/*** $Id: lzio.c,v 1.31 2005/06/03 20:15:29 roberto Exp $** a generic input stream interface** See Copyright Notice in lua.h*/#include <string.h>#define lzio_c#define LUA_CORE#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;  z->p = buff;  return char2int(*(z->p++));}int luaZ_lookahead (ZIO *z) {  if (z->n == 0) {    if (luaZ_fill(z) == EOZ)      return EOZ;    else {      z->n++;  /* luaZ_fill removed first byte; put back it */      z->p--;    }  }  return char2int(*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 (luaZ_lookahead(z) == EOZ)      return n;  /* return number of missing bytes */    m = (n <= z->n) ? n : z->n;  /* min. between n and z->n */    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;    luaZ_resizebuffer(L, buff, n);  }  return buff->buffer;}