From b0d801d715fad8104ed36e1c96de347009e2bf3e Mon Sep 17 00:00:00 2001
From: =?utf8?q?Vitaliy=20Cherepanov/SRR-AI=20Tools=20Lab/=2E/=EC=82=BC?=
 =?utf8?q?=EC=84=B1=EC=A0=84=EC=9E=90?= <v.cherepanov@samsung.com>
Date: Thu, 17 May 2018 11:38:47 +0300
Subject: [PATCH] nnc: dynamic library interface (#228)

* nnc: dynamic library interface

This commit implements interface for loading dynamic libraries
and calling its interfaces.

This functional will be used to load and communicate with plugins.

Signed-off-by: Vitaliy Cherepanov <v.cherepanov@samsung.com>

* nnc: dynamic library interface

move sources to contrib/nnc

Signed-off-by: Vitaliy Cherepanov <v.cherepanov@samsung.com>

* nnc: dynamic library interface

fix namespaces and code style

Signed-off-by: Vitaliy Cherepanov <v.cherepanov@samsung.com>

* nnc: dynamic library interface

fix build

Signed-off-by: Vitaliy Cherepanov <v.cherepanov@samsung.com>

* nnc: dynamic library interface

add info to "<<" operator

Signed-off-by: Vitaliy Cherepanov <v.cherepanov@samsung.com>

* nnc: dynamic library interface

fix issues

Signed-off-by: Vitaliy Cherepanov <v.cherepanov@samsung.com>

* nnc: dynamic library interface

fix issues

Signed-off-by: Vitaliy Cherepanov <v.cherepanov@samsung.com>
---
 contrib/nnc/CMakeLists.txt                         |  1 +
 contrib/nnc/include/module/plugin/shared_library.h | 38 ++++++++++++
 contrib/nnc/src/module/plugin/shared_library.cpp   | 72 ++++++++++++++++++++++
 3 files changed, 111 insertions(+)
 create mode 100644 contrib/nnc/include/module/plugin/shared_library.h
 create mode 100644 contrib/nnc/src/module/plugin/shared_library.cpp

diff --git a/contrib/nnc/CMakeLists.txt b/contrib/nnc/CMakeLists.txt
index aea34cd..cd2c828 100644
--- a/contrib/nnc/CMakeLists.txt
+++ b/contrib/nnc/CMakeLists.txt
@@ -5,6 +5,7 @@ file(GLOB_RECURSE CL_SRC src/*.cpp include/*.h)
 add_executable(nnc ${CL_SRC})
 target_link_libraries(nnc PRIVATE nncc_core)
 target_link_libraries(nnc PRIVATE nncc_foundation)
+target_link_libraries(nnc PRIVATE dl)
 target_include_directories(nnc PUBLIC include)
 
 add_subdirectory(libs)
diff --git a/contrib/nnc/include/module/plugin/shared_library.h b/contrib/nnc/include/module/plugin/shared_library.h
new file mode 100644
index 0000000..24e9029
--- /dev/null
+++ b/contrib/nnc/include/module/plugin/shared_library.h
@@ -0,0 +1,38 @@
+#pragma once
+
+#include <ostream>
+#include <string>
+
+namespace nncc
+{
+namespace contrib
+{
+namespace module
+{
+namespace plugin
+{
+
+class SharedLibrary
+{
+public:
+  explicit SharedLibrary(const std::string &fullPath);
+
+  void *findFunc(const std::string &funcName);
+  std::string getPath() const;
+
+
+private:
+  bool loadLibrary();
+
+private:
+  std::string _path;
+  void *_handle;
+  bool _isLoaded;
+};
+
+std::ostream &operator<<(std::ostream &st, const SharedLibrary &lib);
+
+} // namespase plugin
+} // namespace module
+} // namespace contrib
+} // namespace nncc
diff --git a/contrib/nnc/src/module/plugin/shared_library.cpp b/contrib/nnc/src/module/plugin/shared_library.cpp
new file mode 100644
index 0000000..b3a8cf8
--- /dev/null
+++ b/contrib/nnc/src/module/plugin/shared_library.cpp
@@ -0,0 +1,72 @@
+#include <dlfcn.h>
+#include <iostream>
+
+#include "module/plugin/shared_library.h"
+
+namespace nncc
+{
+namespace contrib
+{
+namespace module
+{
+namespace plugin
+{
+
+SharedLibrary::SharedLibrary(const std::string &fullPath)
+    : _handle(nullptr), _path(fullPath), _isLoaded(false)
+{
+}
+
+void *SharedLibrary::findFunc(const std::string &funcName)
+{
+  if (!loadLibrary())
+  {
+    return nullptr;
+  }
+
+  // reset errors
+  dlerror();
+
+  void *func = dlsym(_handle, funcName.c_str());
+  char *dlsym_error = dlerror();
+
+  if (nullptr != dlsym_error)
+  {
+    std::cout << "Cannot load symbol '" << funcName << "': " << dlsym_error << std::endl;
+    return nullptr;
+  }
+  return func;
+}
+
+bool SharedLibrary::loadLibrary()
+{
+  if (nullptr == _handle && !_isLoaded)
+  {
+    _isLoaded = true;
+
+    // open the library
+    std::cout << "Opening " << _path << std::endl;
+
+    _handle = dlopen(_path.c_str(), RTLD_LAZY);
+
+    if (!_handle)
+    {
+      std::cout << "Cannot open library <" << _path << ">: " << dlerror() << std::endl;
+    }
+  }
+
+  return (nullptr != _handle);
+}
+
+std::string SharedLibrary::getPath() const { return _path; }
+
+std::ostream &operator<<(std::ostream &st, const SharedLibrary &lib)
+{
+  st << lib.getPath();
+  return st;
+}
+
+} // namespase plugin
+} // namespace module
+} // namespace contrib
+} // namespace nncc
-- 
2.7.4