3 : 0xc2;
351     mp_buf_append(buf,&b,1);
352 }
353 
354 /* Lua 5.3 has a built in 64-bit integer type */
355 static void mp_encode_lua_integer(lua_State *L, mp_buf *buf) {
356 #if (LUA_VERSION_NUM < 503) && BITS_32
357     lua_Number i = lua_tonumber(L,-1);
358 #else
359     lua_Integer i = lua_tointeger(L,-1);
360 #endif
361     mp_encode_int(buf, (int64_t)i);
362 }
363 
364 /* Lua 5.2 and lower only has 64-bit doubles, so we need to
365  * detect if the double may be representable as an int
366  * for Lua < 5.3 */
367 static void mp_encode_lua_number(lua_State *L, mp_buf *buf) {
368     lua_Number n = lua_tonumber(L,-1);
369 
370     if (IS_INT64_EQUIVALENT(n)) {
371         mp_encode_lua_integer(L, buf);
372     } else {
373         mp_encode_double(buf,(double)n);
374     }
375 }
376 
377 static void mp_encode_lua_type(lua_State *L, mp_buf *buf, int level);
378 
379 /* Convert a lua table into a message pack list. */
380 static void mp_encode_lua_table_as_array(lua_State *L, mp_buf *buf, int level) {
381 #if LUA_VERSION_NUM < 502
382     size_t len = lua_objlen(L,-1), j;
383 #else
384     size_t len = lua_rawlen(L,-1), j;
385 #endif
386 
387     mp_encode_array(buf,len);
388     for (j = 1; j <= len; j++) {
389         lua_pushnumber(L,j);
390         lua_gettable(L,-2);
391         mp_encode_lua_type(L,buf,level+1);
392     }
393 }
394 
395 /* Convert a lua table into a message pack key-value map. */
396 static void mp_encode_lua_table_as_map(lua_State *L, mp_buf *buf, int level) {
397     size_t len = 0;
398 
399     /* First step: count keys into table. No other way to do it with the
400      * Lua API, we need to iterate a first time. Note that an alternative
401      * would be to do a single run, and then hack the buffer to insert the
402      * map opcodes for message pack. Too hackish for this lib. */
403     lua_pushnil(L);
404     while(lua_next(L,-2)) {
405         lua_pop(L,1); /* remove value, keep key for next iteration. */
406         len++;
407     }
408 
409     /* Step two: actually encoding of the map. */
410     mp_encode_map(buf,len);
411     lua_pushnil(L);
412     while(lua_next(L,-2)) {
413         /* Stack: ... key value */
414         lua_pushvalue(L,-2); /* Stack: ... key value key */
415         mp_encode_lua_type(L,buf,level+1); /* encode key */
416         mp_encode_lua_type(L,buf,level+1); /* encode val */
417     }
418 }
419 
420 /* Returns true if the Lua table on top of the stack is exclusively composed
421  * of keys from numerical keys from 1 up to N, with N being the total number
422  * of elements, without any hole in the middle. */
423 static int table_is_an_array(lua_State *L) {
424     int count = 0, max = 0;
425 #if LUA_VERSION_NUM < 503
426     lua_Number n;
427 #else
428     lua_Integer n;
429 #endif
430 
431     /* Stack top on function entry */
432     int stacktop;
433 
434     stacktop = lua_gettop(L);
435 
436     lua_pushnil(L);
437     while(lua_next(L,-2)) {
438         /* Stack: ... key value */
439         lua_pop(L,1); /* Stack: ... key */
440         /* The <= 0 check is valid here because we're comparing indexes. */
441 #if LUA_VERSION_NUM < 503
442         if ((LUA_TNUMBER != lua_type(L,-1)) || (n = lua_tonumber(L, -1)) <= 0 ||
443             !IS_INT_EQUIVALENT(n))
444 #else
445         if (!lua_isinteger(L,-1) || (n = lua_tointeger(L, -1)) <= 0)
446 #endif
447         {
448             lua_settop(L, stacktop);
449             return 0;
450         }
451         max = (n > max ? n : max);
452         count++;
453     }
454     /* We have the total number of elements in "count". Also we have
455      * the max index encountered in "max". We can't reach this code
456      * if there are indexes <= 0. If you also note that there can not be
457      * repeated keys into a table, you have that if max==count you are sure
458      * that there are all the keys form 1 to count (both included). */
459     lua_settop(L, stacktop);
460     return max == count;
461 }
462 
463 /* If the length operator returns non-zero, that is, there is at least
464  * an object at key '1', we serialize to message pack list. Otherwise
465  * we use a map. */
466 static void mp_encode_lua_table(lua_State *L, mp_buf *buf, int level) {
467     if (table_is_an_array(L))
468         mp_encode_lua_table_as_array(L,buf,level);
469     else
470         mp_encode_lua_table_as_map(L,buf,level);
471 }
472 
473 static void mp_encode_lua_null(lua_State *L, mp_buf *buf) {
474     unsigned char b[1];
475     (void)L;
476 
477     b[0] = 0xc0;
478     mp_buf_append(buf,b,1);
479 }
480 
481 static void mp_encode_lua_type(lua_State *L, mp_buf *buf, int level) {
482     int t = lua_type(L,-1);
483 
484     /* Limit the encoding of nested tables to a specified maximum depth, so that
485      * we survive when called against circular references in tables. */
486     if (t == LUA_TTABLE && level == LUACMSGPACK_MAX_NESTING) t = LUA_TNIL;
487     switch(t) {
488     case LUA_TSTRING: mp_encode_lua_string(L,buf); break;
489     case LUA_TBOOLEAN: mp_encode_lua_bool(L,buf); break;
490     case LUA_TNUMBER:
491     #if LUA_VERSION_NUM < 503
492         mp_encode_lua_number(L,buf); break;
493     #else
494         if (lua_isinteger(L, -1)) {
495             mp_encode_lua_integer(L, buf);
496         } else {
497             mp_encode_lua_number(L, buf);
498         }
499         break;
500     #endif
501     case LUA_TTABLE: mp_encode_lua_table(L,buf,level); break;
502     default: mp_encode_lua_null(L,buf); break;
503     }
504     lua_pop(L,1);
505 }
506 
507 /*
508  * Packs all arguments as a stream for multiple upacking later.
509  * Returns error if no arguments provided.
510  */
511 static int mp_pack(lua_State *L) {
512     int nargs = lua_gettop(L);
513     int i;
514     mp_buf *buf;
515 
516     if (nargs == 0)
517         return luaL_argerror(L, 0, "MessagePack pack needs input.");
518 
519     buf = mp_buf_new(L);
520     for(i = 1; i <= nargs; i++) {
521         /* Copy argument i to top of stack for _encode processing;
522          * the encode function pops it from the stack when complete. */
523         lua_pushvalue(L, i);
524 
525         mp_encode_lua_type(L,buf,0);
526 
527         lua_pushlstring(L,(char*)buf->b,buf->len);
528 
529         /* Reuse the buffer for the next operation by
530          * setting its free count to the total buffer size
531          * and the current position to zero. */
532         buf->free += buf->len;
533         buf->len = 0;
534     }
535     mp_buf_free(buf);
536 
537     /* Concatenate all nargs buffers together */
538     lua_concat(L, nargs);
539     return 1;
540 }
541 
542 /* ------------------------------- Decoding --------------------------------- */
543 
544 void mp_decode_to_lua_type(lua_State *L, mp_cur *c);
545 
546 void mp_decode_to_lua_array(lua_State *L, mp_cur *c, size_t len) {
547     int index = 1;
548 
549     lua_newtable(L);
550     while(len--) {
551         lua_pushnumber(L,index++);
552         mp_decode_to_lua_type(L,c);
553         if (c->err) return;
554         lua_settable(L,-3);
555     }
556 }
557 
558 void mp_decode_to_lua_hash(lua_State *L, mp_cur *c, size_t len) {
559     lua_newtable(L);
560     while(len--) {
561         mp_decode_to_lua_type(L,c); /* key */
562         if (c->err) return;
563         mp_decode_to_lua_type(L,c); /* value */
564         if (c->err) return;
565         lua_settable(L,-3);
566     }
567 }
568 
569 /* Decode a Message Pack raw object pointed by the string cursor 'c' to
570  * a Lua type, that is left as the only result on the stack. */
571 void mp_decode_to_lua_type(lua_State *L, mp_cur *c) {
572     mp_cur_need(c,1);
573 
574     /* If we return more than 18 elements, we must resize the stack to
575      * fit all our return values.  But, there is no way to
576      * determine how many objects a msgpack will unpack to up front, so
577      * we request a +1 larger stack on each iteration (noop if stack is
578      * big enough, and when stack does require resize it doubles in size) */
579     luaL_checkstack(L, 1,
580         "too many return values at once; "
581         "use unpack_one or unpack_limit instead.");
582 
583     switch(c->p[0]) {
584     case 0xcc:  /* uint 8 */
585         mp_cur_need(c,2);
586         lua_pushunsigned(L,c->p[1]);
587         mp_cur_consume(c,2);
588         break;
589     case 0xd0:  /* int 8 */
590         mp_cur_need(c,2);
591         lua_pushinteger(L,(char)c->p[1]);
592         mp_cur_consume(c,2);
593         break;
594     case 0xcd:  /* uint 16 */
595         mp_cur_need(c,3);
596         lua_pushunsigned(L,
597             (c->p[1] << 8) |
598              c->p[2]);
599         mp_cur_consume(c,3);
600         break;
601     case 0xd1:  /* int 16 */
602         mp_cur_need(c,3);
603         lua_pushinteger(L,(int16_t)
604             (c->p[1] << 8) |
605              c->p[2]);
606         mp_cur_consume(c,3);
607         break;
608     case 0xce:  /* uint 32 */
609         mp_cur_need(c,5);
610         lua_pushunsigned(L,
611             ((uint32_t)c->p[1] << 24) |
612             ((uint32_t)c->p[2] << 16) |
613             ((uint32_t)c->p[3] << 8) |
614              (uint32_t)c->p[4]);
615         mp_cur_consume(c,5);
616         break;
617     case 0xd2:  /* int 32 */
618         mp_cur_need(c,5);
619         lua_pushinteger(L,
620             ((int32_t)c->p[1] << 24) |
621             ((int32_t)c->p[2] << 16) |
622             ((int32_t)c->p[3] << 8) |
623              (int32_t)c->p[4]);
624         mp_cur_consume(c,5);
625         break;
626     case 0xcf:  /* uint 64 */
627         mp_cur_need(c,9);
628         lua_pushunsigned(L,
629             ((uint64_t)c->p[1] << 56) |
630             ((uint64_t)c->p[2] << 48) |
631             ((uint64_t)c->p[3] << 40) |
632             ((uint64_t)c->p[4] << 32) |
633             ((uint64_t)c->p[5] << 24) |
634             ((uint64_t)c->p[6] << 16) |
635             ((uint64_t)c->p[7] << 8) |
636              (uint64_t)c->p[8]);
637         mp_cur_consume(c,9);
638         break;
639     case 0xd3:  /* int 64 */
640         mp_cur_need(c,9);
641 #if LUA_VERSION_NUM < 503
642         lua_pushnumber(L,
643 #else
644         lua_pushinteger(L,
645 #endif
646             ((int64_t)c->p[1] << 56) |
647             ((int64_t)c->p[2] << 48) |
648             ((int64_t)c->p[3] << 40) |
649             ((int64_t)c->p[4] << 32) |
650             ((int64_t)c->p[5] << 24) |
651             ((int64_t)c->p[6] << 16) |
652             ((int64_t)c->p[7] << 8) |
653              (int64_t)c->p[8]);
654         mp_cur_consume(c,9);
655         break;
656     case 0xc0:  /* nil */
657         lua_pushnil(L);
658         mp_cur_consume(c,1);
659         break;
660     case 0xc3:  /* true */
661         lua_pushboolean(L,1);
662         mp_cur_consume(c,1);
663         break;
664     case 0xc2:  /* false */
665         lua_pushboolean(L,0);
666         mp_cur_consume(c,1);
667         break;
668     case 0xca:  /* float */
669         mp_cur_need(c,5);
670         assert(sizeof(float) == 4);
671         {
672             float f;
673             memcpy(&f,c->p+1,4);
674             memrevifle(&f,4);
675             lua_pushnumber(L,f);
676             mp_cur_consume(c,5);
677         }
678         break;
679     case 0xcb:  /* double */
680         mp_cur_need(c,9);
681         assert(sizeof(double) == 8);
682         {
683             double d;
684             memcpy(&d,c->p+1,8);
685             memrevifle(&d,8);
686             lua_pushnumber(L,d);
687             mp_cur_consume(c,9);
688         }
689         break;
690     case 0xda:  /* raw 16 */
691         mp_cur_need(c,3);
692         {
693             size_t l = (c->p[1] << 8) | c->p[2];
694             mp_cur_need(c,3+l);
695             lua_pushlstring(L,(char*)c->p+3,l);
696             mp_cur_consume(c,3+l);
697         }
698         break;
699     case 0xdb:  /* raw 32 */
700         mp_cur_need(c,5);
701         {
702             size_t l = (c->p[1] << 24) |
703                        (c->p[2] << 16) |
704                        (c->p[3] << 8) |
705                        c->p[4];
706             mp_cur_need(c,5+l);
707             lua_pushlstring(L,(char*)c->p+5,l);
708             mp_cur_consume(c,5+l);
709         }
710         break;
711     case 0xdc:  /* array 16 */
712         mp_cur_need(c,3);
713         {
714             size_t l = (c->p[1] << 8) | c->p[2];
715             mp_cur_consume(c,3);
716             mp_decode_to_lua_array(L,c,l);
717         }
718         break;
719     case 0xdd:  /* array 32 */
720         mp_cur_need(c,5);
721         {
722             size_t l = (c->p[1] << 24) |
723                        (c->p[2] << 16) |
724                        (c->p[3] << 8) |
725                        c->p[4];
726             mp_cur_consume(c,5);
727             mp_decode_to_lua_array(L,c,l);
728         }
729         break;
730     case 0xde:  /* map 16 */
731         mp_cur_need(c,3);
732         {
733             size_t l = (c->p[1] << 8) | c->p[2];
734             mp_cur_consume(c,3);
735             mp_decode_to_lua_hash(L,c,l);
736         }
737         break;
738     case 0xdf:  /* map 32 */
739         mp_cur_need(c,5);
740         {
741             size_t l = (c->p[1] << 24) |
742                        (c->p[2] << 16) |
743                        (c->p[3] << 8) |
744                        c->p[4];
745             mp_cur_consume(c,5);
746             mp_decode_to_lua_hash(L,c,l);
747         }
748         break;
749     default:    /* types that can't be idenitified by first byte value. */
750         if ((c->p[0] & 0x80) == 0) {   /* positive fixnum */
751             lua_pushunsigned(L,c->p[0]);
752             mp_cur_consume(c,1);
753         } else if ((c->p[0] & 0xe0) == 0xe0) {  /* negative fixnum */
754             lua_pushinteger(L,(signed char)c->p[0]);
755             mp_cur_consume(c,1);
756         } else if ((c->p[0] & 0xe0) == 0xa0) {  /* fix raw */
757             size_t l = c->p[0] & 0x1f;
758             mp_cur_need(c,1+l);
759             lua_pushlstring(L,(char*)c->p+1,l);
760             mp_cur_consume(c,1+l);
761         } else if ((c->p[0] & 0xf0) == 0x90) {  /* fix map */
762             size_t l = c->p[0] & 0xf;
763             mp_cur_consume(c,1);
764             mp_decode_to_lua_array(L,c,l);
765         } else if ((c->p[0] & 0xf0) == 0x80) {  /* fix map */
766             size_t l = c->p[0] & 0xf;
767             mp_cur_consume(c,1);
768             mp_decode_to_lua_hash(L,c,l);
769         } else {
770             c->err = MP_CUR_ERROR_BADFMT;
771         }
772     }
773 }
774 
775 static int mp_unpack_full(lua_State *L, int limit, int offset) {
776     size_t len;
777     const char *s;
778     mp_cur c;
779     int cnt; /* Number of objects unpacked */
780     int decode_all = (!limit && !offset);
781 
782     s = luaL_checklstring(L,1,&len); /* if no match, exits */
783 
784     if (offset < 0 || limit < 0) /* requesting negative off or lim is invalid */
785         return luaL_error(L,
786             "Invalid request to unpack with offset of %d and limit of %d.",
787             offset, len);
788     else if (offset > len)
789         return luaL_error(L,
790             "Start offset %d greater than input length %d.", offset, len);
791 
792     if (decode_all) limit = INT_MAX;
793 
794     mp_cur_init(&c,(const unsigned char *)s+offset,len-offset);
795 
796     /* We loop over the decode because this could be a stream
797      * of multiple top-level values serialized together */
798     for(cnt = 0; c.left > 0 && cnt < limit; cnt++) {
799         mp_decode_to_lua_type(L,&c);
800 
801         if (c.err == MP_CUR_ERROR_EOF) {
802             return luaL_error(L,"Missing bytes in input.");
803         } else if (c.err == MP_CUR_ERROR_BADFMT) {
804             return luaL_error(L,"Bad data format in input.");
805         }
806     }
807 
808     if (!decode_all) {
809         /* c->left is the remaining size of the input buffer.
810          * subtract the entire buffer size from the unprocessed size
811          * to get our next start offset */
812         int offset = len - c.left;
813         /* Return offset -1 when we have have processed the entire buffer. */
814         lua_pushinteger(L, c.left == 0 ? -1 : offset);
815         /* Results are returned with the arg elements still
816          * in place. Lua takes care of only returning
817          * elements above the args for us.
818          * In this case, we have one arg on the stack
819          * for this function, so we insert our first return
820          * value at position 2. */
821         lua_insert(L, 2);
822         cnt += 1; /* increase return count by one to make room for offset */
823     }
824 
825     return cnt;
826 }
827 
828 static int mp_unpack(lua_State *L) {
829     return mp_unpack_full(L, 0, 0);
830 }
831 
832 static int mp_unpack_one(lua_State *L) {
833     int offset = luaL_optint(L, 2, 0);
834     /* Variable pop because offset may not exist */
835     lua_pop(L, lua_gettop(L)-1);
836     return mp_unpack_full(L, 1, offset);
837 }
838 
839 static int mp_unpack_limit(lua_State *L) {
840     int limit = luaL_checkint(L, 2);
841     int offset = luaL_optint(L, 3, 0);
842     /* Variable pop because offset may not exist */
843     lua_pop(L, lua_gettop(L)-1);
844 
845     return mp_unpack_full(L, limit, offset);
846 }
847 
848 static int mp_safe(lua_State *L) {
849     int argc, err, total_results;
850 
851     argc = lua_gettop(L);
852 
853     /* This adds our function to the bottom of the stack
854      * (the "call this function" position) */
855     lua_pushvalue(L, lua_upvalueindex(1));
856     lua_insert(L, 1);
857 
858     err = lua_pcall(L, argc, LUA_MULTRET, 0);
859     total_results = lua_gettop(L);
860 
861     if (!err) {
862         return total_results;
863     } else {
864         lua_pushnil(L);
865         lua_insert(L,-2);
866         return 2;
867     }
868 }
869 
870 /* -------------------------------------------------------------------------- */
871 static const struct luaL_Reg cmds[] = {
872     {"pack", mp_pack},
873     {"unpack", mp_unpack},
874     {"unpack_one", mp_unpack_one},
875     {"unpack_limit", mp_unpack_limit},
876     {0}
877 };
878 
879 static int luaopen_create(lua_State *L) {
880     int i;
881     /* Manually construct our module table instead of
882      * relying on _register or _newlib */
883     lua_newtable(L);
884 
885     for (i = 0; i < (sizeof(cmds)/sizeof(*cmds) - 1); i++) {
886         lua_pushcfunction(L, cmds[i].func);
887         lua_setfield(L, -2, cmds[i].name);
888     }
889 
890     /* Add metadata */
891     lua_pushliteral(L, LUACMSGPACK_NAME);
892     lua_setfield(L, -2, "_NAME");
893     lua_pushliteral(L, LUACMSGPACK_VERSION);
894     lua_setfield(L, -2, "_VERSION");
895     lua_pushliteral(L, LUACMSGPACK_COPYRIGHT);
896     lua_setfield(L, -2, "_COPYRIGHT");
897     lua_pushliteral(L, LUACMSGPACK_DESCRIPTION);
898     lua_setfield(L, -2, "_DESCRIPTION");
899     return 1;
900 }
901 
902 LUALIB_API int luaopen_cmsgpack(lua_State *L) {
903     luaopen_create(L);
904 
905 #if LUA_VERSION_NUM < 502
906     /* Register name globally for 5.1 */
907     lua_pushvalue(L, -1);
908     lua_setglobal(L, LUACMSGPACK_NAME);
909 #endif
910 
911     return 1;
912 }
913 
914 LUALIB_API int luaopen_cmsgpack_safe(lua_State *L) {
915     int i;
916 
917     luaopen_cmsgpack(L);
918 
919     /* Wrap all functions in the safe handler */
920     for (i = 0; i < (sizeof(cmds)/sizeof(*cmds) - 1); i++) {
921         lua_getfield(L, -1, cmds[i].name);
922         lua_pushcclosure(L, mp_safe, 1);
923         lua_setfield(L, -2, cmds[i].name);
924     }
925 
926 #if LUA_VERSION_NUM < 502
927     /* Register name globally for 5.1 */
928     lua_pushvalue(L, -1);
929     lua_setglobal(L, LUACMSGPACK_SAFE_NAME);
930 #endif
931 
932     return 1;
933 }
934 
935 /******************************************************************************
936 * Copyright (C) 2012 Salvatore Sanfilippo.  All rights reserved.
937 *
938 * Permission is hereby granted, free of charge, to any person obtaining
939 * a copy of this software and associated documentation files (the
940 * "Software"), to deal in the Software without restriction, including
941 * without limitation the rights to use, copy, modify, merge, publish,
942 * distribute, sublicense, and/or sell copies of the Software, and to
943 * permit persons to whom the Software is furnished to do so, subject to
944 * the following conditions:
945 *
946 * The above copyright notice and this permission notice shall be
947 * included in all copies or substantial portions of the Software.
948 *
949 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
950 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
951 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
952 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
953 * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
954 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
955 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
956 ******************************************************************************/
957