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/*
* UCW Library -- Fast Buffered I/O on Static Buffers
*
* (c) 2003--2006 Martin Mares <mj@ucw.cz>
*
* This software may be freely distributed and used according to the terms
* of the GNU Lesser General Public License.
*/
#include <ucw/lib.h>
#include <ucw/fastbuf.h>
#include <stdio.h>
#include <stdlib.h>
static int
fbbuf_refill(struct fastbuf *f)
{
f->bstop = f->bufend;
f->pos = f->bstop - f->buffer;
return f->bptr < f->bstop;
}
static int
fbbuf_seek(struct fastbuf *f, ucw_off_t pos, int whence)
{
/* Somebody might want to seek to the end of buffer, try to be nice to him. */
ucw_off_t len = f->bufend - f->buffer;
if (whence == SEEK_END)
pos += len;
if (pos < 0 || pos > len)
bthrow(f, "seek", "Seek out of range");
f->bstop = f->bptr = f->buffer + pos;
f->pos = pos;
return 1;
}
void
fbbuf_init_read(struct fastbuf *f, byte *buf, uint size, uint can_overwrite)
{
*f = (struct fastbuf) {
.buffer = buf,
.bptr = buf,
.bstop = buf + size,
.bufend = buf + size,
.name = "fbbuf-read",
.pos = size,
.refill = fbbuf_refill,
.seek = fbbuf_seek,
.can_overwrite_buffer = can_overwrite
};
}
static void
fbbuf_spout(struct fastbuf *f)
{
if (f->bptr >= f->bufend)
bthrow(f, "write", "fbbuf: buffer overflow on write");
}
void
fbbuf_init_write(struct fastbuf *f, byte *buf, uint size)
{
*f = (struct fastbuf) {
.buffer = buf,
.bstop = buf,
.bptr = buf,
.bufend = buf + size,
.name = "fbbuf-write",
.spout = fbbuf_spout,
};
}
#ifdef TEST
int main(int argc, char *argv[])
{
if (argc < 2)
{
fprintf(stderr, "You must specify a test (r, w, o)\n");
return 1;
}
switch (*argv[1])
{
case 'r':
{
struct fastbuf fb;
char *data = "Two\nlines\n";
fbbuf_init_read(&fb, data, strlen(data), 0);
char buffer[10];
while (bgets(&fb, buffer, 10))
puts(buffer);
bclose(&fb);
break;
}
case 'w':
{
struct fastbuf fb;
char buff[20];
fbbuf_init_write(&fb, buff, 20);
bputs(&fb, "Hello world\n");
bputc(&fb, 0);
fputs(buff, stdout);
break;
}
case 'o':
{
struct fastbuf fb;
char buff[4];
fbbuf_init_write(&fb, buff, 4);
bputs(&fb, "Hello");
bputc(&fb, 0);
fputs(buff, stdout);
break;
}
}
return 0;
}
#endif