utils: new group_by interface for generic grouping

The old function _group_by has now an own module (hostinfo.utils) and
got a slightly different interface. It is now used in all places,
where a grouping of the different values is required (printing,
searching, printing keys).

3 files changed, 28 insertions, 30 deletions

diff --git a/bin/hostinfo b/bin/hostinfo
index 2270208..ced856a 100755
--- a/bin/hostinfo
+++ b/bin/hostinfo
@@ -13,6 +13,7 @@ if os.path.exists(os.path.join(LIB, 'hostinfo')):
     sys.path = [LIB] + sys.path
 
 from hostinfo import printer
+from hostinfo import utils
 
 def _get_data(path):
     stream = file(path, 'r')
@@ -29,10 +30,10 @@ def match_key(data, keys):
     rest = keys[1:]
 
     if key == 'addresses' and 'addresses' in data:
-        return match_key({a['interface']: a for a in data}, rest)
+        return match_key(utils.group_by(data['addresses'], 'interface'), rest)
 
     if key == 'ports' and 'ports' in data:
-        return match_key({p['process']: p for p in data}, rest)
+        return match_key(utils.group_by(data['ports'], 'process', 'UNKNOWN'), rest)
 
     if isinstance(data, dict):
         if key in data:
@@ -117,14 +118,11 @@ def print_keys(path):
             print "%s%s" % (prefix, key)
 
             if key == 'addresses':
-                for k in set([a['interface'] for a in data[key]]):
+                for k in utils.group_by(data[key], 'interface').keys():
                     print "%s%s.%s" % (prefix, key, k)
             elif key == 'ports':
-                names = [p['process'] for p in data[key] if 'process' in p]
-                for k in set(names):
+                for k in utils.group_by(data[key], 'process', 'UNKNOWN').keys():
                     print "%s%s.%s" % (prefix, key, k)
-                if len([p for p in data[key] if 'process' not in p]) > 0:
-                    print "%s%s.%s" % (prefix, key, 'UNKNOWN')
             elif isinstance(data[key], dict):
                 _print_keys(data[key], "%s%s." % (prefix, key))
             elif isinstance(data[key], list):
diff --git a/hostinfo/printer.py b/hostinfo/printer.py
index 5edc76f..4302e04 100644
--- a/hostinfo/printer.py
+++ b/hostinfo/printer.py
@@ -2,6 +2,7 @@
 
 from __future__ import absolute_import
 from hostinfo import prefix
+from hostinfo import utils
 
 def _get_full_key(prev_key, key):
     if prev_key == '':
@@ -24,15 +25,6 @@ def _space(filter_key, full_key, printer, force=False):
     if filter_key is None and full_key == '':
         printer.space(force)
 
-def _group_by(value, group, display_check, print_value):
-    groups = {}
-    for elem in value:
-        key = group(elem)
-        if key is not None and display_check(key):
-            groups.setdefault(key, []).append(print_value(elem))
-
-    return groups
-
 
 class Printer:
     labels = {
@@ -55,25 +47,13 @@ class Printer:
         prefix.Printer.flags = flags
 
     def cb_print_addresses(self, value, full_key, filter_key):
-        def _group_ip(address):
-            if 'vserver' not in address:
-                return address['interface']
-            else:
-                return None
-
         def _print_ip(address):
             return '%s/%s' % (address['address'], address['netmask'])
 
         display_check = self._is_group_displayed(full_key, filter_key)
-        return _group_by(value, _group_ip, display_check, _print_ip)
+        return utils.group_by(value, 'interface', None, display_check, _print_ip)
 
     def cb_print_ports(self, value, full_key, filter_key):
-        def _group_port(port):
-            if 'process' in port:
-                return port['process']
-            else:
-                return 'UNKNOWN'
-
         def _print_port(port):
             if port['proto'] in ['tcp6', 'udp6']:
                 return '(%s) [%s]:%s' % (port['proto'].replace('6', ''),
@@ -81,7 +61,7 @@ class Printer:
             return '(%s) %s:%s' % (port['proto'], port['ip'], port['port'])
 
         display_check = self._is_group_displayed(full_key, filter_key)
-        return (_group_by(value, _group_port, display_check, _print_port),
+        return (utils.group_by(value, 'process', 'UNKNOWN', display_check, _print_port),
                 ['sshd', 'nrpe', 'munin-node'])
 
     def cb_print_vserver(self, value, full_key, filter_key):
diff --git a/hostinfo/utils.py b/hostinfo/utils.py
new file mode 100644
index 0000000..cfd8de3
--- /dev/null
+++ b/hostinfo/utils.py
@@ -0,0 +1,20 @@
+# -*- coding: utf-8 -*-
+
+def group_by(value, group, default=None, display_check=None, print_value=None):
+    groups = {}
+    for elem in value:
+        key = None
+        if group in elem:
+            key = elem[group]
+        else:
+            key = default
+
+        if display_check is None or display_check(key):
+            output = elem
+            if print_value is not None:
+                output = print_value(elem)
+
+            groups.setdefault(key, []).append(output)
+
+    return groups
+