/// <summary>
/// 设置连接字符串
/// </summary>
/// <param name="operationType"></param>
/// <returns></returns>
internal string SetConnectionString(OperationType operationType)
{
//写
if (operationType == OperationType.Write)
{
CurrentConnectionString = ConnectionString_Write;
return(CurrentConnectionString);
}
//读
//先校验下次执行的连接字符串
if (!string.IsNullOrEmpty(NextConnectionString))
{
CurrentConnectionString = NextConnectionString;
NextConnectionString = string.Empty;
return(CurrentConnectionString);
}
if (ConnectionStrings_Read == null || !ConnectionStrings_Read.Any())
{
CurrentConnectionString = ConnectionString_Write;
}
else if (ConnectionStrings_Read.Length == 1)
{
CurrentConnectionString = ConnectionStrings_Read[0];
}
else
{
if (connectionStatuses == null)
{
throw new NullReferenceException("Connection status list is null,please call Init() first!");
}
//根据策略选取对应的连接字符串
switch (ConnectionLoadBalanceStrategy)
{
case LoadBalanceStrategy.RoundRobin:
CurrentConnectionString = GetByRoundRobin();
break;
case LoadBalanceStrategy.LeastConnection:
CurrentConnectionString = LeastConnection();
break;
default:
CurrentConnectionString = LeastConnection();
break;
}
}
return(CurrentConnectionString);
}
/// <summary>
/// set ConnectionString currently be used
/// </summary>
/// <param name="operationType"></param>
internal void SetConnectionString(OperationType operationType)
{
//first,Verify the next connection string
if (!string.IsNullOrEmpty(NextConnectionString))
{
CurrentConnectionString = NextConnectionString;
NextConnectionString = string.Empty;
return;
}
//write operation
if (operationType == OperationType.Write)
{
CurrentConnectionString = ConnectionString_Write;
return;
}
//read operation
if (ConnectionStrings_Read == null || !ConnectionStrings_Read.Any())
{
CurrentConnectionString = ConnectionString_Write;
}
else if (ConnectionStrings_Read.Length == 1)
{
CurrentConnectionString = ConnectionStrings_Read[0];
}
else
{
if (connectionStatuses == null)
{
throw new NullReferenceException("Connection status list is null,please call Init() first!");
}
switch (ConnectionLoadBalanceStrategy)
{
case LoadBalanceStrategy.RoundRobin:
CurrentConnectionString = GetByRoundRobin();
break;
case LoadBalanceStrategy.LeastConnection:
CurrentConnectionString = LeastConnection();
break;
default:
CurrentConnectionString = LeastConnection();
break;
}
}
}
internal ConnectionManager(string connectionString_Write, string[] connectionStrings_Read)
{
this.ConnectionString_Write = connectionString_Write;
this.ConnectionStrings_Read = connectionStrings_Read?.Distinct()?.ToArray();
//默认当前连接字符串是写
this.CurrentConnectionString = connectionString_Write;
//初始化
//如果写字符串不需要负载策略，则直接返回
if (ConnectionStrings_Read == null || !ConnectionStrings_Read.Any() || ConnectionStrings_Read.Length == 1)
return;
connectionStatuses = new List<ConnectionStatus>();
//初始化连接使用情况集合
ConnectionStrings_Read.Distinct().ToArray().Foreach(item => connectionStatuses.Add(new ConnectionStatus { HashKey = item.GetHashCode(), ConnectionString = item, Count = 0 }));
}
/// <summary>
/// constructed function
/// </summary>
/// <param name="connectionString_Write">the master Database ConnectionString (Only one)</param>
/// <param name="connectionStrings_Read">the slave Database ConnectionStrings</param>
internal ConnectionManager(string connectionString_Write, string[] connectionStrings_Read)
{
this.ConnectionString_Write = connectionString_Write.ToFormativeConnectionString();
this.ConnectionStrings_Read = connectionStrings_Read?.Select(c => c.ToFormativeConnectionString()).Distinct()?.ToArray();
this.CurrentConnectionString = this.ConnectionString_Write;
//don't need Load Balance Strategy
if (ConnectionStrings_Read == null || !ConnectionStrings_Read.Any() || ConnectionStrings_Read.Length == 1)
{
return;
}
this.connectionStatuses = new List <ConnectionStatus>();
//Initialize connection usage collection
ConnectionStrings_Read.Distinct().ToArray().Foreach(item => connectionStatuses.Add(new ConnectionStatus {
HashKey = item.GetHashCode(), ConnectionString = item, Count = 0
}));
}
