Add the *FileWriter helper classes.

Signed-off-by: Torsten Werner <twerner@debian.org>

diff --git a/daklib/contents.py b/daklib/contents.py
index 449fb88e126fdc13038c1fd512edf0631bfff060..1ce5779a09393a8f127bd78ab4ab20ab131f03fa 100755 (executable)
--- a/daklib/contents.py
+++ b/daklib/contents.py
@@ -144,19 +144,17 @@ select bc.file, string_agg(o.section || '/' || b.package, ',' order by b.package
         '''
         return [item for item in self.fetch()]
 
-    def output_filename(self):
+    def writer(self):
         '''
-        Returns the name of the output file.
+        Returns a writer object.
         '''
         values = {
-            'root': Config()['Dir::Root'],
-            'suite': self.suite.suite_name,
-            'architecture': self.architecture.arch_string
+            'suite':        self.suite.suite_name,
+            'architecture': self.architecture.arch_string,
         }
-        if self.component is None:
-            return "%(root)s/dists/%(suite)s/Contents-%(architecture)s.gz" % values
-        values['component'] = self.component.component_name
-        return "%(root)s/dists/%(suite)s/%(component)s/Contents-%(architecture)s.gz" % values
+        if self.component is not None:
+            values['component'] = self.component.component_name
+        return BinaryContentsWriter(values)
 
     def get_header(self):
         '''
@@ -175,19 +173,12 @@ select bc.file, string_agg(o.section || '/' || b.package, ',' order by b.package
         '''
         Write the output file.
         '''
-        command = ['gzip', '--rsyncable']
-        final_filename = self.output_filename()
-        temp_filename = final_filename + '.new'
-        output_file = open(temp_filename, 'w')
-        gzip = Popen(command, stdin = PIPE, stdout = output_file)
-        gzip.stdin.write(self.get_header())
+        writer = self.writer()
+        file = writer.open()
+        file.write(self.get_header())
         for item in self.fetch():
-            gzip.stdin.write(item)
-        gzip.stdin.close()
-        output_file.close()
-        gzip.wait()
-        os.chmod(temp_filename, 0664)
-        os.rename(temp_filename, final_filename)
+            file.write(item)
+        writer.close()
 
 
 class SourceContentsWriter(object):

diff --git a/daklib/filewriter.py b/daklib/filewriter.py
new file mode 100755 (executable)
index 0000000..f52ac76
--- /dev/null
+++ b/daklib/filewriter.py
@@ -0,0 +1,99 @@
+#!/usr/bin/env python
+"""
+Helper code for file writing with optional compression.
+
+@contact: Debian FTPMaster <ftpmaster@debian.org>
+@copyright: 2011 Torsten Werner <twerner@debian.org>
+@license: GNU General Public License version 2 or later
+"""
+
+################################################################################
+
+# 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; either version 2 of the License, or
+# (at your option) any later version.
+
+# 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+################################################################################
+
+from daklib.config import Config
+
+from subprocess import check_call
+
+import os, os.path
+
+class BaseFileWriter(object):
+    '''
+    Base class for compressed and uncompressed file writing.
+    '''
+    def __init__(template, **keywords):
+        '''
+        The template argument is a string template like
+        "dists/%(suite)s/%(component)s/Contents-%(architecture)s.gz" that
+        should be relative to the archive's root directory. The keywords
+        include strings for suite, component, architecture and booleans
+        uncompressed, gzip, bzip2.
+        '''
+        self.uncompressed = keywords.get('uncompressed', True)
+        self.gzip = keywords.get('gzip', False)
+        self.bzip2 = keywords.get('bzip2', False)
+        root_dir = Config()['Dir::Root']
+        relative_dir = template % keywords
+        self.path = os.path.join(root_dir, relative_dir)
+
+    def open(self):
+        '''
+        Returns a file object for writing.
+        '''
+        self.file = open(self.path + '.new')
+
+    # internal helper function
+    def rename(self, filename):
+        tempfilename = filename + '.new'
+        os.chmod(tempfilename, 0664)
+        os.rename(tempfilename, filename)
+
+    def close(self):
+        '''
+        Closes the file object and does the compression and rename work.
+        '''
+        self.file.close()
+        if self.gzip:
+            check_call('gzip --rsyncable <%s.new >%s.gz.new' % (self.path, self.path),
+                shell = True)
+            self.rename('%s.gz' % self.path)
+        if self.bzip2:
+            check_call('bzip2 <%s.new >%s.bz2.new' % (self.path, self.path), shell = True)
+            self.rename('%s.bz2' % self.path)
+        if self.uncompressed:
+            self.rename(self.path)
+        else:
+            os.unlink(self.path)
+
+class BinaryContentsWriter(BaseFileWriter):
+    def __init__(**keywords):
+        '''
+        The value of the keywords suite, component, and architecture are
+        strings. The value of component may be omitted if not applicable.
+        Output files are gzip compressed only.
+        '''
+        flags = {
+            'uncompressed': False,
+            'gzip':         True,
+            'bzip2':        False
+        }
+        flags.update(keywords)
+        if 'component' in flags:
+            template "dists/%(suite)s/%(component)s/Contents-%(architecture)s.gz" % values
+        else:
+            template = "dists/%(suite)s/Contents-%(architecture)s.gz" % values
+        BaseFileWriter.__init__(self, template, **flags)