Line data    Source code

       1             : #pragma once
       2             : 
       3             : #include <memory>
       4             : 
       5             : #include "envoy/common/exception.h"
       6             : #include "envoy/common/pure.h"
       7             : 
       8             : #include "source/common/common/assert.h"
       9             : 
      10             : namespace Envoy {
      11             : namespace Server {
      12             : 
      13             : // Struct for reporting usage for a particular resource.
      14             : struct ResourceUsage {
      15           0 :   bool operator==(const ResourceUsage& rhs) const {
      16           0 :     return resource_pressure_ == rhs.resource_pressure_;
      17           0 :   }
      18             : 
      19             :   // Fraction of (resource usage)/(resource limit).
      20             :   double resource_pressure_;
      21             : };
      22             : 
      23             : /**
      24             :  * Notifies caller of updated resource usage.
      25             :  */
      26             : class ResourceUpdateCallbacks {
      27             : public:
      28           0 :   virtual ~ResourceUpdateCallbacks() = default;
      29             : 
      30             :   /**
      31             :    * Called when the request for updated resource usage succeeds.
      32             :    * @param usage the updated resource usage
      33             :    */
      34             :   virtual void onSuccess(const ResourceUsage& usage) PURE;
      35             : 
      36             :   /**
      37             :    * Called when the request for updated resource usage fails.
      38             :    * @param error the exception caught when trying to get updated resource usage
      39             :    */
      40             :   virtual void onFailure(const EnvoyException& error) PURE;
      41             : };
      42             : 
      43             : class ResourceMonitor {
      44             : public:
      45           0 :   virtual ~ResourceMonitor() = default;
      46             : 
      47             :   /**
      48             :    * Recalculate resource usage.
      49             :    * This must be non-blocking so if RPCs need to be made they should be
      50             :    * done asynchronously and invoke the callback when finished.
      51             :    */
      52             :   virtual void updateResourceUsage(ResourceUpdateCallbacks& callbacks) PURE;
      53             : };
      54             : 
      55             : using ResourceMonitorPtr = std::unique_ptr<ResourceMonitor>;
      56             : 
      57             : } // namespace Server
      58             : } // namespace Envoy