LinkageMapELF: optimize memory usage

This reduces memory consumption by approximately 30%, by replacing
mutable set instances with arrays, tuples, and frozensets where
appropriate. Also, identical frozenset instances are shared when
available.

diff --git a/pym/portage/util/_dyn_libs/LinkageMapELF.py b/pym/portage/util/_dyn_libs/LinkageMapELF.py
index 218ce2a658073d5f6b98a761dcc8deac8922a1ed..49a7d354169f92612ea32111dd440a8e075bd960 100644 (file)
--- a/pym/portage/util/_dyn_libs/LinkageMapELF.py
+++ b/pym/portage/util/_dyn_libs/LinkageMapELF.py
@@ -265,6 +265,10 @@ class LinkageMapELF(object):
                        for x in plibs:
                                lines.append(("plibs", ";".join(['', x, '', '', ''])))
 
+               # Share identical frozenset instances when available,
+               # in order to conserve memory.
+               frozensets = {}
+
                for location, l in lines:
                        l = l.rstrip("\n")
                        if not l:
@@ -278,21 +282,23 @@ class LinkageMapELF(object):
                        arch = fields[0]
                        obj = fields[1]
                        soname = fields[2]
-                       path = set([normalize_path(x) \
+                       path = frozenset(normalize_path(x) \
                                for x in filter(None, fields[3].replace(
                                "${ORIGIN}", os.path.dirname(obj)).replace(
-                               "$ORIGIN", os.path.dirname(obj)).split(":"))])
-                       needed = [x for x in fields[4].split(",") if x]
+                               "$ORIGIN", os.path.dirname(obj)).split(":")))
+                       path = frozensets.setdefault(path, path)
+                       needed = frozenset(x for x in fields[4].split(",") if x)
+                       needed = frozensets.setdefault(needed, needed)
 
                        obj_key = self._obj_key(obj)
                        indexed = True
                        myprops = obj_properties.get(obj_key)
                        if myprops is None:
                                indexed = False
-                               myprops = (arch, needed, path, soname, set())
+                               myprops = (arch, needed, path, soname, [])
                                obj_properties[obj_key] = myprops
                        # All object paths are added into the obj_properties tuple.
-                       myprops[4].add(obj)
+                       myprops[4].append(obj)
 
                        # Don't index the same file more that once since only one
                        # set of data can be correct and therefore mixing data
@@ -309,16 +315,21 @@ class LinkageMapELF(object):
                                soname_map = arch_map.get(soname)
                                if soname_map is None:
                                        soname_map = self._soname_map_class(
-                                               providers=set(), consumers=set())
+                                               providers=[], consumers=[])
                                        arch_map[soname] = soname_map
-                               soname_map.providers.add(obj_key)
+                               soname_map.providers.append(obj_key)
                        for needed_soname in needed:
                                soname_map = arch_map.get(needed_soname)
                                if soname_map is None:
                                        soname_map = self._soname_map_class(
-                                               providers=set(), consumers=set())
+                                               providers=[], consumers=[])
                                        arch_map[needed_soname] = soname_map
-                               soname_map.consumers.add(obj_key)
+                               soname_map.consumers.append(obj_key)
+
+               for arch, sonames in libs.items():
+                       for soname_node in sonames.values():
+                               soname_node.providers = tuple(set(soname_node.providers))
+                               soname_node.consumers = tuple(set(soname_node.consumers))
 
        def listBrokenBinaries(self, debug=False):
                """