ceph/src/civetweb/src/third_party/lua-5.3.3/src/lzio.c

   1 /*
   2 ** $Id: lzio.c,v 1.37 2015/09/08 15:41:05 roberto Exp $
   3 ** Buffered streams
   4 ** See Copyright Notice in lua.h
   5 */
   6
   7 #define lzio_c
   8 #define LUA_CORE
   9
  10 #include "lprefix.h"
  11
  12
  13 #include <string.h>
  14
  15 #include "lua.h"
  16
  17 #include "llimits.h"
  18 #include "lmem.h"
  19 #include "lstate.h"
  20 #include "lzio.h"
  21
  22
  23 int luaZ_fill (ZIO *z) {
  24   size_t size;
  25   lua_State *L = z->L;
  26   const char *buff;
  27   lua_unlock(L);
  28   buff = z->reader(L, z->data, &size);
  29   lua_lock(L);
  30   if (buff == NULL || size == 0)
  31     return EOZ;
  32   z->n = size - 1;  /* discount char being returned */
  33   z->p = buff;
  34   return cast_uchar(*(z->p++));
  35 }
  36
  37
  38 void luaZ_init (lua_State *L, ZIO *z, lua_Reader reader, void *data) {
  39   z->L = L;
  40   z->reader = reader;
  41   z->data = data;
  42   z->n = 0;
  43   z->p = NULL;
  44 }
  45
  46
  47 /* --------------------------------------------------------------- read --- */
  48 size_t luaZ_read (ZIO *z, void *b, size_t n) {
  49   while (n) {
  50     size_t m;
  51     if (z->n == 0) {  /* no bytes in buffer? */
  52       if (luaZ_fill(z) == EOZ)  /* try to read more */
  53         return n;  /* no more input; return number of missing bytes */
  54       else {
  55         z->n++;  /* luaZ_fill consumed first byte; put it back */
  56         z->p--;
  57       }
  58     }
  59     m = (n <= z->n) ? n : z->n;  /* min. between n and z->n */
  60     memcpy(b, z->p, m);
  61     z->n -= m;
  62     z->p += m;
  63     b = (char *)b + m;
  64     n -= m;
  65   }
  66   return 0;
  67 }
  68