ddl_ar tool to work with ddls

tools/ddl_ar_class.h

@@ -0,0 +1,49 @@
+#pragma once
+#include <string>
+#include <filesystem>
+#include <map>
+#include <vector>
+#include <fstream>
+
+class DDLArchive {
+public:
+
+    struct FileRec {
+        uint32_t offset;
+        std::filesystem::path source;
+
+    };
+
+
+    using Directory = std::map<std::string, FileRec, std::less<> >;
+    bool open(std::filesystem::path ar_file);
+    const Directory &get_directory() const {return _directory;}
+    const std::filesystem::path& get_ar_file() const {return _ar_file;}
+
+    struct Extracted {
+        std::string_view name;
+        bool found;
+        std::vector<char> data;
+    };
+
+
+    template<typename Iter, std::invocable<Extracted> CB>
+    void extract(Iter from, Iter to, CB &&cb) {
+        std::ifstream f = begin_read();
+        while (from != to) {
+            std::string_view n = *from;
+            cb(extract_file(f, n));
+            ++from;
+        }
+    }
+
+protected:
+
+    std::filesystem::path _ar_file;
+    Directory _directory;
+
+    std::ifstream begin_read();
+    Extracted extract_file(std::ifstream &s, std::string_view fname);
+
+
+};