public async Task <List <TResult> > ExecuteAsync <TResult>(Func <IQueryable, Task <TResult> > efQuery)
{
if (_mergeContext.Skip.HasValue || _mergeContext.Take.HasValue)
{
throw new InvalidOperationException("aggregate not support skip take");
}
//从各个分表获取数据
List <DbContext> parallelDbContexts = new List <DbContext>(_mergeContext.RouteResults.Count());
try
{
var enumeratorTasks = _mergeContext.RouteResults.Select(routeResult =>
{
return(Task.Run(async() =>
{
var shardingDbContext = _mergeContext.CreateDbContext();
parallelDbContexts.Add(shardingDbContext);
var newQueryable = (IQueryable <T>)_mergeContext.GetReWriteQueryable().ReplaceDbContextQueryable(shardingDbContext);
return await EFCoreExecute(newQueryable, routeResult, efQuery);
}));
}).ToArray();
return((await Task.WhenAll(enumeratorTasks)).ToList());
}
finally
{
parallelDbContexts.ForEach(o => o.Dispose());
}
}
public async Task <IStreamMergeAsyncEnumerator <T> > GetStreamEnumerator()
{
var enumeratorTasks = _mergeContext.RouteResults.Select(routeResult =>
{
return(Task.Run(async() =>
{
var shardingDbContext = _mergeContext.CreateDbContext();
_parallelDbContexts.Add(shardingDbContext);
var newQueryable = (IQueryable <T>)_mergeContext.GetReWriteQueryable().ReplaceDbContextQueryable(shardingDbContext);
var asyncEnumerator = await GetAsyncEnumerator(newQueryable, routeResult);
return new StreamMergeAsyncEnumerator <T>(asyncEnumerator);
}));
}).ToArray();
var streamEnumerators = await Task.WhenAll(enumeratorTasks);
if (_mergeContext.HasSkipTake())
{
return(new NoPaginationStreamMergeEnumerator <T>(_mergeContext, streamEnumerators));
}
if (_mergeContext.HasGroupQuery())
{
return(new MultiAggregateOrderStreamMergeAsyncEnumerator <T>(_mergeContext, streamEnumerators));
}
return(new MultiOrderStreamMergeAsyncEnumerator <T>(_mergeContext, streamEnumerators));
}