components/variations/android/java/src/org/chromium/components/variations/firstrun/VariationsSeedFetcher.java - chromium/src - Git at Google

 // Copyright 2015 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.

 package org.chromium.components.variations.firstrun;

 import android.content.SharedPreferences;
 import android.os.SystemClock;

 import androidx.annotation.IntDef;

 import org.chromium.base.BuildConfig;
 import org.chromium.base.ContextUtils;
 import org.chromium.base.FileUtils;
 import org.chromium.base.Log;
 import org.chromium.base.ThreadUtils;
 import org.chromium.base.VisibleForTesting;
 import org.chromium.base.metrics.CachedMetrics.SparseHistogramSample;
 import org.chromium.base.metrics.CachedMetrics.TimesHistogramSample;

 import java.io.IOException;
 import java.io.InputStream;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 import java.net.HttpURLConnection;
 import java.net.MalformedURLException;
 import java.net.SocketTimeoutException;
 import java.net.URL;
 import java.net.UnknownHostException;
 import java.text.ParseException;
 import java.text.SimpleDateFormat;
 import java.util.Arrays;
 import java.util.Locale;

 /**
  * Fetches the variations seed before the actual first run of Chrome.
  */
 public class VariationsSeedFetcher {
     private static final String TAG = "VariationsSeedFetch";

     @IntDef({VariationsPlatform.ANDROID, VariationsPlatform.ANDROID_WEBVIEW})
     @Retention(RetentionPolicy.SOURCE)
     public @interface VariationsPlatform {
         int ANDROID = 0;
         int ANDROID_WEBVIEW = 1;
     }

     private static final String VARIATIONS_SERVER_URL =
             "https://clientservices.googleapis.com/chrome-variations/seed?osname=";

     private static final int READ_TIMEOUT = 3000; // time in ms
     private static final int REQUEST_TIMEOUT = 1000; // time in ms

     // Values for the "Variations.FirstRun.SeedFetchResult" sparse histogram, which also logs
     // HTTP result codes. These are negative so that they don't conflict with the HTTP codes.
     // These values should not be renumbered or re-used since they are logged to UMA.
     private static final int SEED_FETCH_RESULT_INVALID_DATE_HEADER = -4;
     private static final int SEED_FETCH_RESULT_UNKNOWN_HOST_EXCEPTION = -3;
     private static final int SEED_FETCH_RESULT_TIMEOUT = -2;
     private static final int SEED_FETCH_RESULT_IOEXCEPTION = -1;

     @VisibleForTesting
     static final String VARIATIONS_INITIALIZED_PREF = "variations_initialized";

     // Synchronization lock to make singleton thread-safe.
     private static final Object sLock = new Object();

     private static VariationsSeedFetcher sInstance;

     @VisibleForTesting
     public VariationsSeedFetcher() {}

     public static VariationsSeedFetcher get() {
         // TODO(aberent) Check not running on UI thread. Doing so however makes Robolectric testing
         // of dependent classes difficult.
         synchronized (sLock) {
             if (sInstance == null) {
                 sInstance = new VariationsSeedFetcher();
             }
             return sInstance;
         }
     }

     /**
      * Override the VariationsSeedFetcher, typically with a mock, for testing classes that depend on
      * this one.
      * @param fetcher the mock.
      */
     @VisibleForTesting
     public static void setVariationsSeedFetcherForTesting(VariationsSeedFetcher fetcher) {
         sInstance = fetcher;
     }

     @VisibleForTesting
     protected HttpURLConnection getServerConnection(
             @VariationsPlatform int platform, String restrictMode, String milestone, String channel)
             throws MalformedURLException, IOException {
         String urlString = getConnectionString(platform, restrictMode, milestone, channel);
         URL url = new URL(urlString);
         return (HttpURLConnection) url.openConnection();
     }

     @VisibleForTesting
     protected String getConnectionString(@VariationsPlatform int platform, String restrictMode,
             String milestone, String channel) {
         String urlString = VARIATIONS_SERVER_URL;
         switch (platform) {
             case VariationsPlatform.ANDROID:
                 urlString += "android";
                 break;
             case VariationsPlatform.ANDROID_WEBVIEW:
                 urlString += "android_webview";
                 break;
             default:
                 assert false;
         }
         if (restrictMode != null && !restrictMode.isEmpty()) {
             urlString += "&restrict=" + restrictMode;
         }
         if (milestone != null && !milestone.isEmpty()) {
             urlString += "&milestone=" + milestone;
         }
         if (channel != null && !channel.isEmpty()) {
             urlString += "&channel=" + channel;
         }

         return urlString;
     }

     /**
      * Object holding the seed data and related fields retrieved from HTTP headers.
      */
     public static class SeedInfo {
         // If you add fields, see VariationsTestUtils.
         public String signature;
         public String country;
         // Date according to the Variations server in milliseconds since UNIX epoch GMT.
         public long date;
         public boolean isGzipCompressed;
         public byte[] seedData;

         public static long parseDateHeader(String header) throws ParseException {
             // The date field comes from the HTTP "Date" header, which has this format.
             // (See RFC 2616, sections 3.3.1 and 14.18.) SimpleDateFormat is weirdly not
             // thread-safe, so instantiate a new one for each call.
             return new SimpleDateFormat("EEE, dd MMM yyyy HH:mm:ss z", Locale.US)
                     .parse(header)
                     .getTime();
         }

         @Override
         public String toString() {
             if (BuildConfig.DCHECK_IS_ON) {
                 return "SeedInfo{signature=\"" + signature + "\" country=\"" + country
                         + "\" date=\"" + date + " isGzipCompressed=" + isGzipCompressed
                         + " seedData=" + Arrays.toString(seedData);
             }
             return super.toString();
         }
     }


     /**
      * Fetch the first run variations seed.
      * @param restrictMode The restrict mode parameter to pass to the server via a URL param.
      * @param milestone The milestone parameter to pass to the server via a URL param.
      * @param channel The channel parameter to pass to the server via a URL param.
      */
     public void fetchSeed(String restrictMode, String milestone, String channel) {
         assert !ThreadUtils.runningOnUiThread();
         // Prevent multiple simultaneous fetches
         synchronized (sLock) {
             SharedPreferences prefs = ContextUtils.getAppSharedPreferences();
             // Early return if an attempt has already been made to fetch the seed, even if it
             // failed. Only attempt to get the initial Java seed once, since a failure probably
             // indicates a network problem that is unlikely to be resolved by a second attempt.
             // Note that VariationsSeedBridge.hasNativePref() is a pure Java function, reading an
             // Android preference that is set when the seed is fetched by the native code.
             if (prefs.getBoolean(VARIATIONS_INITIALIZED_PREF, false)
                     || VariationsSeedBridge.hasNativePref()) {
                 return;
             }

             try {
                 SeedInfo info = downloadContent(
                         VariationsPlatform.ANDROID, restrictMode, milestone, channel);
                 VariationsSeedBridge.setVariationsFirstRunSeed(info.seedData, info.signature,
                         info.country, info.date, info.isGzipCompressed);
             } catch (IOException | ParseException e) {
                 Log.e(TAG, "Exception when fetching variations seed.", e);
                 // Exceptions are handled and logged in the downloadContent method, so we don't
                 // need any exception handling here. The only reason we need a catch-statement here
                 // is because those exceptions are re-thrown from downloadContent to skip the
                 // normal logic flow within that method.
             }
             // VARIATIONS_INITIALIZED_PREF should still be set to true when exceptions occur
             prefs.edit().putBoolean(VARIATIONS_INITIALIZED_PREF, true).apply();
         }
     }

     private void recordFetchResultOrCode(int resultOrCode) {
         SparseHistogramSample histogram =
                 new SparseHistogramSample("Variations.FirstRun.SeedFetchResult");
         histogram.record(resultOrCode);
     }

     private void recordSeedFetchTime(long timeDeltaMillis) {
         Log.i(TAG, "Fetched first run seed in " + timeDeltaMillis + " ms");
         TimesHistogramSample histogram =
                 new TimesHistogramSample("Variations.FirstRun.SeedFetchTime");
         histogram.record(timeDeltaMillis);
     }

     private void recordSeedConnectTime(long timeDeltaMillis) {
         TimesHistogramSample histogram =
                 new TimesHistogramSample("Variations.FirstRun.SeedConnectTime");
         histogram.record(timeDeltaMillis);
     }

     /**
      * Download the variations seed data with platform and retrictMode.
      * @param platform the platform parameter to let server only return experiments which can be
      * run on that platform.
      * @param restrictMode the restrict mode parameter to pass to the server via a URL param.
      * @param milestone the milestone parameter to pass to the server via a URL param.
      * @param channel the channel parameter to pass to the server via a URL param.
      * @return the object holds the seed data and its related header fields.
      * @throws ParseException when the seed response has an invalid Date header.
      * @throws SocketTimeoutException when fetching seed connection times out.
      * @throws UnknownHostException when fetching seed connection has an unknown host.
      * @throws IOException when response code is not HTTP_OK or transmission fails on the open
      * connection.
      */
     public SeedInfo downloadContent(
             @VariationsPlatform int platform, String restrictMode, String milestone, String channel)
             throws ParseException, SocketTimeoutException, UnknownHostException, IOException {
         HttpURLConnection connection = null;
         try {
             long startTimeMillis = SystemClock.elapsedRealtime();
             connection = getServerConnection(platform, restrictMode, milestone, channel);
             connection.setReadTimeout(READ_TIMEOUT);
             connection.setConnectTimeout(REQUEST_TIMEOUT);
             connection.setDoInput(true);
             connection.setRequestProperty("A-IM", "gzip");
             connection.connect();
             int responseCode = connection.getResponseCode();
             recordFetchResultOrCode(responseCode);
             if (responseCode != HttpURLConnection.HTTP_OK) {
                 String errorMsg = "Non-OK response code = " + responseCode;
                 Log.w(TAG, errorMsg);
                 throw new IOException(errorMsg);
             }

             recordSeedConnectTime(SystemClock.elapsedRealtime() - startTimeMillis);

             SeedInfo info = new SeedInfo();
             info.seedData = getRawSeed(connection);
             info.signature = getHeaderFieldOrEmpty(connection, "X-Seed-Signature");
             info.country = getHeaderFieldOrEmpty(connection, "X-Country");
             info.date = SeedInfo.parseDateHeader(getHeaderFieldOrEmpty(connection, "Date"));
             info.isGzipCompressed = getHeaderFieldOrEmpty(connection, "IM").equals("gzip");
             recordSeedFetchTime(SystemClock.elapsedRealtime() - startTimeMillis);
             return info;
         } catch (ParseException e) {
             recordFetchResultOrCode(SEED_FETCH_RESULT_INVALID_DATE_HEADER);
             Log.e(TAG, "ParseException parsing Date header when fetching variations seed.", e);
             throw e;
         } catch (SocketTimeoutException e) {
             recordFetchResultOrCode(SEED_FETCH_RESULT_TIMEOUT);
             Log.w(TAG, "SocketTimeoutException timeout when fetching variations seed.", e);
             throw e;
         } catch (UnknownHostException e) {
             recordFetchResultOrCode(SEED_FETCH_RESULT_UNKNOWN_HOST_EXCEPTION);
             Log.w(TAG, "UnknownHostException unknown host when fetching variations seed.", e);
             throw e;
         } catch (IOException e) {
             recordFetchResultOrCode(SEED_FETCH_RESULT_IOEXCEPTION);
             Log.w(TAG, "IOException when fetching variations seed.", e);
             throw e;
         } finally {
             if (connection != null) {
                 connection.disconnect();
             }
         }
     }

     private String getHeaderFieldOrEmpty(HttpURLConnection connection, String name) {
         String headerField = connection.getHeaderField(name);
         if (headerField == null) {
             return "";
         }
         return headerField.trim();
     }

     private byte[] getRawSeed(HttpURLConnection connection) throws IOException {
         InputStream inputStream = null;
         try {
             inputStream = connection.getInputStream();
             return FileUtils.readStream(inputStream);
         } finally {
             if (inputStream != null) {
                 inputStream.close();
             }
         }
     }
 }
	// Copyright 2015 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.

	package org.chromium.components.variations.firstrun;

	import android.content.SharedPreferences;
	import android.os.SystemClock;

	import androidx.annotation.IntDef;

	import org.chromium.base.BuildConfig;
	import org.chromium.base.ContextUtils;
	import org.chromium.base.FileUtils;
	import org.chromium.base.Log;
	import org.chromium.base.ThreadUtils;
	import org.chromium.base.VisibleForTesting;
	import org.chromium.base.metrics.CachedMetrics.SparseHistogramSample;
	import org.chromium.base.metrics.CachedMetrics.TimesHistogramSample;

	import java.io.IOException;
	import java.io.InputStream;
	import java.lang.annotation.Retention;
	import java.lang.annotation.RetentionPolicy;
	import java.net.HttpURLConnection;
	import java.net.MalformedURLException;
	import java.net.SocketTimeoutException;
	import java.net.URL;
	import java.net.UnknownHostException;
	import java.text.ParseException;
	import java.text.SimpleDateFormat;
	import java.util.Arrays;
	import java.util.Locale;

	/**
	* Fetches the variations seed before the actual first run of Chrome.
	*/
	public class VariationsSeedFetcher {
	private static final String TAG = "VariationsSeedFetch";

	@IntDef({VariationsPlatform.ANDROID, VariationsPlatform.ANDROID_WEBVIEW})
	@Retention(RetentionPolicy.SOURCE)
	public @interface VariationsPlatform {
	int ANDROID = 0;
	int ANDROID_WEBVIEW = 1;
	}

	private static final String VARIATIONS_SERVER_URL =
	"https://clientservices.googleapis.com/chrome-variations/seed?osname=";

	private static final int READ_TIMEOUT = 3000; // time in ms
	private static final int REQUEST_TIMEOUT = 1000; // time in ms

	// Values for the "Variations.FirstRun.SeedFetchResult" sparse histogram, which also logs
	// HTTP result codes. These are negative so that they don't conflict with the HTTP codes.
	// These values should not be renumbered or re-used since they are logged to UMA.
	private static final int SEED_FETCH_RESULT_INVALID_DATE_HEADER = -4;
	private static final int SEED_FETCH_RESULT_UNKNOWN_HOST_EXCEPTION = -3;
	private static final int SEED_FETCH_RESULT_TIMEOUT = -2;
	private static final int SEED_FETCH_RESULT_IOEXCEPTION = -1;

	@VisibleForTesting
	static final String VARIATIONS_INITIALIZED_PREF = "variations_initialized";

	// Synchronization lock to make singleton thread-safe.
	private static final Object sLock = new Object();

	private static VariationsSeedFetcher sInstance;

	@VisibleForTesting
	public VariationsSeedFetcher() {}

	public static VariationsSeedFetcher get() {
	// TODO(aberent) Check not running on UI thread. Doing so however makes Robolectric testing
	// of dependent classes difficult.
	synchronized (sLock) {
	if (sInstance == null) {
	sInstance = new VariationsSeedFetcher();
	}
	return sInstance;
	}
	}

	/**
	* Override the VariationsSeedFetcher, typically with a mock, for testing classes that depend on
	* this one.
	* @param fetcher the mock.
	*/
	@VisibleForTesting
	public static void setVariationsSeedFetcherForTesting(VariationsSeedFetcher fetcher) {
	sInstance = fetcher;
	}

	@VisibleForTesting
	protected HttpURLConnection getServerConnection(
	@VariationsPlatform int platform, String restrictMode, String milestone, String channel)
	throws MalformedURLException, IOException {
	String urlString = getConnectionString(platform, restrictMode, milestone, channel);
	URL url = new URL(urlString);
	return (HttpURLConnection) url.openConnection();
	}

	@VisibleForTesting
	protected String getConnectionString(@VariationsPlatform int platform, String restrictMode,
	String milestone, String channel) {
	String urlString = VARIATIONS_SERVER_URL;
	switch (platform) {
	case VariationsPlatform.ANDROID:
	urlString += "android";
	break;
	case VariationsPlatform.ANDROID_WEBVIEW:
	urlString += "android_webview";
	break;
	default:
	assert false;
	}
	if (restrictMode != null && !restrictMode.isEmpty()) {
	urlString += "&restrict=" + restrictMode;
	}
	if (milestone != null && !milestone.isEmpty()) {
	urlString += "&milestone=" + milestone;
	}
	if (channel != null && !channel.isEmpty()) {
	urlString += "&channel=" + channel;
	}

	return urlString;
	}

	/**
	* Object holding the seed data and related fields retrieved from HTTP headers.
	*/
	public static class SeedInfo {
	// If you add fields, see VariationsTestUtils.
	public String signature;
	public String country;
	// Date according to the Variations server in milliseconds since UNIX epoch GMT.
	public long date;
	public boolean isGzipCompressed;
	public byte[] seedData;

	public static long parseDateHeader(String header) throws ParseException {
	// The date field comes from the HTTP "Date" header, which has this format.
	// (See RFC 2616, sections 3.3.1 and 14.18.) SimpleDateFormat is weirdly not
	// thread-safe, so instantiate a new one for each call.
	return new SimpleDateFormat("EEE, dd MMM yyyy HH:mm:ss z", Locale.US)
	.parse(header)
	.getTime();
	}

	@Override
	public String toString() {
	if (BuildConfig.DCHECK_IS_ON) {
	return "SeedInfo{signature=\"" + signature + "\" country=\"" + country
	+ "\" date=\"" + date + " isGzipCompressed=" + isGzipCompressed
	+ " seedData=" + Arrays.toString(seedData);
	}
	return super.toString();
	}
	}


	/**
	* Fetch the first run variations seed.
	* @param restrictMode The restrict mode parameter to pass to the server via a URL param.
	* @param milestone The milestone parameter to pass to the server via a URL param.
	* @param channel The channel parameter to pass to the server via a URL param.
	*/
	public void fetchSeed(String restrictMode, String milestone, String channel) {
	assert !ThreadUtils.runningOnUiThread();
	// Prevent multiple simultaneous fetches
	synchronized (sLock) {
	SharedPreferences prefs = ContextUtils.getAppSharedPreferences();
	// Early return if an attempt has already been made to fetch the seed, even if it
	// failed. Only attempt to get the initial Java seed once, since a failure probably
	// indicates a network problem that is unlikely to be resolved by a second attempt.
	// Note that VariationsSeedBridge.hasNativePref() is a pure Java function, reading an
	// Android preference that is set when the seed is fetched by the native code.
	if (prefs.getBoolean(VARIATIONS_INITIALIZED_PREF, false)
	\|\| VariationsSeedBridge.hasNativePref()) {
	return;
	}

	try {
	SeedInfo info = downloadContent(
	VariationsPlatform.ANDROID, restrictMode, milestone, channel);
	VariationsSeedBridge.setVariationsFirstRunSeed(info.seedData, info.signature,
	info.country, info.date, info.isGzipCompressed);
	} catch (IOException \| ParseException e) {
	Log.e(TAG, "Exception when fetching variations seed.", e);
	// Exceptions are handled and logged in the downloadContent method, so we don't
	// need any exception handling here. The only reason we need a catch-statement here
	// is because those exceptions are re-thrown from downloadContent to skip the
	// normal logic flow within that method.
	}
	// VARIATIONS_INITIALIZED_PREF should still be set to true when exceptions occur
	prefs.edit().putBoolean(VARIATIONS_INITIALIZED_PREF, true).apply();
	}
	}

	private void recordFetchResultOrCode(int resultOrCode) {
	SparseHistogramSample histogram =
	new SparseHistogramSample("Variations.FirstRun.SeedFetchResult");
	histogram.record(resultOrCode);
	}

	private void recordSeedFetchTime(long timeDeltaMillis) {
	Log.i(TAG, "Fetched first run seed in " + timeDeltaMillis + " ms");
	TimesHistogramSample histogram =
	new TimesHistogramSample("Variations.FirstRun.SeedFetchTime");
	histogram.record(timeDeltaMillis);
	}

	private void recordSeedConnectTime(long timeDeltaMillis) {
	TimesHistogramSample histogram =
	new TimesHistogramSample("Variations.FirstRun.SeedConnectTime");
	histogram.record(timeDeltaMillis);
	}

	/**
	* Download the variations seed data with platform and retrictMode.
	* @param platform the platform parameter to let server only return experiments which can be
	* run on that platform.
	* @param restrictMode the restrict mode parameter to pass to the server via a URL param.
	* @param milestone the milestone parameter to pass to the server via a URL param.
	* @param channel the channel parameter to pass to the server via a URL param.
	* @return the object holds the seed data and its related header fields.
	* @throws ParseException when the seed response has an invalid Date header.
	* @throws SocketTimeoutException when fetching seed connection times out.
	* @throws UnknownHostException when fetching seed connection has an unknown host.
	* @throws IOException when response code is not HTTP_OK or transmission fails on the open
	* connection.
	*/
	public SeedInfo downloadContent(
	@VariationsPlatform int platform, String restrictMode, String milestone, String channel)
	throws ParseException, SocketTimeoutException, UnknownHostException, IOException {
	HttpURLConnection connection = null;
	try {
	long startTimeMillis = SystemClock.elapsedRealtime();
	connection = getServerConnection(platform, restrictMode, milestone, channel);
	connection.setReadTimeout(READ_TIMEOUT);
	connection.setConnectTimeout(REQUEST_TIMEOUT);
	connection.setDoInput(true);
	connection.setRequestProperty("A-IM", "gzip");
	connection.connect();
	int responseCode = connection.getResponseCode();
	recordFetchResultOrCode(responseCode);
	if (responseCode != HttpURLConnection.HTTP_OK) {
	String errorMsg = "Non-OK response code = " + responseCode;
	Log.w(TAG, errorMsg);
	throw new IOException(errorMsg);
	}

	recordSeedConnectTime(SystemClock.elapsedRealtime() - startTimeMillis);

	SeedInfo info = new SeedInfo();
	info.seedData = getRawSeed(connection);
	info.signature = getHeaderFieldOrEmpty(connection, "X-Seed-Signature");
	info.country = getHeaderFieldOrEmpty(connection, "X-Country");
	info.date = SeedInfo.parseDateHeader(getHeaderFieldOrEmpty(connection, "Date"));
	info.isGzipCompressed = getHeaderFieldOrEmpty(connection, "IM").equals("gzip");
	recordSeedFetchTime(SystemClock.elapsedRealtime() - startTimeMillis);
	return info;
	} catch (ParseException e) {
	recordFetchResultOrCode(SEED_FETCH_RESULT_INVALID_DATE_HEADER);
	Log.e(TAG, "ParseException parsing Date header when fetching variations seed.", e);
	throw e;
	} catch (SocketTimeoutException e) {
	recordFetchResultOrCode(SEED_FETCH_RESULT_TIMEOUT);
	Log.w(TAG, "SocketTimeoutException timeout when fetching variations seed.", e);
	throw e;
	} catch (UnknownHostException e) {
	recordFetchResultOrCode(SEED_FETCH_RESULT_UNKNOWN_HOST_EXCEPTION);
	Log.w(TAG, "UnknownHostException unknown host when fetching variations seed.", e);
	throw e;
	} catch (IOException e) {
	recordFetchResultOrCode(SEED_FETCH_RESULT_IOEXCEPTION);
	Log.w(TAG, "IOException when fetching variations seed.", e);
	throw e;
	} finally {
	if (connection != null) {
	connection.disconnect();
	}
	}
	}

	private String getHeaderFieldOrEmpty(HttpURLConnection connection, String name) {
	String headerField = connection.getHeaderField(name);
	if (headerField == null) {
	return "";
	}
	return headerField.trim();
	}

	private byte[] getRawSeed(HttpURLConnection connection) throws IOException {
	InputStream inputStream = null;
	try {
	inputStream = connection.getInputStream();
	return FileUtils.readStream(inputStream);
	} finally {
	if (inputStream != null) {
	inputStream.close();
	}
	}
	}
	}