From 7022f39e10551d7ab325d196884de301ddb3087e Mon Sep 17 00:00:00 2001 From: dzwdz Date: Sun, 10 Apr 2022 17:14:10 +0200 Subject: shared: implement a basic ring buffer --- src/shared/container/ring.c | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) create mode 100644 src/shared/container/ring.c (limited to 'src/shared/container/ring.c') diff --git a/src/shared/container/ring.c b/src/shared/container/ring.c new file mode 100644 index 0000000..525fade --- /dev/null +++ b/src/shared/container/ring.c @@ -0,0 +1,35 @@ +#include +#include +// TODO use memcpy + +static bool at_end(ring_t *r) { + return r->_head + 1 == r->_tail + || (r->_head + 1 == r->capacity && r->_tail == 0); +} + +size_t ring_size(ring_t *r) { + if (r->_head >= r->_tail) + return r->_head - r->_tail; + else + return r->_head + r->capacity - r->_tail; +} + +void ring_put(ring_t *r, void *buf, size_t len) { + for (size_t i = 0; i < len; i++) + ring_put1b(r, ((uint8_t*)buf)[i]); +} + +void ring_put1b(ring_t *r, uint8_t byte) { + if (at_end(r)) return; + ((uint8_t*)r->buf)[r->_head++] = byte; + if (r->_head >= r->capacity) r->_head = 0; +} + +size_t ring_get(ring_t *r, void *buf, size_t len) { + for (size_t i = 0; i < len; i++) { + if (at_end(r)) return i; + ((uint8_t*)buf)[i] = ((uint8_t*)r->buf)[r->_tail++]; + if (r->_tail >= r->capacity) r->_tail = 0; + } + return len; +} -- cgit v1.2.3