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new implementation for Generic Buffer manipulation (using userdata as

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temporary buffer space)
This commit is contained in:
Roberto Ierusalimschy
2010-04-09 13:14:46 -03:00
parent 055104f5b6
commit 9100f7479a
3 changed files with 94 additions and 104 deletions
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124
lauxlib.c
View File

@@ -1,5 +1,5 @@
/* /*
** $Id: lauxlib.c,v 1.205 2010/03/22 17:28:31 roberto Exp roberto $ ** $Id: lauxlib.c,v 1.206 2010/03/29 17:44:31 roberto Exp roberto $
** Auxiliary functions for building Lua libraries ** Auxiliary functions for building Lua libraries
** See Copyright Notice in lua.h ** See Copyright Notice in lua.h
*/ */
@@ -347,64 +347,40 @@ LUALIB_API lua_Integer luaL_optinteger (lua_State *L, int narg,
** ======================================================= ** =======================================================
*/ */
/*
#define bufflen(B) ((B)->p - (B)->buffer) ** check whether buffer is using a userdata on the stack as a temporary
#define bufffree(B) ((size_t)(LUAL_BUFFERSIZE - bufflen(B))) ** buffer
*/
#define LIMIT (LUA_MINSTACK/2) #define buffonstack(B) ((B)->b != (B)->initb)
static int emptybuffer (luaL_Buffer *B) { /*
size_t l = bufflen(B); ** returns a pointer to a free area with at least 'sz' bytes
if (l == 0) return 0; /* put nothing on stack */ */
else { LUALIB_API char *luaL_prepbuffsize (luaL_Buffer *B, size_t sz) {
lua_pushlstring(B->L, B->buffer, l); lua_State *L = B->L;
B->p = B->buffer; if (B->size - B->n < sz) { /* not enough space? */
B->lvl++; char *newbuff;
return 1; size_t newsize = B->size * 2; /* double buffer size */
if (newsize - B->n < sz) /* not bit enough? */
newsize = B->n + sz;
if (newsize < B->n || newsize - B->n < sz)
luaL_error(L, "string too large");
newbuff = (char *)lua_newuserdata(L, newsize); /* create larger buffer */
memcpy(newbuff, B->b, B->n); /* move content to new buffer */
if (buffonstack(B))
lua_remove(L, -2); /* remove old buffer */
B->b = newbuff;
B->size = newsize;
} }
} return &B->b[B->n];
static void adjuststack (luaL_Buffer *B) {
if (B->lvl > 1) {
lua_State *L = B->L;
int toget = 1; /* number of levels to concat */
size_t toplen = lua_rawlen(L, -1);
do {
size_t l = lua_rawlen(L, -(toget+1));
if (B->lvl - toget + 1 >= LIMIT || toplen > l) {
toplen += l;
toget++;
}
else break;
} while (toget < B->lvl);
lua_concat(L, toget);
B->lvl = B->lvl - toget + 1;
}
}
LUALIB_API char *luaL_prepbuffer (luaL_Buffer *B) {
if (emptybuffer(B))
adjuststack(B);
return B->buffer;
} }
LUALIB_API void luaL_addlstring (luaL_Buffer *B, const char *s, size_t l) { LUALIB_API void luaL_addlstring (luaL_Buffer *B, const char *s, size_t l) {
while (l) { char *b = luaL_prepbuffsize(B, l);
size_t space = bufffree(B); memcpy(b, s, l);
if (space == 0) { luaL_addsize(B, l);
luaL_prepbuffer(B);
space = LUAL_BUFFERSIZE; /* bufffree(B) == LUAL_BUFFERSIZE */
}
if (space > l) space = l;
memcpy(B->p, s, space);
B->p += space;
s += space;
l -= space;
}
} }
@@ -414,35 +390,41 @@ LUALIB_API void luaL_addstring (luaL_Buffer *B, const char *s) {
LUALIB_API void luaL_pushresult (luaL_Buffer *B) { LUALIB_API void luaL_pushresult (luaL_Buffer *B) {
emptybuffer(B); lua_State *L = B->L;
lua_concat(B->L, B->lvl); lua_pushlstring(L, B->b, B->n);
B->lvl = 1; if (buffonstack(B))
lua_remove(L, -2); /* remove old buffer */
}
LUALIB_API void luaL_pushresultsize (luaL_Buffer *B, size_t sz) {
luaL_addsize(B, sz);
luaL_pushresult(B);
} }
LUALIB_API void luaL_addvalue (luaL_Buffer *B) { LUALIB_API void luaL_addvalue (luaL_Buffer *B) {
lua_State *L = B->L; lua_State *L = B->L;
size_t vl; size_t l;
const char *s = lua_tolstring(L, -1, &vl); const char *s = lua_tolstring(L, -1, &l);
if (vl <= bufffree(B)) { /* fit into buffer? */ if (buffonstack(B))
memcpy(B->p, s, vl); /* put it there */ lua_insert(L, -2); /* put value below buffer */
B->p += vl; luaL_addlstring(B, s, l);
lua_pop(L, 1); /* remove from stack */ lua_remove(L, (buffonstack(B)) ? -2 : -1); /* remove value */
}
else {
if (emptybuffer(B))
lua_insert(L, -2); /* put buffer before new value */
B->lvl++; /* add new value into B stack */
adjuststack(B);
}
} }
LUALIB_API void luaL_buffinit (lua_State *L, luaL_Buffer *B) { LUALIB_API void luaL_buffinit (lua_State *L, luaL_Buffer *B) {
luaL_checkstack(L, LIMIT + LUA_MINSTACK, "no space for new buffer");
B->L = L; B->L = L;
B->p = B->buffer; B->b = B->initb;
B->lvl = 0; B->n = 0;
B->size = LUAL_BUFFERSIZE;
}
LUALIB_API char *luaL_buffinitsize (lua_State *L, luaL_Buffer *B, size_t sz) {
luaL_buffinit(L, B);
return luaL_prepbuffsize(B, sz);
} }
/* }====================================================== */ /* }====================================================== */

25
lauxlib.h
View File

@@ -1,5 +1,5 @@
/* /*
** $Id: lauxlib.h,v 1.100 2010/01/21 16:49:21 roberto Exp roberto $ ** $Id: lauxlib.h,v 1.101 2010/03/17 21:37:37 roberto Exp roberto $
** Auxiliary functions for building Lua libraries ** Auxiliary functions for building Lua libraries
** See Copyright Notice in lua.h ** See Copyright Notice in lua.h
*/ */
@@ -122,28 +122,31 @@ LUALIB_API int (luaL_cpcall) (lua_State *L, lua_CFunction f, int nargs,
** ======================================================= ** =======================================================
*/ */
typedef struct luaL_Buffer { typedef struct luaL_Buffer {
char *p; /* current position in buffer */ char *b; /* buffer address */
int lvl; /* number of strings in the stack (level) */ size_t size; /* buffer size */
size_t n; /* number of characters in buffer */
lua_State *L; lua_State *L;
char buffer[LUAL_BUFFERSIZE]; char initb[LUAL_BUFFERSIZE]; /* initial buffer */
} luaL_Buffer; } luaL_Buffer;
#define luaL_addchar(B,c) \
((void)((B)->p < ((B)->buffer+LUAL_BUFFERSIZE) || luaL_prepbuffer(B)), \
(*(B)->p++ = (char)(c)))
#define luaL_addsize(B,n) ((B)->p += (n)) #define luaL_addchar(B,c) \
((void)((B)->n < (B)->size || luaL_prepbuffsize((B), 1)), \
((B)->b[(B)->n++] = (c)))
#define luaL_addsize(B,s) ((B)->n += (s))
LUALIB_API void (luaL_buffinit) (lua_State *L, luaL_Buffer *B); LUALIB_API void (luaL_buffinit) (lua_State *L, luaL_Buffer *B);
LUALIB_API char *(luaL_prepbuffer) (luaL_Buffer *B); LUALIB_API char *(luaL_prepbuffsize) (luaL_Buffer *B, size_t sz);
LUALIB_API void (luaL_addlstring) (luaL_Buffer *B, const char *s, size_t l); LUALIB_API void (luaL_addlstring) (luaL_Buffer *B, const char *s, size_t l);
LUALIB_API void (luaL_addstring) (luaL_Buffer *B, const char *s); LUALIB_API void (luaL_addstring) (luaL_Buffer *B, const char *s);
LUALIB_API void (luaL_addvalue) (luaL_Buffer *B); LUALIB_API void (luaL_addvalue) (luaL_Buffer *B);
LUALIB_API void (luaL_pushresult) (luaL_Buffer *B); LUALIB_API void (luaL_pushresult) (luaL_Buffer *B);
LUALIB_API void luaL_pushresultsize (luaL_Buffer *B, size_t sz);
LUALIB_API char *(luaL_buffinitsize) (lua_State *L, luaL_Buffer *B, size_t sz);
#define luaL_prepbuffer(B) luaL_prepbuffsize(B, LUAL_BUFFERSIZE)
/* }====================================================== */ /* }====================================================== */

49
lstrlib.c
View File

@@ -1,5 +1,5 @@
/* /*
** $Id: lstrlib.c,v 1.147 2009/12/17 12:50:20 roberto Exp roberto $ ** $Id: lstrlib.c,v 1.148 2010/01/04 16:37:19 roberto Exp roberto $
** Standard library for string operations and pattern-matching ** Standard library for string operations and pattern-matching
** See Copyright Notice in lua.h ** See Copyright Notice in lua.h
*/ */
@@ -65,12 +65,13 @@ static int str_sub (lua_State *L) {
static int str_reverse (lua_State *L) { static int str_reverse (lua_State *L) {
size_t l; size_t l, i;
luaL_Buffer b; luaL_Buffer b;
const char *s = luaL_checklstring(L, 1, &l); const char *s = luaL_checklstring(L, 1, &l);
luaL_buffinit(L, &b); char *p = luaL_buffinitsize(L, &b, l);
while (l--) luaL_addchar(&b, s[l]); for (i = 0; i < l; i++)
luaL_pushresult(&b); p[i] = s[l - i - 1];
luaL_pushresultsize(&b, l);
return 1; return 1;
} }
@@ -80,10 +81,10 @@ static int str_lower (lua_State *L) {
size_t i; size_t i;
luaL_Buffer b; luaL_Buffer b;
const char *s = luaL_checklstring(L, 1, &l); const char *s = luaL_checklstring(L, 1, &l);
luaL_buffinit(L, &b); char *p = luaL_buffinitsize(L, &b, l);
for (i=0; i<l; i++) for (i=0; i<l; i++)
luaL_addchar(&b, tolower(uchar(s[i]))); p[i] = tolower(uchar(s[i]));
luaL_pushresult(&b); luaL_pushresultsize(&b, l);
return 1; return 1;
} }
@@ -93,10 +94,10 @@ static int str_upper (lua_State *L) {
size_t i; size_t i;
luaL_Buffer b; luaL_Buffer b;
const char *s = luaL_checklstring(L, 1, &l); const char *s = luaL_checklstring(L, 1, &l);
luaL_buffinit(L, &b); char *p = luaL_buffinitsize(L, &b, l);
for (i=0; i<l; i++) for (i=0; i<l; i++)
luaL_addchar(&b, toupper(uchar(s[i]))); p[i] = toupper(uchar(s[i]));
luaL_pushresult(&b); luaL_pushresultsize(&b, l);
return 1; return 1;
} }
@@ -136,13 +137,13 @@ static int str_char (lua_State *L) {
int n = lua_gettop(L); /* number of arguments */ int n = lua_gettop(L); /* number of arguments */
int i; int i;
luaL_Buffer b; luaL_Buffer b;
luaL_buffinit(L, &b); char *p = luaL_buffinitsize(L, &b, n);
for (i=1; i<=n; i++) { for (i=1; i<=n; i++) {
int c = luaL_checkint(L, i); int c = luaL_checkint(L, i);
luaL_argcheck(L, uchar(c) == c, i, "invalid value"); luaL_argcheck(L, uchar(c) == c, i, "invalid value");
luaL_addchar(&b, uchar(c)); p[i - 1] = uchar(c);
} }
luaL_pushresult(&b); luaL_pushresultsize(&b, n);
return 1; return 1;
} }
@@ -773,6 +774,9 @@ static const char *scanformat (lua_State *L, const char *strfrmt, char *form) {
} }
/*
** add length modifier into integer formats
*/
static void addintlen (char *form) { static void addintlen (char *form) {
size_t l = strlen(form); size_t l = strlen(form);
char spec = form[l - 1]; char spec = form[l - 1];
@@ -796,12 +800,13 @@ static int str_format (lua_State *L) {
luaL_addchar(&b, *strfrmt++); /* %% */ luaL_addchar(&b, *strfrmt++); /* %% */
else { /* format item */ else { /* format item */
char form[MAX_FORMAT]; /* to store the format (`%...') */ char form[MAX_FORMAT]; /* to store the format (`%...') */
char buff[MAX_ITEM]; /* to store the formatted item */ char *buff = luaL_prepbuffsize(&b, MAX_ITEM); /* to put formatted item */
int nb = 0; /* number of bytes in added item */
arg++; arg++;
strfrmt = scanformat(L, strfrmt, form); strfrmt = scanformat(L, strfrmt, form);
switch (*strfrmt++) { switch (*strfrmt++) {
case 'c': { case 'c': {
sprintf(buff, form, luaL_checkint(L, arg)); nb = sprintf(buff, form, luaL_checkint(L, arg));
break; break;
} }
case 'd': case 'i': case 'd': case 'i':
@@ -810,17 +815,17 @@ static int str_format (lua_State *L) {
LUA_INTFRM_T r = (n < 0) ? (LUA_INTFRM_T)n : LUA_INTFRM_T r = (n < 0) ? (LUA_INTFRM_T)n :
(LUA_INTFRM_T)(unsigned LUA_INTFRM_T)n; (LUA_INTFRM_T)(unsigned LUA_INTFRM_T)n;
addintlen(form); addintlen(form);
sprintf(buff, form, r); nb = sprintf(buff, form, r);
break; break;
} }
case 'e': case 'E': case 'f': case 'e': case 'E': case 'f':
case 'g': case 'G': { case 'g': case 'G': {
sprintf(buff, form, (double)luaL_checknumber(L, arg)); nb = sprintf(buff, form, (double)luaL_checknumber(L, arg));
break; break;
} }
case 'q': { case 'q': {
addquoted(L, &b, arg); addquoted(L, &b, arg);
continue; /* skip the 'addsize' at the end */ break;
} }
case 's': { case 's': {
size_t l; size_t l;
@@ -830,10 +835,10 @@ static int str_format (lua_State *L) {
keep original string */ keep original string */
lua_pushvalue(L, arg); lua_pushvalue(L, arg);
luaL_addvalue(&b); luaL_addvalue(&b);
continue; /* skip the `addsize' at the end */ break;
} }
else { else {
sprintf(buff, form, s); nb = sprintf(buff, form, s);
break; break;
} }
} }
@@ -842,7 +847,7 @@ static int str_format (lua_State *L) {
LUA_QL("format"), *(strfrmt - 1)); LUA_QL("format"), *(strfrmt - 1));
} }
} }
luaL_addlstring(&b, buff, strlen(buff)); luaL_addsize(&b, nb);
} }
} }
luaL_pushresult(&b); luaL_pushresult(&b);