Method decode

src/crush/CrushWrapper.cc:3268–3410

}

void CrushWrapper::decode(bufferlist::const_iterator& blp)
{
  using ceph::decode;
  create();

  __u32 magic;
  decode(magic, blp);
  if (magic != CRUSH_MAGIC)
    throw ceph::buffer::malformed_input("bad magic number");

  decode(crush->max_buckets, blp);
  decode(crush->max_rules, blp);
  decode(crush->max_devices, blp);

  // legacy tunables, unless we decode something newer
  set_tunables_legacy();

  try {
    // buckets
    crush->buckets = (crush_bucket**)calloc(1, crush->max_buckets * sizeof(crush_bucket*));
    for (int i=0; i<crush->max_buckets; i++) {
      decode_crush_bucket(&crush->buckets[i], blp);
    }

    // rules
    crush->rules = (crush_rule**)calloc(1, crush->max_rules * sizeof(crush_rule*));
    for (unsigned i = 0; i < crush->max_rules; ++i) {
      __u32 yes;
      decode(yes, blp);
      if (!yes) {
	crush->rules[i] = NULL;
	continue;
      }

      __u32 len;
      decode(len, blp);
      crush->rules[i] = reinterpret_cast<crush_rule*>(calloc(1, crush_rule_size(len)));
      crush->rules[i]->len = len;

      __u8 ruleset; // ignore + discard
      decode(ruleset, blp);
      if (ruleset != i) {
	throw ::ceph::buffer::malformed_input("crush ruleset_id != rule_id; encoding is too old");
      }
      decode(crush->rules[i]->type, blp);
      decode(crush->rules[i]->deprecated_min_size, blp);
      decode(crush->rules[i]->deprecated_max_size, blp);
      
      for (unsigned j=0; j<crush->rules[i]->len; j++)
	decode(crush->rules[i]->steps[j], blp);
    }

    // name info
    // NOTE: we had a bug where we were incoding int instead of int32, which means the
    // 'key' field for these maps may be either 32 or 64 bits, depending.  tolerate
    // both by assuming the string is always non-empty.
    decode_32_or_64_string_map(type_map, blp);
    decode_32_or_64_string_map(name_map, blp);