/// <summary>
/// Opens a database in context of this transaction.
/// </summary>
/// <param name="name">Database name (optional). If null then the default name is used.</param>
/// <param name="configuration">Database open options.</param>
/// <returns>Created database wrapper.</returns>
public LightningDatabase OpenDatabase(string name = null, DatabaseConfiguration configuration = null)
{
configuration = configuration ?? new DatabaseConfiguration();
var db = new LightningDatabase(name, this, configuration);
return(db);
}
/// <summary>
/// The number of items in the database.
/// </summary>
/// <param name="db">The database we are counting items in.</param>
/// <returns>The number of items.</returns>
public long GetEntriesCount(LightningDatabase db)
{
MDBStat stat;
Lmdb.mdb_stat(_handle, db.Handle(), out stat);
return(stat.ms_entries.ToInt64());
}
/// <summary>
/// Delete items from a database.
/// This function removes key/data pairs from the database.
/// If the database does not support sorted duplicate data items (MDB_DUPSORT) the data parameter is ignored.
/// If the database supports sorted duplicates and the data parameter is NULL, all of the duplicate data items for the key will be deleted.
/// Otherwise, if the data parameter is non-NULL only the matching data item will be deleted.
/// This function will return MDB_NOTFOUND if the specified key/data pair is not in the database.
/// </summary>
/// <param name="db">A database handle returned by mdb_dbi_open()</param>
/// <param name="key">The key to delete from the database</param>
/// <param name="value">The data to delete (optional)</param>
public void Delete(LightningDatabase db, byte[] key, byte[] value)
{
if (db == null)
{
throw new ArgumentNullException(nameof(db));
}
Lmdb.mdb_del(_handle, db.Handle(), key, value);
}
/// <summary>
/// Put data into a database.
/// </summary>
/// <param name="db">Database.</param>
/// <param name="key">Key byte array.</param>
/// <param name="value">Value byte array.</param>
/// <param name="options">Operation options (optional).</param>
public void Put(LightningDatabase db, byte[] key, byte[] value, PutOptions options = PutOptions.None)
{
if (db == null)
{
throw new ArgumentNullException(nameof(db));
}
Lmdb.mdb_put(_handle, db.Handle(), key, value, options);
}
/// <summary>
/// Tries to get a value by its key.
/// </summary>
/// <param name="db">Database.</param>
/// <param name="key">Key byte array.</param>
/// <param name="value">Value byte array if exists.</param>
/// <returns>True if key exists, false if not.</returns>
public bool TryGet(LightningDatabase db, byte[] key, out byte[] value)
{
if (db == null)
{
throw new ArgumentNullException(nameof(db));
}
return(Lmdb.mdb_get(_handle, db.Handle(), key, out value) != Lmdb.MDB_NOTFOUND);
}
/// <summary>
/// Check whether data exists in database.
/// </summary>
/// <param name="db">Database.</param>
/// <param name="key">Key.</param>
/// <returns>True if key exists, false if not.</returns>
public bool ContainsKey(LightningDatabase db, byte[] key)
{
if (db == null)
{
throw new ArgumentNullException(nameof(db));
}
byte[] value;
return(TryGet(db, key, out value));
}
public long GetUsedSize(LightningDatabase db)
{
if (db == null)
{
throw new ArgumentNullException(nameof(db));
}
MDBStat stat;
Lmdb.mdb_stat(_handle, db.Handle(), out stat);
return(stat.ms_psize *
(stat.ms_leaf_pages.ToInt64() + stat.ms_branch_pages.ToInt64() +
stat.ms_overflow_pages.ToInt64()));
}
/// <summary>
/// Creates new instance of LightningCursor
/// </summary>
/// <param name="db">Database</param>
/// <param name="txn">Transaction</param>
internal LightningCursor(LightningDatabase db, LightningTransaction txn)
{
if (db == null)
{
throw new ArgumentNullException(nameof(db));
}
if (txn == null)
{
throw new ArgumentNullException(nameof(txn));
}
Lmdb.mdb_cursor_open(txn.Handle(), db.Handle(), out _handle);
Transaction = txn;
Transaction.Disposing += Dispose;
}
internal IDisposable ConfigureDatabase(LightningTransaction tx, LightningDatabase db)
{
var pinnedComparer = new ComparerKeepAlive();
if (_comparer != null)
{
CompareFunction compare = Compare;
pinnedComparer.AddComparer(compare);
Lmdb.mdb_set_compare(tx.Handle(), db.Handle(), compare);
}
if (_duplicatesComparer != null)
{
CompareFunction dupCompare = IsDuplicate;
pinnedComparer.AddComparer(dupCompare);
Lmdb.mdb_set_dupsort(tx.Handle(), db.Handle(), dupCompare);
}
return(pinnedComparer);
}
public LightningStats GetStats(LightningDatabase db)
{
if (db == null)
{
throw new ArgumentNullException(nameof(db));
}
MDBStat stat;
Lmdb.mdb_stat(_handle, db.Handle(), out stat);
var bytes = stat.ms_psize *
(stat.ms_leaf_pages.ToInt64() + stat.ms_branch_pages.ToInt64() +
stat.ms_overflow_pages.ToInt64());
return(new LightningStats()
{
UsedBytes = bytes,
BTreeDepth = stat.ms_depth,
EntryCount = stat.ms_entries.ToInt64()
});
}
/// <summary>
/// Delete items from a database.
/// This function removes key/data pairs from the database.
/// If the database does not support sorted duplicate data items (MDB_DUPSORT) the data parameter is ignored.
/// If the database supports sorted duplicates and the data parameter is NULL, all of the duplicate data items for the key will be deleted.
/// Otherwise, if the data parameter is non-NULL only the matching data item will be deleted.
/// This function will return MDB_NOTFOUND if the specified key/data pair is not in the database.
/// </summary>
/// <param name="db">A database handle returned by mdb_dbi_open()</param>
/// <param name="key">The key to delete from the database</param>
public void Delete(LightningDatabase db, byte[] key)
{
Lmdb.mdb_del(_handle, db.Handle(), key);
}
/// <summary>
/// Get value from a database.
/// </summary>
/// <param name="db">Database </param>
/// <param name="key">Key byte array.</param>
/// <returns>Requested value's byte array if exists, or null if not.</returns>
public byte[] Get(LightningDatabase db, byte[] key)
{
byte[] value;
TryGet(db, key, out value);
return(value);
}
/// <summary>
/// Create a cursor.
/// Cursors are associated with a specific transaction and database and may not span threads.
/// </summary>
/// <param name="db">A database.</param>
public LightningCursor CreateCursor(LightningDatabase db)
{
return(new LightningCursor(db, this));
}
/// <summary>
/// Truncates all data from the database.
/// </summary>
public void TruncateDatabase(LightningDatabase database)
{
database.Truncate(this);
}
/// <summary>
/// Drops the database.
/// </summary>
public void DropDatabase(LightningDatabase database)
{
database.Drop(this);
}
