lander/lsm/src/store/lsm_store_entry.c

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

#include "lsm.h"
#include "lsm/store_internal.h"

lsm_error lsm_entry_init(lsm_entry **ptr) {
  lsm_entry *entry = calloc(1, sizeof(lsm_entry));

  if (entry == NULL) {
    return lsm_error_failed_alloc;
  }

  *ptr = entry;

  return lsm_error_ok;
}

bool lsm_entry_attr_present(lsm_entry *entry, lsm_attr_type type) {
  return (entry->attrs.bitmap & type) != 0;
}

lsm_error lsm_entry_attr_get(lsm_str **out, lsm_entry *entry,
                             lsm_attr_type type) {
  if (!lsm_entry_attr_present(entry, type)) {
    return lsm_error_not_found;
  }

  uint64_t i = 0;

  while (entry->attrs.items[i].type != type) {
    i++;
  }

  *out = entry->attrs.items[i].str;

  return lsm_error_ok;
}

lsm_error lsm_entry_attr_remove(lsm_str **out, lsm_entry *entry,
                                lsm_attr_type type) {
  if (!lsm_entry_attr_present(entry, type)) {
    return lsm_error_not_found;
  }

  if (entry->attrs.count == 1) {
    *out = entry->attrs.items[0].str;

    free(entry->attrs.items);
    entry->attrs.items = NULL;
    entry->attrs.count = 0;
    entry->attrs.bitmap = 0;

    return lsm_error_ok;
  }

  uint64_t i = 0;

  while (entry->attrs.items[i].type != type) {
    i++;
  }

  lsm_attr *new_attrs = malloc((entry->attrs.count - 1) * sizeof(lsm_attr));

  if (new_attrs == NULL) {
    return lsm_error_failed_alloc;
  }

  if (out != NULL) {
    *out = entry->attrs.items[i].str;
  }

  memcpy(new_attrs, entry->attrs.items, i * sizeof(lsm_attr));
  memcpy(&new_attrs[i], &entry->attrs.items[i + 1],
         (entry->attrs.count - i - 1) * sizeof(lsm_attr));

  free(entry->attrs.items);

  entry->attrs.items = new_attrs;
  entry->attrs.count--;
  entry->attrs.bitmap &= ~type;

  return lsm_error_ok;
}

lsm_error lsm_entry_attr_insert(lsm_entry *entry, lsm_attr_type type,
                                lsm_str *data) {
  if (lsm_entry_attr_present(entry, type)) {
    return lsm_error_already_present;
  }

  lsm_attr *new_attrs =
      realloc(entry->attrs.items, (entry->attrs.count + 1) * sizeof(lsm_attr));

  if (new_attrs == NULL) {
    return lsm_error_failed_alloc;
  }

  new_attrs[entry->attrs.count].type = type;
  new_attrs[entry->attrs.count].str = data;

  entry->attrs.items = new_attrs;
  entry->attrs.count++;
  entry->attrs.bitmap |= type;

  return lsm_error_ok;
}