index: Add --compression-types option

With this option, the compression type of index file can be selected.
It is possible to pass multiple types separated by comma.

e.g. pisi index --skip-signing --compression-types=bz2,xz

pisi/api.py

@@ -763,7 +763,9 @@ def info_name(package_name, useinstalldb=False):
         files = None
     return metadata, files, repo
 
-def index(dirs=None, output='pisi-index.xml', skip_sources=False, skip_signing=False):
+def index(dirs=None, output='pisi-index.xml',
+          skip_sources=False, skip_signing=False,
+          compression=0):
     """Accumulate PiSi XML files in a directory, and write an index."""
     index = pisi.index.Index()
     index.distribution = None
@@ -774,7 +776,6 @@ def index(dirs=None, output='pisi-index.xml', skip_sources=False, skip_signing=F
         ctx.ui.info(_('* Building index of PiSi files under %s') % repo_dir)
         index.index(repo_dir, skip_sources)
 
-    compression = pisi.file.File.COMPRESSION_TYPE_XZ
     sign = None if skip_signing else pisi.file.File.detached
     index.write(output, sha1sum=True, compress=compression, sign=sign)
     ctx.ui.info(_('* Index file written'))

pisi/cli/index.py

@@ -57,6 +57,12 @@ class Index(command.Command):
                          default='pisi-index.xml',
                          help=_("Index output file"))
 
+        group.add_option("--compression-types",
+                         action="store",
+                         default="xz",
+                         help=_("Comma-separated compression types "
+                                "for index file"))
+
         group.add_option("--skip-sources",
                          action="store_true",
                          default=False,
@@ -73,7 +79,15 @@ class Index(command.Command):
         self.init(database=True, write=False)
 
         from pisi.api import index
+        from pisi.file import File
+
+        ctypes = {"bz2": File.COMPRESSION_TYPE_BZ2,
+                  "xz": File.COMPRESSION_TYPE_XZ}
+        compression = 0
+        for type_str in ctx.get_option("compression_types").split(","):
+            compression |= ctypes.get(type_str, 0)
 
         index(self.args or ["."], ctx.get_option('output'),
               skip_sources=ctx.get_option('skip_sources'),
-              skip_signing=ctx.get_option('skip_signing'))
+              skip_signing=ctx.get_option('skip_signing'),
+              compression=compression)