diff options
| author | Tom Lane <tgl@sss.pgh.pa.us> | 2019-01-09 19:47:38 -0500 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2019-01-09 19:47:46 -0500 |
| commit | c64d0cd5ce24a344798534f1bc5827a9199b7a6e (patch) | |
| tree | 3968456d54c3f18d07976e5a139ca60589a8fbf0 /src/tools/msvc/Solution.pm | |
| parent | 5d59a6c5eaff4a58322683e450e76a11d943d322 (diff) | |
| download | postgresql-c64d0cd5ce24a344798534f1bc5827a9199b7a6e.tar.gz postgresql-c64d0cd5ce24a344798534f1bc5827a9199b7a6e.zip | |
Use perfect hashing, instead of binary search, for keyword lookup.
We've been speculating for a long time that hash-based keyword lookup
ought to be faster than binary search, but up to now we hadn't found
a suitable tool for generating the hash function. Joerg Sonnenberger
provided the inspiration, and sample code, to show us that rolling our
own generator wasn't a ridiculous idea. Hence, do that.
The method used here requires a lookup table of approximately 4 bytes
per keyword, but that's less than what we saved in the predecessor commit
afb0d0712, so it's not a big problem. The time savings is indeed
significant: preliminary testing suggests that the total time for raw
parsing (flex + bison phases) drops by ~20%.
Patch by me, but it owes its existence to Joerg Sonnenberger;
thanks also to John Naylor for review.
Discussion: https://postgr.es/m/20190103163340.GA15803@britannica.bec.de
Diffstat (limited to 'src/tools/msvc/Solution.pm')
| -rw-r--r-- | src/tools/msvc/Solution.pm | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/src/tools/msvc/Solution.pm b/src/tools/msvc/Solution.pm index 937bf184e27..e4bb9d2394d 100644 --- a/src/tools/msvc/Solution.pm +++ b/src/tools/msvc/Solution.pm @@ -414,7 +414,7 @@ sub GenerateFiles 'src/include/parser/kwlist.h')) { print "Generating kwlist_d.h...\n"; - system('perl src/tools/gen_keywordlist.pl --extern -o src/common src/include/parser/kwlist.h'); + system('perl -I src/tools src/tools/gen_keywordlist.pl --extern -o src/common src/include/parser/kwlist.h'); } if (IsNewer( @@ -426,8 +426,8 @@ sub GenerateFiles { print "Generating pl_reserved_kwlist_d.h and pl_unreserved_kwlist_d.h...\n"; chdir('src/pl/plpgsql/src'); - system('perl ../../../tools/gen_keywordlist.pl --varname ReservedPLKeywords pl_reserved_kwlist.h'); - system('perl ../../../tools/gen_keywordlist.pl --varname UnreservedPLKeywords pl_unreserved_kwlist.h'); + system('perl -I ../../../tools ../../../tools/gen_keywordlist.pl --varname ReservedPLKeywords pl_reserved_kwlist.h'); + system('perl -I ../../../tools ../../../tools/gen_keywordlist.pl --varname UnreservedPLKeywords pl_unreserved_kwlist.h'); chdir('../../../..'); } @@ -440,8 +440,8 @@ sub GenerateFiles { print "Generating c_kwlist_d.h and ecpg_kwlist_d.h...\n"; chdir('src/interfaces/ecpg/preproc'); - system('perl ../../../tools/gen_keywordlist.pl --varname ScanCKeywords c_kwlist.h'); - system('perl ../../../tools/gen_keywordlist.pl --varname ScanECPGKeywords ecpg_kwlist.h'); + system('perl -I ../../../tools ../../../tools/gen_keywordlist.pl --varname ScanCKeywords --no-case-fold c_kwlist.h'); + system('perl -I ../../../tools ../../../tools/gen_keywordlist.pl --varname ScanECPGKeywords ecpg_kwlist.h'); chdir('../../../..'); } |