PATCH: _deb_packages caching

[Clint Adams <schizo@debian.org>]

This adds caching layer support to _deb_packages, a la _rpm.
It should probably make use of _call as well.

Index: Completion/Debian/_deb_packages
===================================================================
RCS file: /cvsroot/zsh/zsh/Completion/Debian/_deb_packages,v
retrieving revision 1.2
diff -u -r1.2 _deb_packages
--- Completion/Debian/_deb_packages	2000/04/11 07:57:57	1.2
+++ Completion/Debian/_deb_packages	2001/03/30 20:59:11
@@ -3,19 +3,26 @@
 # Usage: _deb_packages expl... avail|installed|uninstalled
 
 _deb_packages_update_avail () {
-  if (( ! $+_deb_packages_cache_avail )); then
+  if ( [[ ${+_deb_packages_cache_avail} -eq 0 ]] ||
+      _cache_invalid DEBS_avail ) && ! _retrieve_cache DEBS_avail;
+  then
     _deb_packages_cache_avail=(
       ${(f)"$(apt-cache dumpavail | awk '/^Package:/ { print $2 }')"}
     )
+
+    _store_cache DEBS_avail _deb_packages_cache_avail
   fi
   cachevar=_deb_packages_cache_avail
 }
 
 _deb_packages_update_installed () {
-  if (( ! $+_deb_packages_cache_installed )); then
+  if ( [[ ${+_deb_packages_cache_installed} -eq 0 ]] ||
+      _cache_invalid DEBS_installed ) && ! _retrieve_cache DEBS_installed;
+  then
     _deb_packages_cache_installed=(
       ${${${(f)"$(dpkg --get-selections)"}:#*deinstall}%%	*}
     )
+    _store_cache DEBS_installed _deb_packages_cache_installed
   fi
   cachevar=_deb_packages_cache_installed
 }
@@ -32,7 +39,12 @@
 }
 
 _deb_packages () {
-  local command="$argv[$#]" expl cachevar pkgset
+  local command="$argv[$#]" expl cachevar pkgset update_policy
+
+  zstyle -s ":completion:*:*:$service:*" cache-policy update_policy
+  if [[ -z "$update_policy" ]]; then
+    zstyle ":completion:*:*:$service:*" cache-policy _debs_caching_policy
+  fi
 
   [[ "$command" = (installed|uninstalled|avail) ]] || {
     _message "_deb_packages:unknown command: $command"
@@ -53,5 +65,16 @@
 
   _tags packages && compadd "$expl[@]" - "${(@P)cachevar}"
 }
+
+ _debs_caching_policy () {
+    # rebuild if cache is more than a week old
+      oldp=( "$1"(mw+1) )
+        (( $#oldp )) && return 0
+
+	  [[ /var/cache/apt/pkgcache.bin -nt "$1" ||
+	     /var/lib/dpkg/available -nt "$1" ]]
+	  }
+
+
 
 _deb_packages "$@"