private void CreateNewDatabase()
{
const int initialNextPageNumber = 0;
State = new StorageEnvironmentState(null, initialNextPageNumber)
{
Options = Options
};
var transactionPersistentContext = new TransactionPersistentContext();
using (var tx = NewLowLevelTransaction(transactionPersistentContext, TransactionFlags.ReadWrite))
using (var root = Tree.Create(tx, null, Constants.RootTreeNameSlice))
{
// important to first create the root trees, then set them on the env
tx.UpdateRootsIfNeeded(root);
using (var treesTx = new Transaction(tx))
{
DbId = Guid.NewGuid();
FillBase64Id(DbId);
var metadataTree = treesTx.CreateTree(Constants.MetadataTreeNameSlice);
metadataTree.Add("db-id", DbId.ToByteArray());
metadataTree.Add("schema-version", EndianBitConverter.Little.GetBytes(Options.SchemaVersion));
treesTx.PrepareForCommit();
tx.Commit();
}
}
}
private void InitializeDatabase()
{
using (var tx = _env.NewTransaction(TransactionFlags.ReadWrite))
{
_env.CreateTree(tx, LogsTreeName);
_env.CreateTree(tx, EntryTermsTreeName);
var metadata = _env.CreateTree(tx, MetadataTreeName);
var versionReadResult = metadata.Read("version");
if (versionReadResult == null) // new db
{
metadata.Add("version", Encoding.UTF8.GetBytes(CurrentVersion));
DbId = Guid.NewGuid();
metadata.Add("db-id", DbId.ToByteArray());
metadata.Add("current-term", EndianBitConverter.Little.GetBytes(0L));
metadata.Add("voted-for", Encoding.UTF8.GetBytes(string.Empty));
metadata.Add("voted-for-term", EndianBitConverter.Little.GetBytes(-1L));
metadata.Add("is-leader-potential", EndianBitConverter.Little.GetBytes(0));
}
else
{
var dbVersion = versionReadResult.Reader.ToStringValue();
if (dbVersion != CurrentVersion)
{
throw new InvalidOperationException("Cannot open db because its version is " + dbVersion +
" but the library expects version " + CurrentVersion);
}
int used;
var bytes = metadata.Read("db-id").Reader.ReadBytes(16, out used).Take(16).ToArray();
DbId = new Guid(bytes);
CurrentTerm = metadata.Read("current-term").Reader.ReadLittleEndianInt64();
var votedFor = metadata.Read("voted-for");
VotedFor = votedFor.Reader.Length == 0 ? null : votedFor.Reader.ToStringValue();
var votedForTerm = metadata.Read("voted-for-term");
VotedForTerm = votedForTerm.Reader.ReadLittleEndianInt64();
}
tx.Commit();
}
}
private unsafe void LoadExistingDatabase()
{
var header = stackalloc TransactionHeader[1];
bool hadIntegrityIssues = _journal.RecoverDatabase(header);
if (hadIntegrityIssues)
{
var message = _journal.Files.Count == 0 ? "Unrecoverable database" : "Database recovered partially. Some data was lost.";
_options.InvokeRecoveryError(this, message, null);
}
var entry = _headerAccessor.CopyHeader();
var nextPageNumber = (header->TransactionId == 0 ? entry.LastPageNumber : header->LastPageNumber) + 1;
State = new StorageEnvironmentState(null, nextPageNumber)
{
NextPageNumber = nextPageNumber,
Options = Options
};
_transactionsCounter = (header->TransactionId == 0 ? entry.TransactionId : header->TransactionId);
var transactionPersistentContext = new TransactionPersistentContext(true);
using (var tx = NewLowLevelTransaction(transactionPersistentContext, TransactionFlags.ReadWrite))
{
using (var root = Tree.Open(tx, null, Constants.RootTreeNameSlice, header->TransactionId == 0 ? &entry.Root : &header->Root))
{
tx.UpdateRootsIfNeeded(root);
using (var treesTx = new Transaction(tx))
{
var metadataTree = treesTx.ReadTree(Constants.MetadataTreeNameSlice);
if (metadataTree == null)
{
VoronUnrecoverableErrorException.Raise(this,
"Could not find metadata tree in database, possible mismatch / corruption?");
}
var dbId = metadataTree.Read("db-id");
if (dbId == null)
{
VoronUnrecoverableErrorException.Raise(this,
"Could not find db id in metadata tree, possible mismatch / corruption?");
}
var buffer = new byte[16];
var dbIdBytes = dbId.Reader.Read(buffer, 0, 16);
if (dbIdBytes != 16)
{
VoronUnrecoverableErrorException.Raise(this,
"The db id value in metadata tree wasn't 16 bytes in size, possible mismatch / corruption?");
}
var databseGuidId = _options.GenerateNewDatabaseId == false ? new Guid(buffer) : Guid.NewGuid();
DbId = databseGuidId;
FillBase64Id(databseGuidId);
if (_options.GenerateNewDatabaseId)
{
// save the new database id
metadataTree.Add("db-id", DbId.ToByteArray());
}
var schemaVersion = metadataTree.Read("schema-version");
if (schemaVersion == null)
{
VoronUnrecoverableErrorException.Raise(this,
"Could not find schema version in metadata tree, possible mismatch / corruption?");
}
var schemaVersionVal = schemaVersion.Reader.ReadLittleEndianInt32();
if (Options.SchemaVersion != 0 &&
schemaVersionVal != Options.SchemaVersion)
{
VoronUnrecoverableErrorException.Raise(this,
"The schema version of this database is expected to be " +
Options.SchemaVersion + " but is actually " + schemaVersionVal +
". You need to upgrade the schema.");
}
tx.Commit();
}
}
}
}
