ring: implement drain in terms of read

I think this makes it easier to reason about it and avoids duplicate
logic.
This commit is contained in:
wm4 2014-05-29 02:24:05 +02:00
parent 3238cd3dac
commit 690ea07b7a
1 changed files with 9 additions and 12 deletions

View File

@ -55,18 +55,8 @@ struct mp_ring *mp_ring_new(void *talloc_ctx, int size)
return ringbuffer; return ringbuffer;
} }
int mp_ring_drain(struct mp_ring *buffer, int len)
{
int buffered = mp_ring_buffered(buffer);
int drain_len = FFMIN(len, buffered);
atomic_fetch_add(&buffer->rpos, drain_len);
return drain_len;
}
int mp_ring_read(struct mp_ring *buffer, unsigned char *dest, int len) int mp_ring_read(struct mp_ring *buffer, unsigned char *dest, int len)
{ {
if (!dest) return mp_ring_drain(buffer, len);
int size = mp_ring_size(buffer); int size = mp_ring_size(buffer);
int buffered = mp_ring_buffered(buffer); int buffered = mp_ring_buffered(buffer);
int read_len = FFMIN(len, buffered); int read_len = FFMIN(len, buffered);
@ -75,14 +65,21 @@ int mp_ring_read(struct mp_ring *buffer, unsigned char *dest, int len)
int len1 = FFMIN(size - read_ptr, read_len); int len1 = FFMIN(size - read_ptr, read_len);
int len2 = read_len - len1; int len2 = read_len - len1;
if (dest) {
memcpy(dest, buffer->buffer + read_ptr, len1); memcpy(dest, buffer->buffer + read_ptr, len1);
memcpy(dest + len1, buffer->buffer, len2); memcpy(dest + len1, buffer->buffer, len2);
}
atomic_fetch_add(&buffer->rpos, read_len); atomic_fetch_add(&buffer->rpos, read_len);
return read_len; return read_len;
} }
int mp_ring_drain(struct mp_ring *buffer, int len)
{
return mp_ring_read(buffer, NULL, len);
}
int mp_ring_write(struct mp_ring *buffer, unsigned char *src, int len) int mp_ring_write(struct mp_ring *buffer, unsigned char *src, int len)
{ {
int size = mp_ring_size(buffer); int size = mp_ring_size(buffer);