[pacman-dev] [PATCH 4/8] Add shims to return views on Python dicts.

[Jeremy Heiner]

Reported by 2to3. The .items, .keys, and .values methods in Python 2
make expensive copies, so the test framework uses the .iter*
flavors. But in Python 3 the .iter* (and even the 2.7 .view*)
flavors are removed and the original methods return fast views.
The shims examine the runtime's version and calls the right method to
avoid making copies.

Signed-off-by: Jeremy Heiner <ScalaProtractor at gmail.com>
---
 test/pacman/pmdb.py   |  4 ++--
 test/pacman/pmpkg.py  |  2 +-
 test/pacman/pmtest.py |  6 +++---
 test/pacman/util.py   | 15 ++++++++++++---
 4 files changed, 18 insertions(+), 9 deletions(-)

diff --git a/test/pacman/pmdb.py b/test/pacman/pmdb.py
index b7b3522..f4bc71d 100644
--- a/test/pacman/pmdb.py
+++ b/test/pacman/pmdb.py
@@ -236,7 +236,7 @@ def generate(self):
             for pkg, entry in pkg_entries:
                 path = os.path.join(self.dbdir, pkg.fullname())
                 util.mkdir(path)
-                for name, data in entry.iteritems():
+                for name, data in util.itemsview(entry):
                     util.mkfile(path, name, data)
 
         if self.dbfile:
@@ -247,7 +247,7 @@ def generate(self):
                 info = tarfile.TarInfo(pkg.fullname())
                 info.type = tarfile.DIRTYPE
                 tar.addfile(info)
-                for name, data in entry.iteritems():
+                for name, data in util.itemsview(entry):
                     filename = os.path.join(pkg.fullname(), name)
                     info = tarfile.TarInfo(filename)
                     info.size = len(data)
diff --git a/test/pacman/pmpkg.py b/test/pacman/pmpkg.py
index 0c1ea68..69734b0 100644
--- a/test/pacman/pmpkg.py
+++ b/test/pacman/pmpkg.py
@@ -225,7 +225,7 @@ def local_backup_entries(self):
 
     def installfile(self):
         data = []
-        for key, value in self.install.iteritems():
+        for key, value in util.itemsview(self.install):
             if value:
                 data.append("%s() {\n%s\n}\n" % (key, value))
 
diff --git a/test/pacman/pmtest.py b/test/pacman/pmtest.py
index 57e6538..a3e4a47 100644
--- a/test/pacman/pmtest.py
+++ b/test/pacman/pmtest.py
@@ -58,7 +58,7 @@ def findpkg(self, name, version, allow_local=False):
         """Find a package object matching the name and version specified in
         either sync databases or the local package collection. The local database
         is allowed to match if allow_local is True."""
-        for db in self.db.itervalues():
+        for db in util.valuesview(self.db):
             if db.is_local and not allow_local:
                 continue
             pkg = db.getpkg(name)
@@ -154,7 +154,7 @@ def generate(self, pacman):
             vprint("\t%s" % os.path.join(util.TMPDIR, pkg.filename()))
             pkg.finalize()
             pkg.makepkg(tmpdir)
-        for key, value in self.db.iteritems():
+        for key, value in util.itemsview(self.db):
             for pkg in value.pkgs:
                 pkg.finalize()
             if key == "local" and not self.createlocalpkgs:
@@ -170,7 +170,7 @@ def generate(self, pacman):
 
         # Creating sync database archives
         vprint("    Creating databases")
-        for key, value in self.db.iteritems():
+        for key, value in util.itemsview(self.db):
             vprint("\t" + value.treename)
             value.generate()
 
diff --git a/test/pacman/util.py b/test/pacman/util.py
index 77dd804..107a224 100644
--- a/test/pacman/util.py
+++ b/test/pacman/util.py
@@ -59,6 +59,15 @@ def vprint(msg):
 PERM_DIR  = int("755",8) # 0o755
 PERM_FILE = int("644",8) # 0o644
 
+def keysview(x):
+    return x.keys() if sys.hexversion >= 0x03000000 else x.iterkeys()
+
+def valuesview(x):
+    return x.values() if sys.hexversion >= 0x03000000 else x.itervalues()
+
+def itemsview(x):
+    return x.items() if sys.hexversion >= 0x03000000 else x.iteritems()
+
 
 #
 # Methods to generate files
@@ -125,13 +134,13 @@ def writedata(filename, data):
 def mkcfgfile(filename, root, option, db):
     # Options
     data = ["[options]"]
-    for key, value in option.iteritems():
+    for key, value in itemsview(option):
         data.extend(["%s = %s" % (key, j) for j in value])
 
     # Repositories
     # sort by repo name so tests can predict repo order, rather than be
     # subjects to the whims of python dict() ordering
-    for key in sorted(db.iterkeys()):
+    for key in sorted(keysview(db)):
         if key != "local":
             value = db[key]
             data.append("[%s]\n" \
@@ -139,7 +148,7 @@ def mkcfgfile(filename, root, option, db):
                     "Server = file://%s" \
                      % (value.treename, value.getverify(), \
                         os.path.join(root, SYNCREPO, value.treename)))
-            for optkey, optval in value.option.iteritems():
+            for optkey, optval in itemsview(value.option):
                 data.extend(["%s = %s" % (optkey, j) for j in optval])
 
     mkfile(root, filename, "\n".join(data))
-- 
1.8.4