staging: smolblok

smolblok is a replacement for the current lib/urlfilter AdBlockPlus
and hostlist format filter parser. It is a library that uses plugins to
provide support for different filter formats.

staging/adblock: AdBlockPlus parser plugin
plugins/smolblok_hostlist: hostlist format parser plugin

Headers will be installed to include/smolbote/

Remove lib/urlfilter

8 files changed, 243 insertions, 0 deletions

diff --git a/staging/smolblok/README.md b/staging/smolblok/README.md
new file mode 100644
index 0000000..1793009
--- /dev/null
+++ b/staging/smolblok/README.md
@@ -0,0 +1,8 @@
+## smolblok
+
+### What is this
+This is a C++ library for URL filtering for Qt applications using QtWebEngine. 
+
+### Supported formats
+- AdblockPlus without element hiding rules
+
diff --git a/staging/smolblok/filtermanager.hpp b/staging/smolblok/filtermanager.hpp
new file mode 100644
index 0000000..6ee4d3f
--- /dev/null
+++ b/staging/smolblok/filtermanager.hpp
@@ -0,0 +1,41 @@
+/*
+ * This file is part of smolbote. It's copyrighted by the contributors recorded
+ * in the version control history of the file, available from its original
+ * location: https://library.iserlohn-fortress.net/aqua/smolbote.git
+ *
+ * SPDX-License-Identifier: GPL-3.0
+ */
+
+#pragma once
+
+#include <QWebEngineUrlRequestInterceptor>
+#include <smolbote/filterinterface.hpp>
+
+class FilterManager : public QWebEngineUrlRequestInterceptor
+{
+public:
+    FilterManager(QObject *parent = nullptr)
+        : QWebEngineUrlRequestInterceptor(parent)
+    {
+    }
+    ~FilterManager()
+    {
+        qDeleteAll(filters);
+    }
+
+    void addFilterList(FilterList  *list) {
+        filters.append(list);
+    }
+
+    void interceptRequest(QWebEngineUrlRequestInfo &info) override
+    {
+        for(const auto *filter : qAsConst(filters)) {
+            if(filter->filter(info)) {
+                return;
+            }
+        }
+    }
+
+private:
+    QList<FilterList *> filters;
+};
diff --git a/staging/smolblok/meson.build b/staging/smolblok/meson.build
new file mode 100644
index 0000000..6105179
--- /dev/null
+++ b/staging/smolblok/meson.build
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+dep_smolblok = declare_dependency(
+  include_directories: [ '.', smolbote_interfaces ],
+  link_with: library('smolblok',
+    [ 'smolblok.cpp' ],
+    include_directories: smolbote_interfaces,
+    dependencies: dep_qt5
+  )
+)
+
+smolblok_load = executable('smolblok-load',
+  dependencies: [ dep_qt5, dep_spdlog, dep_smolblok ],
+  sources: [ 'test/loader.cpp' ]
+)
+
+test('load', smolblok_load, suite: 'smolblok', should_fail: true)
+test('load', smolblok_load, suite: 'smolblok', args: files('meson.build'), should_fail: true)
+
diff --git a/staging/smolblok/smolblok.cpp b/staging/smolblok/smolblok.cpp
new file mode 100644
index 0000000..465c348
--- /dev/null
+++ b/staging/smolblok/smolblok.cpp
@@ -0,0 +1,40 @@
+/*
+ * This file is part of smolbote. It's copyrighted by the contributors recorded
+ * in the version control history of the file, available from its original
+ * location: https://library.iserlohn-fortress.net/aqua/smolbote.git
+ *
+ * SPDX-License-Identifier: GPL-3.0
+ */
+
+#include "smolblok.hpp"
+#include <QFile>
+#include <QSettings>
+
+bool smolblok::addSubscriptions(const QString &filename)
+{
+    if(filename.isEmpty()) {
+        return false;
+    }
+
+    QSettings listconf(filename, QSettings::IniFormat);
+
+    for(auto &group : listconf.childGroups()) {
+        listconf.beginGroup(group);
+        const auto *loader = m_formats.value(listconf.value("Format").toString()).instance;
+        if(loader != nullptr) {
+            QFile f(listconf.value("File").toString());
+            if(!f.exists()) {
+                continue;
+            }
+
+            auto *list = loader->load(f);
+            f.seek(0);
+            if(loader->parse(list, f)) {
+                m_subscriptions.addFilterList(list);
+            }
+        }
+        listconf.endGroup();
+    }
+    return false;
+}
+
diff --git a/staging/smolblok/smolblok.hpp b/staging/smolblok/smolblok.hpp
new file mode 100644
index 0000000..e547d67
--- /dev/null
+++ b/staging/smolblok/smolblok.hpp
@@ -0,0 +1,80 @@
+/*
+ * This file is part of smolbote. It's copyrighted by the contributors recorded
+ * in the version control history of the file, available from its original
+ * location: https://library.iserlohn-fortress.net/aqua/smolbote.git
+ *
+ * SPDX-License-Identifier: GPL-3.0
+ */
+
+#ifndef SMOLBOTE_SMOLBLOK_HPP
+#define SMOLBOTE_SMOLBLOK_HPP
+
+#include "filtermanager.hpp"
+#include <QPluginLoader>
+#include <QWebEngineUrlRequestInterceptor>
+#include <smolbote/filterinterface.hpp>
+
+class smolblok
+{
+public:
+    smolblok() = default;
+    ~smolblok()
+    {
+        for(auto &plugin : m_formats) {
+            delete plugin.loader;
+        }
+    }
+
+    auto registerFormatPlugin(const QString &format, const QString &filename)
+    {
+        struct {
+            bool loaded = false;
+            QString error;
+        } ret;
+
+        if(format.isEmpty() || filename.isEmpty()) {
+            ret.error = "Format or filename is empty";
+            return ret;
+        }
+
+        auto *plugin = new QPluginLoader(filename);
+        if(!plugin->load()) {
+            ret.error = plugin->errorString();
+            delete plugin;
+            return ret;
+        }
+
+        auto *instance = qobject_cast<FilterPlugin *>(plugin->instance());
+        if(instance == nullptr) {
+            ret.error = "Unable to cast";
+            delete plugin;
+            return ret;
+        }
+
+        m_formats[format] = PluginInfo{ plugin, instance };
+        ret.loaded = true;
+        return ret;
+    }
+
+    const auto formats() const
+    {
+        return m_formats.keys();
+    }
+
+    bool addSubscriptions(const QString &filename);
+    QWebEngineUrlRequestInterceptor *interceptor()
+    {
+        return &m_subscriptions;
+    }
+
+private:
+    struct PluginInfo {
+        QPluginLoader *loader = nullptr;
+        FilterPlugin *instance = nullptr;
+    };
+
+    QHash<QString, PluginInfo> m_formats;
+    FilterManager m_subscriptions;
+};
+
+#endif // SMOLBOTE_SMOLBLOK_HPP
diff --git a/staging/smolblok/test/loader.cpp b/staging/smolblok/test/loader.cpp
new file mode 100644
index 0000000..9e27a26
--- /dev/null
+++ b/staging/smolblok/test/loader.cpp
@@ -0,0 +1,25 @@
+#include "smolblok.hpp"
+#include <spdlog/spdlog.h>
+
+int main(int argc, char** argv)
+{
+    if(argc != 2) {
+        spdlog::error("usage: {} path/to/plugin.so", argv[0]);
+        return -1;
+    }
+
+    smolblok filter;
+    {
+        const auto r = filter.registerFormatPlugin("unused", argv[1]);
+        if(r.loaded) {
+            spdlog::info("Loaded plugin {}", argv[1]);
+        } else {
+            spdlog::error("Failed loading plugin {}", argv[1]);
+            spdlog::error(qUtf8Printable(r.error));
+            return -1;
+        }
+    }
+
+    return 0;
+}
+
diff --git a/staging/smolblok/test/main.cpp b/staging/smolblok/test/main.cpp
new file mode 100644
index 0000000..5624ee9
--- /dev/null
+++ b/staging/smolblok/test/main.cpp
@@ -0,0 +1,22 @@
+#define CATCH_CONFIG_MAIN
+
+#include "smolblok.hpp"
+#include <catch2/catch.hpp>
+
+SCENARIO("smolblok")
+{
+    smolblok s;
+
+    GIVEN("invalid plugins")
+    {
+        REQUIRE(!s.registerFormatPlugin("", ""));
+        REQUIRE(!s.registerFormatPlugin("Format", "missing.dll"));
+    }
+
+    GIVEN("invalid subscriptions")
+    {
+        REQUIRE(!s.addSubscriptions(""));
+        REQUIRE(!s.addSubscriptions("missing.txt"));
+    }
+}
+
diff --git a/staging/smolblok/test/sample-filters.txt b/staging/smolblok/test/sample-filters.txt
new file mode 100644
index 0000000..59e0e7b
--- /dev/null
+++ b/staging/smolblok/test/sample-filters.txt
@@ -0,0 +1,10 @@
+[easylist-noelemhide]
+Format = AdblockPlus
+File = easylist_noelemhide.txt
+Href = https://easylist-downloads.adblockplus.org/easylist_noelemhide.txt
+
+[StevenBlack]
+Format = Hostlist
+File = stevenblack.txt
+Href = https://raw.githubusercontent.com/StevenBlack/hosts/master/hosts
+