|
public OpenDatabase ( string name = null, |
||
| name | string | Database name (optional). If null then the default name is used. |
| configuration | Database open options. | |
| return | ||
/// <summary>
/// Gets a value by its key.
/// </summary>
/// <typeparam name="TKey">Key type.</typeparam>
/// <param name="txn">Transaction.</param>
/// <param name="key">Key.</param>
/// <returns>Value converter or null if not exists.</returns>
public static GetByOperation GetBy <TKey>(this LightningTransaction txn, TKey key)
{
return(txn.GetBy(txn.OpenDatabase(), key));
}
/// <summary>
/// Put data into a database.
/// </summary>
/// <param name="txn">A transaction</param>
/// <param name="key">Key byte array.</param>
/// <param name="value">Value byte array.</param>
/// <param name="options">Operation options (optional).</param>
public static void Put(this LightningTransaction txn, byte[] key, byte[] value, PutOptions options = PutOptions.None)
{
txn.Put(txn.OpenDatabase(), key, value, options);
}
/// <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="txn">A transaction</param>
/// <param name="key">The key to delete from the database</param>
/// <param name="value">The data to delete (optional)</param>
public static void Delete(this LightningTransaction txn, byte[] key, byte[] value = null)
{
txn.Delete(txn.OpenDatabase(), key, value);
}
/// <summary>
/// Check whether data exists in database.
/// </summary>
/// <param name="txn">A transaction</param>
/// <param name="key">Key.</param>
/// <returns>True if key exists, false if not.</returns>
public static bool ContainsKey(this LightningTransaction txn, byte[] key)
{
return(txn.ContainsKey(txn.OpenDatabase(), key));
}
/// <summary>
/// Gets a cursor to enumerate a whole database not converting key-value pair during the enumeration.
/// </summary>
/// <param name="txn">Transaction.</param>
/// <returns>A database cursor wrapped into. IEnumerable<CursorGetByOperation>.</returns>
public static IEnumerable <CursorGetByOperation> EnumerateDatabase(this LightningTransaction txn)
{
return(txn.EnumerateDatabase(txn.OpenDatabase()));
}
/// <summary>
/// Put a key-value pair into a database.
/// </summary>
/// <typeparam name="TKey">Type of a key.</typeparam>
/// <typeparam name="TValue">Type of a value.</typeparam>
/// <param name="txn">Transaction.</param>
/// <param name="key">Key.</param>
/// <param name="value">Value.</param>
/// <param name="options">Operation options.</param>
public static void Put <TKey, TValue>(this LightningTransaction txn, TKey key, TValue value, PutOptions options = PutOptions.None)
{
txn.Put(txn.OpenDatabase(), value, options);
}
/// <summary>
/// Gets a cursor to enumerate a whole database.
/// </summary>
/// <typeparam name="TKey">Key type.</typeparam>
/// <typeparam name="TValue">Value type.</typeparam>
/// <param name="txn">Transaction.</param>
/// <returns>A database cursor wrapped into IEnumerable<KeyValuePair<TKey, TValue>>.</returns>
public static IEnumerable <KeyValuePair <TKey, TValue> > EnumerateDatabase <TKey, TValue>(this LightningTransaction txn)
{
return(txn.EnumerateDatabase <TKey, TValue>(txn.OpenDatabase()));
}
/// <summary>
/// Deletes data from database by key.
/// </summary>
/// <typeparam name="TKey">Key type.</typeparam>
/// <param name="txn">Transaction.</param>
/// <param name="key">Key.</param>
public static void Delete <TKey>(this LightningTransaction txn, TKey key)
{
txn.Delete(txn.OpenDatabase(), key);
}
/// <summary>
/// Deletes a value from a database for duplicated key values.
/// </summary>
/// <typeparam name="TKey">Key type.</typeparam>
/// <typeparam name="TValue"></typeparam>
/// <param name="txn">Transaction.</param>
/// <param name="key">Key.</param>
/// <param name="value">Value.</param>
public static void Delete <TKey, TValue>(this LightningTransaction txn, TKey key, TValue value)
{
txn.Delete(txn.OpenDatabase(), key, value);
}
/// <summary>
/// Gets a value by its key.
/// </summary>
/// <typeparam name="TKey">Key type.</typeparam>
/// <typeparam name="TValue">Value type.</typeparam>
/// <param name="txn">Transaction.</param>
/// <param name="key">Key.</param>
/// <returns>Value or default(TValue) if not exists.</returns>
public static TValue Get <TKey, TValue>(this LightningTransaction txn, TKey key)
{
return(txn.Get <TKey, TValue>(txn.OpenDatabase(), key));
}
/// <summary>
/// Gets a value by its key as a byte array.
/// </summary>
/// <typeparam name="TKey">Key type.</typeparam>
/// <param name="txn">Transaction.</param>
/// <param name="key">Key.</param>
/// <returns>Value as a byte array or null if not exists.</returns>
public static byte[] GetRawValue <TKey>(this LightningTransaction txn, TKey key)
{
return(txn.GetRawValue(txn.OpenDatabase(), key));
}
/// <summary>
/// Gets and converts a value by its key for key-value pairs of a single type.
/// </summary>
/// <typeparam name="TType">Key and value type.</typeparam>
/// <param name="txn">Transaction.</param>
/// <param name="key">Key.</param>
/// <returns>Value or default(TType) if not exists.</returns>
public static TType Get <TType>(this LightningTransaction txn, TType key)
{
return(txn.Get(txn.OpenDatabase(), key));
}
/// <summary>
/// Tries obtaining a value by key, converting it to a concrete type
/// </summary>
/// <typeparam name="TKey">Type of a key.</typeparam>
/// <typeparam name="TValue">Type to convert value to.</typeparam>
/// <param name="txn">A transaction.</param>
/// <param name="key">Key.</param>
/// <param name="value">Obtained and converted value if successful.</param>
/// <returns>Returns true if key-value pair exists in database or false if not.</returns>
public static bool TryGet <TKey, TValue>(this LightningTransaction txn, TKey key, out TValue value)
{
return(txn.TryGet(txn.OpenDatabase(), key, out value));
}
/// <summary>
/// Get value from a database.
/// </summary>
/// <param name="txn">A transaction</param>
/// <param name="key">Key byte array.</param>
/// <returns>Requested value's byte array if exists, or null if not.</returns>
public static byte[] Get(this LightningTransaction txn, byte[] key)
{
return(txn.Get(txn.OpenDatabase(), key));
}
