1 #include <geekos/ring_buffer.h>
2 #include <geekos/malloc.h>
3 #include <geekos/ktypes.h>
7 void init_ring_buffer(struct ring_buffer * ring, uint_t size) {
8 ring->buf = Malloc(size);
13 ring->current_len = 0;
17 struct ring_buffer * create_ring_buffer(uint_t size) {
18 struct ring_buffer * ring = (struct ring_buffer *)Malloc(sizeof(struct ring_buffer));
20 init_ring_buffer(ring, size);
25 void free_ring_buffer(struct ring_buffer * ring) {
34 static inline uchar_t * get_read_ptr(struct ring_buffer * ring) {
35 return (uchar_t *)&(ring->buf + ring->start);
38 static inline uchar_t * get_write_ptr(struct ring_buffer * ring) {
39 return (uchar_t *)&(ring->buf + ring->end);
43 static inline int get_read_section_size(struct ring_buffer * ring) {
44 return ring->size - ring->start;
47 static inline int get_write_section_size(struct ring_buffer * ring) {
48 return ring->size - ring->end;
51 static inline int is_read_loop(struct ring_buffer * ring, uint_t len) {
52 if ((ring->start >= ring->end) && (ring->current_len > 0)) {
53 // end is past the end of the buffer
54 if (get_read_section_size(ring) < len) {
62 static inline int is_write_loop(struct ring_buffer * ring, uint_t len) {
63 if ((ring->end >= ring->start) && (ring->current_len < ring->size)) {
64 // end is past the end of the buffer
65 if (get_write_section_size(ring) < len) {
73 int rb_data_len(struct ring_buffer * ring) {
74 return ring->current_len;
77 int rb_capacity(struct ring_buffer * ring) {
81 int rb_read(struct ring_buffer * ring, char * dst, uint_t len) {
83 int ring_data_len = ring->current_len;
85 read_len = (len > ring_data_len) ? ring_data_len : len;
87 if (is_read_loop(ring, read_len)) {
88 int section_len = get_read_section_size(ring);
90 memcpy(dst, get_read_ptr(ring), section_len);
93 memcpy(dst + section_len, get_read_ptr(ring), read_len - section_len);
95 ring->start += read_len - section_len;
97 memcpy(dst, get_read_ptr(ring), read_len);
99 ring->start += read_len;
102 ring->current_len -= read_len;
108 int rb_write(struct ring_buffer * ring, char * src, uint_t len) {
110 int ring_avail_space = ring->size - ring->current_len;
112 write_len = (len > ring_avail_space) ? ring_avail_space : len;
115 if (is_write_loop(ring, write_len)) {
116 int section_len = get_write_section_size(ring);
118 memcpy(get_write_ptr(ring), src, section_len);
121 memcpy(get_write_ptr(ring), src + section_len, write_len - section_len);
123 ring->end += write_len - section_len;
125 memcpy(get_write_ptr(ring), src, write_len);
127 ring->end += write_len;
130 ring->current_len += write_len;