1 /* BEGIN CSTYLED */ 2 /* 3 ** $Id: lzio.c,v 1.35.1.1 2013/04/12 18:48:47 roberto Exp $ 4 ** Buffered streams 5 ** See Copyright Notice in lua.h 6 */ 7 8 9 #define lzio_c 10 #define LUA_CORE 11 12 #include <sys/lua/lua.h> 13 14 #include "llimits.h" 15 #include "lmem.h" 16 #include "lstate.h" 17 #include "lzio.h" 18 19 20 int luaZ_fill (ZIO *z) { 21 size_t size; 22 lua_State *L = z->L; 23 const char *buff; 24 lua_unlock(L); 25 buff = z->reader(L, z->data, &size); 26 lua_lock(L); 27 if (buff == NULL || size == 0) 28 return EOZ; 29 z->n = size - 1; /* discount char being returned */ 30 z->p = buff; 31 return cast_uchar(*(z->p++)); 32 } 33 34 35 void luaZ_init (lua_State *L, ZIO *z, lua_Reader reader, void *data) { 36 z->L = L; 37 z->reader = reader; 38 z->data = data; 39 z->n = 0; 40 z->p = NULL; 41 } 42 43 44 /* --------------------------------------------------------------- read --- */ 45 size_t luaZ_read (ZIO *z, void *b, size_t n) { 46 while (n) { 47 size_t m; 48 if (z->n == 0) { /* no bytes in buffer? */ 49 if (luaZ_fill(z) == EOZ) /* try to read more */ 50 return n; /* no more input; return number of missing bytes */ 51 else { 52 z->n++; /* luaZ_fill consumed first byte; put it back */ 53 z->p--; 54 } 55 } 56 m = (n <= z->n) ? n : z->n; /* min. between n and z->n */ 57 memcpy(b, z->p, m); 58 z->n -= m; 59 z->p += m; 60 b = (char *)b + m; 61 n -= m; 62 } 63 return 0; 64 } 65 66 /* ------------------------------------------------------------------------ */ 67 char *luaZ_openspace (lua_State *L, Mbuffer *buff, size_t n) { 68 if (n > buff->buffsize) { 69 if (n < LUA_MINBUFFER) n = LUA_MINBUFFER; 70 luaZ_resizebuffer(L, buff, n); 71 } 72 return buff->buffer; 73 } 74 /* END CSTYLED */ 75