1#include "stdio_impl.h"
2#include <wchar.h>
3#include <errno.h>
4#include <limits.h>
5#include <string.h>
6
7struct cookie {
8	wchar_t **bufp;
9	size_t *sizep;
10	size_t pos;
11	wchar_t *buf;
12	size_t len;
13	size_t space;
14	mbstate_t mbs;
15};
16
17static off_t wms_seek(FILE *f, off_t off, int whence)
18{
19	ssize_t base;
20	struct cookie *c = f->cookie;
21	if (whence>2U) {
22fail:
23		errno = EINVAL;
24		return -1;
25	}
26	base = (size_t [3]){0, c->pos, c->len}[whence];
27	if (off < -base || off > SSIZE_MAX/4-base) goto fail;
28	memset(&c->mbs, 0, sizeof c->mbs);
29	return c->pos = base+off;
30}
31
32static size_t wms_write(FILE *f, const unsigned char *buf, size_t len)
33{
34	struct cookie *c = f->cookie;
35	size_t len2;
36	wchar_t *newbuf;
37	if (len + c->pos >= c->space) {
38		len2 = 2*c->space+1 | c->pos+len+1;
39		if (len2 > SSIZE_MAX/4) return 0;
40		newbuf = realloc(c->buf, len2*4);
41		if (!newbuf) return 0;
42		*c->bufp = c->buf = newbuf;
43		memset(c->buf + c->space, 0, 4*(len2 - c->space));
44		c->space = len2;
45	}
46
47	len2 = mbsnrtowcs(c->buf+c->pos, (void *)&buf, len, c->space-c->pos, &c->mbs);
48	if (len2 == -1) return 0;
49	c->pos += len2;
50	if (c->pos >= c->len) c->len = c->pos;
51	*c->sizep = c->pos;
52	return len;
53}
54
55static int wms_close(FILE *f)
56{
57	return 0;
58}
59
60FILE *open_wmemstream(wchar_t **bufp, size_t *sizep)
61{
62	FILE *f;
63	struct cookie *c;
64	wchar_t *buf;
65
66	if (!(f=malloc(sizeof *f + sizeof *c))) return 0;
67	if (!(buf=malloc(sizeof *buf))) {
68		free(f);
69		return 0;
70	}
71	memset(f, 0, sizeof *f + sizeof *c);
72	f->cookie = c = (void *)(f+1);
73
74	c->bufp = bufp;
75	c->sizep = sizep;
76	c->pos = c->len = c->space = *sizep = 0;
77	c->buf = *bufp = buf;
78	*buf = 0;
79
80	f->flags = F_NORD;
81	f->fd = -1;
82	f->buf = (void *)(c+1);
83	f->buf_size = 0;
84	f->lbf = EOF;
85	f->write = wms_write;
86	f->seek = wms_seek;
87	f->close = wms_close;
88
89	if (!libc.threaded) f->lock = -1;
90
91	return __ofl_add(f);
92}
93