cache/sqlite.py: dynamically add columns to table

diff --git a/pym/portage/cache/sqlite.py b/pym/portage/cache/sqlite.py
index fcc62ff94fd470c4f5189dc0e737050d8351bfd2..a6a3e066d20aec0946f26b4dddaa7b76ee2e8eb4 100644 (file)
--- a/pym/portage/cache/sqlite.py
+++ b/pym/portage/cache/sqlite.py
@@ -1,6 +1,7 @@
-# Copyright 1999-2011 Gentoo Foundation
+# Copyright 1999-2012 Gentoo Foundation
 # Distributed under the terms of the GNU General Public License v2
 
+import re
 import sys
 from portage.cache import fs_template
 from portage.cache import cache_errors
@@ -117,7 +118,13 @@ class database(fs_template.FsBased):
                for k, v in self._db_table.items():
                        if self._db_table_exists(v["table_name"]):
                                create_statement = self._db_table_get_create(v["table_name"])
-                               if create_statement != v["create"]:
+                               table_ok, missing_keys = self._db_validate_create_statement(create_statement)
+                               if table_ok:
+                                       if missing_keys:
+                                               for k in sorted(missing_keys):
+                                                       cursor.execute("ALTER TABLE %s ADD COLUMN %s TEXT" %
+                                                               (self._db_table["packages"]["table_name"], k))
+                               else:
                                        writemsg(_("sqlite: dropping old table: %s\n") % v["table_name"])
                                        cursor.execute("DROP TABLE %s" % v["table_name"])
                                        cursor.execute(v["create"])
@@ -138,6 +145,37 @@ class database(fs_template.FsBased):
                        self._db_escape_string(table_name))
                return cursor.fetchall()[0][0]
 
+       def _db_validate_create_statement(self, statement):
+               missing_keys = None
+               if statement == self._db_table["packages"]["create"]:
+                       return True, missing_keys
+
+               m = re.match(r'^\s*CREATE\s*TABLE\s*%s\s*\(\s*%s\s*INTEGER\s*PRIMARY\s*KEY\s*AUTOINCREMENT\s*,(.*)\)\s*$' %
+                       (self._db_table["packages"]["table_name"],
+                       self._db_table["packages"]["package_id"]),
+                       statement)
+               if m is None:
+                       return False, missing_keys
+
+               unique_constraints = set([self._db_table["packages"]["package_key"]])
+               missing_keys = set(self._allowed_keys)
+               unique_re = re.compile(r'^\s*UNIQUE\s*\(\s*(\w*)\s*\)\s*$')
+               column_re = re.compile(r'^\s*(\w*)\s*TEXT\s*$')
+               for x in m.group(1).split(","):
+                       m = column_re.match(x)
+                       if m is not None:
+                               missing_keys.discard(m.group(1))
+                               continue
+                       m = unique_re.match(x)
+                       if m is not None:
+                               unique_constraints.discard(m.group(1))
+                               continue
+
+               if unique_constraints:
+                       return False, missing_keys
+
+               return True, missing_keys
+
        def _db_init_cache_size(self, cache_bytes):
                cursor = self._db_cursor
                cursor.execute("PRAGMA page_size")