Partial rewrite of the sysdeps code:sysdeps-split

* added support for reading multiple sysdeps files (so they can be split and thus the redundancy reduced)
* fallback to unstable distro version if current version is unknown (so it won't stop working when Fedora switches versions)
* abort if no sysdeps are available (since sugar-jhbuild will break in unexpected ways otherwise)
* cache distribution information and dependency list to speed up execution

3 files changed, 73 insertions, 50 deletions

diff --git a/sjhbuild/config.py b/sjhbuild/config.py
index 321669c..d209a29 100644
--- a/sjhbuild/config.py
+++ b/sjhbuild/config.py
@@ -17,8 +17,13 @@ class Config(jhbuild.config.Config):
 
         self.checkoutroot = os.path.join(self.base_dir, 'source')
         self.tarballdir =   os.path.join(self.base_dir, 'source')
-        
-        for package, source in sysdeps.get_packages():
+
+        deps = sysdeps.get_packages()
+        if not deps:
+            sys.stderr.write("ERROR: Dependencies information is missing (unknown distribution/version).\n")
+            sys.exit(126)
+
+        for package, source in deps :
             if source and source not in self.skip:
                 self.skip.append(source)
 
diff --git a/sjhbuild/depscheck.py b/sjhbuild/depscheck.py
index f55f19e..f68a31a 100644
--- a/sjhbuild/depscheck.py
+++ b/sjhbuild/depscheck.py
@@ -20,10 +20,6 @@ class cmd_depscheck(Command):
 
     def run(self, config, options, args):
         deps = sysdeps.get_packages()
-        if not options.script and not deps:
-            print 'Dependencies information is missing, skip sanity check.'
-            return
-
         missing_deps = []
         for package, source in deps:
             if not sysdeps.check_package(package):
diff --git a/sjhbuild/sysdeps.py b/sjhbuild/sysdeps.py
index cd92253..bd10b73 100644
--- a/sjhbuild/sysdeps.py
+++ b/sjhbuild/sysdeps.py
@@ -1,48 +1,38 @@
+import operator
 import os
 import subprocess
+import sys
 
 from xml.dom import minidom
 
 scripts_dir = os.path.dirname(__file__)
 base_dir = os.path.dirname(scripts_dir)
 
-def get_distribution():
-    if 'SJH_DISTRIBUTION' in os.environ:
-        return os.environ['SJH_DISTRIBUTION'].split('-')
+_cached_dname, _cached_dversion = None, None
 
-    # Fedora
-    if os.path.exists('/etc/fedora-release'):
-        name = 'fedora'
+def _pipe_lower(args) :
+    out, err = subprocess.Popen(args,
+                                stdout=subprocess.PIPE).communicate()
+    return out.strip().lower()
 
-        f = open('/etc/fedora-release')
-        full_name = f.read()
-        f.close()
+def get_distribution():
+    global _cached_dname, _cached_dversion
 
-        if 'Rawhide' in full_name:
-            version = 'rawhide'
-        else:
-            version = full_name.split(' ')[2]
+    if _cached_dname :
+      return _cached_dname, _cached_dversion
 
-        return name, version
+    if 'SJH_DISTRIBUTION' in os.environ:
+        _cached_dname, _cached_dversion = os.environ['SJH_DISTRIBUTION'].split('-')
+        return _cached_dname, _cached_dversion
 
-    # Debian and Ubuntu
     try:
-        out, err = subprocess.Popen(['lsb_release', '-is'],
-                                    stdout=subprocess.PIPE).communicate()
-        name = out.strip().lower()
+        _cached_dname = _pipe_lower(['lsb_release', '-is'])
+        _cached_dversion = _pipe_lower(['lsb_release', '-rs'])
 
-        out, err = subprocess.Popen(['lsb_release', '-rs'],
-                                    stdout=subprocess.PIPE).communicate()
-        version = out.strip()
-
-        if name == 'debian' and version == 'testing':
-            version = 'unstable'
-
-        return name, version
     except OSError:
         pass
 
-    return None, None
+    return _cached_dname, _cached_dversion
 
 def check_package(package):
     name, version = get_distribution()
@@ -56,28 +46,60 @@ def check_package(package):
 
     return None
 
-def parse_dependencies():
-    name, version = get_distribution()
-    if name is None or version is None:
-        return None
+def _check_prefix(name, prefixes, suffix="") :
+  return [name for p in prefixes if name.startswith(p) and name.endswith(suffix)]
+
+_unstable_names = {
+    'debian': 'unstable',
+    'fedora': 'rawhide',
+    'mandrivalinux': 'cooker',
+    'ubuntu': 'unstable',
+}
+def _parse_dependencies(dname, dversion):
+    if not (dname and dversion):
+        return []
 
-    filename = os.path.join(base_dir, 'config', 'sysdeps',
-                            '%s-%s.xml' % (name, version))
+    prefixes = ['alldistros', '%s-allversions' % (dname,),
+                '%s-%s' % (dname, dversion)]
 
-    if not os.path.exists(filename):
-        return None
+    dirname = os.path.join(base_dir, 'config', 'sysdeps')
+    filenames = [os.path.join(dirname, fname)
+        for fname in os.listdir(dirname)
+        if _check_prefix(fname, prefixes, ".xml")]
 
-    return minidom.parse(filename)
+    # check whether we have a file matching the exact distro version
+    if not [name for name in filenames if prefixes[-1] in name] :
+        # will break for unknown distros, but that's fine
+        # (=> bug report => add support for distro)
+        uversion = _unstable_names[dname]
+        if (dversion == uversion) :
+            # no config for unstable
+            return []
 
+        sys.stderr.write("Warning: unknown distro version, automatic fallback to %s.\n" % (uversion,))
+        return _parse_dependencies(dname, uversion)
+
+
+    return [minidom.parse(fname)
+            for fname in filenames if os.path.exists(fname)]
+
+_cached_packages = None
 def get_packages():
-    document = parse_dependencies()
-    if document is None:
-        return []
+    global _cached_packages
+
+    if _cached_packages is not None :
+        return _cached_packages
+
+    dname, dversion = get_distribution()
+    documents = _parse_dependencies(dname, dversion)
+    _cached_packages = []
+
+    if not documents :
+        return _cached_packages
 
-    packages = []
-    root = document.childNodes[0]
+    roots = [doc.childNodes[0] for doc in documents]
 
-    for node in root.childNodes:
+    for node in reduce(operator.add, [root.childNodes for root in roots]) :
         if node.nodeType == node.ELEMENT_NODE:
             if node.nodeName == 'package':
                 name = node.getAttribute('name')
@@ -86,6 +108,6 @@ def get_packages():
                 else:
                     source = None
 
-                packages.append((name, source))
+                _cached_packages.append((name, source))
 
-    return packages
+    return _cached_packages