Reimplement the settings to use async callbacks

1 files changed, 182 insertions, 81 deletions

diff --git a/core/java/android/webkit/WebStorage.java b/core/java/android/webkit/WebStorage.java
index ae560fb..0022248 100644
--- a/core/java/android/webkit/WebStorage.java
+++ b/core/java/android/webkit/WebStorage.java
@@ -20,9 +20,8 @@ import android.os.Handler;
 import android.os.Message;
 import android.util.Log;
 
-import java.util.concurrent.locks.Condition;
-import java.util.concurrent.locks.Lock;
-import java.util.concurrent.locks.ReentrantLock;
+import java.util.Collection;
+import java.util.Map;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Iterator;
@@ -51,28 +50,41 @@ public final class WebStorage {
     // Global instance of a WebStorage
     private static WebStorage sWebStorage;
 
-    // We keep the origins, quotas and usages as member values
-    // that we protect via a lock and update in syncValues().
-    // This is needed to transfer this data across threads.
-    private static Lock mLock = new ReentrantLock();
-    private static Condition mUpdateCondition = mLock.newCondition();
-    private static boolean mUpdateAvailable;
-
     // Message ids
     static final int UPDATE = 0;
     static final int SET_QUOTA_ORIGIN = 1;
     static final int DELETE_ORIGIN = 2;
     static final int DELETE_ALL = 3;
+    static final int GET_ORIGINS = 4;
+    static final int GET_USAGE_ORIGIN = 5;
+    static final int GET_QUOTA_ORIGIN = 6;
+
+    // Message ids on the UI thread
+    static final int RETURN_ORIGINS = 0;
+    static final int RETURN_USAGE_ORIGIN = 1;
+    static final int RETURN_QUOTA_ORIGIN = 2;
+
+    private static final String ORIGINS = "origins";
+    private static final String ORIGIN = "origin";
+    private static final String CALLBACK = "callback";
+    private static final String USAGE = "usage";
+    private static final String QUOTA = "quota";
 
-    private Set <String> mOrigins;
-    private HashMap <String, Long> mQuotas = new HashMap<String, Long>();
-    private HashMap <String, Long> mUsages = new HashMap<String, Long>();
+    private Map <String, Origin> mOrigins;
 
     private Handler mHandler = null;
+    private Handler mUIHandler = null;
 
-    private static class Origin {
+    static class Origin {
         String mOrigin = null;
         long mQuota = 0;
+        long mUsage = 0;
+
+        public Origin(String origin, long quota, long usage) {
+            mOrigin = origin;
+            mQuota = quota;
+            mUsage = usage;
+        }
 
         public Origin(String origin, long quota) {
             mOrigin = origin;
@@ -90,11 +102,49 @@ public final class WebStorage {
         public long getQuota() {
             return mQuota;
         }
+
+        public long getUsage() {
+            return mUsage;
+        }
+    }
+
+    /**
+     * @hide
+     * Message handler, UI side
+     */
+    public void createUIHandler() {
+        if (mUIHandler == null) {
+            mUIHandler = new Handler() {
+                @Override
+                public void handleMessage(Message msg) {
+                    switch (msg.what) {
+                        case RETURN_ORIGINS: {
+                            Map values = (Map) msg.obj;
+                            Map origins = (Map) values.get(ORIGINS);
+                            ValueCallback<Map> callback = (ValueCallback<Map>) values.get(CALLBACK);
+                            callback.onReceiveValue(origins);
+                            } break;
+
+                        case RETURN_USAGE_ORIGIN: {
+                            Map values = (Map) msg.obj;
+                            ValueCallback<Long> callback = (ValueCallback<Long>) values.get(CALLBACK);
+                            callback.onReceiveValue((Long)values.get(USAGE));
+                            } break;
+
+                        case RETURN_QUOTA_ORIGIN: {
+                            Map values = (Map) msg.obj;
+                            ValueCallback<Long> callback = (ValueCallback<Long>) values.get(CALLBACK);
+                            callback.onReceiveValue((Long)values.get(QUOTA));
+                            } break;
+                    }
+                }
+            };
+        }
     }
 
     /**
      * @hide
-     * Message handler
+     * Message handler, webcore side
      */
     public void createHandler() {
         if (mHandler == null) {
@@ -117,6 +167,46 @@ public final class WebStorage {
                             nativeDeleteAllData();
                             break;
 
+                        case GET_ORIGINS: {
+                            syncValues();
+                            ValueCallback callback = (ValueCallback) msg.obj;
+                            Map origins = new HashMap(mOrigins);
+                            Map values = new HashMap<String, Object>();
+                            values.put(CALLBACK, callback);
+                            values.put(ORIGINS, origins);
+                            postUIMessage(Message.obtain(null, RETURN_ORIGINS, values));
+                            } break;
+
+                        case GET_USAGE_ORIGIN: {
+                            syncValues();
+                            Map values = (Map) msg.obj;
+                            String origin = (String) values.get(ORIGIN);
+                            ValueCallback callback = (ValueCallback) values.get(CALLBACK);
+                            Origin website = mOrigins.get(origin);
+                            Map retValues = new HashMap<String, Object>();
+                            retValues.put(CALLBACK, callback);
+                            if (website != null) {
+                                long usage = website.getUsage();
+                                retValues.put(USAGE, new Long(usage));
+                            }
+                            postUIMessage(Message.obtain(null, RETURN_USAGE_ORIGIN, retValues));
+                            } break;
+
+                        case GET_QUOTA_ORIGIN: {
+                            syncValues();
+                            Map values = (Map) msg.obj;
+                            String origin = (String) values.get(ORIGIN);
+                            ValueCallback callback = (ValueCallback) values.get(CALLBACK);
+                            Origin website = mOrigins.get(origin);
+                            Map retValues = new HashMap<String, Object>();
+                            retValues.put(CALLBACK, callback);
+                            if (website != null) {
+                                long quota = website.getQuota();
+                                retValues.put(QUOTA, new Long(quota));
+                            }
+                            postUIMessage(Message.obtain(null, RETURN_QUOTA_ORIGIN, retValues));
+                            } break;
+
                         case UPDATE:
                             syncValues();
                             break;
@@ -126,82 +216,91 @@ public final class WebStorage {
         }
     }
 
+    /*
+     * When calling getOrigins(), getUsageForOrigin() and getQuotaForOrigin(),
+     * we need to get the values from webcore, but we cannot block while doing so
+     * as we used to do, as this could result in a full deadlock (other webcore
+     * messages received while we are still blocked here, see http://b/2127737).
+     *
+     * We have to do everything asynchronously, by providing a callback function.
+     * We post a message on the webcore thread (mHandler) that will get the result
+     * from webcore, and we post it back on the UI thread (using mUIHandler).
+     * We can then use the callback function to return the value.
+     */
+
     /**
      * @hide
      * Returns a list of origins having a database
      */
-    public Set getOrigins() {
-        Set ret = null;
-        mLock.lock();
-        try {
-            mUpdateAvailable = false;
-            update();
-            while (!mUpdateAvailable) {
-                mUpdateCondition.await();
+    public void getOrigins(ValueCallback<Map> callback) {
+        if (callback != null) {
+            if (WebViewCore.THREAD_NAME.equals(Thread.currentThread().getName())) {
+                syncValues();
+                callback.onReceiveValue(mOrigins);
+            } else {
+                postMessage(Message.obtain(null, GET_ORIGINS, callback));
             }
-            ret = mOrigins;
-        } catch (InterruptedException e) {
-            Log.e(TAG, "Exception while waiting on the updated origins", e);
-        } finally {
-            mLock.unlock();
         }
-        return ret;
+    }
+
+    /**
+     * Returns a list of origins having a database
+     * should only be called from WebViewCore.
+     */
+    Collection<Origin> getOriginsSync() {
+        if (WebViewCore.THREAD_NAME.equals(Thread.currentThread().getName())) {
+            update();
+            return mOrigins.values();
+        }
+        return null;
     }
 
     /**
      * @hide
      * Returns the use for a given origin
      */
-    public long getUsageForOrigin(String origin) {
-        long ret = 0;
+    public void getUsageForOrigin(String origin, ValueCallback<Long> callback) {
+        if (callback == null) {
+            return;
+        }
         if (origin == null) {
-          return ret;
+            callback.onReceiveValue(null);
+            return;
         }
-        mLock.lock();
-        try {
-            mUpdateAvailable = false;
-            update();
-            while (!mUpdateAvailable) {
-                mUpdateCondition.await();
-            }
-            Long usage = mUsages.get(origin);
-            if (usage != null) {
-                ret = usage.longValue();
-            }
-        } catch (InterruptedException e) {
-            Log.e(TAG, "Exception while waiting on the updated origins", e);
-        } finally {
-            mLock.unlock();
+        if (WebViewCore.THREAD_NAME.equals(Thread.currentThread().getName())) {
+            syncValues();
+            Origin website = mOrigins.get(origin);
+            callback.onReceiveValue(new Long(website.getUsage()));
+        } else {
+            HashMap values = new HashMap<String, Object>();
+            values.put(ORIGIN, origin);
+            values.put(CALLBACK, callback);
+            postMessage(Message.obtain(null, GET_USAGE_ORIGIN, values));
         }
-        return ret;
     }
 
     /**
      * @hide
      * Returns the quota for a given origin
      */
-    public long getQuotaForOrigin(String origin) {
-        long ret = 0;
+    public void getQuotaForOrigin(String origin, ValueCallback<Long> callback) {
+        if (callback == null) {
+            return;
+        }
         if (origin == null) {
-          return ret;
+            callback.onReceiveValue(null);
+            return;
         }
-        mLock.lock();
-        try {
-            mUpdateAvailable = false;
-            update();
-            while (!mUpdateAvailable) {
-                mUpdateCondition.await();
-            }
-            Long quota = mQuotas.get(origin);
-            if (quota != null) {
-                ret = quota.longValue();
-            }
-        } catch (InterruptedException e) {
-            Log.e(TAG, "Exception while waiting on the updated origins", e);
-        } finally {
-            mLock.unlock();
+        if (WebViewCore.THREAD_NAME.equals(Thread.currentThread().getName())) {
+            syncValues();
+            Origin website = mOrigins.get(origin);
+            callback.onReceiveValue(new Long(website.getUsage()));
+        } else {
+            HashMap values = new HashMap<String, Object>();
+            values.put(ORIGIN, origin);
+            values.put(CALLBACK, callback);
+            postMessage(Message.obtain(null, GET_QUOTA_ORIGIN, values));
         }
-        return ret;
     }
 
     /**
@@ -256,6 +355,15 @@ public final class WebStorage {
     }
 
     /**
+     * Utility function to send a message to the handler on the UI thread
+     */
+    private void postUIMessage(Message msg) {
+        if (mUIHandler != null) {
+            mUIHandler.sendMessage(msg);
+        }
+    }
+
+    /**
      * @hide
      * Get the global instance of WebStorage.
      * @return A single instance of WebStorage.
@@ -284,21 +392,14 @@ public final class WebStorage {
      * set the local values with the current ones
      */
     private void syncValues() {
-        mLock.lock();
-        Set tmp = nativeGetOrigins();
-        mOrigins = new HashSet<String>();
-        mQuotas.clear();
-        mUsages.clear();
-        Iterator<String> iter = tmp.iterator();
-        while (iter.hasNext()) {
-            String origin = iter.next();
-            mOrigins.add(origin);
-            mQuotas.put(origin, new Long(nativeGetQuotaForOrigin(origin)));
-            mUsages.put(origin, new Long(nativeGetUsageForOrigin(origin)));
+        Set<String> tmp = nativeGetOrigins();
+        mOrigins = new HashMap<String, Origin>();
+        for (String origin : tmp) {
+            Origin website = new Origin(origin,
+                                 nativeGetUsageForOrigin(origin),
+                                 nativeGetQuotaForOrigin(origin));
+            mOrigins.put(origin, website);
         }
-        mUpdateAvailable = true;
-        mUpdateCondition.signal();
-        mLock.unlock();
     }
 
     // Native functions