Package: command-not-found
Version: 20.10.1-1
Severity: normal
Tags: patch
Dear Maintainer,
cnf-update-db is fairly slow on my machine. After I remove
/var/lib/command-not-found/commands.db.metadata, cnf-update-db takes about 16
seconds on my machine.
A large chunk of this time is checking whether files are in /usr/bin and
similar directories. I'm attaching a small patch that optimizes this check,
taking the same update down to about 10 seconds on my machine. It's a 4-line
change that seems like an easy win.
I confirmed that I have the same number of commands and packages in the
commands.db database with and without this change.
Please let me know if you prefer to receive this patch in a different format or
channel.
Regards,
Diego
-- System Information:
Debian Release: 10.7
APT prefers stable-updates
APT policy: (560, 'stable-updates'), (550, 'stable'), (160, 'testing'), (150,
'unstable')
Architecture: amd64 (x86_64)
Foreign Architectures: i386
Kernel: Linux 5.9.0-0.bpo.2-amd64 (SMP w/16 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8),
LANGUAGE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled
Versions of packages command-not-found depends on:
ii apt-file 3.2.2
ii lsb-release 10.2019051400
ii python3 3.7.3-1
ii python3-apt 1.8.4.3
command-not-found recommends no packages.
Versions of packages command-not-found suggests:
pn snapd <none>
From: Diego Ongaro <ongar...@gmail.com>
Date: Wed, 13 Jan 2021 17:44:50 -0800
Subject: cnf-update-db: Speed up Contents files
---
CommandNotFound/db/creator.py | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/CommandNotFound/db/creator.py b/CommandNotFound/db/creator.py
index 08564f5..fce5e67 100755
--- a/CommandNotFound/db/creator.py
+++ b/CommandNotFound/db/creator.py
@@ -4,6 +4,7 @@ import errno
import json
import logging
import os
+import re
import sqlite3
import subprocess
import sys
@@ -234,12 +235,12 @@ class DbCreator:
def _parse_single_contents_file(self, con, f, fp):
# read header
suite=None # FIXME
+ pattern = re.compile(b'usr/sbin|usr/bin|sbin|bin')
for l in fp:
- l = l.decode("utf-8")
- if not (l.startswith('usr/sbin') or l.startswith('usr/bin') or
- l.startswith('bin') or l.startswith('sbin')):
+ if not pattern.match(l):
continue
+ l = l.decode("utf-8")
try:
command, pkgnames = l.split(None, 1)
except ValueError:
