AdBlock: Use fast search tree for basic rules

For all rules that can be matched with simple string-contains match,
use fast tree searching.
Only in EasyList, there is 6000 those rules.
It improves overall performance of AdBlock matching by 5 - 10 times,
at the cost of memory.
The tree needs about 1.5MB memory for 1000 rules, which is a great
tradeoff for such big performance improvement.

src/lib/adblock/adblocksearchtree.cpp

@@ -0,0 +1,134 @@
+/* ============================================================
+* QupZilla - WebKit based browser
+* Copyright (C) 2013  David Rosca <nowrep@gmail.com>
+*
+* This program is free software: you can redistribute it and/or modify
+* it under the terms of the GNU General Public License as published by
+* the Free Software Foundation, either version 3 of the License, or
+* (at your option) any later version.
+*
+* This program is distributed in the hope that it will be useful,
+* but WITHOUT ANY WARRANTY; without even the implied warranty of
+* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+* GNU General Public License for more details.
+*
+* You should have received a copy of the GNU General Public License
+* along with this program.  If not, see <http://www.gnu.org/licenses/>.
+* ============================================================ */
+#include "adblocksearchtree.h"
+#include "adblockrule.h"
+
+#include <QDebug>
+
+AdBlockSearchTree::AdBlockSearchTree()
+    : m_root(new Node)
+{
+}
+
+bool AdBlockSearchTree::add(const AdBlockRule* rule)
+{
+    if (rule->m_type != AdBlockRule::StringContainsMatchRule) {
+        return false;
+    }
+
+    const QString &filter = rule->m_matchString;
+    int len = filter.size();
+
+    if (len <= 0) {
+        qDebug() << "AdBlockSearchTree: Inserting rule with filter len <= 0!";
+        return false;
+    }
+
+    Node* node = m_root;
+
+    for (int i = 0; i < len; ++i) {
+        const QChar &c = filter.at(i);
+        if (!node->childs.contains(c)) {
+            Node* n = new Node;
+            n->c = c;
+
+            node->childs[c] = n;
+        }
+
+        node = node->childs[c];
+    }
+
+    node->rule = rule;
+
+    return true;
+}
+
+const AdBlockRule* AdBlockSearchTree::find(const QNetworkRequest &request, const QString &domain, const QString &string)
+{
+    int len = string.size();
+
+    if (len <= 0) {
+        return 0;
+    }
+
+    for (int i = 0; i < len; ++i) {
+        const AdBlockRule* rule = prefixSearch(request, domain, string, string.mid(i));
+        if (rule) {
+            return rule;
+        }
+    }
+
+    return 0;
+}
+
+const AdBlockRule* AdBlockSearchTree::prefixSearch(const QNetworkRequest &request, const QString &domain, const QString &urlString, const QString &string)
+{
+    int len = string.size();
+
+    if (len <= 0) {
+        return 0;
+    }
+
+    QChar c = string.at(0);
+
+    if (!m_root->childs.contains(c)) {
+        return 0;
+    }
+
+    Node* node = m_root->childs[c];
+
+    for (int i = 1; i < len; ++i) {
+        const QChar &c = string.at(i);
+
+        if (node->rule && node->rule->networkMatch(request, domain, urlString)) {
+            return node->rule;
+        }
+
+        if (!node->childs.contains(c)) {
+            return 0;
+        }
+
+        node = node->childs[c];
+    }
+
+    if (node->rule && node->rule->networkMatch(request, domain, urlString)) {
+        return node->rule;
+    }
+
+    return 0;
+}
+
+void AdBlockSearchTree::deleteNode(AdBlockSearchTree::Node* node)
+{
+    if (!node) {
+        return;
+    }
+
+    QHashIterator<QChar, Node*> i(node->childs);
+    while (i.hasNext()) {
+        i.next();
+        deleteNode(i.value());
+    }
+
+    delete node;
+}
+
+AdBlockSearchTree::~AdBlockSearchTree()
+{
+    deleteNode(m_root);
+}

src/lib/adblock/adblocksearchtree.h

@@ -0,0 +1,56 @@
+/* ============================================================
+* QupZilla - WebKit based browser
+* Copyright (C) 2013  David Rosca <nowrep@gmail.com>
+*
+* This program is free software: you can redistribute it and/or modify
+* it under the terms of the GNU General Public License as published by
+* the Free Software Foundation, either version 3 of the License, or
+* (at your option) any later version.
+*
+* This program is distributed in the hope that it will be useful,
+* but WITHOUT ANY WARRANTY; without even the implied warranty of
+* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+* GNU General Public License for more details.
+*
+* You should have received a copy of the GNU General Public License
+* along with this program.  If not, see <http://www.gnu.org/licenses/>.
+* ============================================================ */
+#ifndef ADBLOCKSEARCHTREE_H
+#define ADBLOCKSEARCHTREE_H
+
+#include <QChar>
+#include <QHash>
+
+#include "qz_namespace.h"
+
+class QNetworkRequest;
+
+class AdBlockRule;
+
+class QT_QUPZILLA_EXPORT AdBlockSearchTree
+{
+public:
+    explicit AdBlockSearchTree();
+    ~AdBlockSearchTree();
+
+    bool add(const AdBlockRule* rule);
+    const AdBlockRule* find(const QNetworkRequest &request, const QString &domain, const QString &string);
+
+private:
+    struct Node {
+        QChar c;
+        const AdBlockRule* rule;
+        QHash<QChar, Node*> childs;
+
+        Node() : c(0) , rule(0) { }
+    };
+
+    const AdBlockRule* prefixSearch(const QNetworkRequest &request, const QString &domain,
+                                    const QString &urlString, const QString &string);
+
+    void deleteNode(Node* node);
+
+    Node* m_root;
+};
+
+#endif // ADBLOCKSEARCHTREE_H

src/lib/adblock/adblocksubscription.cpp

@@ -44,6 +44,7 @@
  */
 #include "adblocksubscription.h"
 #include "adblockmanager.h"
+#include "adblocksearchtree.h"
 #include "mainapplication.h"
 #include "networkmanager.h"
 #include "qztools.h"
@@ -57,6 +58,8 @@
 AdBlockSubscription::AdBlockSubscription(const QString &title, QObject* parent)
     : QObject(parent)
     , m_reply(0)
+    , m_networkBlockTree(0)
+    , m_networkExceptionTree(0)
     , m_title(title)
     , m_updated(false)
 {
@@ -200,6 +203,14 @@ void AdBlockSubscription::saveDownloadedData(const QByteArray &data)
 
 const AdBlockRule* AdBlockSubscription::match(const QNetworkRequest &request, const QString &urlDomain, const QString &urlString) const
 {
+    if (m_networkExceptionTree->find(request, urlDomain, urlString)) {
+        return 0;
+    }
+
+    if (const AdBlockRule* rule = m_networkBlockTree->find(request, urlDomain, urlString)) {
+        return rule;
+    }
+
     int count = m_networkExceptionRules.count();
     for (int i = 0; i < count; ++i) {
         const AdBlockRule* rule = m_networkExceptionRules.at(i);
@@ -373,6 +384,12 @@ void AdBlockSubscription::populateCache()
     m_documentRules.clear();
     m_elemhideRules.clear();
 
+    delete m_networkBlockTree;
+    delete m_networkExceptionTree;
+
+    m_networkBlockTree = new AdBlockSearchTree;
+    m_networkExceptionTree = new AdBlockSearchTree;
+
     // Apparently, excessive amount of selectors for one CSS rule is not what WebKit likes.
     // (In my testings, 4931 is the number that makes it crash)
     // So let's split it by 1000 selectors...
@@ -406,10 +423,14 @@ void AdBlockSubscription::populateCache()
             m_elemhideRules.append(rule);
         }
         else if (rule->isException()) {
-            m_networkExceptionRules.append(rule);
+            if (!m_networkExceptionTree->add(rule)) {
+                m_networkExceptionRules.append(rule);
+            }
         }
         else {
-            m_networkBlockRules.append(rule);
+            if (!m_networkBlockTree->add(rule)) {
+                m_networkBlockRules.append(rule);
+            }
         }
     }
 
@@ -422,6 +443,8 @@ void AdBlockSubscription::populateCache()
 AdBlockSubscription::~AdBlockSubscription()
 {
     qDeleteAll(m_rules);
+    delete m_networkBlockTree;
+    delete m_networkExceptionTree;
 }
 
 // AdBlockCustomList

src/lib/adblock/adblocksubscription.h

@@ -56,6 +56,7 @@ class QNetworkRequest;
 class QNetworkReply;
 class QUrl;
 
+class AdBlockSearchTree;
 class FollowRedirectReply;
 
 class QT_QUPZILLA_EXPORT AdBlockSubscription : public QObject
@@ -123,6 +124,9 @@ protected:
     QVector<const AdBlockRule*> m_documentRules;
     QVector<const AdBlockRule*> m_elemhideRules;
 
+    AdBlockSearchTree* m_networkBlockTree;
+    AdBlockSearchTree* m_networkExceptionTree;
+
 private:
     QString m_title;
     QString m_filePath;

src/lib/lib.pro

@@ -247,7 +247,8 @@ SOURCES += \
     autofill/passwordbackends/passwordbackend.cpp \
     tools/aesinterface.cpp \
     autofill/passwordbackends/databaseencryptedpasswordbackend.cpp \
-    network/sslerrordialog.cpp
+    network/sslerrordialog.cpp \
+    adblock/adblocksearchtree.cpp
 
 
 HEADERS  += \
@@ -431,7 +432,8 @@ HEADERS  += \
     autofill/passwordbackends/databasepasswordbackend.h \
     tools/aesinterface.h \
     autofill/passwordbackends/databaseencryptedpasswordbackend.h \
-    network/sslerrordialog.h
+    network/sslerrordialog.h \
+    adblock/adblocksearchtree.h
 
 FORMS    += \
     preferences/autofillmanager.ui \