uhd

//

// Copyright 2011 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 <uhd/property_tree.hpp>

#include <uhd/types/dict.hpp>

#include <boost/foreach.hpp>

#include <boost/thread/mutex.hpp>

#include <boost/make_shared.hpp>

#include <iostream>

using namespace uhd;

/***********************************************************************

 * Helper function to iterate through paths

 **********************************************************************/

#include <boost/tokenizer.hpp>

#define path_tokenizer(path) \

    boost::tokenizer<boost::char_separator<char> > \

    (path, boost::char_separator<char>("/"))

/***********************************************************************

 * Property path implementation wrapper

 **********************************************************************/

fs_path::fs_path(void): std::string(){}

fs_path::fs_path(const char *p): std::string(p){}

fs_path::fs_path(const std::string &p): std::string(p){}

std::string fs_path::leaf(void) const{

    const size_t pos = this->rfind("/");

    if (pos == std::string::npos) return *this;

    return this->substr(pos+1);

}

fs_path fs_path::branch_path(void) const{

    const size_t pos = this->rfind("/");

    if (pos == std::string::npos) return *this;

    return fs_path(this->substr(0, pos));

}

fs_path uhd::operator/(const fs_path &lhs, const fs_path &rhs){

    //strip trailing slash on left-hand-side

    if (not lhs.empty() and *lhs.rbegin() == '/'){

        return fs_path(lhs.substr(0, lhs.size()-1)) / rhs;

    }

    //strip leading slash on right-hand-side

    if (not rhs.empty() and *rhs.begin() == '/'){

        return lhs / fs_path(rhs.substr(1));

    }

    return fs_path(lhs + "/" + rhs);

}

/***********************************************************************

 * Property tree implementation

 **********************************************************************/

class property_tree_impl : public uhd::property_tree{

public:

    property_tree_impl(const fs_path &root = fs_path()):

        _root(root)

    {

        _guts = boost::make_shared<tree_guts_type>();

    }

    sptr subtree(const fs_path &path_) const{

        const fs_path path = _root / path_;

        boost::mutex::scoped_lock lock(_guts->mutex);

        property_tree_impl *subtree = new property_tree_impl(path);

        subtree->_guts = this->_guts; //copy the guts sptr

        return sptr(subtree);

    }

    void remove(const fs_path &path_){

        const fs_path path = _root / path_;

        boost::mutex::scoped_lock lock(_guts->mutex);

        node_type *parent = NULL;

        node_type *node = &_guts->root;

        BOOST_FOREACH(const std::string &name, path_tokenizer(path)){

            if (not node->has_key(name)) throw_path_not_found(path);

            parent = node;

            node = &(*node)[name];

        }

        if (parent == NULL) throw uhd::runtime_error("Cannot uproot");

        parent->pop(fs_path(path.leaf()));

    }

    bool exists(const fs_path &path_) const{

        const fs_path path = _root / path_;

        boost::mutex::scoped_lock lock(_guts->mutex);

        node_type *node = &_guts->root;

        BOOST_FOREACH(const std::string &name, path_tokenizer(path)){

            if (not node->has_key(name)) return false;

            node = &(*node)[name];

        }

        return true;

    }

    std::vector<std::string> list(const fs_path &path_) const{

        const fs_path path = _root / path_;

        boost::mutex::scoped_lock lock(_guts->mutex);

        node_type *node = &_guts->root;

        BOOST_FOREACH(const std::string &name, path_tokenizer(path)){

            if (not node->has_key(name)) throw_path_not_found(path);

            node = &(*node)[name];

        }

        return node->keys();

    }

    void _create(const fs_path &path_, const boost::shared_ptr<void> &prop){

        const fs_path path = _root / path_;

        boost::mutex::scoped_lock lock(_guts->mutex);

        node_type *node = &_guts->root;

        BOOST_FOREACH(const std::string &name, path_tokenizer(path)){

            if (not node->has_key(name)) (*node)[name] = node_type();

            node = &(*node)[name];

        }

        if (node->prop.get() != NULL) throw uhd::runtime_error("Cannot create! Property already exists at: " + path);

        node->prop = prop;

    }

    boost::shared_ptr<void> &_access(const fs_path &path_) const{

        const fs_path path = _root / path_;

        boost::mutex::scoped_lock lock(_guts->mutex);

        node_type *node = &_guts->root;

        BOOST_FOREACH(const std::string &name, path_tokenizer(path)){

            if (not node->has_key(name)) throw_path_not_found(path);

            node = &(*node)[name];

        }

        if (node->prop.get() == NULL) throw uhd::runtime_error("Cannot access! Property uninitialized at: " + path);

        return node->prop;

    }

private:

    void throw_path_not_found(const fs_path &path) const{

        throw uhd::lookup_error("Path not found in tree: " + path);

    }

    //basic structural node element

    struct node_type : uhd::dict<std::string, node_type>{

        boost::shared_ptr<void> prop;

    };

    //tree guts which may be referenced in a subtree

    struct tree_guts_type{

        node_type root;

        boost::mutex mutex;

    };

    //members, the tree and root prefix

    boost::shared_ptr<tree_guts_type> _guts;

    const fs_path _root;

};

/***********************************************************************

 * Property tree factory

 **********************************************************************/

uhd::property_tree::sptr uhd::property_tree::make(void){

    return sptr(new property_tree_impl());

}