[packager] Optimize archive accesses.

python/mozbuild/mozpack/packager/l10n.py

@@ -37,6 +37,7 @@ from mozpack.chrome.manifest import (
     Manifest,
 )
 from mozpack.errors import errors
+from mozpack.mozjar import JAR_DEFLATED
 from mozpack.packager.unpack import UnpackFinder
 from createprecomplete import generate_precomplete
 
@@ -241,16 +242,17 @@ def repack(source, l10n, extra_l10n={}, non_resources=[], non_chrome=set()):
             finders[base] = UnpackFinder(path)
         l10n_finder = ComposedFinder(finders)
     copier = FileCopier()
+    compress = min(app_finder.compressed, JAR_DEFLATED)
     if app_finder.kind == 'flat':
         formatter = FlatFormatter(copier)
     elif app_finder.kind == 'jar':
         formatter = JarFormatter(copier,
                                  optimize=app_finder.optimizedjars,
-                                 compress=app_finder.compressed)
+                                 compress=compress)
     elif app_finder.kind == 'omni':
         formatter = OmniJarFormatter(copier, app_finder.omnijar,
                                      optimize=app_finder.optimizedjars,
-                                     compress=app_finder.compressed,
+                                     compress=compress,
                                      non_resources=non_resources)
 
     with errors.accumulate():

python/mozbuild/mozpack/packager/unpack.py

@@ -54,7 +54,7 @@ class UnpackFinder(BaseFinder):
         self.omnijar = None
         self.jarlogs = {}
         self.optimizedjars = False
-        self.compressed = True
+        self.compressed = False
 
         jars = set()
 
@@ -146,8 +146,7 @@ class UnpackFinder(BaseFinder):
         jar = JarReader(fileobj=file.open())
         if jar.is_optimized:
             self.optimizedjars = True
-        if not any(f.compressed for f in jar):
-            self.compressed = False
+        self.compressed = max(self.compressed, jar.compression)
         if jar.last_preloaded:
             jarlog = jar.entries.keys()
             self.jarlogs[path] = jarlog[:jarlog.index(jar.last_preloaded) + 1]