Add initial code for reading in APK files.

apkkit/base/package.py

+"""Contains the Package class and related helper classes and functions."""
+
+pkginfo_template = """
+# Generated by APK Kit for Adélie Linux
+# {builduser}@{buildhost} {builddate}
+pkgname = {name}
+pkgver = {ver}
+pkgdesc = {desc}
+arch = {arch}
+"""
+
+class Package:
+    """The base package class."""
+
+    def __init__(self, name, version, arch, description=None, url=None, size=0,
+                 provides=None, depends=None):
+        """Initialise a package object.
+
+        :param str name:
+            The name of the package.
+
+        :param str version:
+            The version of the package.
+
+        :param str arch:
+            The architecture of the package.
+
+        :param str description:
+            (Recommended) The description of the package.  Defaults to the name
+            if not set.
+
+        :param int size:
+            (Recommended) The installed size of the package.  You almost always
+            want to set this to something other than 0 if you don't want unhappy
+            users. :)
+
+        :param str url:
+            (Optional) The URL of the homepage for the package.
+
+        :param list provides:
+            (Optional) One or more virtuals that this package provides.
+
+        :param list depends:
+            (Optional) One or more packages that are required to be installed
+            to use this package.
+        """
+        
+        self._pkgname = name
+        self._pkgver = version
+        self._pkgdesc = description or name
+        self._url = url
+        self._size = int(size)
+        self._arch = arch
+        self._provides = provides or list()
+        self._depends = depends or list()
+
+    @property
+    def name(self):
+        """The name of the package."""
+        return self._pkgname
+
+    @property
+    def version(self):
+        """The version of the package."""
+        return self._pkgver
+
+    @property
+    def description(self):
+        """The description of the package."""
+        return self._pkgdesc
+
+    @property
+    def url(self):
+        """The URL of the homepage of the package."""
+        return self._url
+
+    @property
+    def size(self):
+        """The installed size of the package in bytes."""
+        return self._size
+
+    @property
+    def arch(self):
+        """The architecture of the package."""
+        return self._arch
+
+    @property
+    def depends(self):
+        """The dependencies of the package."""
+        return self._depends
+
+    def __repr__(self):
+        return 'Package(name="{name}", version="{ver}", arch="{arch}", '\
+               'description="{desc}", url="{url}", size={size}, '\
+               'provides={prov}, depends={dep})'.format(
+                   name=self._pkgname, ver=self._pkgver, arch=self._arch,
+                   desc=self._pkgdesc, prov=self._provides, dep=self._depends,
+                   url=self._url, size=self._size)
+
+    def to_pkginfo(self):
+        """Serialises the package's information into the PKGINFO format.
+
+        :returns str: The PKGINFO for this package.  Unicode str, ready to be
+                      written to a file.
+
+        .. note:: To write a file, see the :py:meth:`.write_pkginfo` helper
+                  method.
+        """
+
+    @classmethod
+    def from_pkginfo(cls, buf):
+        """Create a new :py:class:`Package` object from an existing PKGINFO.
+        
+        :param buf:
+            The buffer to read from (whether file, StringIO, etc).
+
+        :returns:
+            A :py:class:`Package` object with the details from the PKGINFO.
+
+        :throws ValueError:
+            If a required field is missing from the PKGINFO.
+        """
+
+        params = {}
+        param_map = {'pkgname': 'name', 'pkgver': 'version', 'arch': 'arch',
+                     'pkgdesc': 'description', 'provides': 'provides',
+                     'depend': 'depends', 'url': 'url', 'size': 'size'}
+        list_keys = {'provides', 'depend'}
+
+        params['provides'] = list()
+        params['depends'] = list()
+
+        for line in buf.readlines():
+            # XXX TODO make this better
+            if type(line) != str:
+                line = line.decode('utf-8')
+
+            # Skip comments.
+            if len(line) == 0 or line[0] == '#':
+                continue
+
+            if line.index('=') == -1:
+                print('!!! malformed line? {} !!!'.format(line))
+                continue
+
+            (key, value) = line.split('=', 1)
+            key = key.strip()
+            value = value.strip()
+
+            if key in param_map:
+                if key in list_keys:
+                    params[param_map[key]].append(value)
+                else:
+                    params[param_map[key]] = value
+            else:
+                print('!!! unrecognised PKGINFO key {} !!!'.format(key))
+
+        return cls(**params)

apkkit/io/apkfile.py

+from apkkit.base.package import Package
+import gzip  # Not used, but we need to raise ImportError if gzip isn't built.
+import tarfile
+
+class APKFile:
+    """Represents an APK file on disk (or in memory)."""
+
+    def __init__(self, filename, mode='r'):
+        self.tar = tarfile.open(filename, mode)
+        self.package = Package.from_pkginfo(self.tar.extractfile('.PKGINFO'))