/// <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(LMDBDatabase 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(LMDBDatabase 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(LMDBDatabase 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(LMDBDatabase 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>
/// Creates new instance of LMDBCursor
/// </summary>
/// <param name="db">Database</param>
/// <param name="txn">Transaction</param>
internal LMDBCursor(LMDBDatabase db, LMDBTransaction 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;
}
/// <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(LMDBDatabase db, byte[] key)
{
Lmdb.mdb_del(_handle, db.Handle(), key);
}
