/*
** $Id: lzio.c $
** Buffered streams
** See Copyright Notice in lua.h
*/
#define lzio_c
#define LUA_CORE
#include "lprefix.h"
#include <string.h>
#include "lua.h"
#include "llimits.h"
#include "lmem.h"
#include "lstate.h"
#include "lzio.h"
int luaZ_fill (ZIO *z) {
size_t size;
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; /* discount char being returned */
z->p = buff;
return cast_uchar(*(z->p++));
}
void luaZ_init (lua_State *L, ZIO *z, lua_Reader reader, void *data) {
z->L = L;
z->reader = reader;
z->data = data;
z->n = 0;
z->p = NULL;
}
/* --------------------------------------------------------------- read --- */
size_t luaZ_read (ZIO *z, void *b, size_t n) {
while (n) {
size_t m;
if (z->n == 0) { /* no bytes in buffer? */
if (luaZ_fill(z) == EOZ) /* try to read more */
return n; /* no more input; return number of missing bytes */
else {
z->n++; /* luaZ_fill consumed first byte; put it back */
z->p--;
}
}
m = (n <= z->n) ? n : z->n; /* min. between n and z->n */
z->n -= m;
z->p += m;
b = (char *)b + m;
n -= m;
}
return 0;
}