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Lua struct library updated to version 0.2.
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There was a bug in the previous version of this library that caused a
crash under the circumstances described in issue redis#901.

The newer version of the library appears to be fixed (I tested it
manually with valgrind and everything seems fine now).

For more information about this library please visit this web site:

    http://www.inf.puc-rio.br/~roberto/struct/
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@antirez
antirez committed Jan 23, 2013
1 parent 88015b8 commit 61853a9
Showing 1 changed file with 119 additions and 52 deletions.
171 changes: 119 additions & 52 deletions deps/lua/src/lua_struct.c
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Original file line number Diff line number Diff line change
@@ -1,18 +1,7 @@

#include <assert.h>
#include <ctype.h>
#include <limits.h>
#include <string.h>


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


/*
** {======================================================
** Library for packing/unpacking structures.
** $Id: struct.c,v 1.2 2008/04/18 20:06:01 roberto Exp $
** $Id: struct.c,v 1.4 2012/07/04 18:54:29 roberto Exp $
** See Copyright Notice at the end of this file
** =======================================================
*/
Expand All @@ -25,6 +14,7 @@
** b/B - signed/unsigned byte
** h/H - signed/unsigned short
** l/L - signed/unsigned long
** T - size_t
** i/In - signed/unsigned integer with size `n' (default is size of int)
** cn - sequence of `n' chars (from/to a string); when packing, n==0 means
the whole string; when unpacking, n==0 means use the previous
Expand All @@ -36,6 +26,38 @@
*/


#include <assert.h>
#include <ctype.h>
#include <limits.h>
#include <stddef.h>
#include <string.h>


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


#if (LUA_VERSION_NUM >= 502)

#define luaL_register(L,n,f) luaL_newlib(L,f)

#endif


/* basic integer type */
#if !defined(STRUCT_INT)
#define STRUCT_INT long
#endif

typedef STRUCT_INT Inttype;

/* corresponding unsigned version */
typedef unsigned STRUCT_INT Uinttype;


/* maximum size (in bytes) for integral types */
#define MAXINTSIZE 32

/* is 'x' a power of 2? */
#define isp2(x) ((x) > 0 && ((x) & ((x) - 1)) == 0)

Expand Down Expand Up @@ -67,11 +89,11 @@ typedef struct Header {
} Header;


static size_t getnum (const char **fmt, size_t df) {
static int getnum (const char **fmt, int df) {
if (!isdigit(**fmt)) /* no number? */
return df; /* return default value */
else {
size_t a = 0;
int a = 0;
do {
a = a*10 + *((*fmt)++) - '0';
} while (isdigit(**fmt));
Expand All @@ -89,33 +111,40 @@ static size_t optsize (lua_State *L, char opt, const char **fmt) {
case 'B': case 'b': return sizeof(char);
case 'H': case 'h': return sizeof(short);
case 'L': case 'l': return sizeof(long);
case 'T': return sizeof(size_t);
case 'f': return sizeof(float);
case 'd': return sizeof(double);
case 'x': return 1;
case 'c': return getnum(fmt, 1);
case 's': case ' ': case '<': case '>': case '!': return 0;
case 'i': case 'I': {
int sz = getnum(fmt, sizeof(int));
if (!isp2(sz))
luaL_error(L, "integral size %d is not a power of 2", sz);
if (sz > MAXINTSIZE)
luaL_error(L, "integral size %d is larger than limit of %d",
sz, MAXINTSIZE);
return sz;
}
default: {
const char *msg = lua_pushfstring(L, "invalid format option [%c]", opt);
return luaL_argerror(L, 1, msg);
}
default: return 0; /* other cases do not need alignment */
}
}


/*
** return number of bytes needed to align an element of size 'size'
** at current position 'len'
*/
static int gettoalign (size_t len, Header *h, int opt, size_t size) {
if (size == 0 || opt == 'c') return 0;
if (size > (size_t)h->align) size = h->align; /* respect max. alignment */
return (size - (len & (size - 1))) & (size - 1);
if (size > (size_t)h->align)
size = h->align; /* respect max. alignment */
return (size - (len & (size - 1))) & (size - 1);
}


static void commoncases (lua_State *L, int opt, const char **fmt, Header *h) {
/*
** options to control endianess and alignment
*/
static void controloptions (lua_State *L, int opt, const char **fmt,
Header *h) {
switch (opt) {
case ' ': return; /* ignore white spaces */
case '>': h->endian = BIG; return;
Expand All @@ -127,29 +156,38 @@ static void commoncases (lua_State *L, int opt, const char **fmt, Header *h) {
h->align = a;
return;
}
default: assert(0);
default: {
const char *msg = lua_pushfstring(L, "invalid format option '%c'", opt);
luaL_argerror(L, 1, msg);
}
}
}


static void putinteger (lua_State *L, luaL_Buffer *b, int arg, int endian,
int size) {
lua_Number n = luaL_checknumber(L, arg);
unsigned long value;
if (n < (lua_Number)LONG_MAX)
value = (long)n;
Uinttype value;
char buff[MAXINTSIZE];
if (n < 0)
value = (Uinttype)(Inttype)n;
else
value = (unsigned long)n;
value = (Uinttype)n;
if (endian == LITTLE) {
int i;
for (i = 0; i < size; i++)
luaL_addchar(b, (value >> 8*i) & 0xff);
for (i = 0; i < size; i++) {
buff[i] = (value & 0xff);
value >>= 8;
}
}
else {
int i;
for (i = size - 1; i >= 0; i--)
luaL_addchar(b, (value >> 8*i) & 0xff);
for (i = size - 1; i >= 0; i--) {
buff[i] = (value & 0xff);
value >>= 8;
}
}
luaL_addlstring(b, buff, size);
}


Expand Down Expand Up @@ -179,15 +217,15 @@ static int b_pack (lua_State *L) {
size_t size = optsize(L, opt, &fmt);
int toalign = gettoalign(totalsize, &h, opt, size);
totalsize += toalign;
while (toalign-- > 0) luaL_putchar(&b, '\0');
while (toalign-- > 0) luaL_addchar(&b, '\0');
switch (opt) {
case 'b': case 'B': case 'h': case 'H':
case 'l': case 'L': case 'i': case 'I': { /* integer types */
case 'l': case 'L': case 'T': case 'i': case 'I': { /* integer types */
putinteger(L, &b, arg++, h.endian, size);
break;
}
case 'x': {
luaL_putchar(&b, '\0');
luaL_addchar(&b, '\0');
break;
}
case 'f': {
Expand All @@ -209,12 +247,12 @@ static int b_pack (lua_State *L) {
luaL_argcheck(L, l >= (size_t)size, arg, "string too short");
luaL_addlstring(&b, s, size);
if (opt == 's') {
luaL_putchar(&b, '\0'); /* add zero at the end */
luaL_addchar(&b, '\0'); /* add zero at the end */
size++;
}
break;
}
default: commoncases(L, opt, &fmt, &h);
default: controloptions(L, opt, &fmt, &h);
}
totalsize += size;
}
Expand All @@ -225,24 +263,27 @@ static int b_pack (lua_State *L) {

static lua_Number getinteger (const char *buff, int endian,
int issigned, int size) {
unsigned long l = 0;
Uinttype l = 0;
int i;
if (endian == BIG) {
int i;
for (i = 0; i < size; i++)
l |= (unsigned long)(unsigned char)buff[size - i - 1] << (i*8);
for (i = 0; i < size; i++) {
l <<= 8;
l |= (Uinttype)(unsigned char)buff[i];
}
}
else {
int i;
for (i = 0; i < size; i++)
l |= (unsigned long)(unsigned char)buff[i] << (i*8);
for (i = size - 1; i >= 0; i--) {
l <<= 8;
l |= (Uinttype)(unsigned char)buff[i];
}
}
if (!issigned)
return (lua_Number)l;
else { /* signed format */
unsigned long mask = ~(0UL) << (size*8 - 1);
Uinttype mask = (Uinttype)(~((Uinttype)0)) << (size*8 - 1);
if (l & mask) /* negative value? */
l |= mask; /* signal extension */
return (lua_Number)(long)l;
return (lua_Number)(Inttype)l;
}
}

Expand All @@ -260,9 +301,10 @@ static int b_unpack (lua_State *L) {
size_t size = optsize(L, opt, &fmt);
pos += gettoalign(pos, &h, opt, size);
luaL_argcheck(L, pos+size <= ld, 2, "data string too short");
luaL_checkstack(L, 1, "too many results");
switch (opt) {
case 'b': case 'B': case 'h': case 'H':
case 'l': case 'L': case 'i': case 'I': { /* integer types */
case 'l': case 'L': case 'T': case 'i': case 'I': { /* integer types */
int issigned = islower(opt);
lua_Number res = getinteger(data+pos, h.endian, issigned, size);
lua_pushnumber(L, res);
Expand Down Expand Up @@ -304,34 +346,58 @@ static int b_unpack (lua_State *L) {
lua_pushlstring(L, data+pos, size - 1);
break;
}
default: commoncases(L, opt, &fmt, &h);
default: controloptions(L, opt, &fmt, &h);
}
pos += size;
}
lua_pushinteger(L, pos + 1);
return lua_gettop(L) - 2;
}


static int b_size (lua_State *L) {
Header h;
const char *fmt = luaL_checkstring(L, 1);
size_t pos = 0;
defaultoptions(&h);
while (*fmt) {
int opt = *fmt++;
size_t size = optsize(L, opt, &fmt);
pos += gettoalign(pos, &h, opt, size);
if (opt == 's')
luaL_argerror(L, 1, "option 's' has no fixed size");
else if (opt == 'c' && size == 0)
luaL_argerror(L, 1, "option 'c0' has no fixed size");
if (!isalnum(opt))
controloptions(L, opt, &fmt, &h);
pos += size;
}
lua_pushinteger(L, pos);
return 1;
}

/* }====================================================== */



static const struct luaL_reg thislib[] = {
static const struct luaL_Reg thislib[] = {
{"pack", b_pack},
{"unpack", b_unpack},
{"size", b_size},
{NULL, NULL}
};


LUALIB_API int luaopen_struct (lua_State *L);

LUALIB_API int luaopen_struct (lua_State *L) {
luaL_register(L, "struct", thislib);
return 1;
}



/******************************************************************************
* Copyright (C) 2010 Lua.org, PUC-Rio. All rights reserved.
* Copyright (C) 2010-2012 Lua.org, PUC-Rio. All rights reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
Expand All @@ -352,3 +418,4 @@ LUALIB_API int luaopen_struct (lua_State *L) {
* 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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