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Diffstat (limited to 'libodb/odb/vector-traits.txx')
-rw-r--r-- | libodb/odb/vector-traits.txx | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/libodb/odb/vector-traits.txx b/libodb/odb/vector-traits.txx new file mode 100644 index 0000000..6c33876 --- /dev/null +++ b/libodb/odb/vector-traits.txx @@ -0,0 +1,100 @@ +// file : odb/vector-traits.txx +// license : GNU GPL v2; see accompanying LICENSE file + +namespace odb +{ + template <typename V, typename A LIBODB_VECTOR_ARG_DECL> + bool access::container_traits<vector<V, A LIBODB_VECTOR_ARG_USE> >:: + changed (const container_type& c) + { + // Because modifications can cancel each other (e.g., push and pop), + // it is tricky to keep track of whether there are any changes in + // the container. Instead, we are just going to examine each element + // just like update(). + // + + // We should either be tracking or summarily changed. + // + if (c._tracking ()) + { + const vector_impl& impl (c._impl ()); + + for (std::size_t i (0), n (impl.size ()); i < n; ++i) + { + if (impl.state (i) != vector_impl::state_unchanged) + return true; + } + } + else + return true; + + return false; + } + + template <typename V, typename A LIBODB_VECTOR_ARG_DECL> + void access::container_traits<vector<V, A LIBODB_VECTOR_ARG_USE> >:: + update (const container_type& c, const functions& f) + { + bool u (false); // Updated flag. + + if (c._tracking ()) + { + const vector_impl& impl (c._impl ()); + + for (std::size_t i (0), n (impl.size ()); i < n; ++i) + { + vector_impl::element_state_type s (impl.state (i)); + + switch (s) + { + case vector_impl::state_unchanged: + { + break; + } + case vector_impl::state_inserted: + { + f.insert (i, c[static_cast<index_type> (i)]); + u = u || true; + break; + } + case vector_impl::state_updated: + { + f.update (i, c[static_cast<index_type> (i)]); + u = u || true; + break; + } + case vector_impl::state_erased: + { + f.delete_ (i); // Delete from i onwards. + u = u || true; + break; + } + } + + // We delete all trailing elements in one go. + // + if (s == vector_impl::state_erased) + break; + } + } + else + { + // Fall back to delete all/insert all. + // + f.delete_ (0); + + for (index_type i (0), n (c.size ()); i < n; ++i) + f.insert (i, c[i]); + + u = true; + } + + // Arm the rollback callback and (re)start change tracking. + // + if (u) + { + c._arm (transaction::current ()); + c._start (); + } + } +} |