[devtools] add has_cache for postgres (closes #5739624)
devtools stores info about existing dbs in the db handler, but in the
case of postgresql that doesn't take into account the path to the
cluster's datadir. Which means if we run two test modules (in the same
test run), we'll create a "__default_empty_db__" for the first one,
cache its existence, and then when moving on to the other module,
believe the template already exists (but since the datadir depends on
the test module's path, it does not). This patch is a bit of a kludge,
and it would be better to make the cache key include enough data to not
need this, but I'm not sure how to do that.
"""This module compare the Schema on the file system to the one in the database"""
from cStringIO import StringIO
from cubicweb.web.schemaviewer import SchemaViewer
from logilab.common.ureports import TextWriter
import difflib
viewer = SchemaViewer()
layout_db = viewer.visit_schema(schema, display_relations=True)
layout_fs = viewer.visit_schema(fsschema, display_relations=True)
writer = TextWriter()
stream_db = StringIO()
stream_fs = StringIO()
writer.format(layout_db, stream=stream_db)
writer.format(layout_fs, stream=stream_fs)
stream_db.seek(0)
stream_fs.seek(0)
db = stream_db.getvalue().splitlines()
fs = stream_fs.getvalue().splitlines()
open('db_schema.txt', 'w').write(stream_db.getvalue())
open('fs_schema.txt', 'w').write(stream_fs.getvalue())
#for diff in difflib.ndiff(fs, db):
# print diff