Multithreading UrlRequestInterceptor

- Add parse() free function to UrlRequestInterceptor
- hostlists are loaded in parallel via QtConcurrent

2 files changed, 52 insertions, 51 deletions

diff --git a/src/webengine/urlinterceptor.cpp b/src/webengine/urlinterceptor.cpp
index 91919ea..e88e5b7 100644
--- a/src/webengine/urlinterceptor.cpp
+++ b/src/webengine/urlinterceptor.cpp
@@ -9,76 +9,76 @@
 #include "urlinterceptor.h"
 #include <QDir>
 #include <QTextStream>
+#include <QtConcurrent>
 
 UrlRequestInterceptor::UrlRequestInterceptor(const QString &path, QObject *parent)
     : QWebEngineUrlRequestInterceptor(parent)
 {
-#ifdef QT_DEBUG
-    qDebug("Reading request blocklist: %s", qUtf8Printable(path));
-#endif
-
     QDir hostsD(path);
     const QStringList hostFiles = hostsD.entryList(QDir::Files);
     for(const QString &file : hostFiles) {
-        qDebug("Parsing hosts.d/%s: %i", qUtf8Printable(file), parseHostfile(hostsD.absoluteFilePath(file)));
-    }
+        const QString absPath = hostsD.absoluteFilePath(file);
+        QtConcurrent::run([this, absPath]() {
+            auto r = parse(absPath);
+#ifdef QT_DEBUG
+            qDebug("Parsed %i rules from %s", r.count(), qUtf8Printable(absPath));
+#endif
 
-    qDebug("Total number of rules: %i", m_rules.count());
+            rulesLock.lock();
+            for(const auto &k : r.keys()) {
+                if(rules.contains(k)) {
+                    //
+                } else {
+                    rules.insert(k, r.value(k));
+                }
+            }
+            rulesLock.unlock();
+        });
+    }
 }
 
-UrlRequestInterceptor::~UrlRequestInterceptor()
-{
-    qDeleteAll(m_rules);
-}
+UrlRequestInterceptor::~UrlRequestInterceptor() = default;
 
 void UrlRequestInterceptor::interceptRequest(QWebEngineUrlRequestInfo &info)
 {
-    if(m_rules.contains(info.requestUrl().host())) {
-        if(m_rules.value(info.requestUrl().host())->isBlocking) {
-            info.block(true);
-        }
+    rulesLock.lock();
+    if(rules.contains(info.requestUrl().host())) {
+        info.block(rules.value(info.requestUrl().host()).isBlocking);
     }
+    rulesLock.unlock();
 }
 
-int UrlRequestInterceptor::parseHostfile(const QString &filename)
+QHash<QString, UrlRequestInterceptor::HostRule> parse(const QString &filename)
 {
-    int numRules = 0;
-    QFile file(filename);
+    QHash<QString, UrlRequestInterceptor::HostRule> rules;
 
-    // try to open the file
-    if(file.open(QIODevice::ReadOnly | QIODevice::Text)) {
+    QFile hostfile(filename);
+    if(hostfile.open(QIODevice::ReadOnly | QIODevice::Text)) {
 
         // with a QTextStream we can read lines without getting linebreaks at the end
-        QTextStream out(&file);
-        while(!out.atEnd()) {
-            const QString &line = out.readLine().trimmed();
+        QTextStream hostfile_stream(&hostfile);
+        while(!hostfile_stream.atEnd()) {
+            // read line and remove any whitespace at the end
+            const QString &line = hostfile_stream.readLine().trimmed();
 
             // skip comments and empty lines
-            if(!line.startsWith('#') && !line.isEmpty()) {
-                // format is <redirect> <host>
-                //0.0.0.0 host
-                QStringList parts = line.split(' ');
-                QString redirect = parts.at(0);
-                QString host = parts.at(1);
+            // everything else should be a rule
+            // format is <redirect> <host>
+            // 0.0.0.0 hostname
+            const QStringList &parts = line.split(' ');
+            const QString &redirect = parts.at(0);
 
-                if(m_rules.contains(host)) {
-                    qWarning("Duplicate rule %s", qUtf8Printable(line));
-                }
-
-                if(redirect == "0.0.0.0") {
-                    HostRule *rule = new HostRule;
-                    rule->isBlocking = true;
-                    m_rules.insert(host, rule);
-
-                    ++numRules;
-                } else {
-                    qDebug("Ignoring rule %s", qUtf8Printable(line));
+            for(const QString &host : parts.mid(1)) {
+                if(!rules.contains(host)) {
+                    UrlRequestInterceptor::HostRule rule{};
+                    rule.isBlocking = redirect == "0.0.0.0";
+                    rules.insert(host, rule);
                 }
             }
         }
 
-        // close once we're done with it
-        file.close();
+        hostfile.close();
     }
-    return numRules;
-}
+
+    return rules;
+};
\ No newline at end of file
diff --git a/src/webengine/urlinterceptor.h b/src/webengine/urlinterceptor.h
index b34d9ff..af15f99 100644
--- a/src/webengine/urlinterceptor.h
+++ b/src/webengine/urlinterceptor.h
@@ -10,6 +10,7 @@
 #define URLREQUESTINTERCEPTOR_H
 
 #include <QWebEngineUrlRequestInterceptor>
+#include <QMutex>
 
 class UrlRequestInterceptor : public QWebEngineUrlRequestInterceptor
 {
@@ -20,15 +21,15 @@ public:
     };
 
     explicit UrlRequestInterceptor(const QString &path, QObject *parent = nullptr);
-    ~UrlRequestInterceptor();
+    ~UrlRequestInterceptor() override;
 
-    void interceptRequest(QWebEngineUrlRequestInfo &info);
-
-public slots:
-    int parseHostfile(const QString &filename);
+    void interceptRequest(QWebEngineUrlRequestInfo &info) override;
 
 private:
-    QHash<QString, HostRule *> m_rules;
+    QHash<QString, HostRule> rules;
+    QMutex rulesLock;
 };
 
+QHash<QString, UrlRequestInterceptor::HostRule> parse(const QString &filename);
+
 #endif // URLREQUESTINTERCEPTOR_H