mirror of
https://git.postgresql.org/git/postgresql.git
synced 2024-09-01 05:37:26 +02:00
ea1268f630
Previously, each pair of capturing parentheses gave rise to a separate subre tree node, whose only function was to identify that we ought to capture the match details for this particular sub-expression. In most cases we don't really need that, since we can perfectly well put a "capture this" annotation on the child node that does the real matching work. As with the two preceding commits, the main value of this is to avoid generating and optimizing an NFA for a tree node that's not really pulling its weight. The chosen data representation only allows one capture annotation per subre node. In the legal-per-spec, but seemingly not very useful, case where there are multiple capturing parens around the exact same bit of the regex (i.e. "((xyz))"), wrap the child node in N-1 capture nodes that act the same as before. We could work harder at that but I'll refrain, pending some evidence that such cases are worth troubling over. In passing, improve the comments in regex.h to say what all the different re_info bits mean. Some of them were pretty obvious but others not so much, so reverse-engineer some documentation. This is part of a patch series that in total reduces the regex engine's runtime by about a factor of four on a large corpus of real-world regexes. Patch by me, reviewed by Joel Jacobson Discussion: https://postgr.es/m/1340281.1613018383@sss.pgh.pa.us |
||
|---|---|---|
| .. | ||
| access | ||
| bootstrap | ||
| catalog | ||
| commands | ||
| executor | ||
| foreign | ||
| jit | ||
| lib | ||
| libpq | ||
| main | ||
| nodes | ||
| optimizer | ||
| parser | ||
| partitioning | ||
| po | ||
| port | ||
| postmaster | ||
| regex | ||
| replication | ||
| rewrite | ||
| snowball | ||
| statistics | ||
| storage | ||
| tcop | ||
| tsearch | ||
| utils | ||
| .gitignore | ||
| common.mk | ||
| Makefile | ||
| nls.mk | ||