Add libarchive decompression backend

compressed_archive/libarchive/compressed_archive.h

@@ -0,0 +1,44 @@
+#ifndef COMPRESSED_ARCHIVE_H
+#define COMPRESSED_ARCHIVE_H
+
+#include "extract_delegate.h"
+
+#include <QObject>
+#include <QDebug>
+
+extern "C" {
+#include <archive.h>
+#include <archive_entry.h>
+}
+
+class CompressedArchive : public QObject
+{
+    Q_OBJECT
+public:
+    explicit CompressedArchive(const QString &filePath, QObject *parent = nullptr);
+    ~CompressedArchive() override;
+
+public slots:
+    void getAllData(const QVector<quint32> &indexes, ExtractDelegate *delegate = nullptr);
+    QByteArray getRawDataAtIndex(int index);
+
+    int getNumFiles() { return num_entries; }
+    QList<QString> getFileNames() { return entries; }
+    bool isValid() { return valid; }
+    bool toolsLoaded() { return true; }
+
+private:
+    archive *a;
+    QStringList entries;
+    int num_entries;
+    bool valid;
+    quint32 idx;
+    QString filename;
+
+    bool open_archive();
+    void close_archive();
+    bool archive_seek(quint32 index);
+    QByteArray read_entry();
+};
+
+#endif // COMPRESSED_ARCHIVE_H