SQLRETURN PythonLibrarySession::InstallLibrary()

in language-extensions/python/src/PythonLibrarySession.cpp [52:139]

• 62 lines of code
• 7 McCabe index (conditional complexity)

SQLRETURN PythonLibrarySession::InstallLibrary(
	string     tempFolder,
	SQLCHAR    *libraryName,
	SQLINTEGER libraryNameLength,
	SQLCHAR    *libraryFile,
	SQLINTEGER libraryFileLength,
	SQLCHAR    *libraryInstallDirectory,
	SQLINTEGER libraryInstallDirectoryLength)
{
	LOG("PythonLibrarySession::InstallExternalLibrary");
	SQLRETURN result = SQL_ERROR;

	string errorString;

	string libName = string(reinterpret_cast<char *>(libraryName), libraryNameLength);

	string installDir = string(reinterpret_cast<char *>(libraryInstallDirectory), libraryInstallDirectoryLength);
	installDir = PythonExtensionUtils::NormalizePathString(installDir);
	string libFilePath = string(reinterpret_cast<char *>(libraryFile), libraryFileLength);
	libFilePath = PythonExtensionUtils::NormalizePathString(libFilePath);
	
	string extractScript = "import zipfile\n"
		"with zipfile.ZipFile('" + libFilePath + "') as zip:\n"
		"    zip.extractall('" + tempFolder + "')";

	bp::exec(extractScript.c_str(), m_mainNamespace);

	string installPath = "";

	// Find the python package inside the zip to use for installation.
	//
	for (const fs::directory_entry &entry : fs::directory_iterator(tempFolder))
	{
		string type = entry.path().extension().generic_string();

		if (type.compare(".whl") == 0 ||
			type.compare(".zip") == 0 ||
			type.compare(".gz") == 0)
		{
			installPath = entry.path().generic_string();
			break;
		}
	}

	if (installPath.empty())
	{
		throw runtime_error("Could not find the package inside the zip - "
			"external library must be a python package inside a zip.");
	}

	string pathToPython = PythonExtensionUtils::GetPathToPython();

	// Set the TMPDIR so that pip uses our destination as temp. This allows us to use a
	// non-default instance.
	// Without this, TMPDIR will have MSSQL##$INSTANCE in the path, and the $ causes problems
	// with pip because they interpret $INSTANCE as a variable, not part of the path.
	//
	string setTemp = "import os;oldtemp = os.environ['TMPDIR'] if 'TMPDIR' in os.environ else None;"
		"os.environ['TMPDIR'] = '" + tempFolder + "'";
	bp::exec(setTemp.c_str(), m_mainNamespace);

	string installScript = 
		"import subprocess;pipresult = subprocess.run(['" + pathToPython +
		"', '-m', 'pip', 'install', '" + installPath +
		"', '--no-deps', '--ignore-installed', '--no-cache-dir'"
		", '-t', '" + installDir + "']).returncode";

	bp::exec(installScript.c_str(), m_mainNamespace);

	int pipResult = bp::extract<int>(m_mainNamespace["pipresult"]);

	string resetTemp =  "if oldtemp: \n"
						"    os.environ['TMPDIR'] = oldtemp\n"
						"else:\n"
						"    del os.environ['TMPDIR']";
	bp::exec(resetTemp.c_str(), m_mainNamespace);


	if (pipResult != 0)
	{
		throw runtime_error("Pip failed to install the package with exit code " +
			to_string(pipResult));
	}

	result = SQL_SUCCESS;

	return result;
}