VBUFPROTO int
vbuf_peek(VBUF *v)
{
if (vbuf_is_empty(v))
return EOF;
return (unsigned char)(*v->head);
}
VBUFPROTO char *
vbuf_cstr (VBUF *v)
{
size_t sz;
if (vbuf_is_empty(v))
return NULL;
// if the buffer is cstr safe, simply return
if (v->tail > v->head)
{
*v->tail = 0;
return v->head;
}
// wrapped ring buffer. now reverse 3 times to merge:
// [buf head tail buf_end]
sz = vbuf_size(v);
vbuf_reverse(v->buf, v->tail);
vbuf_reverse(v->head, v->buf_end);
memmove(v->tail, v->head, v->buf_end - v->head);
v->head = v->buf;
v->tail = v->buf + sz;
v->buf[sz] = 0;
vbuf_reverse(v->head, v->tail);
return v->buf;
}
VBUFPROTO int
vbuf_strchr(VBUF *v, char c)
{
const char *s = v->head, *d = v->tail;
if (vbuf_is_empty(v))
return EOF;
if (d < s)
d = v->buf_end;
while (s < d)
if (*s++ == c)
return s - v->head -1;
if (v->tail > v->head)
return EOF;
s = v->buf; d = v->tail;
while (s < d)
if (*s++ == c)
return (v->buf_end - v->head) + s - v->buf -1;
return EOF;
}
void vbuf_dbg_rpt(VBUF *v)
{
printf("v: [ cap: %u, size: %2lu, empty: %s, ptr=(%p,h=%p,t=%p,%p)]\n",
(unsigned int)vbuf_capacity(v), vbuf_size(v),
vbuf_is_empty(v) ? "YES" : "NO",
v->buf, v->head, v->tail, v->buf_end);
assert(v->buf_end == v->buf + v->capacity +1);
}
VBUFPROTO char *
vbuf_getstr (VBUF *v, char *s, size_t sz)
{
char *sbase = s;
assert(sz > 0);
if (vbuf_is_empty(v))
return NULL;
while (sz-- > 0 && !vbuf_is_empty(v))
{
if ('\0' == (*s++ = vbuf_pop(v)))
return sbase;
}
// need to pad NUL.
s[ sz == 0 ? 0 : -1] = '\0';
return sbase;
}
VBUFPROTO int
vbuf_peekat(VBUF *v, int i)
{
const char *s = v->head + i;
if (vbuf_is_empty(v) || i >= vbuf_capacity(v))
return EOF;
if (s < v->tail)
return (unsigned char)*s;
if (s >= v->buf_end)
s -= v->buf_end - v->buf;
if (s < v->tail)
return (unsigned char)*s;
return EOF;
}
// TODO add API unit tests
int main()
{
int i, r;
const int szbuf = 40, szfrag = szbuf / 4 * 3;
const char src[szbuf *2] = "hello, world";
const char *fragstring = "1234567890ABCDEFGHIJabcdefhijk";
const char *s;
char dest[szbuf*2] = "";
VBUF vbuf, *v = &vbuf;
vbuf_new(v, szbuf);
// check basic structure
assert(v->buf && v->capacity == szbuf -1);
assert(v->head == v->tail && v->tail == v->buf);
assert(v->buf_end == v->buf + v->capacity + 1);
// fragmentize it!
vbuf_dbg_fragmentize(v);
assert(vbuf_is_empty(v) && !vbuf_is_full(v));
vbuf_putblk(v, src, szfrag);
// check macro API
assert(!vbuf_is_empty(v));
assert(!vbuf_is_full(v));
assert(vbuf_capacity(v) == szbuf-1);
assert(vbuf_size(v) == szfrag);
assert(vbuf_space(v) == vbuf_capacity(v) - szfrag);
assert(vbuf_peek(v) == src[0]);
// try filling buffer with putblk/getblk
vbuf_dbg_fragmentize(v);
for (i = 0; i < 10; i++)
{
r = vbuf_putblk(v, src, szbuf / 10);
vbuf_dbg_rpt(v);
assert( i == 9 ? !r : r);
assert(!vbuf_is_full(v));
}
r = vbuf_putblk(v, src, vbuf_capacity(v) - vbuf_size(v));
assert(r && vbuf_is_full(v) && !vbuf_is_empty(v));
for (i = 0; i < 10; i++)
{
r = vbuf_getblk(v, dest, szbuf / 10);
dest[szbuf/10] = 0;
printf("%2d. [got: %s] ", i+1, dest);
vbuf_dbg_rpt(v);
assert(i == 9 ? !r : r);
assert(!vbuf_is_full(v) && !vbuf_is_empty(v));
}
r = vbuf_getblk(v, dest, vbuf_size(v));
assert(r && vbuf_is_empty(v) && !vbuf_is_full(v));
// try unframgented
vbuf_clear(v);
r = vbuf_putblk(v, src, vbuf_capacity(v));
assert(r && vbuf_is_full(v));
r = vbuf_putblk(v, src, 1);
assert(!r);
r = vbuf_getblk(v, dest, szbuf-1);
assert(r && vbuf_is_empty(v));
r = vbuf_getblk(v, dest, 1);
assert(!r && vbuf_is_empty(v));
r = vbuf_putblk(v, src, szbuf);
assert(!r && vbuf_is_empty(v));
// string operation
vbuf_clear(v);
vbuf_putstr(v, "str test(1)");
vbuf_putstr(v, "str test(2)");
vbuf_putstr(v, "str test(3)");
for (i = 0; i < 4; i++)
{
s = vbuf_getstr(v, dest, sizeof(dest));
printf("put/getstr(%d): %s\n", i+1,
s ? s : "(NULL)");
assert(i < 3 ? s != NULL : s == NULL);
}
// cstr test
vbuf_clear(v);
vbuf_putstr(v, fragstring);
vbuf_dbg_rpt(v);
s = vbuf_cstr(v);
printf("cstr test(simple): %s\n", s);
assert(strcmp(s, fragstring) == 0);
vbuf_dbg_fragmentize(v);
vbuf_putstr(v, fragstring);
vbuf_dbg_rpt(v);
s = vbuf_cstr(v);
printf("cstr test(unwrap): %s\n", s);
assert(strcmp(s, fragstring) == 0);
vbuf_dbg_fragmentize(v);
vbuf_putblk(v, "*** peek test OK\n", sizeof("*** peek test OK\n"));
while (EOF != (i = vbuf_pop(v)))
putchar(i);
// read/write test
vbuf_dbg_fragmentize(v);
printf("give me some input for finding location of 't': "); fflush(stdout);
vbuf_read(v, 0, VBUF_RWSZ_MIN);
printf("index of 't' = %d\n", vbuf_strchr(v, 't'));
vbuf_dbg_rpt(v);
printf("give me 4 chars: "); fflush(stdout);
vbuf_read(v, 0, 4);
vbuf_dbg_rpt(v);
printf("\n flushing vbuf: ["); fflush(stdout);
vbuf_write(v, 1, VBUF_RWSZ_ALL);
printf("]\n");
return 0;
}
/**
* cin_is_buffer_empty(): quick check if input buffer is empty
*/
CIN_PROTO int
cin_is_buffer_empty()
{
return vbuf_is_empty(cin);
}
