|
public Get ( |
||
| db | Database | |
| key | byte | Key byte array. |
| return | byte[] | |
public static TValue Get <TKey, TValue>(this LightningTransaction txn, LightningDatabase db, TKey key)
{
var keyBytes = db.ToBytes(key);
var valueBytes = txn.Get(db, keyBytes);
return(db.FromBytes <TValue>(valueBytes));
}
public static bool TryGet(this LightningTransaction tx, LightningDatabase db, ReadOnlySpan <byte> key, out byte[] value)
{
var(resultCode, _, mdbValue) = tx.Get(db, key);
if (resultCode == MDBResultCode.Success)
{
value = mdbValue.CopyToNewArray();
return(true);
}
value = default;
return(false);
}
public static bool TryGet(this LightningTransaction tx, LightningDatabase db, ReadOnlySpan <byte> key, byte[] destinationValueBuffer)
{
var(resultCode, _, mdbValue) = tx.Get(db, key);
if (resultCode != MDBResultCode.Success)
{
return(false);
}
var valueSpan = mdbValue.AsSpan();
if (valueSpan.TryCopyTo(destinationValueBuffer))
{
return(true);
}
throw new LightningException("Incorrect buffer size given in destinationValueBuffer", (int)MDBResultCode.BadValSize);
}
public static byte[] GetRawValue <TKey>(this LightningTransaction txn, LightningDatabase db, TKey key)
{
var keyBytes = db.ToBytes(key);
return(txn.Get(db, keyBytes));
}
public static TType Get <TType>(this LightningTransaction txn, LightningDatabase db, TType key)
{
return(txn.Get <TType, TType>(db, key));
}
public static bool ContainsKey(this LightningTransaction tx, LightningDatabase db, ReadOnlySpan <byte> key)
{
var(resultCode, _, _) = tx.Get(db, key);
return(resultCode == MDBResultCode.Success);
}
/// <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 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>
/// 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));
}
