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 #include <sys/zfs_context.h>
9
10 #define lzio_c
11 #define LUA_CORE
12
13 #include "lua.h"
14
15 #include "llimits.h"
16 #include "lmem.h"
17 #include "lstate.h"
18 #include "lzio.h"
19
20
luaZ_fill(ZIO * z)21 int luaZ_fill (ZIO *z) {
22 size_t size;
23 lua_State *L = z->L;
24 const char *buff;
25 lua_unlock(L);
26 buff = z->reader(L, z->data, &size);
27 lua_lock(L);
28 if (buff == NULL || size == 0)
29 return EOZ;
30 z->n = size - 1; /* discount char being returned */
31 z->p = buff;
32 return cast_uchar(*(z->p++));
33 }
34
35
luaZ_init(lua_State * L,ZIO * z,lua_Reader reader,void * data)36 void luaZ_init (lua_State *L, ZIO *z, lua_Reader reader, void *data) {
37 z->L = L;
38 z->reader = reader;
39 z->data = data;
40 z->n = 0;
41 z->p = NULL;
42 }
43
44
45 /* --------------------------------------------------------------- read --- */
luaZ_read(ZIO * z,void * b,size_t n)46 size_t luaZ_read (ZIO *z, void *b, size_t n) {
47 while (n) {
48 size_t m;
49 if (z->n == 0) { /* no bytes in buffer? */
50 if (luaZ_fill(z) == EOZ) /* try to read more */
51 return n; /* no more input; return number of missing bytes */
52 else {
53 z->n++; /* luaZ_fill consumed first byte; put it back */
54 z->p--;
55 }
56 }
57 m = (n <= z->n) ? n : z->n; /* min. between n and z->n */
58 memcpy(b, z->p, m);
59 z->n -= m;
60 z->p += m;
61 b = (char *)b + m;
62 n -= m;
63 }
64 return 0;
65 }
66
67 /* ------------------------------------------------------------------------ */
luaZ_openspace(lua_State * L,Mbuffer * buff,size_t n)68 char *luaZ_openspace (lua_State *L, Mbuffer *buff, size_t n) {
69 if (n > buff->buffsize) {
70 if (n < LUA_MINBUFFER) n = LUA_MINBUFFER;
71 luaZ_resizebuffer(L, buff, n);
72 }
73 return buff->buffer;
74 }
75
76
77