gistfile1.hpp

/**
 * @file Defines the API for a QueryRewriter.  
 */

namespace drizzled
{

namespace plugin
{

/**
 * Class which rewrites queries
 */
class QueryRewriter : public Plugin
{
  
public:

  explicit QueryRewriter(std::string name_arg)
    :
      Plugin(name_arg, "QueryRewriter")
  {}

  virtual ~QueryRewriter() {}

  /**
   * Rewrite a query in the form of a std::string
   *
   * @param[out] to_rewrite string representing the query to rewrite
   */
  virtual void rewrite(std::string &to_rewrite)= 0;

  static bool addPlugin(QueryRewriter *in_rewriter);
  static void removePlugin(QueryRewriter *in_rewriter);

  /**
   * Take a query to be rewritten and go through all the rewriters that are registered as plugins
   * and let the enabled ones rewrite they query.
   * TODO: does it make sense to have multiple rewriters?
   *
   * @param[out] to_rewrite string representing the query to rewrite
   */
  static void rewriteQuery(std::string &to_rewrite);

private:

  QueryRewriter();
  QueryRewriter(const QueryRewriter&);
  QueryRewriter& operator=(const QueryRewriter&);


};

} /* namespace plugin */

} /* namespace drizzled */