File: lzio.c

package info (click to toggle)
tup 0.7.8-3
  • links: PTS, VCS
  • area: main
  • in suites: bullseye, buster
  • size: 18,448 kB
  • sloc: ansic: 217,845; sh: 17,432; perl: 184; python: 67; lisp: 63; makefile: 62
file content (68 lines) | stat: -rw-r--r-- 1,361 bytes parent folder | download | duplicates (54)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
/*
** $Id: lzio.c,v 1.37 2015/09/08 15:41:05 roberto Exp $
** Buffered streams
** See Copyright Notice in lua.h
*/

#define lzio_c
#define LUA_CORE

#include "lprefix.h"


#include <string.h>

#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;
}