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[英]Failed to allocate a managed memory buffer of 268435456 bytes. The amount of available memory may be low
[英]Dynamics CRM Xrm Tooling error “Failed to allocate a managed memory buffer of 2147483647 bytes.”
我创建了一个XRMTool(WPF),以将Dynamics CRM Online中的数据提取到XML文件。 输出文件可能有一百万行,但是出现以下错误。
无法分配2147483647字节的托管内存缓冲区。 可用内存量可能不足。
我可以添加一些过滤器并减少行数,但是根据应用程序的要求,我必须一次提取至少一个月的数据,大约一百万行。
如何在WPF应用程序中增加内存缓冲区?
以下是我的代码
string fetchaudit = @"<fetch version='1.0' mapping='logical' output-format='xml-platform'>
<entity name='audit'>
<attribute name='action' />
<attribute name='auditid' />
<attribute name='callinguserid' />
<attribute name='objecttypecode' />
<attribute name='createdon' />
<attribute name='objectid' />
<attribute name='objectid' />
<attribute name='operation' />
<attribute name='regardingobjectid' />
<attribute name='transactionid' />
<attribute name='userid' />
<filter type='and'>
<condition attribute='createdon' operator='on-or-after' value='" + Fromdate + @"' />
<condition attribute='createdon' operator='on-or-before' value='" + Todate + @"' />
</filter>
</entity>
</fetch>";
while (true)
{
string xml = CreateXml(fetchaudit, pagingCookie, pageNumber, fetchCount);
RetrieveMultipleRequest fetchRequest1 = new RetrieveMultipleRequest
{
Query = new FetchExpression(xml) // Error occurs here when page number reaches 100
};
EntityCollection returnCollection = ((RetrieveMultipleResponse)_ctrl.CrmConnectionMgr.CrmSvc.Execute(fetchRequest1)).EntityCollection;
// var collection = _ctrl.CrmConnectionMgr.CrmSvc.GetEntityDataByFetchSearchEC(xml);
if (returnCollection != null)
{
if (returnCollection.Entities.Count >= 0)
Entities.AddRange(returnCollection.Entities);
}
if (returnCollection.MoreRecords)
{
pageNumber++;
pagingCookie = returnCollection.PagingCookie;
}
else
{
break;
}
} // end while
我正在使用SDK中的以下方法来分页SampleCode \\ CS \\ GeneralProgramming \\ Queries \\ FetchPagingWithCookie.cs( https://msdn.microsoft.com/zh-cn/library/gg309717.aspx )
如果是这样,则很可能不会在第一个请求上发生异常,从而减少返回的行数。
您当前的问题是您将所有内容存储在内存中,直到检索结束
Entities.AddRange(returnCollection.Entities);
Entities
的集合正在迅速增长,但是添加时并不会失败,因为在实际的SDK检索中会发生内存分配。
要使用DataContractSerializer
将查询结果序列化为单个集合,可以使用下一个IEnumerable实现按包读取数据( 以及代码的更多说明 ):
public class XrmEnumerator<T> : IEnumerator<T> where T : Entity
{
private readonly Queue<T> _collected = new Queue<T>();
private IOrganizationService _service;
private QueryExpression _query;
private string _lastCookie;
private bool _moreRecords;
public T Current { get; private set; }
object IEnumerator.Current => Current;
public XrmEnumerator(IOrganizationService service, QueryExpression query)
{
_service = service;
_query = query;
if (query.PageInfo == null)
query.PageInfo = new PagingInfo
{
Count = 5000,
PageNumber = 1
};
FillThePack();
}
private void FillThePack()
{
var result = _service.RetrieveMultiple(_query);
_lastCookie = result.PagingCookie;
result.Entities.ToList().ForEach(e=>_collected.Enqueue(e.ToEntity<T>()));
_moreRecords = result.MoreRecords;
}
public void Dispose()
{
_service = null;
_query = null;
}
public bool MoveNext()
{
if(_collected.Count == 0)
{
if (!_moreRecords)
{
return false;
}
_query.PageInfo.PagingCookie = _lastCookie;
_query.PageInfo.PageNumber++;
FillThePack();
}
Current = _collected.Dequeue();
return true;
}
public void Reset()
{
_query.PageInfo.PagingCookie = string.Empty;
_query.PageInfo.PageNumber = 1;
}
}
public class XrmEnumerable<T> : IEnumerable<T> where T : Entity
{
private readonly XrmEnumerator<T> _enumerator;
public XrmEnumerable(IOrganizationService service, QueryExpression query)
{
_enumerator = new XrmEnumerator<T>(service, query);
}
public IEnumerator<T> GetEnumerator() => _enumerator;
IEnumerator IEnumerable.GetEnumerator()
{
return _enumerator;
}
public virtual void Add(T entity)
{
// do your code on item deserialization
}
}
它使用QueryExpression
而不是FetchXml
,但是您可以轻松地将其转换
用法样本:
var enumerable = new XrmEnumerable<Contact>(service, query);
var serializer = new DataContractSerializer(typeof(XrmEnumerable<Contact>));
using (var file = File.OpenWrite("contacts.xml"))
serializer.WriteObject(file, enumerable);
另外,您可以创建XrmEnumerable
的子类,并在Add
函数中执行逻辑
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