db_lmdb: add versioning, to detect incompatible format changes

This commit is contained in:
moneromooo-monero 2015-10-26 15:52:07 +00:00
parent 7003e7c156
commit f7e99047e4
No known key found for this signature in database
GPG Key ID: 686F07454D6CEFC3
2 changed files with 85 additions and 8 deletions

View File

@ -39,6 +39,10 @@
using epee::string_tools::pod_to_hex;
// 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
{
@ -122,6 +126,19 @@ private:
std::unique_ptr<char[]> data;
};
template<>
struct MDB_val_copy<const char*>: public MDB_val
{
MDB_val_copy(const char *s) :
data(strdup(s))
{
mv_size = strlen(s) + 1; // include the NUL, makes it easier for compares
mv_data = data.get();
}
private:
std::unique_ptr<char[]> data;
};
auto compare_uint64 = [](const MDB_val *a, const MDB_val *b)
{
const uint64_t va = *(const uint64_t*)a->mv_data;
@ -154,6 +171,13 @@ int compare_hash32(const MDB_val *a, const MDB_val *b)
return 0;
}
int compare_string(const MDB_val *a, const MDB_val *b)
{
const char *va = (const char*) a->mv_data;
const char *vb = (const char*) b->mv_data;
return strcmp(va, vb);
}
const char* const LMDB_BLOCKS = "blocks";
const char* const LMDB_BLOCK_TIMESTAMPS = "block_timestamps";
const char* const LMDB_BLOCK_HEIGHTS = "block_heights";
@ -178,6 +202,8 @@ const char* const LMDB_SPENT_KEYS = "spent_keys";
const char* const LMDB_HF_STARTING_HEIGHTS = "hf_starting_heights";
const char* const LMDB_HF_VERSIONS = "hf_versions";
const char* const LMDB_PROPERTIES = "properties";
inline void lmdb_db_open(MDB_txn* txn, const char* name, int flags, MDB_dbi& dbi, const std::string& error_string)
{
if (mdb_dbi_open(txn, name, flags, &dbi))
@ -1037,6 +1063,8 @@ void BlockchainLMDB::open(const std::string& filename, const int mdb_flags)
lmdb_db_open(txn, LMDB_HF_STARTING_HEIGHTS, MDB_CREATE, m_hf_starting_heights, "Failed to open db handle for m_hf_starting_heights");
lmdb_db_open(txn, LMDB_HF_VERSIONS, MDB_CREATE, m_hf_versions, "Failed to open db handle for m_hf_versions");
lmdb_db_open(txn, LMDB_PROPERTIES, MDB_CREATE, m_properties, "Failed to open db handle for m_properties");
mdb_set_dupsort(txn, m_output_amounts, compare_uint64);
mdb_set_dupsort(txn, m_tx_outputs, compare_uint64);
mdb_set_compare(txn, m_spent_keys, compare_hash32);
@ -1046,6 +1074,7 @@ void BlockchainLMDB::open(const std::string& filename, const int mdb_flags)
mdb_set_compare(txn, m_tx_heights, compare_hash32);
mdb_set_compare(txn, m_hf_starting_heights, compare_uint8);
mdb_set_compare(txn, m_hf_versions, compare_uint64);
mdb_set_compare(txn, m_properties, compare_string);
// get and keep current height
MDB_stat db_stats;
@ -1059,6 +1088,8 @@ void BlockchainLMDB::open(const std::string& filename, const int mdb_flags)
throw0(DB_ERROR("Failed to query m_output_indices"));
m_num_outputs = db_stats.ms_entries;
bool compatible = true;
// ND: This "new" version of the lmdb database is incompatible with
// the previous version. Ensure that the output_keys database is
// sizeof(output_data_t) in length. Otherwise, inform user and
@ -1077,6 +1108,32 @@ void BlockchainLMDB::open(const std::string& filename, const int mdb_flags)
// LOG_PRINT_L0("Output keys size: " << v.mv_size);
if(v.mv_size != sizeof(output_data_t))
compatible = false;
}
MDB_val_copy<const char*> k("version");
MDB_val v;
auto get_result = mdb_get(txn, m_properties, &k, &v);
if(get_result == MDB_SUCCESS)
{
if (*(const uint32_t*)v.mv_data > VERSION)
{
LOG_PRINT_RED_L0("Existing lmdb database was made by a later version. We don't know how it will change yet.");
compatible = false;
}
else if (VERSION > 0 && *(const uint32_t*)v.mv_data < 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)
{
txn.abort();
mdb_env_close(m_env);
@ -1085,6 +1142,24 @@ void BlockchainLMDB::open(const std::string& filename, const int mdb_flags)
LOG_PRINT_RED_L0("Please delete the existing database and resync.");
return;
}
if (!(mdb_flags & MDB_RDONLY))
{
// only write version on an empty DB
if (m_height == 0)
{
MDB_val_copy<const char*> k("version");
MDB_val_copy<uint32_t> v(VERSION);
auto put_result = mdb_put(txn, m_properties, &k, &v, 0);
if (put_result != MDB_SUCCESS)
{
txn.abort();
mdb_env_close(m_env);
m_open = false;
LOG_PRINT_RED_L0("Failed to write version to database.");
return;
}
}
}
// commit the transaction

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@ -306,6 +306,8 @@ private:
MDB_dbi m_hf_starting_heights;
MDB_dbi m_hf_versions;
MDB_dbi m_properties;
uint64_t m_height;
uint64_t m_num_outputs;
std::string m_folder;