diff -r 000000000000 -r 6474c204b198 mobile/android/base/favicons/Favicons.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mobile/android/base/favicons/Favicons.java	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,483 @@
+/* -*- 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.favicons;
+
+import org.mozilla.gecko.AboutPages;
+import org.mozilla.gecko.AppConstants;
+import org.mozilla.gecko.GeckoAppShell;
+import org.mozilla.gecko.R;
+import org.mozilla.gecko.Tab;
+import org.mozilla.gecko.Tabs;
+import org.mozilla.gecko.db.BrowserDB;
+import org.mozilla.gecko.favicons.cache.FaviconCache;
+import org.mozilla.gecko.util.GeckoJarReader;
+import org.mozilla.gecko.util.NonEvictingLruCache;
+import org.mozilla.gecko.util.ThreadUtils;
+
+import android.content.Context;
+import android.content.res.Resources;
+import android.graphics.Bitmap;
+import android.graphics.BitmapFactory;
+import android.text.TextUtils;
+import android.util.Log;
+import android.util.SparseArray;
+
+import java.io.File;
+import java.net.URI;
+import java.net.URISyntaxException;
+import java.util.Arrays;
+import java.util.Iterator;
+import java.util.List;
+
+public class Favicons {
+    private static final String LOGTAG = "GeckoFavicons";
+
+    // A magic URL representing the app's own favicon, used for about: pages.
+    private static final String BUILT_IN_FAVICON_URL = "about:favicon";
+
+    // Size of the favicon bitmap cache, in bytes (Counting payload only).
+    public static final int FAVICON_CACHE_SIZE_BYTES = 512 * 1024;
+
+    // Number of URL mappings from page URL to Favicon URL to cache in memory.
+    public static final int NUM_PAGE_URL_MAPPINGS_TO_STORE = 128;
+
+    public static final int NOT_LOADING  = 0;
+    public static final int LOADED       = 1;
+    public static final int FLAG_PERSIST = 2;
+    public static final int FLAG_SCALE   = 4;
+
+    protected static Context context;
+
+    // The default Favicon to show if no other can be found.
+    public static Bitmap defaultFavicon;
+
+    // The density-adjusted default Favicon dimensions.
+    public static int defaultFaviconSize;
+
+    // The density-adjusted maximum Favicon dimensions.
+    public static int largestFaviconSize;
+
+    private static final SparseArray<LoadFaviconTask> loadTasks = new SparseArray<LoadFaviconTask>();
+
+    // Cache to hold mappings between page URLs and Favicon URLs. Used to avoid going to the DB when
+    // doing so is not necessary.
+    private static final NonEvictingLruCache<String, String> pageURLMappings = new NonEvictingLruCache<String, String>(NUM_PAGE_URL_MAPPINGS_TO_STORE);
+
+    public static String getFaviconURLForPageURLFromCache(String pageURL) {
+        return pageURLMappings.get(pageURL);
+    }
+
+    /**
+     * Insert the given pageUrl->faviconUrl mapping into the memory cache of such mappings.
+     * Useful for short-circuiting local database access.
+     */
+    public static void putFaviconURLForPageURLInCache(String pageURL, String faviconURL) {
+        pageURLMappings.put(pageURL, faviconURL);
+    }
+
+    private static FaviconCache faviconsCache;
+
+    /**
+     * Returns either NOT_LOADING, or LOADED if the onFaviconLoaded call could
+     * be made on the main thread.
+     * If no listener is provided, NOT_LOADING is returned.
+     */
+    static int dispatchResult(final String pageUrl, final String faviconURL, final Bitmap image,
+            final OnFaviconLoadedListener listener) {
+        if (listener == null) {
+            return NOT_LOADING;
+        }
+
+        if (ThreadUtils.isOnUiThread()) {
+            listener.onFaviconLoaded(pageUrl, faviconURL, image);
+            return LOADED;
+        }
+
+        // We want to always run the listener on UI thread.
+        ThreadUtils.postToUiThread(new Runnable() {
+            @Override
+            public void run() {
+                listener.onFaviconLoaded(pageUrl, faviconURL, image);
+            }
+        });
+        return NOT_LOADING;
+    }
+
+    /**
+     * Only returns a non-null Bitmap if the entire path is cached -- the
+     * page URL to favicon URL, and the favicon URL to in-memory bitmaps.
+     *
+     * Returns null otherwise.
+     */
+    public static Bitmap getSizedFaviconForPageFromCache(final String pageURL, int targetSize) {
+        final String faviconURL = pageURLMappings.get(pageURL);
+        if (faviconURL == null) {
+            return null;
+        }
+        return getSizedFaviconFromCache(faviconURL, targetSize);
+    }
+
+    /**
+     * Get a Favicon as close as possible to the target dimensions for the URL provided.
+     * If a result is instantly available from the cache, it is returned and the listener is invoked.
+     * Otherwise, the result is drawn from the database or network and the listener invoked when the
+     * result becomes available.
+     *
+     * @param pageURL Page URL for which a Favicon is desired.
+     * @param faviconURL URL of the Favicon to be downloaded, if known. If none provided, an educated
+     *                    guess is made by the system.
+     * @param targetSize Target size of the returned Favicon
+     * @param listener Listener to call with the result of the load operation, if the result is not
+     *                  immediately available.
+     * @return The id of the asynchronous task created, NOT_LOADING if none is created, or
+     *         LOADED if the value could be dispatched on the current thread.
+     */
+    public static int getSizedFavicon(String pageURL, String faviconURL, int targetSize, int flags, OnFaviconLoadedListener listener) {
+        // Do we know the favicon URL for this page already?
+        String cacheURL = faviconURL;
+        if (cacheURL == null) {
+            cacheURL = pageURLMappings.get(pageURL);
+        }
+
+        // If there's no favicon URL given, try and hit the cache with the default one.
+        if (cacheURL == null)  {
+            cacheURL = guessDefaultFaviconURL(pageURL);
+        }
+
+        // If it's something we can't even figure out a default URL for, just give up.
+        if (cacheURL == null) {
+            return dispatchResult(pageURL, null, defaultFavicon, listener);
+        }
+
+        Bitmap cachedIcon = getSizedFaviconFromCache(cacheURL, targetSize);
+        if (cachedIcon != null) {
+            return dispatchResult(pageURL, cacheURL, cachedIcon, listener);
+        }
+
+        // Check if favicon has failed.
+        if (faviconsCache.isFailedFavicon(cacheURL)) {
+            return dispatchResult(pageURL, cacheURL, defaultFavicon, listener);
+        }
+
+        // Failing that, try and get one from the database or internet.
+        return loadUncachedFavicon(pageURL, faviconURL, flags, targetSize, listener);
+    }
+
+    /**
+     * Returns the cached Favicon closest to the target size if any exists or is coercible. Returns
+     * null otherwise. Does not query the database or network for the Favicon is the result is not
+     * immediately available.
+     *
+     * @param faviconURL URL of the Favicon to query for.
+     * @param targetSize The desired size of the returned Favicon.
+     * @return The cached Favicon, rescaled to be as close as possible to the target size, if any exists.
+     *         null if no applicable Favicon exists in the cache.
+     */
+    public static Bitmap getSizedFaviconFromCache(String faviconURL, int targetSize) {
+        return faviconsCache.getFaviconForDimensions(faviconURL, targetSize);
+    }
+
+    /**
+     * Attempts to find a Favicon for the provided page URL from either the mem cache or the database.
+     * Does not need an explicit favicon URL, since, as we are accessing the database anyway, we
+     * can query the history DB for the Favicon URL.
+     * Handy for easing the transition from caching with page URLs to caching with Favicon URLs.
+     *
+     * A null result is passed to the listener if no value is locally available. The Favicon is not
+     * added to the failure cache.
+     *
+     * @param pageURL Page URL for which a Favicon is wanted.
+     * @param targetSize Target size of the desired Favicon to pass to the cache query
+     * @param callback Callback to fire with the result.
+     * @return The job ID of the spawned async task, if any.
+     */
+    public static int getSizedFaviconForPageFromLocal(final String pageURL, final int targetSize, final OnFaviconLoadedListener callback) {
+        // Firstly, try extremely hard to cheat.
+        // Have we cached this favicon URL? If we did, we can consult the memcache right away.
+        String targetURL = pageURLMappings.get(pageURL);
+        if (targetURL != null) {
+            // Check if favicon has failed.
+            if (faviconsCache.isFailedFavicon(targetURL)) {
+                return dispatchResult(pageURL, targetURL, null, callback);
+            }
+
+            // Do we have a Favicon in the cache for this favicon URL?
+            Bitmap result = getSizedFaviconFromCache(targetURL, targetSize);
+            if (result != null) {
+                // Victory - immediate response!
+                return dispatchResult(pageURL, targetURL, result, callback);
+            }
+        }
+
+        // No joy using in-memory resources. Go to background thread and ask the database.
+        LoadFaviconTask task = new LoadFaviconTask(ThreadUtils.getBackgroundHandler(), pageURL, targetURL, 0, callback, targetSize, true);
+        int taskId = task.getId();
+        synchronized(loadTasks) {
+            loadTasks.put(taskId, task);
+        }
+        task.execute();
+        return taskId;
+    }
+
+    public static int getSizedFaviconForPageFromLocal(final String pageURL, final OnFaviconLoadedListener callback) {
+        return getSizedFaviconForPageFromLocal(pageURL, defaultFaviconSize, callback);
+    }
+
+    /**
+     * Helper method to determine the URL of the Favicon image for a given page URL by querying the
+     * history database. Should only be called from the background thread - does database access.
+     *
+     * @param pageURL The URL of a webpage with a Favicon.
+     * @return The URL of the Favicon used by that webpage, according to either the History database
+     *         or a somewhat educated guess.
+     */
+    public static String getFaviconURLForPageURL(String pageURL) {
+        // Attempt to determine the Favicon URL from the Tabs datastructure. Can dodge having to use
+        // the database sometimes by doing this.
+        String targetURL;
+        Tab theTab = Tabs.getInstance().getFirstTabForUrl(pageURL);
+        if (theTab != null) {
+            targetURL = theTab.getFaviconURL();
+            if (targetURL != null) {
+                return targetURL;
+            }
+        }
+
+        targetURL = BrowserDB.getFaviconUrlForHistoryUrl(context.getContentResolver(), pageURL);
+        if (targetURL == null) {
+            // Nothing in the history database. Fall back to the default URL and hope for the best.
+            targetURL = guessDefaultFaviconURL(pageURL);
+        }
+        return targetURL;
+    }
+
+    /**
+     * Helper function to create an async job to load a Favicon which does not exist in the memcache.
+     * Contains logic to prevent the repeated loading of Favicons which have previously failed.
+     * There is no support for recovery from transient failures.
+     *
+     * @param pageUrl URL of the page for which to load a Favicon. If null, no job is created.
+     * @param faviconUrl The URL of the Favicon to load. If null, an attempt to infer the value from
+     *                   the history database will be made, and ultimately an attempt to guess will
+     *                   be made.
+     * @param flags Flags to be used by the LoadFaviconTask while loading. Currently only one flag
+     *              is supported, LoadFaviconTask.FLAG_PERSIST.
+     *              If FLAG_PERSIST is set and the Favicon is ultimately loaded from the internet,
+     *              the downloaded Favicon is subsequently stored in the local database.
+     *              If FLAG_PERSIST is unset, the downloaded Favicon is stored only in the memcache.
+     *              FLAG_PERSIST has no effect on loads which come from the database.
+     * @param listener The OnFaviconLoadedListener to invoke with the result of this Favicon load.
+     * @return The id of the LoadFaviconTask handling this job.
+     */
+    private static int loadUncachedFavicon(String pageUrl, String faviconUrl, int flags, int targetSize, OnFaviconLoadedListener listener) {
+        // Handle the case where we have no page url.
+        if (TextUtils.isEmpty(pageUrl)) {
+            dispatchResult(null, null, null, listener);
+            return NOT_LOADING;
+        }
+
+        LoadFaviconTask task = new LoadFaviconTask(ThreadUtils.getBackgroundHandler(), pageUrl, faviconUrl, flags, listener, targetSize, false);
+
+        int taskId = task.getId();
+        synchronized(loadTasks) {
+            loadTasks.put(taskId, task);
+        }
+
+        task.execute();
+
+        return taskId;
+    }
+
+    public static void putFaviconInMemCache(String pageUrl, Bitmap image) {
+        faviconsCache.putSingleFavicon(pageUrl, image);
+    }
+
+    /**
+     * Adds the bitmaps given by the specified iterator to the cache associated with the url given.
+     * Future requests for images will be able to select the least larger image than the target
+     * size from this new set of images.
+     *
+     * @param pageUrl The URL to associate the new favicons with.
+     * @param images An iterator over the new favicons to put in the cache.
+     */
+    public static void putFaviconsInMemCache(String pageUrl, Iterator<Bitmap> images, boolean permanently) {
+        faviconsCache.putFavicons(pageUrl, images, permanently);
+    }
+
+    public static void putFaviconsInMemCache(String pageUrl, Iterator<Bitmap> images) {
+        putFaviconsInMemCache(pageUrl, images, false);
+    }
+
+    public static void clearMemCache() {
+        faviconsCache.evictAll();
+        pageURLMappings.evictAll();
+    }
+
+    public static void putFaviconInFailedCache(String faviconURL) {
+        faviconsCache.putFailed(faviconURL);
+    }
+
+    public static boolean cancelFaviconLoad(int taskId) {
+        if (taskId == NOT_LOADING) {
+            return false;
+        }
+
+        boolean cancelled;
+        synchronized (loadTasks) {
+            if (loadTasks.indexOfKey(taskId) < 0) {
+                return false;
+            }
+
+            Log.v(LOGTAG, "Cancelling favicon load " + taskId + ".");
+
+            LoadFaviconTask task = loadTasks.get(taskId);
+            cancelled = task.cancel(false);
+        }
+        return cancelled;
+    }
+
+    public static void close() {
+        Log.d(LOGTAG, "Closing Favicons database");
+
+        // Cancel any pending tasks
+        synchronized (loadTasks) {
+            final int count = loadTasks.size();
+            for (int i = 0; i < count; i++) {
+                cancelFaviconLoad(loadTasks.keyAt(i));
+            }
+            loadTasks.clear();
+        }
+
+        LoadFaviconTask.closeHTTPClient();
+    }
+
+    /**
+     * Get the dominant colour of the Favicon at the URL given, if any exists in the cache.
+     *
+     * @param url The URL of the Favicon, to be used as the cache key for the colour value.
+     * @return The dominant colour of the provided Favicon.
+     */
+    public static int getFaviconColor(String url) {
+        return faviconsCache.getDominantColor(url);
+    }
+
+    /**
+     * Called by GeckoApp on startup to pass this class a reference to the GeckoApp object used as
+     * the application's Context.
+     * Consider replacing with references to a staticly held reference to the GeckoApp object.
+     *
+     * @param context A reference to the GeckoApp instance.
+     */
+    public static void attachToContext(Context context) throws Exception {
+        final Resources res = context.getResources();
+        Favicons.context = context;
+
+        // Decode the default Favicon ready for use.
+        defaultFavicon = BitmapFactory.decodeResource(res, R.drawable.favicon);
+        if (defaultFavicon == null) {
+            throw new Exception("Null default favicon was returned from the resources system!");
+        }
+
+        defaultFaviconSize = res.getDimensionPixelSize(R.dimen.favicon_bg);
+
+        // Screen-density-adjusted upper limit on favicon size. Favicons larger than this are
+        // downscaled to this size or discarded.
+        largestFaviconSize = context.getResources().getDimensionPixelSize(R.dimen.favicon_largest_interesting_size);
+        faviconsCache = new FaviconCache(FAVICON_CACHE_SIZE_BYTES, largestFaviconSize);
+
+        // Initialize page mappings for each of our special pages.
+        for (String url : AboutPages.getDefaultIconPages()) {
+            pageURLMappings.putWithoutEviction(url, BUILT_IN_FAVICON_URL);
+        }
+
+        // Load and cache the built-in favicon in each of its sizes.
+        // TODO: don't open the zip twice!
+        List<Bitmap> toInsert = Arrays.asList(loadBrandingBitmap(context, "favicon64.png"),
+                                              loadBrandingBitmap(context, "favicon32.png"));
+
+        putFaviconsInMemCache(BUILT_IN_FAVICON_URL, toInsert.iterator(), true);
+    }
+
+    /**
+     * Compute a string like:
+     * "jar:jar:file:///data/app/org.mozilla.firefox-1.apk!/assets/omni.ja!/chrome/chrome/content/branding/favicon64.png"
+     */
+    private static String getBrandingBitmapPath(Context context, String name) {
+        final String apkPath = context.getPackageResourcePath();
+        return "jar:jar:" + new File(apkPath).toURI() + "!/" +
+               AppConstants.OMNIJAR_NAME + "!/" +
+               "chrome/chrome/content/branding/" + name;
+    }
+
+    private static Bitmap loadBrandingBitmap(Context context, String name) {
+        Bitmap b = GeckoJarReader.getBitmap(context.getResources(),
+                                            getBrandingBitmapPath(context, name));
+        if (b == null) {
+            throw new IllegalStateException("Bitmap " + name + " missing from JAR!");
+        }
+        return b;
+    }
+
+    /**
+     * Helper method to get the default Favicon URL for a given pageURL. Generally: somewhere.com/favicon.ico
+     *
+     * @param pageURL Page URL for which a default Favicon URL is requested
+     * @return The default Favicon URL.
+     */
+    public static String guessDefaultFaviconURL(String pageURL) {
+        // Special-casing for about: pages. The favicon for about:pages which don't provide a link tag
+        // is bundled in the database, keyed only by page URL, hence the need to return the page URL
+        // here. If the database ever migrates to stop being silly in this way, this can plausibly
+        // be removed.
+        if (AboutPages.isAboutPage(pageURL) || pageURL.startsWith("jar:")) {
+            return pageURL;
+        }
+
+        try {
+            // Fall back to trying "someScheme:someDomain.someExtension/favicon.ico".
+            URI u = new URI(pageURL);
+            return new URI(u.getScheme(),
+                           u.getAuthority(),
+                           "/favicon.ico", null,
+                           null).toString();
+        } catch (URISyntaxException e) {
+            Log.e(LOGTAG, "URISyntaxException getting default favicon URL", e);
+            return null;
+        }
+    }
+
+    public static void removeLoadTask(int taskId) {
+        synchronized(loadTasks) {
+            loadTasks.delete(taskId);
+        }
+    }
+
+    /**
+     * Method to wrap FaviconCache.isFailedFavicon for use by LoadFaviconTask.
+     *
+     * @param faviconURL Favicon URL to check for failure.
+     */
+    static boolean isFailedFavicon(String faviconURL) {
+        return faviconsCache.isFailedFavicon(faviconURL);
+    }
+
+    /**
+     * Sidestep the cache and get, from either the database or the internet, a favicon
+     * suitable for use as an app icon for the provided URL.
+     *
+     * Useful for creating homescreen shortcuts without being limited
+     * by possibly low-resolution values in the cache.
+     *
+     * Deduces the favicon URL from the browser database, guessing if necessary.
+     *
+     * @param url page URL to get a large favicon image for.
+     * @param onFaviconLoadedListener listener to call back with the result.
+     */
+    public static void getPreferredSizeFaviconForPage(String url, OnFaviconLoadedListener onFaviconLoadedListener) {
+        int preferredSize = GeckoAppShell.getPreferredIconSize();
+        loadUncachedFavicon(url, null, 0, preferredSize, onFaviconLoadedListener);
+    }
+}