/**
* Sort the interim StringTable and store it to the real protobuf StringTable.
* while storing to the real table, this function fills the id2id_map with
* pairs, mapping the interim-ids to final and real StringTable ids.
*
* Note that the m_strings table is a std::map and as such is sorted lexicographically.
* When the transformation into the sortedby multimap is done, it gets sorted by
* the count. The end result (at least with the glibc standard container/algorithm
* implementation) is that the string table is sorted first by reverse count (ie descending)
* and then by reverse lexicographic order.
*/
void store_stringtable(OSMPBF::StringTable* st) {
typedef std::multimap<string_info, std::string> cmap;
cmap sortedbycount;
m_id2id_map.resize(m_size+1);
std::transform(m_strings.begin(), m_strings.end(),
std::inserter(sortedbycount, sortedbycount.begin()), flip_pair<std::string, string_info>);
int n=0;
cmap::const_iterator end=sortedbycount.end();
for (cmap::const_iterator it = sortedbycount.begin(); it != end; ++it) {
// add the string of the current item to the pbf StringTable
st->add_s(it->second);
// store the mapping from the interim-id to the real id
m_id2id_map[it->first.interim_id] = ++n;
}
}
/**
* Sort the interim StringTable and store it to the real protobuf StringTable.
* while storing to the real table, this function fills the id2id_map with
* pairs, mapping the interim-ids to final and real StringTable ids.
*
* Note that the m_strings table is a std::map and as such is sorted lexicographically.
* When the transformation into the sortedby multimap is done, it gets sorted by
* the count. The end result (at least with the glibc standard container/algorithm
* implementation) is that the string table is sorted first by reverse count (ie descending)
* and then by reverse lexicographic order.
*/
void store_stringtable(OSMPBF::StringTable* st) {
// add empty StringTable entry at index 0
// StringTable index 0 is reserved as delimiter in the densenodes key/value list
// this line also ensures that there's always a valid StringTable
st->add_s("");
typedef std::multimap<string_info, std::string> cmap;
cmap sortedbycount;
m_id2id_map.resize(m_size+1);
std::transform(m_strings.begin(), m_strings.end(),
std::inserter(sortedbycount, sortedbycount.begin()), flip_pair<std::string, string_info>);
int n=0;
cmap::const_iterator end=sortedbycount.end();
for (cmap::const_iterator it = sortedbycount.begin(); it != end; ++it) {
// add the string of the current item to the pbf StringTable
st->add_s(it->second);
// store the mapping from the interim-id to the real id
m_id2id_map[it->first.interim_id] = ++n;
}
}
/**
* Clear the stringtable, preparing for the next block.
*/
void clear() {
m_strings.clear();
m_id2id_map.clear();
m_size = 0;
}