db_bdb: add versioning, to detect incompatible format changes

This commit is contained in:
moneromooo-monero 2015-10-26 17:57:44 +00:00
parent f7e99047e4
commit ecf0b83406
No known key found for this signature in database
GPG key ID: 686F07454D6CEFC3
2 changed files with 83 additions and 0 deletions

View file

@ -38,6 +38,10 @@
using epee::string_tools::pod_to_hex;
#define DB_DEFAULT_TX (m_write_txn != nullptr ? *m_write_txn : (DbTxn*) nullptr)
// Increase when the DB changes in a non backward compatible way, and there
// is no automatic conversion, so that a full resync is needed.
#define VERSION 0
namespace
{
@ -121,6 +125,8 @@ const char* const BDB_SPENT_KEYS = "spent_keys";
const char* const BDB_HF_STARTING_HEIGHTS = "hf_starting_heights";
const char* const BDB_HF_VERSIONS = "hf_versions";
const char* const BDB_PROPERTIES = "properties";
const unsigned int MB = 1024 * 1024;
// ND: FIXME: db keeps running out of locks when doing full syncs. Possible bug??? Set it to 5K for now.
const unsigned int DB_MAX_LOCKS = 5000;
@ -180,6 +186,22 @@ private:
std::unique_ptr<char[]> m_data;
};
template<>
struct Dbt_copy<const char*>: public Dbt
{
Dbt_copy(const char *s) :
m_data(strdup(s))
{
size_t len = strlen(s) + 1; // include the NUL, makes it easier for compare
set_data(m_data.get());
set_size(len);
set_ulen(len);
set_flags(DB_DBT_USERMEM);
}
private:
std::unique_ptr<char[]> m_data;
};
struct Dbt_safe : public Dbt
{
Dbt_safe()
@ -793,6 +815,8 @@ void BlockchainBDB::open(const std::string& filename, const int db_flags)
m_hf_starting_heights = new Db(m_env, 0);
m_hf_versions = new Db(m_env, 0);
m_properties = new Db(m_env, 0);
// Tell DB about Dbs that need duplicate support
// Note: no need to tell about sorting,
// as the default is insertion order, which we want
@ -845,6 +869,8 @@ void BlockchainBDB::open(const std::string& filename, const int db_flags)
m_hf_starting_heights->open(txn, BDB_HF_STARTING_HEIGHTS, NULL, DB_RECNO, DB_CREATE, 0);
m_hf_versions->open(txn, BDB_HF_VERSIONS, NULL, DB_RECNO, DB_CREATE, 0);
m_properties->open(txn, BDB_PROPERTIES, NULL, DB_HASH, DB_CREATE, 0);
txn.commit();
DB_BTREE_STAT* stats;
@ -865,6 +891,56 @@ void BlockchainBDB::open(const std::string& filename, const int db_flags)
m_num_outputs = stats->bt_nkeys;
delete stats;
// checks for compatibility
bool compatible = true;
Dbt_copy<const char*> key("version");
Dbt_copy<uint32_t> result;
auto get_result = m_properties->get(DB_DEFAULT_TX, &key, &result, 0);
if (get_result == 0)
{
if (result > VERSION)
{
LOG_PRINT_RED_L0("Existing BerkeleyDB database was made by a later version. We don't know how it will change yet.");
compatible = false;
}
else if (VERSION > 0 && result < VERSION)
{
compatible = false;
}
}
else
{
// if not found, but we're on version 0, it's fine. If the DB's empty, it's fine too.
if (VERSION > 0 && m_height > 0)
compatible = false;
}
if (!compatible)
{
m_open = false;
LOG_PRINT_RED_L0("Existing BerkeleyDB database is incompatible with this version.");
LOG_PRINT_RED_L0("Please delete the existing database and resync.");
return;
}
if (1 /* this can't be set readonly atm */)
{
// only write version on an empty DB
if (m_height == 0)
{
Dbt_copy<const char*> k("version");
Dbt_copy<uint32_t> v(VERSION);
auto put_result = m_properties->put(DB_DEFAULT_TX, &k, &v, 0);
if (put_result != 0)
{
m_open = false;
LOG_PRINT_RED_L0("Failed to write version to database.");
return;
}
}
}
// run checkpoint thread
m_run_checkpoint = true;
m_checkpoint_thread.reset(new boost::thread(&BlockchainBDB::checkpoint_worker, this));
@ -920,6 +996,8 @@ void BlockchainBDB::sync()
m_hf_starting_heights->sync(0);
m_hf_versions->sync(0);
m_properties->sync(0);
}
catch (const std::exception& e)
{
@ -1000,6 +1078,9 @@ std::vector<std::string> BlockchainBDB::get_filenames() const
m_hf_versions->get_dbname(pfname, pdbname);
filenames.push_back(fname);
m_properties->get_dbname(pfname, pdbname);
filenames.push_back(fname);
std::vector<std::string> full_paths;
for (auto& filename : filenames)

View file

@ -445,6 +445,8 @@ private:
Db* m_hf_starting_heights;
Db* m_hf_versions;
Db* m_properties;
uint64_t m_height;
uint64_t m_num_outputs;
std::string m_folder;