public bool WriteQueryCommand(ref CommandListPosition commandListPosition, IDictionary <string, CachedProcedure?> cachedProcedures, ByteBufferWriter writer)
{
writer.Write((byte)CommandKind.Multi);
bool?firstResult = default;
bool wroteCommand;
do
{
// save room for command length
var position = writer.Position;
writer.Write(Padding);
wroteCommand = SingleCommandPayloadCreator.Instance.WriteQueryCommand(ref commandListPosition, cachedProcedures, writer);
if (firstResult is null)
{
firstResult = wroteCommand;
}
// write command length
var commandLength = writer.Position - position - Padding.Length;
var span = writer.ArraySegment.AsSpan().Slice(position);
span[0] = 0xFE;
BinaryPrimitives.WriteUInt64LittleEndian(span.Slice(1), (ulong)commandLength);
} while (wroteCommand);
// remove the padding that was saved for the final command (which wasn't written)
writer.TrimEnd(Padding.Length);
return(firstResult.Value);
}
public bool WriteQueryCommand(ref CommandListPosition commandListPosition, IDictionary <string, CachedProcedure> cachedProcedures, ByteBufferWriter writer)
{
if (commandListPosition.CommandIndex == commandListPosition.Commands.Count)
{
return(false);
}
var command = commandListPosition.Commands[commandListPosition.CommandIndex];
var preparedStatements = command.TryGetPreparedStatements();
if (preparedStatements is null)
{
if (Log.IsDebugEnabled())
{
Log.Debug("Session{0} Preparing command payload; CommandText: {1}", command.Connection.Session.Id, command.CommandText);
}
if (command.CommandType == CommandType.StoredProcedure)
{
WriteStoredProcedure(command, cachedProcedures, writer);
}
else
{
WriteCommand(command, writer);
}
commandListPosition.CommandIndex++;
}
else
{
WritePreparedStatement(command, preparedStatements.Statements[commandListPosition.PreparedStatementIndex], writer);
// advance to next prepared statement or next command
if (++commandListPosition.PreparedStatementIndex == preparedStatements.Statements.Count)
{
commandListPosition.CommandIndex++;
commandListPosition.PreparedStatementIndex = 0;
}
}
return(true);
}
public bool WriteQueryCommand(ref CommandListPosition commandListPosition, IDictionary <string, CachedProcedure?> cachedProcedures, ByteBufferWriter writer)
{
if (commandListPosition.CommandIndex == commandListPosition.Commands.Count)
{
return(false);
}
writer.Write((byte)CommandKind.Query);
bool isComplete;
do
{
var command = commandListPosition.Commands[commandListPosition.CommandIndex];
if (Log.IsTraceEnabled())
{
Log.Trace("Session{0} Preparing command payload; CommandText: {1}", command.Connection !.Session.Id, command.CommandText);
}
isComplete = SingleCommandPayloadCreator.WriteQueryPayload(command, cachedProcedures, writer);
commandListPosition.CommandIndex++;
}while (commandListPosition.CommandIndex < commandListPosition.Commands.Count && isComplete);
return(true);
}
public bool WriteQueryCommand(ref CommandListPosition commandListPosition, IDictionary <string, CachedProcedure?> cachedProcedures, ByteBufferWriter writer)
{
if (commandListPosition.CommandIndex == commandListPosition.Commands.Count)
{
return(false);
}
var command = commandListPosition.Commands[commandListPosition.CommandIndex];
var preparedStatements = command.TryGetPreparedStatements();
if (preparedStatements is null)
{
if (Log.IsTraceEnabled())
{
Log.Trace("Session{0} Preparing command payload; CommandText: {1}", command.Connection !.Session.Id, command.CommandText);
}
writer.Write((byte)CommandKind.Query);
WriteQueryPayload(command, cachedProcedures, writer);
commandListPosition.CommandIndex++;
}
else
{
writer.Write((byte)CommandKind.StatementExecute);
WritePreparedStatement(command, preparedStatements.Statements[commandListPosition.PreparedStatementIndex], writer);
// advance to next prepared statement or next command
if (++commandListPosition.PreparedStatementIndex == preparedStatements.Statements.Count)
{
commandListPosition.CommandIndex++;
commandListPosition.PreparedStatementIndex = 0;
}
}
return(true);
}
public static async Task <DbDataReader> ExecuteReaderAsync(IReadOnlyList <IMySqlCommand> commands, ICommandPayloadCreator payloadCreator, CommandBehavior behavior, IOBehavior ioBehavior, CancellationToken cancellationToken)
{
cancellationToken.ThrowIfCancellationRequested();
var commandListPosition = new CommandListPosition(commands);
var command = commands[0];
// pre-requisite: Connection is non-null must be checked before calling this method
var connection = command.Connection !;
if (Log.IsDebugEnabled())
{
Log.Debug("Session{0} ExecuteReader {1} CommandCount: {2}", connection.Session.Id, ioBehavior, commands.Count);
}
Dictionary <string, CachedProcedure?>?cachedProcedures = null;
foreach (var command2 in commands)
{
if (command2.CommandType == CommandType.StoredProcedure)
{
cachedProcedures ??= new Dictionary <string, CachedProcedure?>();
var commandText = command2.CommandText !;
if (!cachedProcedures.ContainsKey(commandText))
{
cachedProcedures.Add(commandText, await connection.GetCachedProcedure(ioBehavior, commandText, cancellationToken).ConfigureAwait(false));
// because the connection was used to execute a MySqlDataReader with the connection's DefaultCommandTimeout,
// we need to reapply the command's CommandTimeout (even if some of the time has elapsed)
command.CancellableCommand.ResetCommandTimeout();
}
}
}
var writer = new ByteBufferWriter();
// cachedProcedures will be non-null if there is a stored procedure, which is also the only time it will be read
if (!payloadCreator.WriteQueryCommand(ref commandListPosition, cachedProcedures !, writer))
{
throw new InvalidOperationException("ICommandPayloadCreator failed to write query payload");
}
cancellationToken.ThrowIfCancellationRequested();
using var payload = writer.ToPayloadData();
using var registration = command.CancellableCommand.RegisterCancel(cancellationToken);
connection.Session.StartQuerying(command.CancellableCommand);
command.SetLastInsertedId(-1);
try
{
await connection.Session.SendAsync(payload, ioBehavior, CancellationToken.None).ConfigureAwait(false);
return(await MySqlDataReader.CreateAsync(commandListPosition, payloadCreator, cachedProcedures, command, behavior, ioBehavior, cancellationToken).ConfigureAwait(false));
}
catch (MySqlException ex) when(ex.Number == (int)MySqlErrorCode.QueryInterrupted && cancellationToken.IsCancellationRequested)
{
Log.Warn("Session{0} query was interrupted", connection.Session.Id);
throw new OperationCanceledException(cancellationToken);
}
catch (Exception ex) when(payload.Span.Length > 4_194_304 && (ex is SocketException || ex is IOException || ex is MySqlProtocolException))
{
// the default MySQL Server value for max_allowed_packet (in MySQL 5.7) is 4MiB: https://dev.mysql.com/doc/refman/5.7/en/server-system-variables.html#sysvar_max_allowed_packet
// use "decimal megabytes" (to round up) when creating the exception message
int megabytes = payload.Span.Length / 1_000_000;
throw new MySqlException("Error submitting {0}MB packet; ensure 'max_allowed_packet' is greater than {0}MB.".FormatInvariant(megabytes), ex);
}
}
public static async Task <DbDataReader> ExecuteReaderAsync(IReadOnlyList <IMySqlCommand> commands, ICommandPayloadCreator payloadCreator, CommandBehavior behavior, IOBehavior ioBehavior, CancellationToken cancellationToken)
{
cancellationToken.ThrowIfCancellationRequested();
var commandListPosition = new CommandListPosition(commands);
var command = commands[0];
if (Log.IsDebugEnabled())
{
Log.Debug("Session{0} ExecuteReader {1} CommandCount: {2}", command.Connection.Session.Id, ioBehavior, commands.Count);
}
Dictionary <string, CachedProcedure> cachedProcedures = null;
foreach (var command2 in commands)
{
if (command2.CommandType == CommandType.StoredProcedure)
{
if (cachedProcedures is null)
{
cachedProcedures = new Dictionary <string, CachedProcedure>();
}
if (!cachedProcedures.ContainsKey(command2.CommandText))
{
cachedProcedures.Add(command2.CommandText, await command2.Connection.GetCachedProcedure(ioBehavior, command2.CommandText, cancellationToken).ConfigureAwait(false));
}
}
}
var writer = new ByteBufferWriter();
if (!payloadCreator.WriteQueryCommand(ref commandListPosition, cachedProcedures, writer))
{
throw new InvalidOperationException("ICommandPayloadCreator failed to write query payload");
}
cancellationToken.ThrowIfCancellationRequested();
using (var payload = writer.ToPayloadData())
using (command.CancellableCommand.RegisterCancel(cancellationToken))
{
command.Connection.Session.StartQuerying(command.CancellableCommand);
command.SetLastInsertedId(-1);
try
{
await command.Connection.Session.SendAsync(payload, ioBehavior, CancellationToken.None).ConfigureAwait(false);
return(await MySqlDataReader.CreateAsync(commandListPosition, payloadCreator, cachedProcedures, command, behavior, ioBehavior, cancellationToken).ConfigureAwait(false));
}
catch (MySqlException ex) when(ex.Number == (int)MySqlErrorCode.QueryInterrupted && cancellationToken.IsCancellationRequested)
{
Log.Warn("Session{0} query was interrupted", command.Connection.Session.Id);
throw new OperationCanceledException(cancellationToken);
}
catch (Exception ex) when(payload.ArraySegment.Count > 4_194_304 && (ex is SocketException || ex is IOException || ex is MySqlProtocolException))
{
// the default MySQL Server value for max_allowed_packet (in MySQL 5.7) is 4MiB: https://dev.mysql.com/doc/refman/5.7/en/server-system-variables.html#sysvar_max_allowed_packet
// use "decimal megabytes" (to round up) when creating the exception message
int megabytes = payload.ArraySegment.Count / 1_000_000;
throw new MySqlException("Error submitting {0}MB packet; ensure 'max_allowed_packet' is greater than {0}MB.".FormatInvariant(megabytes), ex);
}
}
}
