shared/src/main/java/com/android/tools/analytics/AnalyticsSettings.java - platform/tools/analytics-library - Git at Google

 /*
  * Copyright (C) 2016 The Android Open Source Project
  *
  * Licensed under the Eclipse Public License, Version 1.0 (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.eclipse.org/org/documents/epl-v10.php
  *
  * 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.
  */

 package com.android.tools.analytics;

 import com.android.annotations.NonNull;
 import com.android.annotations.Nullable;
 import com.android.annotations.VisibleForTesting;
 import com.android.utils.DateProvider;
 import com.android.utils.ILogger;
 import com.google.common.base.Charsets;
 import com.google.common.io.Files;
 import com.google.gson.Gson;
 import com.google.gson.GsonBuilder;
 import com.google.gson.JsonParseException;
 import com.google.gson.annotations.SerializedName;
 import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.io.OutputStream;
 import java.io.OutputStreamWriter;
 import java.io.RandomAccessFile;
 import java.math.BigInteger;
 import java.nio.channels.Channels;
 import java.nio.channels.FileChannel;
 import java.nio.channels.FileLock;
 import java.nio.channels.OverlappingFileLockException;
 import java.nio.file.Paths;
 import java.security.SecureRandom;
 import java.time.Instant;
 import java.time.LocalDate;
 import java.time.ZoneOffset;
 import java.time.temporal.ChronoUnit;
 import java.util.UUID;

 /**
  * Settings related to analytics reporting. These settings are stored in
  * ~/.android/analytics.settings as a json file.
  */
 public class AnalyticsSettings {
     private static final LocalDate EPOCH = LocalDate.ofEpochDay(0);
     // the gate is used to ensure settings are only in process of loading once.
     private static final transient Object sGate = new Object();

     @VisibleForTesting static AnalyticsSettings sInstance;

     @VisibleForTesting static DateProvider sDateProvider = DateProvider.SYSTEM;

     @SerializedName("userId")
     private String mUserId;

     @SerializedName("hasOptedIn")
     private boolean mHasOptedIn;

     @SerializedName("debugDisablePublishing")
     private boolean mDebugDisablePublishing;

     @SerializedName("saltValue")
     private BigInteger mSaltValue;

     @SerializedName("saltSkew")
     private int mSaltSkew;

     /**
      * Gets a user id used for reporting analytics. This id is pseudo-anonymous.
      */
     public String getUserId() {
         return mUserId;
     }

     /**
      * Indicates whether the user has opted in to sending analytics reporting to Google.
      */
     public boolean hasOptedIn() {
         return mHasOptedIn;
     }

     /**
      * Sets a new user id to be used for reporting analytics. This id should be pseudo-anonymous.
      */
     public void setUserId(String userId) {
         this.mUserId = userId;
     }

     /**
      * Sets the user's choice for opting in to sending analytics reporting to Google or not.
      */
     public void setHasOptedIn(boolean mHasOptedIn) {
         this.mHasOptedIn = mHasOptedIn;
     }

     /** Indicates whether the user has disabled publishing for debugging purposes. */
     public boolean hasDebugDisablePublishing() {
         return mDebugDisablePublishing;
     }

     /**
      * Gets a binary blob to ensure per user anonymization. Gets automatically rotated every 28
      * days. Primarily used by {@link Anonymizer}.
      */
     public byte[] getSalt() throws IOException {
         synchronized (sGate) {
             int currentSaltSkew = currentSaltSkew();
             if (mSaltSkew != currentSaltSkew) {
                 mSaltSkew = currentSaltSkew;
                 SecureRandom random = new SecureRandom();
                 byte[] data = new byte[24];
                 random.nextBytes(data);
                 mSaltValue = new BigInteger(data);
                 saveSettings();
             }
             byte[] blob = mSaltValue.toByteArray();
             byte[] fullBlob = blob;
             if (blob.length < 24) {
                 fullBlob = new byte[24];
                 System.arraycopy(blob, 0, fullBlob, 0, blob.length);
             }
             return fullBlob;
         }
     }

     /**
      * Gets the current salt skew, this is used by {@link #getSalt()} to update the salt every 28
      * days with a consistent window. This window size allows 4 week and 1 week analyses.
      */
     @VisibleForTesting
     static int currentSaltSkew() {
         LocalDate now =
                 LocalDate.from(
                         Instant.ofEpochMilli(sDateProvider.now().getTime()).atZone(ZoneOffset.UTC));
         // Unix epoch was on a Thursday, but we want Monday to be the day the salt is refreshed.
         long days = ChronoUnit.DAYS.between(EPOCH, now) + 3;
         return (int) (days / 28);
     }

     /**
      * Loads an existing settings file from disk, or creates a new valid settings object if none
      * exists. In case of the latter, will try to load uid.txt for maintaining the same uid with
      * previous metrics reporting.
      *
      * @throws IOException if there are any issues reading the settings file.
      */
     @VisibleForTesting
     @Nullable
     public static AnalyticsSettings loadSettings() throws IOException {
         File file = getSettingsFile();
         if (!file.exists()) {
             return null;
         }
         FileChannel channel = new RandomAccessFile(file, "rw").getChannel();
         try (FileLock ignored = channel.tryLock()) {
             InputStream inputStream = Channels.newInputStream(channel);
             Gson gson = new GsonBuilder().create();
             AnalyticsSettings settings =
                     gson.fromJson(new InputStreamReader(inputStream), AnalyticsSettings.class);
             sInstance = settings;
             return settings;
         } catch (OverlappingFileLockException e) {
             throw new IOException("Unable to lock settings file " + file.toString(), e);
         } catch (JsonParseException e) {
             throw new IOException("Unable to parse settings file " + file.toString(), e);
         }
     }

     /**
      * Creates a new settings object and writes it to disk. Will try to load uid.txt for maintaining
      * the same uid with previous metrics reporting.
      *
      * @throws IOException if there are any issues writing the settings file.
      */
     @VisibleForTesting
     @NonNull
     public static AnalyticsSettings createNewAnalyticsSettings() throws IOException {
         AnalyticsSettings settings = new AnalyticsSettings();

         File uidFile = Paths.get(AnalyticsPaths.getAndroidSettingsHome(), "uid.txt").toFile();
         if (uidFile.exists()) {
             try {
                 String uid = Files.readFirstLine(uidFile, Charsets.UTF_8);
                 settings.setUserId(uid);
             } catch (IOException e) {
                 // Ignore and set new UID.
             }
         }
         if (settings.getUserId() == null) {
             settings.setUserId(UUID.randomUUID().toString());
         }
         settings.saveSettings();
         return settings;
     }

     /**
      * Get or creates an instance of the settings. Uses the following strategies in order:
      *
      * <ul>
      * <li>Use existing instance
      * <li>Load existing 'analytics.settings' file from disk
      * <li>Create new 'analytics.settings' file
      * <li>Create instance without persistence
      * </ul>
      *
      * Any issues reading/writing the config file will be logged to the logger.
      */
     public static AnalyticsSettings getInstance(ILogger logger) {
         synchronized (sGate) {
             if (sInstance != null) {
                 return sInstance;
             }
             try {
                 sInstance = loadSettings();
             } catch (IOException e) {
                 logger.error(e, "Unable to load analytics settings.");
             }
             if (sInstance == null) {
                 try {
                     sInstance = createNewAnalyticsSettings();
                 } catch (IOException e) {
                     logger.error(e, "Unable to create new analytics settings.");
                 }
             }
             if (sInstance == null) {
                 sInstance = new AnalyticsSettings();
                 sInstance.setUserId(UUID.randomUUID().toString());
             }
             return sInstance;
         }
     }

     /**
      * Allows test to set a custom version of the AnalyticsSettings to test different setting
      * states.
      */
     @VisibleForTesting
     public static void setInstanceForTest(@Nullable AnalyticsSettings settings) {
         sInstance = settings;
     }

     /**
      * Helper to get the file to read/write settings from based on the configured android settings
      * home.
      */
     private static File getSettingsFile() {
         return Paths.get(AnalyticsPaths.getAndroidSettingsHome(), "analytics.settings").toFile();
     }

     /**
      * Writes this settings object to disk.
      * @throws IOException if there are any issues writing the settings file.
      */
     public void saveSettings() throws IOException {
         File file = getSettingsFile();
         try (RandomAccessFile settingsFile = new RandomAccessFile(file, "rw");
                 FileChannel channel = settingsFile.getChannel();
                 FileLock lock = channel.tryLock()) {
             if (lock == null) {
                 throw new IOException("Unable to lock settings file " + file.toString());
             }
             channel.truncate(0);
             OutputStream outputStream = Channels.newOutputStream(channel);
             Gson gson = new GsonBuilder().create();
             OutputStreamWriter writer = new OutputStreamWriter(outputStream);
             gson.toJson(this, writer);
             writer.flush();
             outputStream.flush();

         } catch (OverlappingFileLockException e) {
             throw new IOException("Unable to lock settings file " + file.toString(), e);
         }
     }
 }
	/*
	* Copyright (C) 2016 The Android Open Source Project
	*
	* Licensed under the Eclipse Public License, Version 1.0 (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.eclipse.org/org/documents/epl-v10.php
	*
	* 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.
	*/

	package com.android.tools.analytics;

	import com.android.annotations.NonNull;
	import com.android.annotations.Nullable;
	import com.android.annotations.VisibleForTesting;
	import com.android.utils.DateProvider;
	import com.android.utils.ILogger;
	import com.google.common.base.Charsets;
	import com.google.common.io.Files;
	import com.google.gson.Gson;
	import com.google.gson.GsonBuilder;
	import com.google.gson.JsonParseException;
	import com.google.gson.annotations.SerializedName;
	import java.io.File;
	import java.io.IOException;
	import java.io.InputStream;
	import java.io.InputStreamReader;
	import java.io.OutputStream;
	import java.io.OutputStreamWriter;
	import java.io.RandomAccessFile;
	import java.math.BigInteger;
	import java.nio.channels.Channels;
	import java.nio.channels.FileChannel;
	import java.nio.channels.FileLock;
	import java.nio.channels.OverlappingFileLockException;
	import java.nio.file.Paths;
	import java.security.SecureRandom;
	import java.time.Instant;
	import java.time.LocalDate;
	import java.time.ZoneOffset;
	import java.time.temporal.ChronoUnit;
	import java.util.UUID;

	/**
	* Settings related to analytics reporting. These settings are stored in
	* ~/.android/analytics.settings as a json file.
	*/
	public class AnalyticsSettings {
	private static final LocalDate EPOCH = LocalDate.ofEpochDay(0);
	// the gate is used to ensure settings are only in process of loading once.
	private static final transient Object sGate = new Object();

	@VisibleForTesting static AnalyticsSettings sInstance;

	@VisibleForTesting static DateProvider sDateProvider = DateProvider.SYSTEM;

	@SerializedName("userId")
	private String mUserId;

	@SerializedName("hasOptedIn")
	private boolean mHasOptedIn;

	@SerializedName("debugDisablePublishing")
	private boolean mDebugDisablePublishing;

	@SerializedName("saltValue")
	private BigInteger mSaltValue;

	@SerializedName("saltSkew")
	private int mSaltSkew;

	/**
	* Gets a user id used for reporting analytics. This id is pseudo-anonymous.
	*/
	public String getUserId() {
	return mUserId;
	}

	/**
	* Indicates whether the user has opted in to sending analytics reporting to Google.
	*/
	public boolean hasOptedIn() {
	return mHasOptedIn;
	}

	/**
	* Sets a new user id to be used for reporting analytics. This id should be pseudo-anonymous.
	*/
	public void setUserId(String userId) {
	this.mUserId = userId;
	}

	/**
	* Sets the user's choice for opting in to sending analytics reporting to Google or not.
	*/
	public void setHasOptedIn(boolean mHasOptedIn) {
	this.mHasOptedIn = mHasOptedIn;
	}

	/** Indicates whether the user has disabled publishing for debugging purposes. */
	public boolean hasDebugDisablePublishing() {
	return mDebugDisablePublishing;
	}

	/**
	* Gets a binary blob to ensure per user anonymization. Gets automatically rotated every 28
	* days. Primarily used by {@link Anonymizer}.
	*/
	public byte[] getSalt() throws IOException {
	synchronized (sGate) {
	int currentSaltSkew = currentSaltSkew();
	if (mSaltSkew != currentSaltSkew) {
	mSaltSkew = currentSaltSkew;
	SecureRandom random = new SecureRandom();
	byte[] data = new byte[24];
	random.nextBytes(data);
	mSaltValue = new BigInteger(data);
	saveSettings();
	}
	byte[] blob = mSaltValue.toByteArray();
	byte[] fullBlob = blob;
	if (blob.length < 24) {
	fullBlob = new byte[24];
	System.arraycopy(blob, 0, fullBlob, 0, blob.length);
	}
	return fullBlob;
	}
	}

	/**
	* Gets the current salt skew, this is used by {@link #getSalt()} to update the salt every 28
	* days with a consistent window. This window size allows 4 week and 1 week analyses.
	*/
	@VisibleForTesting
	static int currentSaltSkew() {
	LocalDate now =
	LocalDate.from(
	Instant.ofEpochMilli(sDateProvider.now().getTime()).atZone(ZoneOffset.UTC));
	// Unix epoch was on a Thursday, but we want Monday to be the day the salt is refreshed.
	long days = ChronoUnit.DAYS.between(EPOCH, now) + 3;
	return (int) (days / 28);
	}

	/**
	* Loads an existing settings file from disk, or creates a new valid settings object if none
	* exists. In case of the latter, will try to load uid.txt for maintaining the same uid with
	* previous metrics reporting.
	*
	* @throws IOException if there are any issues reading the settings file.
	*/
	@VisibleForTesting
	@Nullable
	public static AnalyticsSettings loadSettings() throws IOException {
	File file = getSettingsFile();
	if (!file.exists()) {
	return null;
	}
	FileChannel channel = new RandomAccessFile(file, "rw").getChannel();
	try (FileLock ignored = channel.tryLock()) {
	InputStream inputStream = Channels.newInputStream(channel);
	Gson gson = new GsonBuilder().create();
	AnalyticsSettings settings =
	gson.fromJson(new InputStreamReader(inputStream), AnalyticsSettings.class);
	sInstance = settings;
	return settings;
	} catch (OverlappingFileLockException e) {
	throw new IOException("Unable to lock settings file " + file.toString(), e);
	} catch (JsonParseException e) {
	throw new IOException("Unable to parse settings file " + file.toString(), e);
	}
	}

	/**
	* Creates a new settings object and writes it to disk. Will try to load uid.txt for maintaining
	* the same uid with previous metrics reporting.
	*
	* @throws IOException if there are any issues writing the settings file.
	*/
	@VisibleForTesting
	@NonNull
	public static AnalyticsSettings createNewAnalyticsSettings() throws IOException {
	AnalyticsSettings settings = new AnalyticsSettings();

	File uidFile = Paths.get(AnalyticsPaths.getAndroidSettingsHome(), "uid.txt").toFile();
	if (uidFile.exists()) {
	try {
	String uid = Files.readFirstLine(uidFile, Charsets.UTF_8);
	settings.setUserId(uid);
	} catch (IOException e) {
	// Ignore and set new UID.
	}
	}
	if (settings.getUserId() == null) {
	settings.setUserId(UUID.randomUUID().toString());
	}
	settings.saveSettings();
	return settings;
	}

	/**
	* Get or creates an instance of the settings. Uses the following strategies in order:
	*
	* <ul>
	* <li>Use existing instance
	* <li>Load existing 'analytics.settings' file from disk
	* <li>Create new 'analytics.settings' file
	* <li>Create instance without persistence
	* </ul>
	*
	* Any issues reading/writing the config file will be logged to the logger.
	*/
	public static AnalyticsSettings getInstance(ILogger logger) {
	synchronized (sGate) {
	if (sInstance != null) {
	return sInstance;
	}
	try {
	sInstance = loadSettings();
	} catch (IOException e) {
	logger.error(e, "Unable to load analytics settings.");
	}
	if (sInstance == null) {
	try {
	sInstance = createNewAnalyticsSettings();
	} catch (IOException e) {
	logger.error(e, "Unable to create new analytics settings.");
	}
	}
	if (sInstance == null) {
	sInstance = new AnalyticsSettings();
	sInstance.setUserId(UUID.randomUUID().toString());
	}
	return sInstance;
	}
	}

	/**
	* Allows test to set a custom version of the AnalyticsSettings to test different setting
	* states.
	*/
	@VisibleForTesting
	public static void setInstanceForTest(@Nullable AnalyticsSettings settings) {
	sInstance = settings;
	}

	/**
	* Helper to get the file to read/write settings from based on the configured android settings
	* home.
	*/
	private static File getSettingsFile() {
	return Paths.get(AnalyticsPaths.getAndroidSettingsHome(), "analytics.settings").toFile();
	}

	/**
	* Writes this settings object to disk.
	* @throws IOException if there are any issues writing the settings file.
	*/
	public void saveSettings() throws IOException {
	File file = getSettingsFile();
	try (RandomAccessFile settingsFile = new RandomAccessFile(file, "rw");
	FileChannel channel = settingsFile.getChannel();
	FileLock lock = channel.tryLock()) {
	if (lock == null) {
	throw new IOException("Unable to lock settings file " + file.toString());
	}
	channel.truncate(0);
	OutputStream outputStream = Channels.newOutputStream(channel);
	Gson gson = new GsonBuilder().create();
	OutputStreamWriter writer = new OutputStreamWriter(outputStream);
	gson.toJson(this, writer);
	writer.flush();
	outputStream.flush();

	} catch (OverlappingFileLockException e) {
	throw new IOException("Unable to lock settings file " + file.toString(), e);
	}
	}
	}