Introduce dynamic scope_path regexps
Instead of relying on scope_path's being "one slash deep", we should
instead allow for either:
1. scope_paths that have a pre-defined depth
2. scope_paths that can be arbitrarily deep
We achieve 1 by setting an entities scope_logic to another logic
module. We then recursively call getScopeDepth until we get to the
topmost entity (that is, an unscoped entity).
A little different is the solution to 2, since some entities can have
an arbitrarily deep scope (such as Documents), we need to have some
way of signaling this to getScopePattern. A clean solution is to
return None, rather than a number. If None is returned, the
SCOPE_PATH_ARG_PATTERN is returned as regexp instead, which will
match an arbitrarily deeply nested scope.
The solution for 2 requires that we return None somewhere in the
scope_logic chain, the most straight forward method to do so is to
override getScopeDepth anywhere such a scope is needed and make it
return None. A more elegant solution however, is to set the
scope_logic to that module in all entities that require it.
Patch by: Sverre Rabbelier
"""
Extracts the version of the PostgreSQL server.
"""
import re
VERSION_RE = re.compile(r'PostgreSQL (\d+)\.(\d+)\.')
def get_version(cursor):
"""
Returns a tuple representing the major and minor version number of the
server. For example, (7, 4) or (8, 3).
"""
cursor.execute("SELECT version()")
version = cursor.fetchone()[0]
major, minor = VERSION_RE.search(version).groups()
return int(major), int(minor)