1 /* 2 ** $Id: lzio.c,v 1.35.1.1 2013/04/12 18:48:47 roberto Exp $ 3 ** Buffered streams 4 ** See Copyright Notice in lua.h 5 */ 6 7 8 #define lzio_c 9 #define LUA_CORE 10 11 #include <sys/lua/lua.h> 12 13 #include "llimits.h" 14 #include "lmem.h" 15 #include "lstate.h" 16 #include "lzio.h" 17 18 19 int luaZ_fill (ZIO *z) { 20 size_t size; 21 lua_State *L = z->L; 22 const char *buff; 23 lua_unlock(L); 24 buff = z->reader(L, z->data, &size); 25 lua_lock(L); 26 if (buff == NULL || size == 0) 27 return EOZ; 28 z->n = size - 1; /* discount char being returned */ 29 z->p = buff; 30 return cast_uchar(*(z->p++)); 31 } 32 33 34 void luaZ_init (lua_State *L, ZIO *z, lua_Reader reader, void *data) { 35 z->L = L; 36 z->reader = reader; 37 z->data = data; 38 z->n = 0; 39 z->p = NULL; 40 } 41 42 43 /* --------------------------------------------------------------- read --- */ 44 size_t luaZ_read (ZIO *z, void *b, size_t n) { 45 while (n) { 46 size_t m; 47 if (z->n == 0) { /* no bytes in buffer? */ 48 if (luaZ_fill(z) == EOZ) /* try to read more */ 49 return n; /* no more input; return number of missing bytes */ 50 else { 51 z->n++; /* luaZ_fill consumed first byte; put it back */ 52 z->p--; 53 } 54 } 55 m = (n <= z->n) ? n : z->n; /* min. between n and z->n */ 56 memcpy(b, z->p, m); 57 z->n -= m; 58 z->p += m; 59 b = (char *)b + m; 60 n -= m; 61 } 62 return 0; 63 } 64 65 /* ------------------------------------------------------------------------ */ 66 char *luaZ_openspace (lua_State *L, Mbuffer *buff, size_t n) { 67 if (n > buff->buffsize) { 68 if (n < LUA_MINBUFFER) n = LUA_MINBUFFER; 69 luaZ_resizebuffer(L, buff, n); 70 } 71 return buff->buffer; 72 } 73