components/power_metrics/smc_mac.h

   1 // Copyright 2021 The Chromium Authors
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 // The System Management Controller (SMC) is a hardware component that controls
   6 // the power functions of Intel-based Macs. This file defines a class to read
   7 // known SMC keys.
   8
   9 #ifndef COMPONENTS_POWER_METRICS_SMC_MAC_H_
  10 #define COMPONENTS_POWER_METRICS_SMC_MAC_H_
  11
  12 #import <Foundation/Foundation.h>
  13
  14 #include <memory>
  15
  16 #include "base/containers/flat_map.h"
  17 #include "base/mac/scoped_ioobject.h"
  18 #include "components/power_metrics/smc_internal_types_mac.h"
  19 #include "third_party/abseil-cpp/absl/types/optional.h"
  20
  21 namespace power_metrics {
  22
  23 class SMCReader {
  24  public:
  25   // Creates an SMC Reader. Returns nullptr in case of failure.
  26   static std::unique_ptr<SMCReader> Create();
  27
  28   virtual ~SMCReader();
  29
  30   // Returns the value of a key, or nullopt if not available.
  31   // Virtual for testing.
  32   virtual absl::optional<double> ReadKey(SMCKeyIdentifier identifier);
  33
  34  protected:
  35   explicit SMCReader(base::mac::ScopedIOObject<io_object_t> connect);
  36
  37  private:
  38   class SMCKey {
  39    public:
  40     SMCKey(base::mac::ScopedIOObject<io_object_t> connect,
  41            SMCKeyIdentifier key_identifier);
  42     SMCKey(SMCKey&&);
  43     SMCKey& operator=(SMCKey&&);
  44     ~SMCKey();
  45
  46     bool Exists() const;
  47     absl::optional<double> Read();
  48
  49    private:
  50     bool CallSMCFunction(uint8_t function, SMCParamStruct* out);
  51
  52     base::mac::ScopedIOObject<io_object_t> connect_;
  53     SMCKeyIdentifier key_identifier_;
  54     SMCKeyInfoData key_info_;
  55   };
  56
  57   base::mac::ScopedIOObject<io_object_t> connect_;
  58   base::flat_map<SMCKeyIdentifier, SMCKey> keys_;
  59 };
  60
  61 }  // namespace power_metrics
  62
  63 #endif  // COMPONENTS_POWER_METRICS_SMC_MAC_H_