Add functions for creating and unpacking binary chunks.

3 files changed, 128 insertions, 0 deletions

diff --git a/morphlib/__init__.py b/morphlib/__init__.py
index 51651a9f..f4869eb1 100644
--- a/morphlib/__init__.py
+++ b/morphlib/__init__.py
@@ -20,6 +20,7 @@
 __version__ = '0.0'
 
 
+import bins
 import builder
 import cachedir
 import execute
diff --git a/morphlib/bins.py b/morphlib/bins.py
new file mode 100644
index 00000000..de946020
--- /dev/null
+++ b/morphlib/bins.py
@@ -0,0 +1,49 @@
+# Copyright (C) 2011  Codethink Limited
+# 
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; version 2 of the License.
+# 
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+# 
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+
+'''Functions for dealing with Baserock binaries.
+
+Binaries are chunks, strata, and system images.
+
+'''
+
+
+import logging
+import tarfile
+
+import morphlib
+
+
+def create_chunk(rootdir, chunk_filename):
+    '''Create a chunk from the contents of a directory.'''
+    logging.debug('Creating chunk file %s from %s' % (chunk_filename, rootdir))
+    tar = tarfile.open(name=chunk_filename, mode='w:gz')
+    tar.add(rootdir, arcname='.')
+    tar.close()
+
+
+def unpack_chunk(chunk_filename, dirname):
+    '''Unpack a chunk into a directory.
+    
+    The directory must exist already.
+    
+    '''
+
+    logging.debug('Unpacking chunk %s into %s' % (chunk_filename, dirname))
+    tar = tarfile.open(name=chunk_filename)
+    tar.extractall(path=dirname)
+    tar.close()
+
diff --git a/morphlib/bins_tests.py b/morphlib/bins_tests.py
new file mode 100644
index 00000000..b3c13a64
--- /dev/null
+++ b/morphlib/bins_tests.py
@@ -0,0 +1,78 @@
+# Copyright (C) 2011  Codethink Limited
+# 
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; version 2 of the License.
+# 
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+# 
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+
+import os
+import shutil
+import tempfile
+import unittest
+
+import morphlib
+
+
+def recursive_lstat(root):
+    '''Return a list of (pathname, stat result) pairs for everything in root.
+    
+    Pathnames are relative to root. Directories are recursed into.
+    The stat result is selective, not all fields are used.
+    
+    '''
+    
+    def remove_root(pathname):
+        assert pathname.startswith(root)
+        if pathname == root:
+            return '.'
+        else:
+            return pathname[len(root):]
+    
+    def lstat(filename):
+        st = os.lstat(filename)
+        return (st.st_mode, st.st_size, int(st.st_mtime))
+
+    result = []
+    
+    for dirname, subdirs, basenames in os.walk(root):
+        result.append((remove_root(dirname), lstat(dirname)))
+        for basename in sorted(basenames):
+            filename = os.path.join(dirname, basename)
+            result.append((remove_root(filename), lstat(filename)))
+        subdirs.sort()
+    
+    return result
+
+
+class ChunkTests(unittest.TestCase):
+
+    def setUp(self):
+        self.tempdir = tempfile.mkdtemp()
+        self.instdir = os.path.join(self.tempdir, 'inst')
+        self.chunk_file = os.path.join(self.tempdir, 'chunk')
+        self.unpacked = os.path.join(self.tempdir, 'unpacked')
+        
+    def tearDown(self):
+        shutil.rmtree(self.tempdir)
+
+    def populate_instdir(self):
+        os.mkdir(self.instdir)
+        os.mkdir(os.path.join(self.instdir, 'bin'))
+
+    def test_creates_and_unpacks_chunk_exactly(self):
+        self.populate_instdir()
+        morphlib.bins.create_chunk(self.instdir, self.chunk_file)
+        os.mkdir(self.unpacked)
+        morphlib.bins.unpack_chunk(self.chunk_file, self.unpacked)
+        self.assertEqual(recursive_lstat(self.instdir),
+                         recursive_lstat(self.unpacked))
+