我正在使用 azure 表存储,并且正在尝试快速迭代表。
我一定是做错了,但我终生无法明白为什么;
当我只指定一个分区时,我最终会得到 MULTIPLE 分区的结果。即,如果我只使用“pkey1”来约束查询,我会为“pkey1”返回 1000 个结果,然后为“pkey2”返回 325 个结果
完全困惑这怎么会发生..
这是我正在使用的代码:
private CloudTableClient _client;
private string _tableName;
private class QueryState
{
public CloudTableQuery<T> Ctq;
public Action<IEnumerable<T>> Populator;
public ManualResetEvent Mre;
public string Pkey;
public QueryState(CloudTableQuery<T> ctq, Action<IEnumerable<T>> populator, ManualResetEvent mre, string pkey)
{
Populator = populator;
Ctq = ctq;
Mre = mre;
Pkey = pkey;
}
}
public void ParallelQueryWithClause(Action<IEnumerable<T>> populator, string[] partitionKeys)
{
List<ManualResetEvent> mre = new List<ManualResetEvent>();
foreach (string pKey in partitionKeys)
{
//_retry.Go(tsc =>
// {
TableServiceContext tsc = _client.GetDataServiceContext();
ManualResetEvent m = new ManualResetEvent(false);
mre.Add(m);
CloudTableQuery<T> query = tsc.CreateQuery<T>(_tableName).Where(e => e.PartitionKey == pKey).AsTableServiceQuery<T>();
Action<IAsyncResult> act = null;
act = result =>
{
int retries = 0;
while (retries++ < 5)
{
try
{
QueryState qsInternal = result.AsyncState as QueryState;
CloudTableQuery<T> ctq = qsInternal.Ctq;
ResultSegment<T> seg = ctq.EndExecuteSegmented(result);
if (seg.Results.Count() > 0)
populator(seg.Results);
if (seg.ContinuationToken != null)
{
ctq.BeginExecuteSegmented(seg.ContinuationToken, iasync => act(iasync), qsInternal);
}
else
{
m.Set();
}
break;
}
catch(Exception ex)
{
Logger.LogError(ex);
}
}
};
query.BeginExecuteSegmented(iasync => act(iasync), new QueryState(query, populator, m, pKey));
//});
}
ManualResetEvent.WaitAll(mre.ToArray());
}
和示例调用代码:
AzureTableStorage<ProductEntity> _ats = new AzureTableStorage<ProductEntity>("Products");
string[] partitions = new string[] { "pkey1" };
Dictionary<string, int> cntr = new Dictionary<string, int>();
_ats.ParallelQueryWithClause(p =>
{
lock (cntr)
{
foreach (ProductEntity pe in p)
{
if (cntr.ContainsKey(pe.PartitionKey))
cntr[pe.PartitionKey]++;
else
cntr.Add(pe.PartitionKey, 1);
}
}
}, partitions);
希望这是有道理的,有人可以提供帮助!