1 #include <geekos/ring_buffer.h>
2 #include <geekos/malloc.h>
3 #include <geekos/ktypes.h>
4 #include <geekos/debug.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);
91 memcpy(dst + section_len, ring->buf, read_len - section_len);
93 ring->start = read_len - section_len;
95 memcpy(dst, get_read_ptr(ring), read_len);
97 ring->start += read_len;
100 ring->current_len -= read_len;
108 int rb_peek(struct ring_buffer * ring, char * dst, uint_t len) {
110 int ring_data_len = ring->current_len;
112 read_len = (len > ring_data_len) ? ring_data_len : len;
114 if (is_read_loop(ring, read_len)) {
115 int section_len = get_read_section_size(ring);
117 memcpy(dst, get_read_ptr(ring), section_len);
118 memcpy(dst + section_len, ring->buf, read_len - section_len);
120 memcpy(dst, get_read_ptr(ring), read_len);
127 int rb_delete(struct ring_buffer * ring, uint_t len) {
129 int ring_data_len = ring->current_len;
131 del_len = (len > ring_data_len) ? ring_data_len : len;
133 if (is_read_loop(ring, del_len)) {
134 int section_len = get_read_section_size(ring);
135 ring->start = del_len - section_len;
137 ring->start += del_len;
140 ring->current_len -= del_len;
145 int rb_write(struct ring_buffer * ring, char * src, uint_t len) {
147 int ring_avail_space = ring->size - ring->current_len;
149 write_len = (len > ring_avail_space) ? ring_avail_space : len;
152 if (is_write_loop(ring, write_len)) {
153 int section_len = get_write_section_size(ring);
155 memcpy(get_write_ptr(ring), src, section_len);
158 memcpy(get_write_ptr(ring), src + section_len, write_len - section_len);
160 ring->end += write_len - section_len;
162 memcpy(get_write_ptr(ring), src, write_len);
164 ring->end += write_len;
167 ring->current_len += write_len;
173 void print_ring_buffer(struct ring_buffer * ring) {
176 for (ctr = 0; ctr < ring->current_len; ctr++) {
177 int index = (ctr + ring->start) % ring->size;
179 PrintBoth("Entry %d (index=%d): %c\n", ctr, index, ring->buf[index]);