Move the chunk cache logic into buildcommand

This avoids needing to pass the cache to the staging area since
lac.get returns a path to a directory tree rather than a file
handle now, so we also don't need to do any unpacking.

2 files changed, 23 insertions, 22 deletions

diff --git a/morphlib/buildcommand.py b/morphlib/buildcommand.py
index 8572450d..38057365 100644
--- a/morphlib/buildcommand.py
+++ b/morphlib/buildcommand.py
@@ -494,8 +494,27 @@ class BuildCommand(object):
                 chunk_name=artifact.name,
                 cache=artifact.source.cache_key[:7],
                 chatty=True)
-            handle = self.lac.get(artifact)
-            staging_area.install_artifact(handle)
+            chunk_cache_dir = os.path.join(self.app.settings['tempdir'],
+                                           'chunks')
+            artifact_checkout = os.path.join(
+                chunk_cache_dir, os.path.basename(artifact.basename()) + '.d')
+            if not os.path.exists(artifact_checkout):
+                self.app.status(
+                    msg='Checking out %(chunk)s from cache.',
+                    chunk=artifact.name
+                    )
+                temp_checkout = os.path.join(self.app.settings['tempdir'],
+                                             artifact.basename())
+                try:
+                    self.lac.get(artifact, temp_checkout)
+                except BaseException:
+                    shutil.rmtree(temp_checkout)
+                    raise
+                # TODO: This rename is not concurrency safe if two builds are
+                #       extracting the same chunk, one build will fail because
+                #       the other renamed its tempdir here first.
+                os.rename(temp_checkout, artifact_checkout)
+            staging_area.install_artifact(artifact, artifact_checkout)
 
         if target_source.build_mode == 'staging':
             morphlib.builder.ldconfig(self.app.runcmd, staging_area.dirname)
diff --git a/morphlib/stagingarea.py b/morphlib/stagingarea.py
index 991a1799..2c036085 100644
--- a/morphlib/stagingarea.py
+++ b/morphlib/stagingarea.py
@@ -187,29 +187,11 @@ class StagingArea(object):
 
         '''
 
-        chunk_cache_dir = os.path.join(self._app.settings['tempdir'], 'chunks')
-        unpacked_artifact = os.path.join(
-            chunk_cache_dir, os.path.basename(handle.name) + '.d')
-        if not os.path.exists(unpacked_artifact):
-            self._app.status(
-                msg='Unpacking chunk from cache %(filename)s',
-                filename=os.path.basename(handle.name))
-            savedir = tempfile.mkdtemp(dir=chunk_cache_dir)
-            try:
-                morphlib.bins.unpack_binary_from_file(
-                    handle, savedir + '/')
-            except BaseException, e: # pragma: no cover
-                shutil.rmtree(savedir)
-                raise
-            # TODO: This rename is not concurrency safe if two builds are
-            #       extracting the same chunk, one build will fail because
-            #       the other renamed its tempdir here first.
-            os.rename(savedir, unpacked_artifact)
-
         if not os.path.exists(self.dirname):
             self._mkdir(self.dirname)
 
-        self.hardlink_all_files(unpacked_artifact, self.dirname)
+        self.hardlink_all_files(artifact_checkout, self.dirname)
+        self.create_devices(artifact.source.morphology)
 
     def remove(self):
         '''Remove the entire staging area.