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#include 
#include 
#include 
#include 
#include 

#include "lua.h"
#include "lauxlib.h"

#define LUACMSGPACK_VERSION     "lua-cmsgpack 0.3.1"
#define LUACMSGPACK_COPYRIGHT   "Copyright (C) 2012, Salvatore Sanfilippo"
#define LUACMSGPACK_DESCRIPTION "MessagePack C implementation for Lua"

#define LUACMSGPACK_MAX_NESTING  16 /* Max tables nesting. */

/* ==============================================================================
 * MessagePack implementation and bindings for Lua 5.1/5.2.
 * Copyright(C) 2012 Salvatore Sanfilippo 
 *
 * http://github.com/antirez/lua-cmsgpack
 *
 * For MessagePack specification check the following web site:
 * http://wiki.msgpack.org/display/MSGPACK/Format+specification
 *
 * See Copyright Notice at the end of this file.
 *
 * CHANGELOG:
 * 19-Feb-2012 (ver 0.1.0): Initial release.
 * 20-Feb-2012 (ver 0.2.0): Tables encoding improved.
 * 20-Feb-2012 (ver 0.2.1): Minor bug fixing.
 * 20-Feb-2012 (ver 0.3.0): Module renamed lua-cmsgpack (was lua-msgpack).
 * 04-Apr-2014 (ver 0.3.1): Lua 5.2 support and minor bug fix.
 * ============================================================================ */

/* --------------------------- Endian conversion --------------------------------
 * We use it only for floats and doubles, all the other conversions are performed
 * in an endian independent fashion. So the only thing we need is a function
 * that swaps a binary string if the arch is little endian (and left it untouched
 * otherwise). */

/* Reverse memory bytes if arch is little endian. Given the conceptual
 * simplicity of the Lua build system we prefer to check for endianess at runtime.
 * The performance difference should be acceptable. */
static void memrevifle(void *ptr, size_t len) {
    unsigned char *p = ptr, *e = p+len-1, aux;
    int test = 1;
    unsigned char *testp = (unsigned char*) &test;

    if (testp[0] == 0) return; /* Big endian, nothign to do. */
    len /= 2;
    while(len--) {
        aux = *p;
        *p = *e;
        *e = aux;
        p++;
        e--;
    }
}

/* ----------------------------- String buffer ----------------------------------
 * This is a simple implementation of string buffers. The only opereation
 * supported is creating empty buffers and appending bytes to it.
 * The string buffer uses 2x preallocation on every realloc for O(N) append
 * behavior.  */

typedef struct mp_buf {
    unsigned char *b;
    size_t len, free;
} mp_buf;

static mp_buf *mp_buf_new(void) {
    mp_buf *buf = malloc(sizeof(*buf));
    
    buf->b = NULL;
    buf->len = buf->free = 0;
    return buf;
}

void mp_buf_append(mp_buf *buf, const unsigned char *s, size_t len) {
    if (buf->free < len) {
        size_t newlen = buf->len+len;

        buf->b = realloc(buf->b,newlen*2);
        buf->free = newlen;
    }
    memcpy(buf->b+buf->len,s,len);
    buf->len += len;
    buf->free -= len;
}

void mp_buf_free(mp_buf *buf) {
    free(buf->b);
    free(buf);
}

/* ------------------------------ String cursor ----------------------------------
 * This simple data structure is used for parsing. Basically you create a cursor
 * using a string pointer and a length, then it is possible to access the
 * current string position with cursor->p, check the remaining length
 * in cursor->left, and finally consume more string using
 * mp_cur_consume(cursor,len), to advance 'p' and subtract 'left'.
 * An additional field cursor->error is set to zero on initialization and can
 * be used to report errors. */

#define MP_CUR_ERROR_NONE   0
#define MP_CUR_ERROR_EOF    1   /* Not enough data to complete the opereation. */
#define MP_CUR_ERROR_BADFMT 2   /* Bad data format */

typedef struct mp_cur {
    const unsigned char *p;
    size_t left;
    int err;
} mp_cur;

static mp_cur *mp_cur_new(const unsigned char *s, size_t len) {
    mp_cur *cursor = malloc(sizeof(*cursor));

    cursor->p = s;
    cursor->left = len;
    cursor->err = MP_CUR_ERROR_NONE;
    return cursor;
}

static void mp_cur_free(mp_cur *cursor) {
    free(cursor);
}

#define mp_cur_consume(_c,_len) do { _c->p += _len; _c->left -= _len; } while(0)

/* When there is not enough room we set an error in the cursor and return, this
 * is very common across the code so we have a macro to make the code look
 * a bit simpler. */
#define mp_cur_need(_c,_len) do { \
    if (_c->left < _len) { \
        _c->err = MP_CUR_ERROR_EOF; \
        return; \
    } \
} while(0)

/* --------------------------- Low level MP encoding -------------------------- */

static void mp_encode_bytes(mp_buf *buf, const unsigned char *s, size_t len) {
    unsigned char hdr[5];
    int hdrlen;

    if (len < 32) {
        hdr[0] = 0xa0 | (len&0xff); /* fix raw */
        hdrlen = 1;
    } else if (len >8;
        hdr[2] = len&0xff;
        hdrlen = 3;
    } else {
        hdr[0] = 0xdb;
        hdr[1] = (len&0xff000000)>>24;
        hdr[2] = (len&0xff0000)>>16;
        hdr[3] = (len&0xff00)>>8;
        hdr[4] = len&0xff;
        hdrlen = 5;
    }
    mp_buf_append(buf,hdr,hdrlen);
    mp_buf_append(buf,s,len);
}

/* we assume IEEE 754 internal format for single and double precision floats. */
static void mp_encode_double(mp_buf *buf, double d) {
    unsigned char b[9];
    float f = d;

    assert(sizeof(f) == 4 && sizeof(d) == 8);
    if (d == (double)f) {
        b[0] = 0xca;    /* float IEEE 754 */
        memcpy(b+1,&f,4);
        memrevifle(b+1,4);
        mp_buf_append(buf,b,5);
    } else if (sizeof(d) == 8) {
        b[0] = 0xcb;    /* double IEEE 754 */
        memcpy(b+1,&d,8);
        memrevifle(b+1,8);
        mp_buf_append(buf,b,9);
    }
}

static void mp_encode_int(mp_buf *buf, int64_t n) {
    unsigned char b[9];
    int enclen;

    if (n >= 0) {
        if (n  24;
            b[2] = (n & 0xff0000) >> 16;
            b[3] = (n & 0xff00) >> 8;
            b[4] = n & 0xff;
            enclen = 5;
        } else {
            b[0] = 0xcf;        /* uint 64 */
            b[1] = (n & 0xff00000000000000LL) >> 56;
            b[2] = (n & 0xff000000000000LL) >> 48;
            b[3] = (n & 0xff0000000000LL) >> 40;
            b[4] = (n & 0xff00000000LL) >> 32;
            b[5] = (n & 0xff000000) >> 24;
            b[6] = (n & 0xff0000) >> 16;
            b[7] = (n & 0xff00) >> 8;
            b[8] = n & 0xff;
            enclen = 9;
        }
    } else {
        if (n >= -32) {
            b[0] = ((char)n);   /* negative fixnum */
            enclen = 1;
        } else if (n >= -128) {
            b[0] = 0xd0;        /* int 8 */
            b[1] = n & 0xff;
            enclen = 2;
        } else if (n >= -32768) {
            b[0] = 0xd1;        /* int 16 */
            b[1] = (n & 0xff00) >> 8;
            b[2] = n & 0xff;
            enclen = 3;
        } else if (n >= -2147483648LL) {
            b[0] = 0xd2;        /* int 32 */
            b[1] = (n & 0xff000000) >> 24;
            b[2] = (n & 0xff0000) >> 16;
            b[3] = (n & 0xff00) >> 8;
            b[4] = n & 0xff;
            enclen = 5;
        } else {
            b[0] = 0xd3;        /* int 64 */
            b[1] = (n & 0xff00000000000000LL) >> 56;
            b[2] = (n & 0xff000000000000LL) >> 48;
            b[3] = (n & 0xff0000000000LL) >> 40;
            b[4] = (n & 0xff00000000LL) >> 32;
            b[5] = (n & 0xff000000) >> 24;
            b[6] = (n & 0xff0000) >> 16;
            b[7] = (n & 0xff00) >> 8;
            b[8] = n & 0xff;
            enclen = 9;
        }
    }
    mp_buf_append(buf,b,enclen);
}

static void mp_encode_array(mp_buf *buf, int64_t n) {
    unsigned char b[5];
    int enclen;

    if (n  8;
        b[2] = n & 0xff;
        enclen = 3;
    } else {
        b[0] = 0xdd;                /* array 32 */
        b[1] = (n & 0xff000000) >> 24;
        b[2] = (n & 0xff0000) >> 16;
        b[3] = (n & 0xff00) >> 8;
        b[4] = n & 0xff;
        enclen = 5;
    }
    mp_buf_append(buf,b,enclen);
}

static void mp_encode_map(mp_buf *buf, int64_t n) {
    unsigned char b[5];
    int enclen;

    if (n  8;
        b[2] = n & 0xff;
        enclen = 3;
    } else {
        b[0] = 0xdf;                /* map 32 */
        b[1] = (n & 0xff000000) >> 24;
        b[2] = (n & 0xff0000) >> 16;
        b[3] = (n & 0xff00) >> 8;
        b[4] = n & 0xff;
        enclen = 5;
    }
    mp_buf_append(buf,b,enclen);
}

/* ----------------------------- Lua types encoding --------------------------- */

static void mp_encode_lua_string(lua_State *L, mp_buf *buf) {
    size_t len;
    const char *s;

    s = lua_tolstring(L,-1,&len);
    mp_encode_bytes(buf,(const unsigned char*)s,len);
}

static void mp_encode_lua_bool(lua_State *L, mp_buf *buf) {
    unsigned char b = lua_toboolean(L,-1) ? 0xc3 : 0xc2;
    mp_buf_append(buf,&b,1);
}

static void mp_encode_lua_number(lua_State *L, mp_buf *buf) {
    lua_Number n = lua_tonumber(L,-1);

    if (floor(n) != n) {
        mp_encode_double(buf,(double)n);
    } else {
        mp_encode_int(buf,(int64_t)n);
    }
}

static void mp_encode_lua_type(lua_State *L, mp_buf *buf, int level);

/* Convert a lua table into a message pack list. */
static void mp_encode_lua_table_as_array(lua_State *L, mp_buf *buf, int level) {
#if LUA_VERSION_NUM < 502
    size_t len = lua_objlen(L,-1), j;
#else
    size_t len = lua_rawlen(L,-1), j;
#endif

    mp_encode_array(buf,len);
    for (j = 1; j p[0] & 0x80) == 0) {   /* positive fixnum */
            lua_pushnumber(L,c->p[0]);
            mp_cur_consume(c,1);
        } else if ((c->p[0] & 0xe0) == 0xe0) {  /* negative fixnum */
            lua_pushnumber(L,(signed char)c->p[0]);
            mp_cur_consume(c,1);
        } else if ((c->p[0] & 0xe0) == 0xa0) {  /* fix raw */
            size_t l = c->p[0] & 0x1f;
            mp_cur_need(c,1+l);
            lua_pushlstring(L,(char*)c->p+1,l);
            mp_cur_consume(c,1+l);
        } else if ((c->p[0] & 0xf0) == 0x90) {  /* fix map */
            size_t l = c->p[0] & 0xf;
            mp_cur_consume(c,1);
            mp_decode_to_lua_array(L,c,l);
        } else if ((c->p[0] & 0xf0) == 0x80) {  /* fix map */
            size_t l = c->p[0] & 0xf;
            mp_cur_consume(c,1);
            mp_decode_to_lua_hash(L,c,l);
        } else {
            c->err = MP_CUR_ERROR_BADFMT;
        }
    }
}

static int mp_unpack(lua_State *L) {
    size_t len;
    const unsigned char *s;
    mp_cur *c;

    if (!lua_isstring(L,-1)) {
        lua_pushstring(L,"MessagePack decoding needs a string as input.");
        lua_error(L);
    }

    s = (const unsigned char*) lua_tolstring(L,-1,&len);
    c = mp_cur_new(s,len);
    mp_decode_to_lua_type(L,c);
    
    if (c->err == MP_CUR_ERROR_EOF) {
        mp_cur_free(c);
        lua_pushstring(L,"Missing bytes in input.");
        lua_error(L);
    } else if (c->err == MP_CUR_ERROR_BADFMT) {
        mp_cur_free(c);
        lua_pushstring(L,"Bad data format in input.");
        lua_error(L);
    } else if (c->left != 0) {
        mp_cur_free(c);
        lua_pushstring(L,"Extra bytes in input.");
        lua_error(L);
    } else {
        mp_cur_free(c);
    }
    return 1;
}

/* ---------------------------------------------------------------------------- */

#if LUA_VERSION_NUM < 502
static const struct luaL_reg thislib[] = {
#else
static const struct luaL_Reg thislib[] = {
#endif
    {"pack", mp_pack},
    {"unpack", mp_unpack},
    {NULL, NULL}
};

LUALIB_API int luaopen_cmsgpack (lua_State *L) {
#if LUA_VERSION_NUM < 502
    luaL_register(L, "cmsgpack", thislib);
#else
    luaL_newlib(L, thislib);
#endif

    lua_pushliteral(L, LUACMSGPACK_VERSION);
    lua_setfield(L, -2, "_VERSION");
    lua_pushliteral(L, LUACMSGPACK_COPYRIGHT);
    lua_setfield(L, -2, "_COPYRIGHT");
    lua_pushliteral(L, LUACMSGPACK_DESCRIPTION);
    lua_setfield(L, -2, "_DESCRIPTION"); 
    return 1;
}

/******************************************************************************
* Copyright (C) 2012 Salvatore Sanfilippo.  All rights reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
******************************************************************************/

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