ringbuf/ringbuf.c

/* SPDX-License-Identifier: MIT */

#include <stdlib.h>
#include <string.h>
#include <stdio.h>

#include "ringbuf.h"

void
rb_init(struct RingBuf *rb, rb_size_t capacity, ALLOC_T malloc_fn,
        rb_size_t struct_size)
{
  rb->struct_size = struct_size;
  rb->capacity = capacity;
  rb->write_idx = 0;
  rb->read_idx = 0;
  rb->buffer = malloc_fn(capacity * struct_size); /* Calloc? */

  // Read from buffer at max position to force a segfault if theres an issue
  printf("Reading from buffer at position %d\n",
         rb->capacity * rb->struct_size);
  void *top = rb->buffer[rb->capacity * rb->struct_size];
  printf("Buffer top successfully read at virtual address: %p\n", &top);

  printf("Initialized ring buffer. Capacit: %d, struct_size: %d, total: %d\n",
         rb->capacity, rb->struct_size, rb->capacity * rb->struct_size);
}

void
rb_destroy(struct RingBuf *rb, void(free)())
{
  free(rb->buffer);
}

enum WriteResult
rb_push(struct RingBuf *rb, void *data, rb_size_t amount, MEMCPY_T memcpy_fn)
{
  printf("\nWriting %d elements\n", amount);

  // We need to do this iteratively, since a memcpy of 
  // multiple elements may overshoot the buffer.
  for(int i = 0; i < amount; i++) {
    void *src = data + i * rb->struct_size; // One element
    void *dest = rb->buffer + (rb->write_idx + i) * rb->struct_size;

    printf("Destination: %p\n", dest);
    printf("Buffer: %p\n", rb->buffer);

    printf("struct_size: %d\n", rb->struct_size);

    // For each byte in the struct, copy it over
    for (int j = 0; j < rb->struct_size; j++) {
      printf("Copying from %p to %p\n", src + j, dest + j);
      printf("j: %d\n", j);
      memcpy_fn(dest+j, src+j, 1);
    }

    // memcpy_fn(dest, src, rb->struct_size);
  }
  return Ok;
}

void
rb_read(struct RingBuf *rb, void *dest, int amount)
{
  printf("\nReading %d elements\n", amount);
  for(int i = 0; i < amount; i++) {
  }
}

void
print_seq(void *begin, int amount)
{
  printf("\nPrinting sequence\n");
  for(int i = 0; i < amount; i++) {
    int *val = (int *)(begin + 4 * i);
    printf("V: %d, A: %u\n", *val, val);
  }
}