/// <summary>
/// Returns the Record at the specified Offset, while also updating Position to match.
/// </summary>
public BtrieveRecord GetRecord(uint offset)
{
Position = offset;
if (_cache.TryGetValue(offset, out var record))
{
return(record);
}
using var cmd = new SqliteCommand($"SELECT data FROM data_t WHERE id = {offset}", _connection);
using var reader = cmd.ExecuteReader(System.Data.CommandBehavior.KeyInfo);
try
{
if (!reader.Read())
{
return(null);
}
using var stream = reader.GetStream(0);
var data = new byte[stream.Length];
stream.Read(data, 0, data.Length);
record = new BtrieveRecord(offset, data);
_cache[offset] = record;
return(record);
}
finally
{
reader.Close();
}
}
/// <summary>
/// Inserts a new Btrieve Record.
/// </summary>
/// <return>Position of the newly inserted item, or 0 on failure</return>
public uint Insert(byte[] record)
{
if (VariableLengthRecords && record.Length != RecordLength)
{
_logger.Warn($"Inserting variable length record of {record.Length} bytes into {FullPath}");
}
if (!VariableLengthRecords && record.Length != RecordLength)
{
_logger.Warn(
$"Btrieve Record Size Mismatch TRUNCATING. Expected Length {RecordLength}, Actual Length {record.Length}");
record = ForceSize(record, RecordLength);
}
using var transaction = _connection.BeginTransaction();
using var insertCmd = new SqliteCommand()
{
Connection = _connection
};
insertCmd.Transaction = transaction;
if (!InsertAutoincrementValues(transaction, record))
{
transaction.Rollback();
return(0);
}
var sb = new StringBuilder("INSERT INTO data_t(data, ");
sb.Append(string.Join(", ", Keys.Values.Select(key => key.SqliteKeyName).ToList()));
sb.Append(") VALUES(@data, ");
sb.Append(string.Join(", ", Keys.Values.Select(key => $"@{key.SqliteKeyName}").ToList()));
sb.Append(");");
insertCmd.CommandText = sb.ToString();
insertCmd.Parameters.AddWithValue("@data", record);
foreach (var key in Keys.Values)
{
insertCmd.Parameters.AddWithValue($"@{key.SqliteKeyName}",
key.ExtractKeyInRecordToSqliteObject(record));
}
int queryResult;
try
{
queryResult = insertCmd.ExecuteNonQuery();
}
catch (SqliteException ex)
{
_logger.Warn(ex, $"{FullPath}: Failed to insert record because {ex.Message}");
transaction.Rollback();
return(0);
}
var lastInsertRowId = Convert.ToUInt32(new SqliteCommand("SELECT last_insert_rowid()", _connection, transaction).ExecuteScalar());
transaction.Commit();
if (queryResult == 0)
{
return(0);
}
_cache[lastInsertRowId] = new BtrieveRecord(lastInsertRowId, record);
return(lastInsertRowId);
}
/// <summary>
/// Updates the Record at the specified Offset.
/// </summary>
public bool Update(uint offset, byte[] recordData)
{
if (VariableLengthRecords && recordData.Length != RecordLength)
{
_logger.Warn($"Updating variable length record of {recordData.Length} bytes into {FullPath}");
}
if (!VariableLengthRecords && recordData.Length != RecordLength)
{
_logger.Warn(
$"Btrieve Record Size Mismatch. Expected Length {RecordLength}, Actual Length {recordData.Length}");
recordData = ForceSize(recordData, RecordLength);
}
using var transaction = _connection.BeginTransaction();
using var updateCmd = new SqliteCommand()
{
Connection = _connection,
Transaction = transaction
};
if (!InsertAutoincrementValues(transaction, recordData))
{
transaction.Rollback();
return(false);
}
var sb = new StringBuilder("UPDATE data_t SET data=@data, ");
sb.Append(
string.Join(", ", Keys.Values.Select(key => $"{key.SqliteKeyName}=@{key.SqliteKeyName}").ToList()));
sb.Append(" WHERE id=@id;");
updateCmd.CommandText = sb.ToString();
updateCmd.Parameters.AddWithValue("@id", offset);
updateCmd.Parameters.AddWithValue("@data", recordData);
foreach (var key in Keys.Values)
{
updateCmd.Parameters.AddWithValue($"@{key.SqliteKeyName}",
key.ExtractKeyInRecordToSqliteObject(recordData));
}
int queryResult;
try
{
queryResult = updateCmd.ExecuteNonQuery();
}
catch (SqliteException ex)
{
_logger.Warn(ex, $"Failed to update record because {ex.Message}");
transaction.Rollback();
return(false);
}
transaction.Commit();
if (queryResult == 0)
{
return(false);
}
_cache[offset] = new BtrieveRecord(offset, recordData);
return(true);
}