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The functions moveins(), copyins(), moveouts(), copyouts() are required to preserve the invariant that there are no duplicate arcs in the regex's NFA. Spencer's original implementation of them was O(N^2) since it checked separately for a match to each source arc. In commit 579840ca0 I improved that by adding sort/merge logic to be used if more than a few arcs are to be moved/copied. However, I now realize that that missed a bet. At many call sites, the target state is newly made and cannot have any existing in-arcs (respectively out-arcs) that could be duplicates. So spending any cycles at all on checking for duplicates is wasted effort; in these cases we can just blindly move/copy all the source arcs. Add code paths to do that. It turns out that for copyins()/copyouts(), *all* the call sites have this property, making all the "improved" logic in them flat out unreachable. Perhaps we'll need the full capability again someday, so I just #ifdef'd those paths out rather than removing them entirely. In passing, add a few test cases to improve code coverage in this area as well as in regc_locale.c/regc_pg_locale.c. Discussion: https://postgr.es/m/810272.1629064063@sss.pgh.pa.us
PostgreSQL Database Management System ===================================== This directory contains the source code distribution of the PostgreSQL database management system. PostgreSQL is an advanced object-relational database management system that supports an extended subset of the SQL standard, including transactions, foreign keys, subqueries, triggers, user-defined types and functions. This distribution also contains C language bindings. PostgreSQL has many language interfaces, many of which are listed here: https://www.postgresql.org/download/ See the file INSTALL for instructions on how to build and install PostgreSQL. That file also lists supported operating systems and hardware platforms and contains information regarding any other software packages that are required to build or run the PostgreSQL system. Copyright and license information can be found in the file COPYRIGHT. A comprehensive documentation set is included in this distribution; it can be read as described in the installation instructions. The latest version of this software may be obtained at https://www.postgresql.org/download/. For more information look at our web site located at https://www.postgresql.org/.