susumu.yata
null+****@clear*****
Tue Dec 2 17:23:52 JST 2014
susumu.yata 2014-12-02 17:23:52 +0900 (Tue, 02 Dec 2014) New Revision: fc19e512b27ea8a8336da7a157245b5512901900 https://github.com/groonga/grnxx/commit/fc19e512b27ea8a8336da7a157245b5512901900 Message: Add TreeIndex<Text>::find_starts_with(). (#124) Modified files: lib/grnxx/impl/index.cpp Modified: lib/grnxx/impl/index.cpp (+41 -0) =================================================================== --- lib/grnxx/impl/index.cpp 2014-12-02 16:25:34 +0900 (40de008) +++ lib/grnxx/impl/index.cpp 2014-12-02 17:23:52 +0900 (3572306) @@ -559,6 +559,8 @@ class TreeIndex<Text> : public Index { const CursorOptions &options) const; std::unique_ptr<Cursor> find_in_range(const IndexRange &range, const CursorOptions &options) const; + std::unique_ptr<Cursor> find_starts_with(const EndPoint &prefix, + const CursorOptions &options) const; private: mutable Map map_; @@ -691,6 +693,45 @@ std::unique_ptr<Cursor> TreeIndex<Text>::find_in_range( } } +std::unique_ptr<Cursor> TreeIndex<Text>::find_starts_with( + const EndPoint &prefix, + const CursorOptions &options) const { + String lower_bound_value; + // TODO: Typecast will be supported in future? + if (prefix.value.type() != TEXT_DATA) { + throw "Data type conflict"; // TODO + } + Text text = prefix.value.as_text(); + if (text.is_na()) { + throw "No prefix"; // TODO + } + lower_bound_value = String(text.raw_data(), text.raw_size()); + + String upper_bound_value = lower_bound_value.clone(); + while (!upper_bound_value.is_empty() && + (static_cast<unsigned char>(upper_bound_value.back()) == 0xFF)) { + upper_bound_value.resize(upper_bound_value.size() - 1); + } + if (!upper_bound_value.is_empty()) { + ++upper_bound_value.back(); + } + + if (prefix.type == EXCLUSIVE_END_POINT) { + lower_bound_value.append('\0'); + } + + auto begin = map_.lower_bound(lower_bound_value); + auto end = (upper_bound_value.size() != 0) ? + map_.lower_bound(upper_bound_value) : map_.end(); + if (options.order_type == CURSOR_REGULAR_ORDER) { + return create_range_cursor( + begin, end, options.offset, options.limit); + } else { + return create_reverse_range_cursor( + begin, end, options.offset, options.limit); + } +} + } // namespace index using namespace index; -------------- next part -------------- HTML����������������������������...Download
