Package: debian-goodies
Version: 0.79
Tags: patch
which-pkg-broke is awfully slow, especially for packages with exuberant
dependency chains:
$ time which-pkg-broke mpv >/dev/null
real 4m43.203s
user 4m32.232s
sys 0m9.287s
This is because w-p-b spawns "apt-cache depends" for every dependency.
The attached patch makes it call "apt-cache depends" for multiple
packages at once. This is slightly faster:
$ time which-pkg-broke mpv >/dev/null
real 0m8.526s
user 0m8.222s
sys 0m0.290s
One side effect of this new implementation that the output order of
packages that have the time timestamp is no longer deterministic.
I don't think this is a big deal, but I'd be happy to fix it if you
think it is.
-- System Information:
Architecture: i386
Versions of packages debian-goodies recommends:
ii apt 1.6~alpha5
ii curl 7.57.0-1
ii dctrl-tools 2.24-2+b1
ii elfutils 0.170-0.1
ii libipc-system-simple-perl 1.25-3
ii man-db 2.7.6.1-4
ii perl 5.26.1-3
un popularity-contest <none>
ii procps 2:3.3.12-3
ii python3 3.6.3-2
ii sensible-utils 0.0.11
ii whiptail 0.52.20-1+b1
ii dialog 1.3-20160828-2
un zenity <none>
--
Jakub Wilk
diff --git a/which-pkg-broke b/which-pkg-broke
index 4f53139..59601fb 100755
--- a/which-pkg-broke
+++ b/which-pkg-broke
@@ -9,9 +9,9 @@ import time
from string import *
from stat import *
-def pkgdeps(pkg):
+def pkgdeps(pkgs):
apt_cache = subprocess.Popen(
- ['apt-cache', 'depends', pkg],
+ ['apt-cache', 'depends', *pkgs],
stdout=subprocess.PIPE, stderr=subprocess.STDOUT,
universal_newlines=True,
env={} # force POSIX locale
@@ -27,21 +27,14 @@ def pkgdeps(pkg):
apt_cache.wait()
return deps
-def alldeps(pkg, ignore):
- deps = {}
- imm_deps = pkgdeps(pkg)
- for i in imm_deps:
- if ignore.get(i) is None:
- deps[i] = 1
- ignore[i] = 1
- childeps = alldeps(i, ignore)
- for c in childeps:
- deps[c] = 1
- ignore[i] = 1
-
- dlist = list(deps.keys())
- return dlist
-
+def alldeps(pkg):
+ seen = set()
+ todo = set([pkg])
+ while todo:
+ new = pkgdeps(todo)
+ seen |= todo
+ todo = set(new) - seen
+ return seen
def localarchitectures():
architectures = []
@@ -88,8 +81,7 @@ def pkginstalltime(pkg, architectures):
return times
def what_broke(pname):
- pkgs = [ pname ]
- pkgs.extend(alldeps(sys.argv[1], {}))
+ pkgs = alldeps(pname)
architectures = localarchitectures()
