From 8e1c4b53b808ebdc828a00266bc535c1ce32e78d Mon Sep 17 00:00:00 2001
From: Marko Budiselic <mbudiselicbuda@gmail.com>
Date: Thu, 22 Oct 2015 00:17:40 +0200
Subject: [PATCH 1/3] cpp program runs compile command, test only code
---
.gitignore | 1 +
dc/README.md | 1 +
dc/test.cpp | 46 ++++++++++++++++++++++++++++++++++++++++++++++
dc/tmp/.gitignore | 2 ++
4 files changed, 50 insertions(+)
create mode 100644 dc/README.md
create mode 100644 dc/test.cpp
create mode 100644 dc/tmp/.gitignore
diff --git a/.gitignore b/.gitignore
index 81a453937..1eff11582 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,5 +4,6 @@
*.swp
*.swo
*.out
+*.so
*.dSYM/
memgraph
diff --git a/dc/README.md b/dc/README.md
new file mode 100644
index 000000000..2bf28fe09
--- /dev/null
+++ b/dc/README.md
@@ -0,0 +1 @@
+## Dynamic Code
diff --git a/dc/test.cpp b/dc/test.cpp
new file mode 100644
index 000000000..685aa8cde
--- /dev/null
+++ b/dc/test.cpp
@@ -0,0 +1,46 @@
+#include <iostream>
+#include <fstream>
+#include <sstream>
+#include <vector>
+#include <iterator>
+#include <cstdlib>
+
+// TODO: clang++ file.cpp -o file.so -shared -fPIC
+
+using namespace std;
+
+void write(const std::string& path, const std::string& content)
+{
+ ofstream stream;
+ stream.open (path.c_str());
+ stream << content;
+ stream.close();
+}
+
+std::string join(const std::vector<std::string>& strings, const char *separator)
+{
+ std::ostringstream oss;
+ std::copy(strings.begin(), strings.end(),
+ std::ostream_iterator<std::string>(oss, separator));
+ return oss.str();
+}
+
+template<typename... Args>
+std::string prints(const Args&... args)
+{
+ std::vector<std::string> strings = {args...};
+ return join(strings, " ");
+}
+
+int main()
+{
+ string tmp_file_path = "tmp/tmp.cpp";
+ string tmp_so_path = "tmp/tmp.so";
+ string for_compile = "#include <iostream>\nint main() { std::cout << \"test\" << std::endl; return 0; }";
+
+ write(tmp_file_path, for_compile);
+ string test_command = prints("clang++", tmp_file_path, "-o", "test.out");
+ system(test_command.c_str());
+
+ return 0;
+}
diff --git a/dc/tmp/.gitignore b/dc/tmp/.gitignore
new file mode 100644
index 000000000..78d910160
--- /dev/null
+++ b/dc/tmp/.gitignore
@@ -0,0 +1,2 @@
+/*
+!.gitignore
From 951448f6b2cd0effb4b45a02c02908b75daec3d7 Mon Sep 17 00:00:00 2001
From: Marko Budiselic <mbudiselicbuda@gmail.com>
Date: Thu, 22 Oct 2015 23:54:28 +0200
Subject: [PATCH 2/3] dynamic lib load work in progress :P
---
dc/README.md | 6 +++++
dc/example/db.hpp | 19 +++++++++++++++
dc/example/memsql.cpp | 28 ++++++++++++++++++++++
dc/example/mysql.cpp | 28 ++++++++++++++++++++++
dc/example/neo4j.cpp | 28 ++++++++++++++++++++++
dc/example/postgresql.cpp | 28 ++++++++++++++++++++++
dc/test.cpp | 50 ++++++++++++++++++++++++++++++++++-----
7 files changed, 181 insertions(+), 6 deletions(-)
create mode 100644 dc/example/db.hpp
create mode 100644 dc/example/memsql.cpp
create mode 100644 dc/example/mysql.cpp
create mode 100644 dc/example/neo4j.cpp
create mode 100644 dc/example/postgresql.cpp
diff --git a/dc/README.md b/dc/README.md
index 2bf28fe09..116d58797 100644
--- a/dc/README.md
+++ b/dc/README.md
@@ -1 +1,7 @@
## Dynamic Code
+
+```
+cd example
+clang++ -std=c++1y mysql.cpp -o ../tmp/mysql.so -shared -fPIC
+clang++ -std=c++1y test.cpp -o test.out -ldl
+```
diff --git a/dc/example/db.hpp b/dc/example/db.hpp
new file mode 100644
index 000000000..a507968df
--- /dev/null
+++ b/dc/example/db.hpp
@@ -0,0 +1,19 @@
+#ifndef MEMGRAPH_DL_EXAMPLE_DB_HPP
+#define MEMGRAPH_DL_EXAMPLE_DB_HPP
+
+#include <iostream>
+
+using namespace std;
+
+class db
+{
+public:
+ virtual void name() const;
+ virtual void type() const;
+ virtual ~db() {}
+};
+
+typedef db* (*produce_t)();
+typedef void (*destruct_t)(db*);
+
+#endif
diff --git a/dc/example/memsql.cpp b/dc/example/memsql.cpp
new file mode 100644
index 000000000..b8fa37ef4
--- /dev/null
+++ b/dc/example/memsql.cpp
@@ -0,0 +1,28 @@
+#include "db.hpp"
+
+class memsql : public db
+{
+public:
+
+ void name() const override
+ {
+ cout << "MemSQL" << endl;
+ }
+
+ void type() const override
+ {
+ cout << "InMemory" << endl;
+ }
+
+ ~memsql() {}
+};
+
+extern "C" db* produce()
+{
+ return new memsql();
+}
+
+extern "C" void destruct(db* p)
+{
+ delete p;
+}
diff --git a/dc/example/mysql.cpp b/dc/example/mysql.cpp
new file mode 100644
index 000000000..3b6c1bb2c
--- /dev/null
+++ b/dc/example/mysql.cpp
@@ -0,0 +1,28 @@
+#include "db.hpp"
+
+class mysql : public db
+{
+public:
+
+ virtual void name() const
+ {
+ cout << "MySQL" << endl;
+ }
+
+ virtual void type() const
+ {
+ cout << "Relational" << endl;
+ }
+
+ ~mysql() {}
+};
+
+extern "C" db* produce()
+{
+ return new mysql();
+}
+
+extern "C" void destruct(db* p)
+{
+ delete p;
+}
diff --git a/dc/example/neo4j.cpp b/dc/example/neo4j.cpp
new file mode 100644
index 000000000..0418bed74
--- /dev/null
+++ b/dc/example/neo4j.cpp
@@ -0,0 +1,28 @@
+#include "db.hpp"
+
+class neo4j : public db
+{
+public:
+
+ void name() const override
+ {
+ cout << "Neo4j" << endl;
+ }
+
+ void type() const override
+ {
+ cout << "Graph" << endl;
+ }
+
+ ~neo4j() {}
+};
+
+extern "C" db* produce()
+{
+ return new neo4j();
+}
+
+extern "C" void destruct(db* p)
+{
+ delete p;
+}
diff --git a/dc/example/postgresql.cpp b/dc/example/postgresql.cpp
new file mode 100644
index 000000000..34b5445fe
--- /dev/null
+++ b/dc/example/postgresql.cpp
@@ -0,0 +1,28 @@
+#include "db.hpp"
+
+class postgresql : public db
+{
+public:
+
+ void name() const override
+ {
+ cout << "PostgreSQL" << endl;
+ }
+
+ void type() const override
+ {
+ cout << "Relational" << endl;
+ }
+
+ ~postgresql() {}
+};
+
+extern "C" db* produce()
+{
+ return new postgresql();
+}
+
+extern "C" void destruct(db* p)
+{
+ delete p;
+}
diff --git a/dc/test.cpp b/dc/test.cpp
index 685aa8cde..ba582ad92 100644
--- a/dc/test.cpp
+++ b/dc/test.cpp
@@ -4,6 +4,8 @@
#include <vector>
#include <iterator>
#include <cstdlib>
+#include <dlfcn.h>
+#include "example/db.hpp"
// TODO: clang++ file.cpp -o file.so -shared -fPIC
@@ -32,15 +34,51 @@ std::string prints(const Args&... args)
return join(strings, " ");
}
+db* database(const std::string& lib_path, const std::string& factory_method)
+{
+ // load lib
+ void* db_lib = dlopen(lib_path.c_str(), RTLD_LAZY);
+ if (!db_lib) {
+ cerr << "Cannot load library: " << dlerror() << '\n';
+ return nullptr;
+ }
+ dlerror();
+
+ // load produce method
+ produce_t produce_db = (produce_t) dlsym(db_lib, factory_method.c_str());
+ const char* dlsym_error = dlerror();
+ if (dlsym_error) {
+ cerr << "Cannot load symbol create: " << dlsym_error << '\n';
+ return nullptr;
+ }
+
+ // load destroy method
+ // destruct_t destruct_db = (destruct_t) dlsym(db_lib, "destruct");
+ // dlsym_error = dlerror();
+ // if (dlsym_error) {
+ // cerr << "Cannot load symbol destroy: " << dlsym_error << '\n';
+ // return nullptr;
+ // }
+
+ db *instance = produce_db();
+
+ return instance;
+}
+
int main()
{
- string tmp_file_path = "tmp/tmp.cpp";
- string tmp_so_path = "tmp/tmp.so";
- string for_compile = "#include <iostream>\nint main() { std::cout << \"test\" << std::endl; return 0; }";
+ // string tmp_file_path = "tmp/tmp.cpp";
+ // string tmp_so_path = "tmp/tmp.so";
+ // string for_compile = "#include <iostream>\nint main() { std::cout << \"test\" << std::endl; return 0; }";
- write(tmp_file_path, for_compile);
- string test_command = prints("clang++", tmp_file_path, "-o", "test.out");
- system(test_command.c_str());
+ // write(tmp_file_path, for_compile);
+ // string test_command = prints("clang++", tmp_file_path, "-o", "test.out");
+ // system(test_command.c_str());
+
+ db *mysql = database("./tmp/mysql.so", "produce");
+ if (mysql) {
+ mysql->name();
+ }
return 0;
}
From 120743e59c4dab339de499ce3090203517437e35 Mon Sep 17 00:00:00 2001
From: Marko Budiselic <mbudiselicbuda@gmail.com>
Date: Sun, 25 Oct 2015 16:11:52 +0100
Subject: [PATCH 3/3] Much better but not perfect version of dynamic compile
and dynamic load code. DynamicLib class and rudimentar example.
---
dc/README.md | 5 ++++
dc/dynamic_lib.hpp | 65 ++++++++++++++++++++++++++++++++++++++++++++
dc/example/db.hpp | 10 +++++--
dc/test.cpp | 68 +++++++++++++++++++++++-----------------------
4 files changed, 112 insertions(+), 36 deletions(-)
create mode 100644 dc/dynamic_lib.hpp
diff --git a/dc/README.md b/dc/README.md
index 116d58797..a4ba9a8ac 100644
--- a/dc/README.md
+++ b/dc/README.md
@@ -1,7 +1,12 @@
## Dynamic Code
```
+man nm
+
+cd memgraph/dc
cd example
clang++ -std=c++1y mysql.cpp -o ../tmp/mysql.so -shared -fPIC
+clang++ -std=c++1y memsql.cpp -o ../tmp/memsql.so -shared -fPIC
+cd ..
clang++ -std=c++1y test.cpp -o test.out -ldl
```
diff --git a/dc/dynamic_lib.hpp b/dc/dynamic_lib.hpp
new file mode 100644
index 000000000..d7b96e2e1
--- /dev/null
+++ b/dc/dynamic_lib.hpp
@@ -0,0 +1,65 @@
+#ifndef MEMGRAPH_DL_DYNAMIC_LIB_HPP
+#define MEMGRAPH_DL_DYNAMIC_LIB_HPP
+
+#include <string>
+#include <stdexcept>
+#include <dlfcn.h>
+
+template<typename T>
+class DynamicLib
+{
+public:
+ typename T::produce produce_method;
+ typename T::destruct destruct_method;
+
+ DynamicLib(const std::string& lib_path) :
+ lib_path(lib_path)
+ {
+ }
+
+ void load()
+ {
+ load_lib();
+ load_produce_func();
+ load_destruct_func();
+ }
+
+private:
+ std::string lib_path;
+ void *dynamic_lib;
+
+ void load_lib()
+ {
+ dynamic_lib = dlopen(lib_path.c_str(), RTLD_LAZY);
+ if (!dynamic_lib) {
+ throw std::runtime_error(dlerror());
+ }
+ dlerror();
+ }
+
+ void load_produce_func()
+ {
+ produce_method = (typename T::produce) dlsym(
+ dynamic_lib,
+ T::produce_name.c_str()
+ );
+ const char* dlsym_error = dlerror();
+ if (dlsym_error) {
+ throw std::runtime_error(dlsym_error);
+ }
+ }
+
+ void load_destruct_func()
+ {
+ destruct_method = (typename T::destruct) dlsym(
+ dynamic_lib,
+ T::destruct_name.c_str()
+ );
+ const char *dlsym_error = dlerror();
+ if (dlsym_error) {
+ throw std::runtime_error(dlsym_error);
+ }
+ }
+};
+
+#endif
diff --git a/dc/example/db.hpp b/dc/example/db.hpp
index a507968df..2c93e4c66 100644
--- a/dc/example/db.hpp
+++ b/dc/example/db.hpp
@@ -8,8 +8,14 @@ using namespace std;
class db
{
public:
- virtual void name() const;
- virtual void type() const;
+ // If virtual methods don't have = 0 the compiler
+ // won't create appropriate _ZTI symbol inside
+ // the .so lib. That will lead to undefined symbol
+ // error while the library is loading.
+ //
+ // TODO: why?
+ virtual void name() const = 0;
+ virtual void type() const = 0;
virtual ~db() {}
};
diff --git a/dc/test.cpp b/dc/test.cpp
index ba582ad92..d40c2ddd3 100644
--- a/dc/test.cpp
+++ b/dc/test.cpp
@@ -4,12 +4,11 @@
#include <vector>
#include <iterator>
#include <cstdlib>
-#include <dlfcn.h>
#include "example/db.hpp"
+#include "dynamic_lib.hpp"
-// TODO: clang++ file.cpp -o file.so -shared -fPIC
-
-using namespace std;
+using std::cout;
+using std::endl;
void write(const std::string& path, const std::string& content)
{
@@ -34,39 +33,24 @@ std::string prints(const Args&... args)
return join(strings, " ");
}
-db* database(const std::string& lib_path, const std::string& factory_method)
+// dependent on specific dynamic code
+// "configuration" of DynamicLib
+// DynamicLib<MemgraphDynamicLib>
+class MemgraphDynamicLib
{
- // load lib
- void* db_lib = dlopen(lib_path.c_str(), RTLD_LAZY);
- if (!db_lib) {
- cerr << "Cannot load library: " << dlerror() << '\n';
- return nullptr;
- }
- dlerror();
-
- // load produce method
- produce_t produce_db = (produce_t) dlsym(db_lib, factory_method.c_str());
- const char* dlsym_error = dlerror();
- if (dlsym_error) {
- cerr << "Cannot load symbol create: " << dlsym_error << '\n';
- return nullptr;
- }
-
- // load destroy method
- // destruct_t destruct_db = (destruct_t) dlsym(db_lib, "destruct");
- // dlsym_error = dlerror();
- // if (dlsym_error) {
- // cerr << "Cannot load symbol destroy: " << dlsym_error << '\n';
- // return nullptr;
- // }
-
- db *instance = produce_db();
-
- return instance;
-}
+public:
+ const static std::string produce_name;
+ const static std::string destruct_name;
+ typedef produce_t produce;
+ typedef destruct_t destruct;
+};
+const std::string MemgraphDynamicLib::produce_name = "produce";
+const std::string MemgraphDynamicLib::destruct_name = "destruct";
int main()
{
+ // -- compile example
+
// string tmp_file_path = "tmp/tmp.cpp";
// string tmp_so_path = "tmp/tmp.so";
// string for_compile = "#include <iostream>\nint main() { std::cout << \"test\" << std::endl; return 0; }";
@@ -74,11 +58,27 @@ int main()
// write(tmp_file_path, for_compile);
// string test_command = prints("clang++", tmp_file_path, "-o", "test.out");
// system(test_command.c_str());
+
+ // -- end compile example
- db *mysql = database("./tmp/mysql.so", "produce");
+ // -- load example
+ using db_lib = DynamicLib<MemgraphDynamicLib>;
+
+ db_lib mysql_db("./tmp/mysql.so");
+ mysql_db.load();
+ auto mysql = mysql_db.produce_method();
if (mysql) {
mysql->name();
}
+ mysql_db.destruct_method(mysql);
+
+ db_lib memsql_db("./tmp/memsql.so");
+ memsql_db.load();
+ auto memsql = memsql_db.produce_method();
+ if (memsql) {
+ memsql->name();
+ }
+ memsql_db.destruct_method(memsql);
return 0;
}