/*

** $Id: lzio.h,v 1.21.1.1 2007/12/27 13:02:25 roberto Exp $

** Buffered streams

** See Copyright Notice in lua.h

*/

#ifndef lzio_h

#define lzio_h

#include "lua.h"

#include "lmem.h"

#define EOZ (-1)            /* end of stream */

typedef struct Zio ZIO;

#define char2int(c) cast(int, cast(unsigned char, (c)))

#define zgetc(z)  (((z)->n--)>0 ?  char2int(*(z)->p++) : luaZ_fill(z))

typedef struct Mbuffer {

  char *buffer;

  size_t n;

  size_t buffsize;

} Mbuffer;

#define luaZ_initbuffer(L, buff) ((buff)->buffer = NULL, (buff)->buffsize = 0)

#define luaZ_buffer(buff)   ((buff)->buffer)

#define luaZ_sizebuffer(buff)   ((buff)->buffsize)

#define luaZ_bufflen(buff)  ((buff)->n)

#define luaZ_resetbuffer(buff) ((buff)->n = 0)

#define luaZ_resizebuffer(L, buff, size) \

    (luaM_reallocvector(L, (buff)->buffer, (buff)->buffsize, size, char), \

    (buff)->buffsize = size)

#define luaZ_freebuffer(L, buff)    luaZ_resizebuffer(L, buff, 0)

LUAI_FUNC char *luaZ_openspace (lua_State *L, Mbuffer *buff, size_t n);

LUAI_FUNC void luaZ_init (lua_State *L, ZIO *z, lua_Reader reader,

                                        void *data);

LUAI_FUNC size_t luaZ_read (ZIO* z, void* b, size_t n); /* read next n bytes */

LUAI_FUNC int luaZ_lookahead (ZIO *z);

/* --------- Private Part ------------------ */

struct Zio {

  size_t n;         /* bytes still unread */

  const char *p;        /* current position in buffer */

  lua_Reader reader;

  void* data;           /* additional data */

  lua_State *L;         /* Lua state (for reader) */

};

LUAI_FUNC int luaZ_fill (ZIO *z);

#endif