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
20int 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
35void 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 --- */
45size_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/* ------------------------------------------------------------------------ */
67char *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