text: /*
   * Copyright (C) 2012 The Android Open Source Project
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  #ifndef __COMMON_CLOCK_H__
  #define __COMMON_CLOCK_H__
  
  #include <stdint.h>
  
  #include <utils/Errors.h>
  #include <utils/LinearTransform.h>
  #include <utils/threads.h>
  
  namespace android {
  
  class CommonClock {
    public:
      CommonClock();
  
      bool      init(uint64_t local_freq);
  
      status_t  localToCommon(int64_t local, int64_t *common_out) const;
      status_t  commonToLocal(int64_t common, int64_t *local_out) const;
      int64_t   localDurationToCommonDuration(int64_t localDur) const;
      uint64_t  getCommonFreq() const { return kCommonFreq; }
      bool      isValid() const { return cur_trans_valid_; }
      status_t  setSlew(int64_t change_time, int32_t ppm);
      void      setBasis(int64_t local, int64_t common);
      void      resetBasis();
    private:
      mutable Mutex lock_;
  
      int32_t  cur_slew_;
      uint32_t local_to_common_freq_numer_;
      uint32_t local_to_common_freq_denom_;
  
      LinearTransform duration_trans_;
      LinearTransform cur_trans_;
      bool cur_trans_valid_;
  
      static const uint64_t kCommonFreq = 1000000ull;
  };
  
  }  // namespace android
  #endif  // __COMMON_CLOCK_H__
  