/* ** $Id: lzio.c,v 1.37.1.1 2017/04/19 17:20:42 roberto Exp $ ** Buffered streams ** See Copyright Notice in lua.h */ #define lzio_c #define LUA_CORE #include "lprefix.h" #include #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 */ memcpy(b, z->p, m); z->n -= m; z->p += m; b = (char *)b + m; n -= m; } return 0; }