XrdRequest.h

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#ifndef Utilities_XrdAdaptor_XrdRequest_h
#define Utilities_XrdAdaptor_XrdRequest_h
 
#include <future>
#include <vector>
 
#include <boost/utility.hpp>
#include <XrdCl/XrdClXRootDResponses.hh>
 
#include "Utilities/StorageFactory/interface/Storage.h"
#include "FWCore/Utilities/interface/get_underlying_safe.h"
 
#include "QualityMetric.h"
 
namespace XrdAdaptor {
 
  class Source;
 
  class RequestManager;
 
  class XrdReadStatistics;
 
  class ClientRequest : boost::noncopyable, public XrdCl::ResponseHandler {
    friend class Source;
 
  public:
    ClientRequest(RequestManager &manager, void *into, IOSize size, IOOffset off)
        : m_failure_count(0), m_into(into), m_size(size), m_off(off), m_iolist(nullptr), m_manager(manager) {}
 
    ClientRequest(RequestManager &manager, std::shared_ptr<std::vector<IOPosBuffer>> iolist, IOSize size = 0)
        : m_failure_count(0), m_into(nullptr), m_size(size), m_off(0), m_iolist(iolist), m_manager(manager) {
      if (!m_iolist->empty() && !m_size) {
        for (IOPosBuffer const &buf : *m_iolist) {
          m_size += buf.size();
        }
      }
    }
 
    void setStatistics(std::shared_ptr<XrdReadStatistics> stats) { m_stats = stats; }
 
    ~ClientRequest() override;
 
    std::future<IOSize> get_future() { return m_promise.get_future(); }
 
    void HandleResponse(XrdCl::XRootDStatus *status, XrdCl::AnyObject *response) override;
 
    IOSize getSize() const { return m_size; }
 
    size_t getCount() const { return m_into ? 1 : m_iolist->size(); }
 
    std::shared_ptr<Source const> getCurrentSource() const { return get_underlying_safe(m_source); }
    std::shared_ptr<Source> &getCurrentSource() { return get_underlying_safe(m_source); }
 
  private:
    std::shared_ptr<ClientRequest const> self_reference() const { return get_underlying_safe(m_self_reference); }
    std::shared_ptr<ClientRequest> &self_reference() { return get_underlying_safe(m_self_reference); }
 
    unsigned m_failure_count;
    void *m_into;
    IOSize m_size;
    IOOffset m_off;
    edm::propagate_const<std::shared_ptr<std::vector<IOPosBuffer>>> m_iolist;
    RequestManager &m_manager;
    edm::propagate_const<std::shared_ptr<Source>> m_source;
    edm::propagate_const<std::shared_ptr<XrdReadStatistics>> m_stats;
 
    // Some explanation is due here.  When an IO is outstanding,
    // Xrootd takes a raw pointer to this object.  Hence we cannot
    // allow it to go out of scope until some indeterminate time in the
    // future.  So, while the IO is outstanding, we take a reference to
    // ourself to prevent the object from being unexpectedly deleted.
    edm::propagate_const<std::shared_ptr<ClientRequest>> m_self_reference;
 
    std::promise<IOSize> m_promise;
 
    QualityMetricWatch m_qmw;
  };
 
}  // namespace XrdAdaptor
 
#endif