Add post-installation trigger scripts

Several things in the GNOME stack have file-based caches, like
gdk-pixbuf's loaders.cache.  These need to be regenerated, and
historically that worked in jhbuild because these modules include bits
in their Makefile to run then relevant commands, if DESTDIR is not
set.

Package managers have post-installation scripts in packages, and OS
builders typically support this as well.

Jhbuild historically relied on the post-installation scripts in
modules, but in (see bug 647231) we switched to using DESTDIR for all
module types.  So we need to move closer to the package model here.

We call them "triggers" as they're run after any kind of build
operation (including "uninstall").

This patch adds a proof-of-concept trigger script for gdk-pixbuf
loaders.

https://bugzilla.gnome.org/show_bug.cgi?id=653842

Makefile.am

@@ -1,4 +1,4 @@
-SUBDIRS = po scripts jhbuild buildbot
+SUBDIRS = po scripts triggers jhbuild buildbot
 
 if DOC_INSTALLATION_ENABLED
 SUBDIRS += doc

configure.ac

@@ -37,6 +37,7 @@ AC_CONFIG_FILES([
 	doc/Makefile
 	po/Makefile.in
 	scripts/Makefile
+	triggers/Makefile
 	jhbuild/Makefile
 	jhbuild/buildbot/Makefile
 	jhbuild/buildbot/status/web/Makefile

jhbuild/frontends/buildscript.py

@@ -19,8 +19,10 @@
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 
 import os
+import logging
 
 from jhbuild.utils import packagedb
+from jhbuild.utils import trigger
 from jhbuild.errors import FatalError, CommandError, SkipToPhase, SkipToEnd
 
 class BuildScript:
@@ -84,6 +86,7 @@ def build(self, phases=None):
         self.start_build()
 
         failures = [] # list of modules that couldn't be built
+        successes = []
         self.module_num = 0
         for module in self.modulelist:
             self.module_num = self.module_num + 1
@@ -197,11 +200,28 @@ def build(self, phases=None):
                     num_phase += 1
 
             self.end_module(module.name, failed)
+            if not failed:
+                self.run_triggers(module.name)
         self.end_build(failures)
         if failures:
             return 1
         return 0
 
+    def run_triggers(self, module_name):
+        """See triggers/README."""
+        all_triggers = trigger.load_all(os.path.join(PKGDATADIR, 'triggers'))
+        triggers_to_run = []
+        for trig in all_triggers:
+            # Skip if somehow the module isn't really installed
+            if self.packagedb.installdate(module_name) is None:
+                continue
+            pkg = self.packagedb.entries[module_name]
+            if trig.matches(pkg.manifest):
+                triggers_to_run.append(trig)
+        for trig in triggers_to_run:
+            logging.info(_('Running post-installation trigger script: %r') % (trig.name, ))
+            trig.run()
+
     def get_build_phases(self, module, targets=None):
         '''returns the list of required phases'''
         if targets:

jhbuild/utils/Makefile.am

@@ -7,6 +7,7 @@ app_PYTHON = \
 	notify.py \
 	packagedb.py \
 	sxml.py \
+	trigger.py \
 	trayicon.py \
 	unpack.py
 

jhbuild/utils/trigger.py

@@ -0,0 +1,89 @@
+# jhbuild - a build script for GNOME 1.x and 2.x
+# Copyright (C) 2011  Red Hat, Inc.
+#
+#   trigger.py - Run scripts after packages are installed
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+import os
+import sys 
+import subprocess
+import re
+
+from . import cmds
+
+class Trigger(object):
+    SUFFIX = '.trigger'
+    def __init__(self, filepath):
+        assert filepath.endswith(self.SUFFIX)
+        self._rematches = []
+        self._literal_matches = []
+        self._executable = None
+        self._file = filepath
+        self.name = os.path.basename(filepath)[:-len(self.SUFFIX)]
+
+        f = open(self._file)
+        for line in f:
+            key = '# IfExecutable: '
+            if line.startswith(key):
+                text = line[len(key):].strip()
+                self._executable = text
+                continue
+            key = '# REMatch: '
+            if line.startswith(key):
+                text = line[len(key):].strip()
+                r = re.compile(text)
+                self._rematches.append(r)
+                continue
+            key = '# LiteralMatch: '
+            if line.startswith(key):
+                text = line[len(key):].strip()
+                self._literal_matches.append(text)
+                continue
+        f.close()
+        if len(self._rematches) == 0 and len(self._literal_matches) == 0:
+            raise ValueError("No keys specified in trigger script %r" % (filepath, ))
+
+    def matches(self, files_list):
+       """@files_list should be a list of absolute file paths.  Return True if this trigger script
+should be run."""
+       if self._executable is not None:
+           if not cmds.has_command(self._executable):
+               return False
+       for path in files_list:
+           for r in self._rematches:
+               match = r.search(path)
+               if match:
+                   return True
+           for literal in self._literal_matches:
+               if path.find(literal) >= 0:
+                   return True
+       return False
+
+    def run(self):
+        """Synchronously execute this trigger script."""
+        assert 'JHBUILD_PREFIX' in os.environ
+        subprocess.check_call(['/bin/sh', self._file], stdin=open('/dev/null'))
+
+def load_all(dirpath):
+    result = []
+    for filename in os.listdir(dirpath):
+        if not filename.endswith(Trigger.SUFFIX):
+            continue
+        filepath = os.path.join(dirpath, filename)
+        p = Trigger(filepath)
+        result.append(p)
+    return result
+

triggers/Makefile.am

@@ -0,0 +1,2 @@
+triggerdir = $(datadir)/jhbuild/triggers
+trigger_DATA = gdk-pixbuf.trigger

triggers/README

@@ -0,0 +1,23 @@
+This directory contains GNOME post-installation trigger scripts (in
+theory these could go with the modules, but there aren't many of them,
+so eh).
+
+A .trigger file is a set of regular expressions (or literal matches)
+which are evaluated against files installed after any "make install
+DESTDIR=", combined with a shell script to run if any of them match.
+In the future, these may also be matched against deleted files.
+
+The contents of a .trigger file are just /bin/sh shell script, with a
+few magic comments.  During the run of a .trigger file, the
+environment variable JHBUILD_PREFIX is guaranteed to be set.
+
+Currently recognized comments:
+
+# IfExecutable: STRING
+  Only run if the given executable is available in $PATH
+# LiteralMatch: STRING
+  Match against installed/removed manifest if the given STRING is a substring of a file or directory.
+# REMatch: REGEXP
+  Match against installed/removed manifest using the given REGEXP in Python syntax.
+
+

triggers/gdk-pixbuf.trigger

@@ -0,0 +1,24 @@
+# Post-installation hook for gdk-pixbuf.  -*- mode: sh -*-
+# Corresponds to gdk-pixbuf/gdk-pixbuf/Makefile.am:install-data-hook
+#
+# Written by Colin Walters <[email protected]>
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+
+# IfExecutable: gdk-pixbuf-query-loaders
+# LiteralMatch: /gdk-pixbuf-2.0/2.10.0/loaders/
+
+gdk-pixbuf-query-loaders --update-cache