thin-provisioning-tools/persistent-data/data-structures/btree_node_checker.h

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#ifndef BTREE_NODE_CHECKER_H
#define BTREE_NODE_CHECKER_H
#include "block-cache/block_cache.h"
#include "persistent-data/block.h"
#include "persistent-data/data-structures/btree.h"
#include "persistent-data/data-structures/btree_disk_structures.h"
#include <boost/optional.hpp>
#include <string>
using bcache::block_address;
//----------------------------------------------------------------
namespace persistent_data {
namespace btree_detail {
class btree_node_checker {
public:
enum error_type {
NO_ERROR,
BLOCK_NR_MISMATCH,
VALUE_SIZES_MISMATCH,
MAX_ENTRIES_TOO_LARGE,
MAX_ENTRIES_NOT_DIVISIBLE,
NR_ENTRIES_TOO_LARGE,
NR_ENTRIES_TOO_SMALL,
KEYS_OUT_OF_ORDER,
VALUE_SIZE_MISMATCH,
PARENT_KEY_MISMATCH,
LEAF_KEY_OVERLAPPED,
};
btree_node_checker():
last_error_(NO_ERROR),
error_location_(0),
error_block_nr_(0),
error_nr_entries_(0),
error_max_entries_(0),
error_value_sizes_{0, 0},
error_keys_{0, 0} {
}
virtual ~btree_node_checker() {}
template <typename ValueTraits>
bool check_block_nr(btree_detail::node_ref<ValueTraits> const &n) {
if (n.get_location() != n.get_block_nr()) {
last_error_ = BLOCK_NR_MISMATCH;
error_block_nr_ = n.get_block_nr();
error_location_ = n.get_location();
return false;
}
return true;
}
template <typename ValueTraits>
bool check_value_size(btree_detail::node_ref<ValueTraits> const &n) {
if (!n.value_sizes_match()) {
last_error_ = VALUE_SIZES_MISMATCH;
error_location_ = n.get_location();
error_value_sizes_[0] = n.get_value_size();
error_value_sizes_[1] = sizeof(typename ValueTraits::disk_type);
return false;
}
return true;
}
template <typename ValueTraits>
bool check_max_entries(btree_detail::node_ref<ValueTraits> const &n) {
size_t elt_size = sizeof(uint64_t) + n.get_value_size();
if (elt_size * n.get_max_entries() + sizeof(node_header) > MD_BLOCK_SIZE) {
last_error_ = MAX_ENTRIES_TOO_LARGE;
error_location_ = n.get_location();
error_max_entries_ = n.get_max_entries();
return false;
}
if (n.get_max_entries() % 3) {
last_error_ = MAX_ENTRIES_NOT_DIVISIBLE;
error_location_ = n.get_location();
error_max_entries_ = n.get_max_entries();
return false;
}
return true;
}
template <typename ValueTraits>
bool check_nr_entries(btree_detail::node_ref<ValueTraits> const &n,
bool is_root) {
if (n.get_nr_entries() > n.get_max_entries()) {
last_error_ = NR_ENTRIES_TOO_LARGE;
error_location_ = n.get_location();
error_nr_entries_ = n.get_nr_entries();
error_max_entries_ = n.get_max_entries();
return false;
}
block_address min = n.get_max_entries() / 3;
if (!is_root && (n.get_nr_entries() < min)) {
last_error_ = NR_ENTRIES_TOO_SMALL;
error_location_ = n.get_location();
error_nr_entries_ = n.get_nr_entries();
error_max_entries_ = n.get_max_entries();
return false;
}
return true;
}
template <typename ValueTraits>
bool check_ordered_keys(btree_detail::node_ref<ValueTraits> const &n) {
unsigned nr_entries = n.get_nr_entries();
if (nr_entries == 0)
return true; // can only happen if a root node
uint64_t last_key = n.key_at(0);
for (unsigned i = 1; i < nr_entries; i++) {
uint64_t k = n.key_at(i);
if (k <= last_key) {
last_error_ = KEYS_OUT_OF_ORDER;
error_location_ = n.get_location();
error_keys_[0] = k;
error_keys_[1] = last_key;
return false;
}
last_key = k;
}
return true;
}
template <typename ValueTraits>
bool check_parent_key(btree_detail::node_ref<ValueTraits> const &n,
boost::optional<uint64_t> key) {
if (!key)
return true;
if (*key > n.key_at(0)) {
last_error_ = PARENT_KEY_MISMATCH;
error_location_ = n.get_location();
error_keys_[0] = n.key_at(0);
error_keys_[1] = *key;
return false;
}
return true;
}
template <typename ValueTraits>
bool check_leaf_key(btree_detail::node_ref<ValueTraits> const &n,
boost::optional<uint64_t> key) {
if (n.get_nr_entries() == 0)
return true; // can only happen if a root node
if (key && *key >= n.key_at(0)) {
last_error_ = LEAF_KEY_OVERLAPPED;
error_location_ = n.get_location();
error_keys_[0] = n.key_at(0);
error_keys_[1] = *key;
return false;
}
return true;
}
error_type get_last_error() const;
std::string get_last_error_string() const;
void reset();
private:
std::string block_nr_mismatch_string() const;
std::string value_sizes_mismatch_string() const;
std::string max_entries_too_large_string() const;
std::string max_entries_not_divisible_string() const;
std::string nr_entries_too_large_string() const;
std::string nr_entries_too_small_string() const;
std::string keys_out_of_order_string() const;
std::string parent_key_mismatch_string() const;
std::string leaf_key_overlapped_string() const;
error_type last_error_;
block_address error_location_;
block_address error_block_nr_;
uint32_t error_nr_entries_;
uint32_t error_max_entries_;
uint32_t error_value_sizes_[2];
uint64_t error_keys_[2];
};
}
}
//----------------------------------------------------------------
#endif