rpm: add gbp.rpm.changelog module

This new module contains basic containers and functionality for parsing
and updating rpm changelogs. It is coupled with the rpm packaging policy
class which now has definitions for rpm changelog formatting.

Signed-off-by: Markus Lehtonen <markus.lehtonen@linux.intel.com>

2 files changed, 262 insertions, 0 deletions

diff --git a/gbp/rpm/changelog.py b/gbp/rpm/changelog.py
new file mode 100644
index 0000000..3ed89f1
--- /dev/null
+++ b/gbp/rpm/changelog.py
@@ -0,0 +1,246 @@
+# vim: set fileencoding=utf-8 :
+#
+# (C) 2014-2015 Intel Corporation <markus.lehtonen@linux.intel.com>
+#    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, please see
+#    <http://www.gnu.org/licenses/>
+"""An RPM Changelog"""
+
+import datetime
+import re
+
+import gbp.log
+
+
+class ChangelogError(Exception):
+    """Problem parsing changelog"""
+    pass
+
+
+class _ChangelogHeader(object):
+    """The header part of one changelog section"""
+
+    def __init__(self, pkgpolicy, time=None, **kwargs):
+        self._pkgpolicy = pkgpolicy
+        self._data = {'time': time}
+        self._data.update(kwargs)
+
+    def __contains__(self, key):
+        return key in self._data
+
+    def __getitem__(self, key):
+        if key in self._data:
+            return self._data[key]
+        return None
+
+    def __str__(self):
+        keys = dict(self._data)
+        keys['time'] = self._data['time'].strftime(
+                            self._pkgpolicy.Changelog.header_time_format)
+        try:
+            return self._pkgpolicy.Changelog.header_format % keys + '\n'
+        except KeyError as err:
+            raise ChangelogError("Unable to format changelog header, missing "
+                                 "property %s" % err)
+
+
+class _ChangelogEntry(object):
+    """An entry (one 'change') in an RPM changelog"""
+
+    def __init__(self, pkgpolicy, author, text):
+        """
+        @param pkgpolicy: RPM packaging policy
+        @type pkgpolicy: L{RpmPkgPolicy}
+        @param author: author of the change
+        @type author: C{str}
+        @param text: message of the changelog entry
+        @type text: C{str} or C{list} of C{str}
+        """
+        self._pkgpolicy = pkgpolicy
+        self.author = author
+        if isinstance(text, str):
+            self._text = text.splitlines()
+        else:
+            self._text = text
+        # Strip trailing empty lines
+        while text and not text[-1].strip():
+            text.pop()
+
+    def __str__(self):
+        # Currently no (re-)formatting, just raw text
+        string = ""
+        for line in self._text:
+            string += line + '\n'
+        return string
+
+
+class _ChangelogSection(object):
+    """One section (set of changes) in an RPM changelog"""
+
+    def __init__(self, pkgpolicy, *args, **kwargs):
+        self._pkgpolicy = pkgpolicy
+        self.header = _ChangelogHeader(pkgpolicy, *args, **kwargs)
+        self.entries = []
+        self._trailer = '\n'
+
+
+    def __str__(self):
+        text = str(self.header)
+        for entry in self.entries:
+            text += str(entry)
+        # Add "section separator"
+        text += self._trailer
+        return text
+
+    def set_header(self, *args, **kwargs):
+        """Change the section header"""
+        self.header = _ChangelogHeader(self._pkgpolicy, *args, **kwargs)
+
+    def append_entry(self, entry):
+        """Add a new entry to the end of the list of entries"""
+        self.entries.append(entry)
+        return entry
+
+
+class Changelog(object):
+    """An RPM changelog"""
+
+    def __init__(self, pkgpolicy):
+        self._pkgpolicy = pkgpolicy
+        self.sections = []
+
+    def __str__(self):
+        string = ""
+        for section in self.sections:
+            string += str(section)
+        return string
+
+    def create_entry(self, *args, **kwargs):
+        """Create and return new entry object"""
+        return _ChangelogEntry(self._pkgpolicy, *args, **kwargs)
+
+    def add_section(self, *args, **kwargs):
+        """Add new empty section"""
+        section = _ChangelogSection(self._pkgpolicy, *args, **kwargs)
+        self.sections.insert(0, section)
+        return section
+
+
+class ChangelogParser(object):
+    """Parser for RPM changelogs"""
+
+    def __init__(self, pkgpolicy):
+        self._pkgpolicy = pkgpolicy
+        self.section_match_re = pkgpolicy.Changelog.section_match_re
+        self.section_split_re = pkgpolicy.Changelog.section_split_re
+        self.header_split_re = pkgpolicy.Changelog.header_split_re
+        self.header_name_split_re = pkgpolicy.Changelog.header_name_split_re
+        self.body_name_re = pkgpolicy.Changelog.body_name_re
+
+    def raw_parse_string(self, string):
+        """Parse changelog - only splits out raw changelog sections."""
+        changelog = Changelog(self._pkgpolicy)
+        ch_section = ""
+        for line in string.splitlines():
+            if re.match(self.section_match_re, line, re.M | re.S):
+                if ch_section:
+                    changelog.sections.append(ch_section)
+                ch_section = line + '\n'
+            elif ch_section:
+                ch_section += line + '\n'
+            else:
+                raise ChangelogError("First line in changelog is invalid")
+        if ch_section:
+            changelog.sections.append(ch_section)
+        return changelog
+
+    def raw_parse_file(self, changelog):
+        """Parse changelog file - only splits out raw changelog sections."""
+        try:
+            with open(changelog) as ch_file:
+                return self.raw_parse_string(ch_file.read())
+        except IOError as err:
+            raise ChangelogError("Unable to read changelog file: %s" % err)
+
+    def _parse_section_header(self, text):
+        """Parse one changelog section header"""
+        # Try to split out time stamp and "changelog name"
+        match = re.match(self.header_split_re, text, re.M)
+        if not match:
+            raise ChangelogError("Unable to parse changelog header: %s" % text)
+        try:
+            time = datetime.datetime.strptime(match.group('ch_time'),
+                                             "%a %b %d %Y")
+        except ValueError:
+            raise ChangelogError("Unable to parse changelog header: invalid "
+                                 "timestamp '%s'" % match.group('ch_time'))
+        # Parse "name" part which consists of name and/or email and an optional
+        # revision
+        name_text = match.group('ch_name')
+        match = re.match(self.header_name_split_re, name_text)
+        if not match:
+            raise ChangelogError("Unable to parse changelog header: invalid "
+                                 "name / revision '%s'" % name_text)
+        kwargs = match.groupdict()
+        return _ChangelogSection(self._pkgpolicy, time=time, **kwargs)
+
+    def _create_entry(self, author, text):
+        """Create a new changelog entry"""
+        return _ChangelogEntry(self._pkgpolicy, author=author, text=text)
+
+    def _parse_section_entries(self, text, default_author):
+        """Parse entries from a string and add them to a section"""
+        entries = []
+        entry_text = []
+        author = default_author
+        for line in text.splitlines():
+            match = re.match(self.body_name_re, line)
+            if match:
+                if entry_text:
+                    entries.append(self._create_entry(author, entry_text))
+                author = match.group('name')
+            else:
+                if line.startswith("-"):
+                    if entry_text:
+                        entries.append(self._create_entry(author, entry_text))
+                    entry_text = [line]
+                else:
+                    if not entry_text:
+                        gbp.log.info("First changelog entry (%s) is garbled, "
+                                     "entries should start with a dash ('-')" %
+                                     line)
+                    entry_text.append(line)
+        if entry_text:
+            entries.append(self._create_entry(author, entry_text))
+
+        return entries
+
+
+    def parse_section(self, text):
+        """Parse one section"""
+        # Check that the first line(s) look like a changelog header
+        match = re.match(self.section_split_re, text, re.M | re.S)
+        if not match:
+            raise ChangelogError("Doesn't look like changelog header: %s..." %
+                                 text.splitlines()[0])
+        # Parse header
+        section = self._parse_section_header(match.group('ch_header'))
+        header = section.header
+        # Parse entries
+        default_author = header['name'] if 'name' in header else header['email']
+        for entry in self._parse_section_entries(match.group('ch_body'),
+                                                 default_author):
+            section.append_entry(entry)
+
+        return section
+
diff --git a/gbp/rpm/policy.py b/gbp/rpm/policy.py
index 80e0abd..f52b870 100644
--- a/gbp/rpm/policy.py
+++ b/gbp/rpm/policy.py
@@ -70,3 +70,19 @@ class RpmPkgPolicy(PkgPolicy):
             return True
         return False
 
+    class Changelog(object):
+        """Container for changelog related policy settings"""
+
+        # Regexps for splitting/parsing the changelog section (of
+        # Tizen / Fedora style changelogs)
+        section_match_re =  r'^\*'
+        section_split_re = r'^\*\s*(?P<ch_header>\S.*?)$\n(?P<ch_body>.*)'
+        header_split_re = r'(?P<ch_time>\S.*\s[0-9]{4})\s+(?P<ch_name>\S.*$)'
+        header_name_split_re = r'(?P<name>[^<]*)\s+<(?P<email>[^>]+)>((\s*-)?\s+(?P<revision>\S+))?$'
+        body_name_re = r'\[(?P<name>.*)\]'
+
+        # Changelog header format (when writing out changelog)
+        header_format = "* %(time)s %(name)s <%(email)s> %(revision)s"
+        header_time_format = "%a %b %d %Y"
+        header_rev_format = "%(version)s"
+