Change directory structure

luprex/cpp/drv/drvutil.hpp

@@ -0,0 +1,99 @@
+////////////////////////////////////////////////////////////////////////////////
+//
+// DRIVER_UTIL
+//
+////////////////////////////////////////////////////////////////////////////////
+
+
+#ifndef DRVUTIL_HPP
+#define DRVUTIL_HPP
+
+#include <vector>
+#include <string>
+#include <memory>
+#include <string_view>
+#include <ostream>
+#include <sstream>
+#include <algorithm>
+
+namespace drvutil {
+
+// Read the lua source from disk into an ostringstream.
+//
+// To pass the lua source into the DLL, here is what you do: Construct an
+// ostringstream.  Use package_lua_source to package all the lua source into
+// the ostringstream.  Fetch the packaged source code using ostringstream::str.
+// Pass the packaged source code into drv_set_lua_source.
+//
+// The DLL must then decode the source package.  Here is how it does that:
+// It creates a StreamBuffer from the packaged up source.  Then it must
+// call these StreamBuffer methods:
+//
+//   - read the number of source files using read_uint32.
+//   - for each file, read the filename using read_string.
+//   - for each file, read the contents using read_string.
+//
+// If package_lua_source encounters an error reading the source code, then it
+// returns an error message.  In this case, the ostream contains garbage.  If
+// there is no error, returns the empty string.
+//
+std::string package_lua_source(const std::string &base, std::ostream *oss);
+
+// Parse a target designation.
+//
+// A target consists of 'cert::host::port'.
+//
+void split_target(std::string_view target, std::string &cert, std::string &host, std::string &port);
+
+// Get a system error message, in an OS-independent manner.
+//
+// These versions of strerror is thread-safe, and it never fails
+// to put a message into the buffer.
+//
+void strerror_safe(int errnum, char result[256]);
+std::string strerror_str(int errnum);
+
+// Get the amount of time elapsed since program start.
+//
+// This is guaranteed to be monotonically increasing.  It is not
+// guaranteed to be accurate.  Error could gradually accumulate over
+// time.
+//
+double get_monotonic_clock();
+
+// drvutil::ostringstream
+//
+// This is a variant of ostringstream in which it is possible
+// to get the contents without copying.   To get the contents
+// without copying, use oss.size() and oss.c_str()
+//
+class ostringstream : public std::ostringstream {
+    class rstringbuf : public std::stringbuf {
+    public:
+        char *eback() { return std::streambuf::eback(); }
+    };
+    rstringbuf rsbuf_;
+public:
+    ostringstream() {
+        std::basic_ostream<char>::rdbuf(&rsbuf_);
+    }
+    size_t size() {
+        return tellp();
+    }
+    const char *c_str() {
+        return rsbuf_.eback();
+    }
+};
+
+// Remove items from a vector that are marked for deletion.
+//
+template<class T>
+void remove_marked_items(T &vec) {
+    auto iter = std::partition(vec.begin(), vec.end(), [] (const auto &x) { return !x.marked_for_deletion(); });
+    vec.erase(iter, vec.end());
+}
+
+
+} // namespace drvutil
+
+#endif // DRVUTIL_HPP