The Tor Browser: mobile/android/base/util/HardwareUtils.java@fc2d59ddac77 (annotated)

mobile/android/base/util/HardwareUtils.java@fc2d59ddac77 (annotated)

mobile/android/base/util/HardwareUtils.java

Wed, 31 Dec 2014 07:22:50 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 07:22:50 +0100
branch: TOR_BUG_3246
changeset 4: fc2d59ddac77
permissions: -rw-r--r--

Correct previous dual key logic pending first delivery installment.

 /* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*-
  * This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 package org.mozilla.gecko.util;
 import android.content.Context;
 import android.content.pm.PackageManager;
 import android.content.res.Configuration;
 import android.os.Build;
 import android.util.Log;
 import android.view.ViewConfiguration;
 import java.io.FileInputStream;
 import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 public final class HardwareUtils {
     private static final String LOGTAG = "GeckoHardwareUtils";
     // Minimum memory threshold for a device to be considered
     // a low memory platform (see isLowMemoryPlatform). This value
     // has be in sync with Gecko's equivalent threshold (defined in
     // xpcom/base/nsMemoryImpl.cpp) and should only be used in cases
     // where we can't depend on Gecko to be up and running e.g. show/hide
     // reading list capabilities in HomePager.
     private static final int LOW_MEMORY_THRESHOLD_MB = 384;
     // Number of bytes of /proc/meminfo to read in one go.
     private static final int MEMINFO_BUFFER_SIZE_BYTES = 256;
     private static volatile int sTotalRAM = -1;
     private static Context sContext;
     private static Boolean sIsLargeTablet;
     private static Boolean sIsSmallTablet;
     private static Boolean sIsTelevision;
     private static Boolean sHasMenuButton;
     private HardwareUtils() {
     }
     public static void init(Context context) {
         if (sContext != null) {
             Log.w(LOGTAG, "HardwareUtils.init called twice!");
         }
         sContext = context;
     }
     public static boolean isTablet() {
         return isLargeTablet() || isSmallTablet();
     }
     public static boolean isLargeTablet() {
         if (sIsLargeTablet == null) {
             int screenLayout = sContext.getResources().getConfiguration().screenLayout;
             sIsLargeTablet = (Build.VERSION.SDK_INT >= 11 &&
                               ((screenLayout & Configuration.SCREENLAYOUT_SIZE_MASK) == Configuration.SCREENLAYOUT_SIZE_XLARGE));
         }
         return sIsLargeTablet;
     }
     public static boolean isSmallTablet() {
         if (sIsSmallTablet == null) {
             int screenLayout = sContext.getResources().getConfiguration().screenLayout;
             sIsSmallTablet = (Build.VERSION.SDK_INT >= 11 &&
                               ((screenLayout & Configuration.SCREENLAYOUT_SIZE_MASK) == Configuration.SCREENLAYOUT_SIZE_LARGE));
         }
         return sIsSmallTablet;
     }
     public static boolean isTelevision() {
         if (sIsTelevision == null) {
             sIsTelevision = sContext.getPackageManager().hasSystemFeature(PackageManager.FEATURE_TELEVISION);
         }
         return sIsTelevision;
     }
     public static boolean hasMenuButton() {
         if (sHasMenuButton == null) {
             sHasMenuButton = Boolean.TRUE;
             if (Build.VERSION.SDK_INT >= 11) {
                 sHasMenuButton = Boolean.FALSE;
             }
             if (Build.VERSION.SDK_INT >= 14) {
                 sHasMenuButton = ViewConfiguration.get(sContext).hasPermanentMenuKey();
             }
         }
         return sHasMenuButton;
     }
     /**
     * Helper functions used to extract key/value data from /proc/meminfo
     * Pulled from:
     * http://androidxref.com/4.2_r1/xref/frameworks/base/core/java/com/android/internal/util/MemInfoReader.java
     */
     private static boolean matchMemText(byte[] buffer, int index, int bufferLength, byte[] text) {
         final int N = text.length;
         if ((index + N) >= bufferLength) {
             return false;
         }
         for (int i = 0; i < N; i++) {
             if (buffer[index + i] != text[i]) {
                 return false;
             }
         }
         return true;
     }
     /**
      * Parses a line like:
      *
      *  MemTotal: 1605324 kB
      *
      * into 1605324.
      *
      * @return the first uninterrupted sequence of digits following the
      *         specified index, parsed as an integer value in KB.
      */
     private static int extractMemValue(byte[] buffer, int offset, int length) {
         if (offset >= length) {
             return 0;
         }
         while (offset < length && buffer[offset] != '\n') {
             if (buffer[offset] >= '0' && buffer[offset] <= '9') {
                 int start = offset++;
                 while (offset < length &&
                        buffer[offset] >= '0' &&
                        buffer[offset] <= '9') {
                     ++offset;
                 }
                 return Integer.parseInt(new String(buffer, start, offset - start), 10);
             }
             ++offset;
         }
         return 0;
     }
     /**
      * Fetch the total memory of the device in MB by parsing /proc/meminfo.
      *
      * Of course, Android doesn't have a neat and tidy way to find total
      * RAM, so we do it by parsing /proc/meminfo.
      *
      * @return 0 if a problem occurred, or memory size in MB.
      */
     public static int getMemSize() {
         if (sTotalRAM >= 0) {
             return sTotalRAM;
         }
         // This is the string "MemTotal" that we're searching for in the buffer.
         final byte[] MEMTOTAL = {'M', 'e', 'm', 'T', 'o', 't', 'a', 'l'};
         try {
             final byte[] buffer = new byte[MEMINFO_BUFFER_SIZE_BYTES];
             final FileInputStream is = new FileInputStream("/proc/meminfo");
             try {
                 final int length = is.read(buffer);
                 for (int i = 0; i < length; i++) {
                     if (matchMemText(buffer, i, length, MEMTOTAL)) {
                         i += 8;
                         sTotalRAM = extractMemValue(buffer, i, length) / 1024;
                         Log.d(LOGTAG, "System memory: " + sTotalRAM + "MB.");
                         return sTotalRAM;
                     }
                 }
             } finally {
                 is.close();
             }
             Log.w(LOGTAG, "Did not find MemTotal line in /proc/meminfo.");
             return sTotalRAM = 0;
         } catch (FileNotFoundException f) {
             return sTotalRAM = 0;
         } catch (IOException e) {
             return sTotalRAM = 0;
         }
     }
     public static boolean isLowMemoryPlatform() {
         final int memSize = getMemSize();
         // Fallback to false if we fail to read meminfo
         // for some reason.
         if (memSize == 0) {
             Log.w(LOGTAG, "Could not compute system memory. Falling back to isLowMemoryPlatform = false.");
             return false;
         }
         return memSize < LOW_MEMORY_THRESHOLD_MB;
     }
 }

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mobile/android/base/util/HardwareUtils.java@fc2d59ddac77 (annotated)

mobile/android/base/util/HardwareUtils.java