using System.Text;
using ConsoleApp2.Helpers;
using Microsoft.Extensions.Logging;
using MySqlConnector;
namespace ConsoleApp2.Services;
///
/// Mysql导出
///
public class MySqlDestination : IDisposable, IAsyncDisposable
{
private readonly Dictionary> _recordCache;
private readonly MySqlConnection _conn;
private readonly ILogger _logger;
private readonly bool _prettyOutput;
public MySqlDestination(string connStr, ILogger logger, bool prettyOutput = false)
{
_conn = new MySqlConnection(connStr);
_conn.Open();
_recordCache = new Dictionary>();
_logger = logger;
_prettyOutput = prettyOutput;
}
public Task WriteRecordAsync(DataRecord record)
{
_recordCache.AddOrUpdate(record.TableName, [record], (key, value) =>
{
value.Add(record);
return value;
});
return Task.CompletedTask;
}
public async Task WriteRecordsAsync(IEnumerable records)
{
foreach (var record in records)
{
await WriteRecordAsync(record);
}
}
public async Task FlushAsync()
{
if (_recordCache.Count == 0)
return;
var cmd = _conn.CreateCommand();
cmd.CommandText = SerializeRecords(_recordCache, _prettyOutput);
try
{
await cmd.ExecuteNonQueryAsync();
_recordCache.Clear();
}
catch (Exception e)
{
_logger.LogCritical(e, "Error when flushing records, sql: {Sql}", cmd.CommandText.Omit(1000));
throw;
}
finally
{
await cmd.DisposeAsync();
}
}
public static string SerializeRecords(IDictionary> tableRecords,
bool prettyOutput = false)
{
var sb = new StringBuilder();
foreach (var (tableName, records) in tableRecords)
{
if (records.Count == 0)
continue;
sb.Append($"INSERT INTO `{tableName}`(");
for (var i = 0; i < records[0].Headers.Length; i++)
{
var header = records[0].Headers[i];
sb.Append($"`{header}`");
if (i != records[0].Headers.Length - 1)
sb.Append(',');
}
sb.Append(") VALUES ");
if (prettyOutput)
sb.AppendLine();
for (var i = 0; i < records.Count; i++)
{
var record = records[i];
sb.Append('(');
for (var j = 0; j < record.Fields.Length; j++)
{
var field = record.Fields[j];
sb.Append(field);
if (j != record.Fields.Length - 1)
sb.Append(',');
}
sb.Append(')');
if (i != records.Count - 1) // not last field
sb.Append(',');
if (prettyOutput) sb.AppendLine();
}
sb.AppendLine(";");
}
return sb.ToString();
}
public void Dispose()
{
_conn.Close();
_conn.Dispose();
}
public async ValueTask DisposeAsync()
{
await _conn.CloseAsync();
await _conn.DisposeAsync();
}
}