1 #include "stdio_impl.h"
12 static off_t ms_seek(FILE *f, off_t off, int whence)
15 struct cookie *c = f->cookie;
21 base = (size_t [3]){0, c->pos, c->len}[whence];
22 if (off < -base || off > SSIZE_MAX-base) goto fail;
23 return c->pos = base+off;
26 static size_t ms_write(FILE *f, const unsigned char *buf, size_t len)
28 struct cookie *c = f->cookie;
29 size_t len2 = f->wpos - f->wbase;
33 if (ms_write(f, f->wbase, len2) < len2) return 0;
35 if (len >= c->space - c->pos) {
36 len2 = 2*c->space+1 | c->space+len+1;
37 newbuf = realloc(c->buf, len2);
38 if (!newbuf) return 0;
39 *c->bufp = c->buf = newbuf;
40 memset(c->buf + c->space, 0, len2 - c->space);
43 memcpy(c->buf+c->pos, buf, len);
45 if (c->pos >= c->len) c->len = c->pos;
50 static int ms_close(FILE *f)
55 FILE *open_memstream(char **bufp, size_t *sizep)
59 if (!(f=malloc(sizeof *f + sizeof *c + BUFSIZ))) return 0;
60 memset(f, 0, sizeof *f + sizeof *c);
61 f->cookie = c = (void *)(f+1);
65 c->pos = c->len = c->space = 0;
70 f->buf = (void *)(c+1);
79 f->next = libc.ofl_head;
80 if (libc.ofl_head) libc.ofl_head->prev = f;