git.sesse.net Git - casparcg/blob - common/ptree.h

   1 /*
   2 * Copyright (c) 2011 Sveriges Television AB <info@casparcg.com>
   3 *
   4 * This file is part of CasparCG (www.casparcg.com).
   5 *
   6 * CasparCG is free software: you can redistribute it and/or modify
   7 * it under the terms of the GNU General Public License as published by
   8 * the Free Software Foundation, either version 3 of the License, or
   9 * (at your option) any later version.
  10 *
  11 * CasparCG is distributed in the hope that it will be useful,
  12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 * GNU General Public License for more details.
  15 *
  16 * You should have received a copy of the GNU General Public License
  17 * along with CasparCG. If not, see <http://www.gnu.org/licenses/>.
  18 *
  19 * Author: Helge Norberg, helge.norberg@svt.se
  20 */
  21
  22 #pragma once
  23
  24 #include "except.h"
  25
  26 #include "memory.h"
  27
  28 #include <boost/property_tree/ptree.hpp>
  29 #include <boost/algorithm/string/replace.hpp>
  30 #include <boost/range/adaptor/transformed.hpp>
  31 #include <boost/lexical_cast.hpp>
  32 #include <boost/iterator/iterator_facade.hpp>
  33
  34 #include <map>
  35
  36 namespace caspar {
  37
  38 struct ptree_exception : virtual user_error { };
  39
  40 static std::string to_xpath(std::string path)
  41 {
  42         path.insert(path.begin(), '/');
  43         boost::replace_all(path, "<xmlattr>.", "@");
  44         boost::replace_all(path, ".", "/");
  45         return path;
  46 }
  47
  48 template <typename T, typename Ptree>
  49 T ptree_get(const Ptree& ptree, const typename Ptree::key_type& path)
  50 {
  51         try
  52         {
  53                 return ptree.template get<T>(path);
  54         }
  55         catch (boost::property_tree::ptree_bad_path&)
  56         {
  57                 CASPAR_THROW_EXCEPTION(ptree_exception() << msg_info("No such element: " + to_xpath(u8(path))));
  58         }
  59         catch (const boost::property_tree::ptree_bad_data& e)
  60         {
  61                 CASPAR_SCOPED_CONTEXT_MSG(to_xpath(u8(path)))
  62                 CASPAR_THROW_EXCEPTION(ptree_exception() << msg_info(e.what()));
  63         }
  64 }
  65
  66 template <typename T, typename Ptree>
  67 T ptree_get_value(const Ptree& ptree)
  68 {
  69         try
  70         {
  71                 return ptree.template get_value<T>();
  72         }
  73         catch (const boost::property_tree::ptree_bad_data& e)
  74         {
  75                 CASPAR_THROW_EXCEPTION(ptree_exception() << msg_info(e.what()));
  76         }
  77 }
  78
  79 template <typename Ptree>
  80 const Ptree& ptree_get_child(const Ptree& ptree, const typename Ptree::key_type& path)
  81 {
  82         try
  83         {
  84                 return ptree.get_child(path);
  85         }
  86         catch (boost::property_tree::ptree_bad_path&)
  87         {
  88                 CASPAR_THROW_EXCEPTION(ptree_exception() << msg_info("No such element: " + to_xpath(u8(path))));
  89         }
  90 }
  91
  92 template <typename Ptree>
  93 class scope_aware_ptree_child_range
  94 {
  95         const Ptree&                                    child_;
  96         spl::shared_ptr<scoped_context> ctx_;
  97
  98         typedef std::pair<const typename Ptree::key_type, Ptree> type;
  99 public:
 100         class scoped_const_iterator : public boost::iterator_facade<scoped_const_iterator, type const, boost::forward_traversal_tag>
 101         {
 102                 spl::shared_ptr<scoped_context> ctx_;
 103                 typename Ptree::const_iterator  wrapped_;
 104         public:
 105                 scoped_const_iterator(spl::shared_ptr<scoped_context> ctx, typename Ptree::const_iterator it)
 106                         : ctx_(std::move(ctx))
 107                         , wrapped_(std::move(it))
 108                 {
 109                 }
 110
 111                 void increment()
 112                 {
 113                         ++wrapped_;
 114                 }
 115
 116                 bool equal(const scoped_const_iterator& other) const
 117                 {
 118                         return wrapped_ == other.wrapped_;
 119                 }
 120
 121                 const type& dereference() const
 122                 {
 123                         return *wrapped_;
 124                 }
 125         };
 126
 127         typedef scoped_const_iterator iterator;
 128         typedef scoped_const_iterator const_iterator;
 129
 130         scope_aware_ptree_child_range(const Ptree& parent, const typename Ptree::key_type& path)
 131                 : child_(ptree_get_child(parent, path))
 132                 , ctx_(spl::make_shared<scoped_context>(to_xpath(u8(path))))
 133         {
 134         }
 135
 136         scoped_const_iterator begin() const
 137         {
 138                 return scoped_const_iterator(ctx_, child_.begin());
 139         }
 140
 141         scoped_const_iterator end() const
 142         {
 143                 return scoped_const_iterator(ctx_, child_.end());
 144         }
 145 };
 146
 147 template <typename Key>
 148 struct iterate_children_tag
 149 {
 150         Key val;
 151
 152         iterate_children_tag(Key val_)
 153                 : val(std::move(val_))
 154         {
 155         }
 156 };
 157
 158 typedef iterate_children_tag<std::wstring> witerate_children;
 159 typedef iterate_children_tag<std::string> iterate_children;
 160
 161 template <typename Ptree>
 162 scope_aware_ptree_child_range<Ptree> operator|(const Ptree& ptree, iterate_children_tag<typename Ptree::key_type> path)
 163 {
 164         return scope_aware_ptree_child_range<Ptree>(ptree, path.val);
 165 }
 166
 167 template<typename Ptree>
 168 struct basic_scoped_element_translator
 169 {
 170         mutable std::shared_ptr<scoped_context>                 ctx;
 171         mutable std::map<typename Ptree::key_type, int> by_name;
 172
 173         typedef const std::pair<const typename Ptree::key_type, Ptree>& result_type;
 174
 175         result_type operator()(result_type pair) const
 176         {
 177                 if (!ctx) // Lazy
 178                         ctx.reset(new scoped_context);
 179
 180                 ctx->replace_msg("/" + u8(pair.first) + "[" + boost::lexical_cast<std::string>(++by_name[pair.first]) + "]");
 181                 return pair;
 182         }
 183 };
 184
 185 template <typename Ptree> struct element_context_iteration_tag { };
 186 static element_context_iteration_tag<typename boost::property_tree::wptree> welement_context_iteration;
 187 static element_context_iteration_tag<typename boost::property_tree::ptree> element_context_iteration;
 188
 189 template <typename Range, typename Ptree>
 190 auto operator|(const Range& rng, element_context_iteration_tag<Ptree> tag) -> decltype(rng | boost::adaptors::transformed(basic_scoped_element_translator<Ptree>()))
 191 {
 192         return rng | boost::adaptors::transformed(basic_scoped_element_translator<Ptree>());
 193 }
 194
 195 template <typename Key, typename Ptree, typename Str>
 196 void ptree_verify_element_name(const std::pair<const Key, Ptree>& elem, const Str& expected)
 197 {
 198         if (elem.first != expected)
 199                 CASPAR_THROW_EXCEPTION(ptree_exception() << msg_info("Expected element named " + u8(expected) + ". Was " + u8(elem.first)));
 200 }
 201
 202 }