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// Copyright 2021 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef COMPONENTS_POWER_METRICS_ENERGY_IMPACT_MAC_H_
#define COMPONENTS_POWER_METRICS_ENERGY_IMPACT_MAC_H_
#include <optional>
#include <string>
#include "base/files/file_path.h"
#include "base/time/time.h"
struct coalition_resource_usage;
namespace power_metrics {
// Coefficients used to compute the Energy Impact score from resource
// coalition metrics. The order of members mimics the order of keys in the
// plist files in /usr/share/pmenergy.
struct EnergyImpactCoefficients {
double kcpu_time;
// In units of seconds/event.
double kcpu_wakeups;
// Coefficients for CPU usage at different QOS.
// Strangely there's no coefficient for maintenance QOS.
double kqos_default;
double kqos_background;
double kqos_utility;
double kqos_legacy;
double kqos_user_initiated;
double kqos_user_interactive;
double kdiskio_bytesread;
double kdiskio_byteswritten;
double kgpu_time;
double knetwork_recv_bytes;
double knetwork_recv_packets;
double knetwork_sent_bytes;
double knetwork_sent_packets;
};
// Reads the Energy Impact coefficients for the current machine from disk, or
// default coefficients if coefficients are not available for the current
// machine.
std::optional<EnergyImpactCoefficients>
ReadCoefficientsForCurrentMachineOrDefault();
// Computes the Energy Impact score for the resource consumption data in
// |coalition_resource_usage| using |coefficients|.
//
// The Energy Impact (EI) score is referenced to CPU time, such that 10ms CPU
// time appears to be equivalent to 1 EI. The Activity Monitor presents EI
// rates to the user in units of 10ms/s of CPU time. This means a process that
// consumes 1000ms/s or 100% CPU, at default QOS, is rated 100 EI, making the
// two units somewhat relatable. Note that this only has relevance on Intel
// architecture, as it looks like on M1 architecture macOS implements more
// granular, and hopefully more accurate, energy metering on the fly.
double ComputeEnergyImpactForResourceUsage(
const coalition_resource_usage& coalition_resource_usage,
const EnergyImpactCoefficients& coefficients,
const mach_timebase_info_data_t& mach_timebase);
namespace internal {
// Reads the coefficients from the "energy_constants" sub-dictionary of the
// plist file at |plist_file|. This is exposed for testing, production code
// should use ReadCoefficientsForCurrentMachineOrDefault().
std::optional<EnergyImpactCoefficients> ReadCoefficientsFromPath(
const base::FilePath& plist_file);
// Given a |directory| and a |board_id|, read the plist file for the board id
// from the directory, or if not available, read the default file.
// Returns true if either file can be loaded, false otherwise. This is exposed
// for testing, production code should use
// ReadCoefficientsForCurrentMachineOrDefault().
std::optional<EnergyImpactCoefficients> ReadCoefficientsForBoardIdOrDefault(
const base::FilePath& directory,
const std::string& board_id);
// Returns the board id to use for reading the Energy Impact coefficients for
// the current machine. This appears to work for Intel Macs only. This is
// exposed for testing, production code should use
// ReadCoefficientsForCurrentMachineOrDefault().
std::optional<std::string> GetBoardIdForThisMachine();
} // namespace internal
} // namespace power_metrics
#endif // COMPONENTS_POWER_METRICS_ENERGY_IMPACT_MAC_H_
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