platform_system_vold/Disk.h
Jeff Sharkey 5a6bfca163 Initial pass at storage benchmarks.
Now that we're offering to store private app data on adopted storage
devices, the performance of those devices is much more important to
overall user experience.

To help set user expectations, this change offers to execute a
real-world benchmark on a storage device, returning a metric that can
be used to compare internal and external storage.  The benchmark is
generated from the strace-instrumented storage access patterns of
typical apps.

A typical device completes the benchmark in under two seconds on
internal storage, a UHS-3 SD card is even faster (!), but a very slow
Class 4 SD card takes about 30 seconds to complete, giving us a clear
signal.

The measured benchmark numbers are logged along with information
about the storage device, such as manufacturer, model, etc.  Card
serial numbers are scrubbed from output.

Bug: 21172095
Change-Id: I9b2713dafdfdfcf5d97bf1bc21841f39409a7e54
2015-05-15 10:48:11 -07:00

121 lines
3.4 KiB
C++

/*
* Copyright (C) 2015 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 ANDROID_VOLD_DISK_H
#define ANDROID_VOLD_DISK_H
#include "Utils.h"
#include <utils/Errors.h>
#include <vector>
namespace android {
namespace vold {
class VolumeBase;
/*
* Representation of detected physical media.
*
* Knows how to create volumes based on the partition tables found, and also
* how to repartition itself.
*/
class Disk {
public:
Disk(const std::string& eventPath, dev_t device, const std::string& nickname, int flags);
virtual ~Disk();
enum Flags {
/* Flag that disk is adoptable */
kAdoptable = 1 << 0,
/* Flag that disk is considered primary when the user hasn't
* explicitly picked a primary storage location */
kDefaultPrimary = 1 << 1,
/* Flag that disk is SD card */
kSd = 1 << 2,
/* Flag that disk is USB disk */
kUsb = 1 << 3,
/* Flag that disk is EMMC internal */
kEmmc = 1 << 4,
};
const std::string& getId() { return mId; }
const std::string& getEventPath() { return mEventPath; }
const std::string& getSysPath() { return mSysPath; }
const std::string& getDevPath() { return mDevPath; }
dev_t getDevice() { return mDevice; }
uint64_t getSize() { return mSize; }
const std::string& getLabel() { return mLabel; }
int getFlags() { return mFlags; }
std::shared_ptr<VolumeBase> findVolume(const std::string& id);
status_t create();
status_t destroy();
status_t readMetadata();
status_t readPartitions();
status_t unmountAll();
status_t partitionPublic();
status_t partitionPrivate();
status_t partitionMixed(int8_t ratio);
void notifyEvent(int msg);
void notifyEvent(int msg, const std::string& value);
private:
/* ID that uniquely references this disk */
std::string mId;
/* Original event path */
std::string mEventPath;
/* Device path under sysfs */
std::string mSysPath;
/* Device path under dev */
std::string mDevPath;
/* Kernel device representing disk */
dev_t mDevice;
/* Size of disk, in bytes */
uint64_t mSize;
/* User-visible label, such as manufacturer */
std::string mLabel;
/* Current partitions on disk */
std::vector<std::shared_ptr<VolumeBase>> mVolumes;
/* Nickname for this disk */
std::string mNickname;
/* Flags applicable to this disk */
int mFlags;
/* Flag indicating object is created */
bool mCreated;
/* Flag that we just partitioned and should format all volumes */
bool mJustPartitioned;
void createPublicVolume(dev_t device);
void createPrivateVolume(dev_t device, const std::string& partGuid);
void destroyAllVolumes();
int getMaxMinors();
DISALLOW_COPY_AND_ASSIGN(Disk);
};
} // namespace vold
} // namespace android
#endif