1 #include "stdio_impl.h"
2 #include <wchar.h>
3 #include <errno.h>
4 #include <limits.h>
5 #include <string.h>
6 #include <stdlib.h>
7 #include <unsupported_api.h>
8 #include "libc.h"
9 
10 struct cookie {
11 	wchar_t **bufp;
12 	size_t *sizep;
13 	size_t pos;
14 	wchar_t *buf;
15 	size_t len;
16 	size_t space;
17 	mbstate_t mbs;
18 };
19 
20 struct wms_FILE {
21 	FILE f;
22 	struct cookie c;
23 	unsigned char buf[1];
24 };
25 
wms_seek(FILE *f, off_t off, int whence)26 static off_t wms_seek(FILE *f, off_t off, int whence)
27 {
28 	ssize_t base;
29 	struct cookie *c = f->cookie;
30 	if (whence>2U) {
31 fail:
32 		errno = EINVAL;
33 		return -1;
34 	}
35 	base = (size_t [3]){0, c->pos, c->len}[whence];
36 	if (off < -base || off > SSIZE_MAX/4-base) goto fail;
37 	memset(&c->mbs, 0, sizeof c->mbs);
38 	return c->pos = base+off;
39 }
40 
wms_write(FILE *f, const unsigned char *buf, size_t len)41 static size_t wms_write(FILE *f, const unsigned char *buf, size_t len)
42 {
43 	struct cookie *c = f->cookie;
44 	size_t len2 = f->wpos - f->wbase;
45 	wchar_t *newbuf;
46 	if (len2) {
47 		f->wpos = f->wbase;
48 		if (wms_write(f, f->wbase, len2) < len2) return 0;
49 	}
50 	if (len + c->pos >= c->space) {
51 		len2 = 2*c->space+1 | c->pos+len+1;
52 		if (len2 > SSIZE_MAX/4) return 0;
53 		newbuf = realloc(c->buf, len2*4);
54 		if (!newbuf) return 0;
55 		*c->bufp = c->buf = newbuf;
56 		memset(c->buf + c->space, 0, 4*(len2 - c->space));
57 		c->space = len2;
58 	}
59 
60 	len2 = mbsnrtowcs(c->buf+c->pos, (void *)&buf, len, c->space-c->pos, &c->mbs);
61 	if (len2 == -1) return 0;
62 	c->pos += len2;
63 	if (c->pos >= c->len) c->len = c->pos;
64 	*c->sizep = c->pos;
65 	return len;
66 }
67 
wms_close(FILE *f)68 static int wms_close(FILE *f)
69 {
70 	return 0;
71 }
72 
open_wmemstream(wchar_t **bufp, size_t *sizep)73 FILE *open_wmemstream(wchar_t **bufp, size_t *sizep)
74 {
75 	struct wms_FILE *f;
76 	wchar_t *buf;
77 
78 	UNSUPPORTED_API_VOID(LITEOS_A);
79 	if (!(f=malloc(sizeof *f))) return 0;
80 	if (!(buf=malloc(sizeof *buf))) {
81 		free(f);
82 		return 0;
83 	}
84 	memset(&f->f, 0, sizeof f->f);
85 	memset(&f->c, 0, sizeof f->c);
86 	f->f.cookie = &f->c;
87 
88 	f->c.bufp = bufp;
89 	f->c.sizep = sizep;
90 	f->c.pos = f->c.len = f->c.space = *sizep = 0;
91 	f->c.buf = *bufp = buf;
92 	*buf = 0;
93 
94 	f->f.flags = F_NORD;
95 	f->f.fd = -1;
96 	f->f.buf = f->buf;
97 	f->f.buf_size = 0;
98 	f->f.lbf = EOF;
99 	f->f.write = wms_write;
100 	f->f.seek = wms_seek;
101 	f->f.close = wms_close;
102 
103 	if (!libc.threaded) f->f.lock = -1;
104 
105 	fwide(&f->f, 1);
106 
107 	return __ofl_add(&f->f);
108 }
109