Rename dirs

lib/ringbuf.c

@@ -0,0 +1,94 @@
+#include <zinnia/alloc.h>
+#include <zinnia/ringbuf.h>
+#include <zinnia/utils.h>
+#include <string.h>
+
+errno_t ringbuf_init(struct ringbuf* rb, size_t capacity) {
+    rb->data = mem_alloc(capacity, ALLOC_NOZERO);
+    if (!rb->data)
+        return ENOMEM;
+    rb->capacity = capacity;
+    rb->head = 0;
+    rb->len = 0;
+    return 0;
+}
+
+void ringbuf_fini(struct ringbuf* rb) {
+    mem_free(rb->data);
+    rb->data = nullptr;
+    rb->capacity = 0;
+    rb->len = 0;
+}
+
+static size_t tail(const struct ringbuf* rb) {
+    return (rb->head + rb->len) % rb->capacity;
+}
+
+static size_t write_chunk(const struct ringbuf* rb, size_t len) {
+    return MIN(len, MIN(ringbuf_space(rb), rb->capacity - tail(rb)));
+}
+
+static size_t read_chunk(const struct ringbuf* rb, size_t len) {
+    return MIN(len, MIN(rb->len, rb->capacity - rb->head));
+}
+
+static void advance_read(struct ringbuf* rb, size_t len) {
+    rb->head = (rb->head + len) % rb->capacity;
+    rb->len -= len;
+    if (rb->len == 0)
+        rb->head = 0;
+}
+
+size_t ringbuf_write(struct ringbuf* rb, const void* src, size_t len) {
+    size_t done = 0;
+    size_t chunk;
+    while ((chunk = write_chunk(rb, len - done))) {
+        memcpy(rb->data + tail(rb), (const uint8_t*)src + done, chunk);
+        rb->len += chunk;
+        done += chunk;
+    }
+    return done;
+}
+
+size_t ringbuf_read(struct ringbuf* rb, void* dst, size_t len) {
+    size_t done = 0;
+    size_t chunk;
+    while ((chunk = read_chunk(rb, len - done))) {
+        memcpy((uint8_t*)dst + done, rb->data + rb->head, chunk);
+        advance_read(rb, chunk);
+        done += chunk;
+    }
+    return done;
+}
+
+errno_t ringbuf_write_iter(struct ringbuf* rb, iovec_iter_t* iter, size_t len, size_t* out_written) {
+    size_t done = 0;
+    errno_t status = 0;
+    size_t chunk;
+    while (!status && (chunk = write_chunk(rb, len - done))) {
+        size_t copied;
+        status = iovec_iter_copy_from(iter, rb->data + tail(rb), chunk, &copied);
+        rb->len += copied;
+        done += copied;
+        if (copied < chunk)
+            break;
+    }
+    *out_written = done;
+    return done ? 0 : status;
+}
+
+errno_t ringbuf_read_iter(struct ringbuf* rb, iovec_iter_t* iter, size_t len, size_t* out_read) {
+    size_t done = 0;
+    errno_t status = 0;
+    size_t chunk;
+    while (!status && (chunk = read_chunk(rb, len - done))) {
+        size_t copied;
+        status = iovec_iter_copy_to(iter, rb->data + rb->head, chunk, &copied);
+        advance_read(rb, copied);
+        done += copied;
+        if (copied < chunk)
+            break;
+    }
+    *out_read = done;
+    return done ? 0 : status;
+}