[Pkg-python-debian-commits] r65 trunk: first checkin of DebFile, which extends ArFile with .deb-specific functionalities

[zack at bononia.it]

------------------------------------------------------------
revno: 65
committer: zack at bononia.it
branch nick: pkg-python-debian.debfile
timestamp: Sat 2007-07-14 10:59:46 +0200
message:
  first checkin of DebFile, which extends ArFile with .deb-specific functionalities
added:
  debian_bundle/debfile.py
-------------- next part --------------
=== added file 'debian_bundle/debfile.py'
--- a/debian_bundle/debfile.py	1970-01-01 00:00:00 +0000
+++ b/debian_bundle/debfile.py	2007-07-14 08:59:46 +0000
@@ -0,0 +1,132 @@
+import arfile
+import gzip
+import tarfile
+
+DATA_PART = 'data.tar.gz'
+CTRL_PART = 'control.tar.gz'
+INFO_PART = 'debian-binary'
+MAINT_SCRIPTS = ['preinst', 'postinst', 'prerm', 'postrm', 'config']
+
+CTRL_FILE = 'control'
+MD5_FILE = 'md5sums'
+
+class DebError(arfile.ArError):
+    pass
+
+
+class DebPart(object):
+    """'Part' of a .deb binary package.
+    
+    A .deb package is considered as made of 2 parts: a 'data' part
+    (corresponding to the 'data.tar.gz' archive embedded in a .deb) and a
+    'control' part (the 'control.tar.gz' archive)."""
+
+    def __init__(self, member):
+        self.__member = member  # arfile.ArMember file member
+        self.__tgz = None
+
+    def tgz(self):
+        """Return a TarFile object corresponding to this part of a .deb
+        package."""
+
+        if self.__tgz is None:
+            gzfile = gzip.GzipFile(fileobj=self.__member)
+            tarfile = tarfile.TarFile(fileobj=gzfile)
+            self.__tgz = tarfile
+        return self.__tgz
+
+    def has_file(self, fname):
+        """Check if this part contains a given file name."""
+
+        return (fname in self.tgz().getnames())
+
+    def get_file(self, fname):
+        """Return a file object corresponding to a given file name."""
+
+        return (self.tgz().extractfile(fname))
+
+    def get_content(self, fname):
+        """Return the string content of a given file."""
+
+        f = self.tgz().extractfile(fname)
+        content = f.read()
+        f.close()
+        return content
+
+    # container emulation
+
+    def __iter__(self):
+        return iter(self.tgz().getnames())
+
+    def __contains__(self, fname):
+        return self.has_file(fname)
+
+    def __getitem__(self, fname):
+        return self.get_content(fname)
+
+
+class DebData(DebPart):
+
+    pass
+
+
+class DebControl(DebPart):
+
+    def scripts(self):
+        """ Return a dictionary of maintainer scripts (postinst, prerm, ...)
+        mapping script names to script text. """
+
+        scripts = {}
+        for fname in MAINT_SCRIPTS:
+            if self.has_file(fname):
+                scripts[fname] = self.get_content(fname)
+
+        return scripts
+
+    def control(self):
+        """ Return the debian/control as a string.
+        
+        Convenience method, same as: .get_content('control') """
+
+        return self.get_content(CTRL_FILE)
+
+    def md5sums(self):
+        """ Return a dictionary mapping filenames (of the data part) to
+        md5sums. Fails if the control part does not contain a 'md5sum' file. """
+
+        if not self.has_file(MD5_FILE):
+            raise DebError("'%s' file not found, can't list MD5 sums" %
+                    MD5_FILE)
+
+        md5_file = self.get_file(MD5_FILE)
+        sums = {}
+        for line in md5_file:
+            md5, fname = line.split()
+            sums[fname] = md5
+        md5_file.close()
+        return sums
+
+class DebFile(arfile.ArFile):
+
+    def __init__(self, **args):
+        ArFile.__init__(self, **args)
+        if set(self.getnames()) != set([INFO_PART, CTRL_PART, DATA_PART])
+            raise DebError('unexpected .deb content')
+
+        self.__parts = {}
+        self.__parts[DATA_PART] = DebData(self.getmember(DATA_PART))
+        self.__parts[CTRL_PART] = DebControl(self.getmember(CTRL_PART))
+
+        f = self.getmember(INFO_PART)
+        self.__version = f.read().strip()
+        f.close()
+
+    def getVersion(self): return self.__version
+    version = property(getVersion)
+
+    def getData(self): return self.__parts[DATA_PART]
+    data = property(getData)
+
+    def getCtrl(self): return self.__parts[CTRL_PART]
+    control = property(getCtrl)
+