// Copyright 2016 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

module device.mojom;

import "sensor.mojom";

struct SensorInitParams {
  // The shared memory handle used to fetch the sensor reading.
  handle<shared_buffer> memory;

  // The offset at which shared buffer must be mapped.
  uint64 buffer_offset;

  // The ReportingMode supported by the sensor.
  ReportingMode mode;

  // Default sensor configuration.
  SensorConfiguration default_configuration;

  // Maximum sampling frequency for the sensor: it considers both
  // |SensorConfiguration::kMaxAllowedFrequency| and actual sensor
  // capabilities.
  double maximum_frequency;

  // Each sensor's read buffer contains 4 tightly packed 64-bit floating
  // point fields (please see sensor_reading.h) and a seqlock, so its size is
  // 5 * 8 = 40 bytes.
  const uint64 kReadBufferSizeForTests = 40;
};

interface SensorProvider {
  // Gets the sensor interface by the given type.
  //
  // |type| type of the sensor.
  //
  // |sensor_request| the Sensor interface instance to be initialized.
  //
  // |init_params| on success will contain the SensorInitParams describing the
  //               sensor details,
  //               contains null on failure.
  // |client_request| on success contains a request to be bound by the client,
  //                  contains null on failure.
  GetSensor(SensorType type, Sensor& sensor_request) => (
      SensorInitParams? init_params,
      SensorClient&? client_request);
};