uhd: created library code to handle paths for images and modules

- read from environment variable paths
- utility functions to get paths and search for images
- modified load modules to call the utility functions
- added private header constants.hpp to contain cmake variables of interest
- modified version.cpp to use this constants file

1 files changed, 103 insertions, 0 deletions

diff --git a/host/lib/utils/paths.cpp b/host/lib/utils/paths.cpp
new file mode 100644
index 000000000..0805a44fe
--- /dev/null
+++ b/host/lib/utils/paths.cpp
@@ -0,0 +1,103 @@
+//
+// Copyright 2010 Ettus Research LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#include "constants.hpp"
+#include <uhd/config.hpp>
+#include <boost/algorithm/string.hpp>
+#include <boost/program_options.hpp>
+#include <boost/filesystem.hpp>
+#include <boost/foreach.hpp>
+#include <boost/bind.hpp>
+#include <stdexcept>
+#include <string>
+#include <vector>
+
+namespace po = boost::program_options;
+namespace fs = boost::filesystem;
+
+/***********************************************************************
+ * Determine the paths separator
+ **********************************************************************/
+#ifdef UHD_PLATFORM_WIN32
+    static const std::string env_path_sep = ";";
+#else
+    static const std::string env_path_sep = ":";
+#endif /*UHD_PLATFORM_WIN32*/
+
+/***********************************************************************
+ * Get a list of paths for an environment variable
+ **********************************************************************/
+static std::string name_mapper(const std::string &key, const std::string &var_name){
+    return (var_name == key)? var_name : "";
+}
+
+static std::vector<fs::path> get_env_paths(const std::string &var_name){
+    //register the options
+    std::string var_value;
+    po::options_description desc;
+    desc.add_options()
+        (var_name.c_str(), po::value<std::string>(&var_value)->default_value(""))
+    ;
+
+    //parse environment variables
+    po::variables_map vm;
+    po::store(po::parse_environment(desc, boost::bind(&name_mapper, var_name, _1)), vm);
+    po::notify(vm);
+
+    //split the path at the path separators
+    std::vector<std::string> path_strings;
+    boost::split(path_strings, var_value, boost::is_any_of(env_path_sep));
+
+    //convert to filesystem path, filter blank paths
+    std::vector<fs::path> paths;
+    BOOST_FOREACH(std::string &path_string, path_strings){
+        if (path_string.size() == 0) continue;
+        paths.push_back(fs::system_complete(path_string));
+    }
+    return paths;
+}
+
+/***********************************************************************
+ * Get a list of special purpose paths
+ **********************************************************************/
+static const fs::path pkg_data_path = fs::path(UHD_INSTALL_PREFIX) / UHD_PKG_DATA_DIR;
+
+std::vector<fs::path> get_image_paths(void){
+    std::vector<fs::path> paths = get_env_paths("UHD_IMAGE_PATH");
+    paths.push_back(pkg_data_path / "images");
+    return paths;
+}
+
+std::vector<fs::path> get_module_paths(void){
+    std::vector<fs::path> paths = get_env_paths("UHD_MODULE_PATH");
+    paths.push_back(pkg_data_path / "modules");
+    return paths;
+}
+
+/***********************************************************************
+ * Find a image in the image paths
+ **********************************************************************/
+std::string find_image_path(const std::string &image_name){
+    if (fs::exists(image_name)){
+        return fs::system_complete(image_name).file_string();
+    }
+    BOOST_FOREACH(const fs::path &path, get_image_paths()){
+        fs::path image_path = path / image_name;
+        if (fs::exists(image_path)) return image_path.file_string();
+    }
+    throw std::runtime_error("Could not find path for image: " + image_name);
+}