blob: 099cd7c7bd809bead2760061ac096be522367f21 [file] [log] [blame]
#pragma once
#include "data_types.hpp"
#include <chrono>
#include <cstddef>
#include <sdeventplus/clock.hpp>
#include <sdeventplus/event.hpp>
#include <sdeventplus/utility/timer.hpp>
namespace phosphor
{
namespace dbus
{
namespace monitoring
{
/** @class Callback
* @brief Callback interface.
*
* Callbacks of any type can be run.
*/
class Callback
{
public:
Callback() = default;
Callback(const Callback&) = delete;
Callback(Callback&&) = default;
Callback& operator=(const Callback&) = delete;
Callback& operator=(Callback&&) = default;
virtual ~Callback() = default;
/** @brief Run the callback.
* @param[in] ctx - caller context
* Context could be Startup or Signal
* Startup: Callback is called as part of process startup.
* Signal: Callback is called as part of watch condition has been met.
*
*/
virtual void operator()(Context ctx) = 0;
/** @brief Run the callback.
* @param[in] ctx - caller context
* Context could be Startup or Signal
* Startup: Callback is called as part of process startup.
* Signal: Callback is called as part of watch condition has been met.
* @param[in] msg - The sdbusplus signal message
*/
virtual void operator()(Context ctx, sdbusplus::message::message& msg){};
};
/** @class Conditional
* @brief Condition interface.
*
* Conditions of any type can be tested for true or false.
*/
class Conditional
{
public:
Conditional() = default;
Conditional(const Conditional&) = delete;
Conditional(Conditional&&) = default;
Conditional& operator=(const Conditional&) = delete;
Conditional& operator=(Conditional&&) = default;
virtual ~Conditional() = default;
/** @brief Test the condition. */
virtual bool operator()() = 0;
};
/** @class IndexedConditional
* @brief Condition with an index.
*/
class IndexedConditional : public Conditional
{
public:
IndexedConditional() = delete;
IndexedConditional(const IndexedConditional&) = delete;
IndexedConditional(IndexedConditional&&) = default;
IndexedConditional& operator=(const IndexedConditional&) = delete;
IndexedConditional& operator=(IndexedConditional&&) = default;
virtual ~IndexedConditional() = default;
explicit IndexedConditional(const PropertyIndex& conditionIndex) :
Conditional(), index(conditionIndex)
{
}
/** @brief Test the condition. */
virtual bool operator()() override = 0;
protected:
/** @brief Property names and their associated storage. */
const PropertyIndex& index;
};
/** @class IndexedCallback
* @brief Callback with an index.
*/
class IndexedCallback : public Callback
{
public:
IndexedCallback() = delete;
IndexedCallback(const IndexedCallback&) = delete;
IndexedCallback(IndexedCallback&&) = default;
IndexedCallback& operator=(const IndexedCallback&) = delete;
IndexedCallback& operator=(IndexedCallback&&) = default;
virtual ~IndexedCallback() = default;
explicit IndexedCallback(const PropertyIndex& callbackIndex) :
Callback(), index(callbackIndex)
{
}
/** @brief Run the callback. */
virtual void operator()(Context ctx) override = 0;
protected:
/** @brief Property names and their associated storage. */
const PropertyIndex& index;
};
/** @class GroupOfCallbacks
* @brief Invoke multiple callbacks.
*
* A group of callbacks is implemented as a vector of array indices
* into an external array of callbacks. The group function call
* operator traverses the vector of indices, invoking each
* callback.
*
* @tparam CallbackAccess - Access to the array of callbacks.
*/
template <typename CallbackAccess>
class GroupOfCallbacks : public Callback
{
public:
GroupOfCallbacks() = delete;
GroupOfCallbacks(const GroupOfCallbacks&) = delete;
GroupOfCallbacks(GroupOfCallbacks&&) = default;
GroupOfCallbacks& operator=(const GroupOfCallbacks&) = delete;
GroupOfCallbacks& operator=(GroupOfCallbacks&&) = default;
~GroupOfCallbacks() = default;
explicit GroupOfCallbacks(const std::vector<size_t>& graphEntry) :
graph(graphEntry)
{
}
/** @brief Run the callbacks. */
void operator()(Context ctx) override
{
for (auto e : graph)
{
(*CallbackAccess::get()[e])(ctx);
}
}
private:
/** @brief The offsets of the callbacks in the group. */
const std::vector<size_t>& graph;
};
/** @class ConditionalCallback
* @brief Callback adaptor that asssociates a condition with a callback.
*/
template <typename CallbackAccess>
class ConditionalCallback : public Callback
{
public:
ConditionalCallback() = delete;
ConditionalCallback(const ConditionalCallback&) = delete;
ConditionalCallback(ConditionalCallback&&) = default;
ConditionalCallback& operator=(const ConditionalCallback&) = delete;
ConditionalCallback& operator=(ConditionalCallback&&) = default;
virtual ~ConditionalCallback() = default;
ConditionalCallback(const std::vector<size_t>& graphEntry,
Conditional& cond) :
graph(graphEntry),
condition(cond)
{
}
/** @brief Run the callback if the condition is satisfied. */
virtual void operator()(Context ctx) override
{
if (condition())
{
(*CallbackAccess::get()[graph[0]])(ctx);
}
}
protected:
/** @brief The index of the callback to conditionally invoke. */
const std::vector<size_t>& graph;
/** @brief The condition to test. */
Conditional& condition;
};
/** @class DeferrableCallback
*
* Deferrable callbacks wait a configurable period before
* invoking their associated callback.
*
* When the callback condition is initially met, start a timer. If the
* condition is tested again before the timer expires and it is not
* met cancel the timer. If the timer expires invoke the associated
* callback.
*
* @tparam CallbackAccess - Provide access to callback group instances.
*/
template <typename CallbackAccess>
class DeferrableCallback : public ConditionalCallback<CallbackAccess>
{
public:
using TimerType =
sdeventplus::utility::Timer<sdeventplus::ClockId::Monotonic>;
DeferrableCallback() = delete;
DeferrableCallback(const DeferrableCallback&) = delete;
DeferrableCallback(DeferrableCallback&&) = delete;
DeferrableCallback& operator=(const DeferrableCallback&) = delete;
DeferrableCallback& operator=(DeferrableCallback&&) = delete;
~DeferrableCallback() = default;
DeferrableCallback(const std::vector<size_t>& graphEntry, Conditional& cond,
const std::chrono::microseconds& delay) :
ConditionalCallback<CallbackAccess>(graphEntry, cond),
delayInterval(delay), timer(nullptr)
{
}
/** @brief Start internal timer if the condition is satisfied.
*
* When the timer expires, it calls operator() for the
* ConditionalCallback with the context saved in
* DeferrableCallback instance.
*/
void operator()(Context ctx) override
{
if (!timer)
{
timer = std::make_unique<TimerType>(
sdeventplus::Event::get_default(),
// **INDENT-OFF**
[this](auto& source) {
// The timer uses the context saved on timer enable
this->ConditionalCallback<CallbackAccess>::operator()(
this->ctx);
});
// **INDENT-ON**
}
if (this->condition())
{
if (!timer->isEnabled())
{
// This is the first time the condition evaluated.
// Save current context for timer use.
this->ctx = ctx;
// Start the countdown.
timer->restartOnce(delayInterval);
}
}
else
{
// The condition did not evaluate. Stop the countdown.
timer->setEnabled(false);
}
}
private:
/** @brief The length to wait for the condition to stop evaluating. */
std::chrono::microseconds delayInterval;
/** @brief Delegated timer functions. */
std::unique_ptr<TimerType> timer;
/** @brief Current context for timer. */
Context ctx;
};
} // namespace monitoring
} // namespace dbus
} // namespace phosphor