/*
** $Id: lzio.h,v 1.26 2011/07/15 12:48:03 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 zgetc(z)  (((z)->n--)>0 ?  cast_uchar(*(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 */



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

struct Zio {
    size_t n;             /* bytes still unread */
    const char *p;        /* current position in buffer */
    lua_Reader reader;    /* reader function */
    void *data;           /* additional data */
    lua_State *L;         /* Lua state (for reader) */
};


LUAI_FUNC int luaZ_fill(ZIO *z);

#endif
