openscad/src/nodecache.h

50 lines
1.4 KiB
C++

#pragma once
#include <vector>
#include <string>
#include "node.h"
/*!
Caches string values per node based on the node.index().
The node index guaranteed to be unique per node tree since the index is reset
every time a new tree is generated.
*/
class NodeCache
{
public:
NodeCache() { }
virtual ~NodeCache() { }
bool contains(const AbstractNode &node) const {
return !(*this)[node].empty();
}
/*! Returns a reference to the cached string copy. NB! don't rely on
* this reference to be valid for long - if the cache is resized
* internally, existing values are lost. */
const std::string & operator[](const AbstractNode &node) const {
if (this->cache.size() > node.index()) return this->cache[node.index()];
else return this->nullvalue;
}
/*! Returns a reference to the cached string copy. NB! don't rely on
* this reference to be valid for long - if the cache is resized
* internally, existing values are lost. */
const std::string &insert(const class AbstractNode &node, const std::string & value) {
if (this->cache.size() <= node.index()) this->cache.resize(node.index() + 1);
return this->cache[node.index()] = value;
}
void remove(const class AbstractNode &node) {
if (this->cache.size() > node.index()) this->cache[node.index()] = std::string();
}
void clear() {
this->cache.clear();
}
private:
std::vector<std::string> cache;
std::string nullvalue;
};