lua/lzio.c

83 lines
1.6 KiB
C
Raw Normal View History

1997-06-16 20:50:22 +04:00
/*
2005-06-04 00:16:16 +04:00
** $Id: lzio.c,v 1.30 2005/05/17 19:49:15 roberto Exp roberto $
1997-09-16 23:25:59 +04:00
** a generic input stream interface
** See Copyright Notice in lua.h
1997-06-16 20:50:22 +04:00
*/
1997-09-16 23:25:59 +04:00
1997-06-16 20:50:22 +04:00
#include <string.h>
1997-09-16 23:25:59 +04:00
2002-12-04 20:38:31 +03:00
#define lzio_c
#define LUA_CORE
2002-12-04 20:38:31 +03:00
#include "lua.h"
#include "llimits.h"
#include "lmem.h"
2003-08-28 00:57:52 +04:00
#include "lstate.h"
1997-09-16 23:25:59 +04:00
#include "lzio.h"
1997-06-16 20:50:22 +04:00
int luaZ_fill (ZIO *z) {
size_t size;
2003-08-28 00:57:52 +04:00
lua_State *L = z->L;
const char *buff;
lua_unlock(L);
buff = z->reader(L, z->data, &size);
lua_lock(L);
if (buff == NULL || size == 0) return EOZ;
z->n = size - 1;
z->p = buff;
return char2int(*(z->p++));
1997-06-16 20:50:22 +04:00
}
2002-06-04 00:11:07 +04:00
int luaZ_lookahead (ZIO *z) {
if (z->n == 0) {
2005-06-04 00:16:16 +04:00
if (luaZ_fill(z) == EOZ)
return EOZ;
else {
z->n++; /* luaZ_fill removed first byte; put back it */
z->p--;
}
2002-06-04 00:11:07 +04:00
}
return char2int(*z->p);
2002-06-04 00:11:07 +04:00
}
2005-05-17 23:49:15 +04:00
void luaZ_init (lua_State *L, ZIO *z, lua_Reader reader, void *data) {
2003-08-26 00:00:50 +04:00
z->L = L;
2002-06-06 16:40:22 +04:00
z->reader = reader;
z->data = data;
z->n = 0;
z->p = NULL;
1997-06-16 20:50:22 +04:00
}
/* --------------------------------------------------------------- read --- */
2002-08-05 22:45:02 +04:00
size_t luaZ_read (ZIO *z, void *b, size_t n) {
1997-06-16 20:50:22 +04:00
while (n) {
2000-05-24 17:54:49 +04:00
size_t m;
2005-06-04 00:16:16 +04:00
if (luaZ_lookahead(z) == EOZ)
return n; /* return number of missing bytes */
1999-02-26 00:07:26 +03:00
m = (n <= z->n) ? n : z->n; /* min. between n and z->n */
1997-06-16 20:50:22 +04:00
memcpy(b, z->p, m);
z->n -= m;
z->p += m;
b = (char *)b + m;
n -= m;
}
return 0;
}
/* ------------------------------------------------------------------------ */
char *luaZ_openspace (lua_State *L, Mbuffer *buff, size_t n) {
if (n > buff->buffsize) {
if (n < LUA_MINBUFFER) n = LUA_MINBUFFER;
2003-11-18 13:44:53 +03:00
luaZ_resizebuffer(L, buff, n);
}
return buff->buffer;
}