[btree_node_checker] first draft

Spin-off from btree_damage_visitor

persistent-data/data-structures/btree_node_checker.cc

@@ -0,0 +1,127 @@
+#include "btree_node_checker.h"
+
+#include <sstream>
+
+using persistent_data::btree_detail::btree_node_checker;
+
+//----------------------------------------------------------------
+
+btree_node_checker::error_type btree_node_checker::get_last_error() {
+	return last_error_;
+}
+
+std::string btree_node_checker::get_last_error_string() {
+	switch (last_error_) {
+	case BLOCK_NR_MISMATCH:
+		return block_nr_mismatch_string();
+	case VALUE_SIZES_MISMATCH:
+		return value_sizes_mismatch_string();
+	case MAX_ENTRIES_TOO_LARGE:
+		return max_entries_too_large_string();
+	case MAX_ENTRIES_NOT_DIVISIBLE:
+		return max_entries_not_divisible_string();
+	case NR_ENTRIES_TOO_LARGE:
+		return nr_entries_too_large_string();
+	case NR_ENTRIES_TOO_SMALL:
+		return nr_entries_too_small_string();
+	case KEYS_OUT_OF_ORDER:
+		return keys_out_of_order_string();
+	case PARENT_KEY_MISMATCH:
+		return parent_key_mismatch_string();
+	case LEAF_KEY_OVERLAPPED:
+		return leaf_key_overlapped_string();
+	default:
+		return std::string();
+	}
+}
+
+void btree_node_checker::reset() {
+	last_error_ = NO_ERROR;
+}
+
+std::string btree_node_checker::block_nr_mismatch_string() {
+	std::ostringstream out;
+	out << "block number mismatch: actually "
+	    << error_location_
+	    << ", claims " << error_block_nr_;
+
+	return out.str();
+}
+
+std::string btree_node_checker::value_sizes_mismatch_string() {
+	std::ostringstream out;
+	out << "value size mismatch: expected " << error_value_sizes_[1]
+	    << ", but got " << error_value_sizes_[0]
+	    << ". This is not the btree you are looking for."
+	    << " (block " << error_location_ << ")";
+
+	return out.str();
+}
+
+std::string btree_node_checker::max_entries_too_large_string() {
+	std::ostringstream out;
+	out << "max entries too large: " << error_max_entries_
+	    << " (block " << error_location_ << ")";
+
+	return out.str();
+}
+
+std::string btree_node_checker::max_entries_not_divisible_string() {
+	std::ostringstream out;
+	out << "max entries is not divisible by 3: " << error_max_entries_
+	    << " (block " << error_location_ << ")";
+
+	return out.str();
+}
+
+std::string btree_node_checker::nr_entries_too_large_string() {
+	std::ostringstream out;
+	out << "bad nr_entries: "
+	    << error_nr_entries_ << " < "
+	    << error_max_entries_
+	    << " (block " << error_location_ << ")";
+
+	return out.str();
+}
+
+std::string btree_node_checker::nr_entries_too_small_string() {
+	std::ostringstream out;
+	out << "too few entries in btree_node: "
+	    << error_nr_entries_
+	    << ", expected at least "
+	    << (error_max_entries_ / 3)
+	    << " (block " << error_location_
+	    << ", max_entries = " << error_max_entries_ << ")";
+
+	return out.str();
+}
+
+std::string btree_node_checker::keys_out_of_order_string() {
+	std::ostringstream out;
+	out << "keys are out of order, "
+	    << error_keys_[0] << " <= " << error_keys_[1]
+	    << " (block " << error_location_ << ")";
+
+	return out.str();
+}
+
+std::string btree_node_checker::parent_key_mismatch_string() {
+	std::ostringstream out;
+	out << "parent key mismatch: parent was " << error_keys_[1]
+	    << ", but lowest in node was " << error_keys_[0]
+	    << " (block " << error_location_ << ")";
+
+	return out.str();
+}
+
+std::string btree_node_checker::leaf_key_overlapped_string() {
+	std::ostringstream out;
+	out << "the last key of the previous leaf was " << error_keys_[1]
+	    << " and the first key of this leaf is " << error_keys_[0]
+	    << " (block " << error_location_ << ")";
+
+	return out.str();
+}
+
+//----------------------------------------------------------------
+